Commit 89eb8eb9 authored by Dean Nelson's avatar Dean Nelson Committed by Tony Luck

[IA64-SGI] SGI Altix cross partition functionality [2/3]

This patch contains the communication module (XPC) for cross partition
communication on a partitioned SGI Altix.
Signed-off-by: default avatarDean Nelson <dcn@sgi.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 21223a9e
...@@ -13,3 +13,5 @@ obj-$(CONFIG_IA64_GENERIC) += machvec.o ...@@ -13,3 +13,5 @@ obj-$(CONFIG_IA64_GENERIC) += machvec.o
obj-$(CONFIG_SGI_TIOCX) += tiocx.o obj-$(CONFIG_SGI_TIOCX) += tiocx.o
obj-$(CONFIG_IA64_SGI_SN_XP) += xp.o obj-$(CONFIG_IA64_SGI_SN_XP) += xp.o
xp-y := xp_main.o xp_nofault.o xp-y := xp_main.o xp_nofault.o
obj-$(CONFIG_IA64_SGI_SN_XP) += xpc.o
xpc-y := xpc_main.o xpc_channel.o xpc_partition.o
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2004-2005 Silicon Graphics, Inc. All Rights Reserved.
*/
/*
* Cross Partition Communication (XPC) structures and macros.
*/
#ifndef _IA64_SN_KERNEL_XPC_H
#define _IA64_SN_KERNEL_XPC_H
#include <linux/config.h>
#include <linux/interrupt.h>
#include <linux/sysctl.h>
#include <linux/device.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/sn/bte.h>
#include <asm/sn/clksupport.h>
#include <asm/sn/addrs.h>
#include <asm/sn/mspec.h>
#include <asm/sn/shub_mmr.h>
#include <asm/sn/xp.h>
/*
* XPC Version numbers consist of a major and minor number. XPC can always
* talk to versions with same major #, and never talk to versions with a
* different major #.
*/
#define _XPC_VERSION(_maj, _min) (((_maj) << 4) | ((_min) & 0xf))
#define XPC_VERSION_MAJOR(_v) ((_v) >> 4)
#define XPC_VERSION_MINOR(_v) ((_v) & 0xf)
/*
* The next macros define word or bit representations for given
* C-brick nasid in either the SAL provided bit array representing
* nasids in the partition/machine or the AMO_t array used for
* inter-partition initiation communications.
*
* For SN2 machines, C-Bricks are alway even numbered NASIDs. As
* such, some space will be saved by insisting that nasid information
* passed from SAL always be packed for C-Bricks and the
* cross-partition interrupts use the same packing scheme.
*/
#define XPC_NASID_W_INDEX(_n) (((_n) / 64) / 2)
#define XPC_NASID_B_INDEX(_n) (((_n) / 2) & (64 - 1))
#define XPC_NASID_IN_ARRAY(_n, _p) ((_p)[XPC_NASID_W_INDEX(_n)] & \
(1UL << XPC_NASID_B_INDEX(_n)))
#define XPC_NASID_FROM_W_B(_w, _b) (((_w) * 64 + (_b)) * 2)
#define XPC_HB_DEFAULT_INTERVAL 5 /* incr HB every x secs */
#define XPC_HB_CHECK_DEFAULT_TIMEOUT 20 /* check HB every x secs */
/* define the process name of HB checker and the CPU it is pinned to */
#define XPC_HB_CHECK_THREAD_NAME "xpc_hb"
#define XPC_HB_CHECK_CPU 0
/* define the process name of the discovery thread */
#define XPC_DISCOVERY_THREAD_NAME "xpc_discovery"
#define XPC_HB_ALLOWED(_p, _v) ((_v)->heartbeating_to_mask & (1UL << (_p)))
#define XPC_ALLOW_HB(_p, _v) (_v)->heartbeating_to_mask |= (1UL << (_p))
#define XPC_DISALLOW_HB(_p, _v) (_v)->heartbeating_to_mask &= (~(1UL << (_p)))
/*
* Reserved Page provided by SAL.
*
* SAL provides one page per partition of reserved memory. When SAL
* initialization is complete, SAL_signature, SAL_version, partid,
* part_nasids, and mach_nasids are set.
*
* Note: Until vars_pa is set, the partition XPC code has not been initialized.
*/
struct xpc_rsvd_page {
u64 SAL_signature; /* SAL unique signature */
u64 SAL_version; /* SAL specified version */
u8 partid; /* partition ID from SAL */
u8 version;
u8 pad[6]; /* pad to u64 align */
u64 vars_pa;
u64 part_nasids[XP_NASID_MASK_WORDS] ____cacheline_aligned;
u64 mach_nasids[XP_NASID_MASK_WORDS] ____cacheline_aligned;
};
#define XPC_RP_VERSION _XPC_VERSION(1,0) /* version 1.0 of the reserved page */
#define XPC_RSVD_PAGE_ALIGNED_SIZE \
(L1_CACHE_ALIGN(sizeof(struct xpc_rsvd_page)))
/*
* Define the structures by which XPC variables can be exported to other
* partitions. (There are two: struct xpc_vars and struct xpc_vars_part)
*/
/*
* The following structure describes the partition generic variables
* needed by other partitions in order to properly initialize.
*
* struct xpc_vars version number also applies to struct xpc_vars_part.
* Changes to either structure and/or related functionality should be
* reflected by incrementing either the major or minor version numbers
* of struct xpc_vars.
*/
struct xpc_vars {
u8 version;
u64 heartbeat;
u64 heartbeating_to_mask;
u64 kdb_status; /* 0 = machine running */
int act_nasid;
int act_phys_cpuid;
u64 vars_part_pa;
u64 amos_page_pa; /* paddr of page of AMOs from MSPEC driver */
AMO_t *amos_page; /* vaddr of page of AMOs from MSPEC driver */
AMO_t *act_amos; /* pointer to the first activation AMO */
};
#define XPC_V_VERSION _XPC_VERSION(3,0) /* version 3.0 of the cross vars */
#define XPC_VARS_ALIGNED_SIZE (L1_CACHE_ALIGN(sizeof(struct xpc_vars)))
/*
* The following structure describes the per partition specific variables.
*
* An array of these structures, one per partition, will be defined. As a
* partition becomes active XPC will copy the array entry corresponding to
* itself from that partition. It is desirable that the size of this
* structure evenly divide into a cacheline, such that none of the entries
* in this array crosses a cacheline boundary. As it is now, each entry
* occupies half a cacheline.
*/
struct xpc_vars_part {
u64 magic;
u64 openclose_args_pa; /* physical address of open and close args */
u64 GPs_pa; /* physical address of Get/Put values */
u64 IPI_amo_pa; /* physical address of IPI AMO_t structure */
int IPI_nasid; /* nasid of where to send IPIs */
int IPI_phys_cpuid; /* physical CPU ID of where to send IPIs */
u8 nchannels; /* #of defined channels supported */
u8 reserved[23]; /* pad to a full 64 bytes */
};
/*
* The vars_part MAGIC numbers play a part in the first contact protocol.
*
* MAGIC1 indicates that the per partition specific variables for a remote
* partition have been initialized by this partition.
*
* MAGIC2 indicates that this partition has pulled the remote partititions
* per partition variables that pertain to this partition.
*/
#define XPC_VP_MAGIC1 0x0053524156435058L /* 'XPCVARS\0'L (little endian) */
#define XPC_VP_MAGIC2 0x0073726176435058L /* 'XPCvars\0'L (little endian) */
/*
* Functions registered by add_timer() or called by kernel_thread() only
* allow for a single 64-bit argument. The following macros can be used to
* pack and unpack two (32-bit, 16-bit or 8-bit) arguments into or out from
* the passed argument.
*/
#define XPC_PACK_ARGS(_arg1, _arg2) \
((((u64) _arg1) & 0xffffffff) | \
((((u64) _arg2) & 0xffffffff) << 32))
#define XPC_UNPACK_ARG1(_args) (((u64) _args) & 0xffffffff)
#define XPC_UNPACK_ARG2(_args) ((((u64) _args) >> 32) & 0xffffffff)
/*
* Define a Get/Put value pair (pointers) used with a message queue.
*/
struct xpc_gp {
s64 get; /* Get value */
s64 put; /* Put value */
};
#define XPC_GP_SIZE \
L1_CACHE_ALIGN(sizeof(struct xpc_gp) * XPC_NCHANNELS)
/*
* Define a structure that contains arguments associated with opening and
* closing a channel.
*/
struct xpc_openclose_args {
u16 reason; /* reason why channel is closing */
u16 msg_size; /* sizeof each message entry */
u16 remote_nentries; /* #of message entries in remote msg queue */
u16 local_nentries; /* #of message entries in local msg queue */
u64 local_msgqueue_pa; /* physical address of local message queue */
};
#define XPC_OPENCLOSE_ARGS_SIZE \
L1_CACHE_ALIGN(sizeof(struct xpc_openclose_args) * XPC_NCHANNELS)
/* struct xpc_msg flags */
#define XPC_M_DONE 0x01 /* msg has been received/consumed */
#define XPC_M_READY 0x02 /* msg is ready to be sent */
#define XPC_M_INTERRUPT 0x04 /* send interrupt when msg consumed */
#define XPC_MSG_ADDRESS(_payload) \
((struct xpc_msg *)((u8 *)(_payload) - XPC_MSG_PAYLOAD_OFFSET))
/*
* Defines notify entry.
*
* This is used to notify a message's sender that their message was received
* and consumed by the intended recipient.
*/
struct xpc_notify {
struct semaphore sema; /* notify semaphore */
u8 type; /* type of notification */
/* the following two fields are only used if type == XPC_N_CALL */
xpc_notify_func func; /* user's notify function */
void *key; /* pointer to user's key */
};
/* struct xpc_notify type of notification */
#define XPC_N_CALL 0x01 /* notify function provided by user */
/*
* Define the structure that manages all the stuff required by a channel. In
* particular, they are used to manage the messages sent across the channel.
*
* This structure is private to a partition, and is NOT shared across the
* partition boundary.
*
* There is an array of these structures for each remote partition. It is
* allocated at the time a partition becomes active. The array contains one
* of these structures for each potential channel connection to that partition.
*
* Each of these structures manages two message queues (circular buffers).
* They are allocated at the time a channel connection is made. One of
* these message queues (local_msgqueue) holds the locally created messages
* that are destined for the remote partition. The other of these message
* queues (remote_msgqueue) is a locally cached copy of the remote partition's
* own local_msgqueue.
*
* The following is a description of the Get/Put pointers used to manage these
* two message queues. Consider the local_msgqueue to be on one partition
* and the remote_msgqueue to be its cached copy on another partition. A
* description of what each of the lettered areas contains is included.
*
*
* local_msgqueue remote_msgqueue
*
* |/////////| |/////////|
* w_remote_GP.get --> +---------+ |/////////|
* | F | |/////////|
* remote_GP.get --> +---------+ +---------+ <-- local_GP->get
* | | | |
* | | | E |
* | | | |
* | | +---------+ <-- w_local_GP.get
* | B | |/////////|
* | | |////D////|
* | | |/////////|
* | | +---------+ <-- w_remote_GP.put
* | | |////C////|
* local_GP->put --> +---------+ +---------+ <-- remote_GP.put
* | | |/////////|
* | A | |/////////|
* | | |/////////|
* w_local_GP.put --> +---------+ |/////////|
* |/////////| |/////////|
*
*
* ( remote_GP.[get|put] are cached copies of the remote
* partition's local_GP->[get|put], and thus their values can
* lag behind their counterparts on the remote partition. )
*
*
* A - Messages that have been allocated, but have not yet been sent to the
* remote partition.
*
* B - Messages that have been sent, but have not yet been acknowledged by the
* remote partition as having been received.
*
* C - Area that needs to be prepared for the copying of sent messages, by
* the clearing of the message flags of any previously received messages.
*
* D - Area into which sent messages are to be copied from the remote
* partition's local_msgqueue and then delivered to their intended
* recipients. [ To allow for a multi-message copy, another pointer
* (next_msg_to_pull) has been added to keep track of the next message
* number needing to be copied (pulled). It chases after w_remote_GP.put.
* Any messages lying between w_local_GP.get and next_msg_to_pull have
* been copied and are ready to be delivered. ]
*
* E - Messages that have been copied and delivered, but have not yet been
* acknowledged by the recipient as having been received.
*
* F - Messages that have been acknowledged, but XPC has not yet notified the
* sender that the message was received by its intended recipient.
* This is also an area that needs to be prepared for the allocating of
* new messages, by the clearing of the message flags of the acknowledged
* messages.
*/
struct xpc_channel {
partid_t partid; /* ID of remote partition connected */
spinlock_t lock; /* lock for updating this structure */
u32 flags; /* general flags */
enum xpc_retval reason; /* reason why channel is disconnect'g */
int reason_line; /* line# disconnect initiated from */
u16 number; /* channel # */
u16 msg_size; /* sizeof each msg entry */
u16 local_nentries; /* #of msg entries in local msg queue */
u16 remote_nentries; /* #of msg entries in remote msg queue*/
void *local_msgqueue_base; /* base address of kmalloc'd space */
struct xpc_msg *local_msgqueue; /* local message queue */
void *remote_msgqueue_base; /* base address of kmalloc'd space */
struct xpc_msg *remote_msgqueue;/* cached copy of remote partition's */
/* local message queue */
u64 remote_msgqueue_pa; /* phys addr of remote partition's */
/* local message queue */
atomic_t references; /* #of external references to queues */
atomic_t n_on_msg_allocate_wq; /* #on msg allocation wait queue */
wait_queue_head_t msg_allocate_wq; /* msg allocation wait queue */
/* queue of msg senders who want to be notified when msg received */
atomic_t n_to_notify; /* #of msg senders to notify */
struct xpc_notify *notify_queue;/* notify queue for messages sent */
xpc_channel_func func; /* user's channel function */
void *key; /* pointer to user's key */
struct semaphore msg_to_pull_sema; /* next msg to pull serialization */
struct semaphore teardown_sema; /* wait for teardown completion */
struct xpc_openclose_args *local_openclose_args; /* args passed on */
/* opening or closing of channel */
/* various flavors of local and remote Get/Put values */
struct xpc_gp *local_GP; /* local Get/Put values */
struct xpc_gp remote_GP; /* remote Get/Put values */
struct xpc_gp w_local_GP; /* working local Get/Put values */
struct xpc_gp w_remote_GP; /* working remote Get/Put values */
s64 next_msg_to_pull; /* Put value of next msg to pull */
/* kthread management related fields */
// >>> rethink having kthreads_assigned_limit and kthreads_idle_limit; perhaps
// >>> allow the assigned limit be unbounded and let the idle limit be dynamic
// >>> dependent on activity over the last interval of time
atomic_t kthreads_assigned; /* #of kthreads assigned to channel */
u32 kthreads_assigned_limit; /* limit on #of kthreads assigned */
atomic_t kthreads_idle; /* #of kthreads idle waiting for work */
u32 kthreads_idle_limit; /* limit on #of kthreads idle */
atomic_t kthreads_active; /* #of kthreads actively working */
// >>> following field is temporary
u32 kthreads_created; /* total #of kthreads created */
wait_queue_head_t idle_wq; /* idle kthread wait queue */
} ____cacheline_aligned;
/* struct xpc_channel flags */
#define XPC_C_WASCONNECTED 0x00000001 /* channel was connected */
#define XPC_C_ROPENREPLY 0x00000002 /* remote open channel reply */
#define XPC_C_OPENREPLY 0x00000004 /* local open channel reply */
#define XPC_C_ROPENREQUEST 0x00000008 /* remote open channel request */
#define XPC_C_OPENREQUEST 0x00000010 /* local open channel request */
#define XPC_C_SETUP 0x00000020 /* channel's msgqueues are alloc'd */
#define XPC_C_CONNECTCALLOUT 0x00000040 /* channel connected callout made */
#define XPC_C_CONNECTED 0x00000080 /* local channel is connected */
#define XPC_C_CONNECTING 0x00000100 /* channel is being connected */
#define XPC_C_RCLOSEREPLY 0x00000200 /* remote close channel reply */
#define XPC_C_CLOSEREPLY 0x00000400 /* local close channel reply */
#define XPC_C_RCLOSEREQUEST 0x00000800 /* remote close channel request */
#define XPC_C_CLOSEREQUEST 0x00001000 /* local close channel request */
#define XPC_C_DISCONNECTED 0x00002000 /* channel is disconnected */
#define XPC_C_DISCONNECTING 0x00004000 /* channel is being disconnected */
/*
* Manages channels on a partition basis. There is one of these structures
* for each partition (a partition will never utilize the structure that
* represents itself).
*/
struct xpc_partition {
/* XPC HB infrastructure */
u64 remote_rp_pa; /* phys addr of partition's rsvd pg */
u64 remote_vars_pa; /* phys addr of partition's vars */
u64 remote_vars_part_pa; /* phys addr of partition's vars part */
u64 last_heartbeat; /* HB at last read */
u64 remote_amos_page_pa; /* phys addr of partition's amos page */
int remote_act_nasid; /* active part's act/deact nasid */
int remote_act_phys_cpuid; /* active part's act/deact phys cpuid */
u32 act_IRQ_rcvd; /* IRQs since activation */
spinlock_t act_lock; /* protect updating of act_state */
u8 act_state; /* from XPC HB viewpoint */
enum xpc_retval reason; /* reason partition is deactivating */
int reason_line; /* line# deactivation initiated from */
int reactivate_nasid; /* nasid in partition to reactivate */
/* XPC infrastructure referencing and teardown control */
u8 setup_state; /* infrastructure setup state */
wait_queue_head_t teardown_wq; /* kthread waiting to teardown infra */
atomic_t references; /* #of references to infrastructure */
/*
* NONE OF THE PRECEDING FIELDS OF THIS STRUCTURE WILL BE CLEARED WHEN
* XPC SETS UP THE NECESSARY INFRASTRUCTURE TO SUPPORT CROSS PARTITION
* COMMUNICATION. ALL OF THE FOLLOWING FIELDS WILL BE CLEARED. (THE
* 'nchannels' FIELD MUST BE THE FIRST OF THE FIELDS TO BE CLEARED.)
*/
u8 nchannels; /* #of defined channels supported */
atomic_t nchannels_active; /* #of channels that are not DISCONNECTED */
struct xpc_channel *channels;/* array of channel structures */
void *local_GPs_base; /* base address of kmalloc'd space */
struct xpc_gp *local_GPs; /* local Get/Put values */
void *remote_GPs_base; /* base address of kmalloc'd space */
struct xpc_gp *remote_GPs;/* copy of remote partition's local Get/Put */
/* values */
u64 remote_GPs_pa; /* phys address of remote partition's local */
/* Get/Put values */
/* fields used to pass args when opening or closing a channel */
void *local_openclose_args_base; /* base address of kmalloc'd space */
struct xpc_openclose_args *local_openclose_args; /* local's args */
void *remote_openclose_args_base; /* base address of kmalloc'd space */
struct xpc_openclose_args *remote_openclose_args; /* copy of remote's */
/* args */
u64 remote_openclose_args_pa; /* phys addr of remote's args */
/* IPI sending, receiving and handling related fields */
int remote_IPI_nasid; /* nasid of where to send IPIs */
int remote_IPI_phys_cpuid; /* phys CPU ID of where to send IPIs */
AMO_t *remote_IPI_amo_va; /* address of remote IPI AMO_t structure */
AMO_t *local_IPI_amo_va; /* address of IPI AMO_t structure */
u64 local_IPI_amo; /* IPI amo flags yet to be handled */
char IPI_owner[8]; /* IPI owner's name */
struct timer_list dropped_IPI_timer; /* dropped IPI timer */
spinlock_t IPI_lock; /* IPI handler lock */
/* channel manager related fields */
atomic_t channel_mgr_requests; /* #of requests to activate chan mgr */
wait_queue_head_t channel_mgr_wq; /* channel mgr's wait queue */
} ____cacheline_aligned;
/* struct xpc_partition act_state values (for XPC HB) */
#define XPC_P_INACTIVE 0x00 /* partition is not active */
#define XPC_P_ACTIVATION_REQ 0x01 /* created thread to activate */
#define XPC_P_ACTIVATING 0x02 /* activation thread started */
#define XPC_P_ACTIVE 0x03 /* xpc_partition_up() was called */
#define XPC_P_DEACTIVATING 0x04 /* partition deactivation initiated */
#define XPC_DEACTIVATE_PARTITION(_p, _reason) \
xpc_deactivate_partition(__LINE__, (_p), (_reason))
/* struct xpc_partition setup_state values */
#define XPC_P_UNSET 0x00 /* infrastructure was never setup */
#define XPC_P_SETUP 0x01 /* infrastructure is setup */
#define XPC_P_WTEARDOWN 0x02 /* waiting to teardown infrastructure */
#define XPC_P_TORNDOWN 0x03 /* infrastructure is torndown */
/*
* struct xpc_partition IPI_timer #of seconds to wait before checking for
* dropped IPIs. These occur whenever an IPI amo write doesn't complete until
* after the IPI was received.
*/
#define XPC_P_DROPPED_IPI_WAIT (0.25 * HZ)
#define XPC_PARTID(_p) ((partid_t) ((_p) - &xpc_partitions[0]))
/* found in xp_main.c */
extern struct xpc_registration xpc_registrations[];
/* >>> found in xpc_main.c only */
extern struct device *xpc_part;
extern struct device *xpc_chan;
extern irqreturn_t xpc_notify_IRQ_handler(int, void *, struct pt_regs *);
extern void xpc_dropped_IPI_check(struct xpc_partition *);
extern void xpc_activate_kthreads(struct xpc_channel *, int);
extern void xpc_create_kthreads(struct xpc_channel *, int);
extern void xpc_disconnect_wait(int);
/* found in xpc_main.c and efi-xpc.c */
extern void xpc_activate_partition(struct xpc_partition *);
/* found in xpc_partition.c */
extern int xpc_exiting;
extern int xpc_hb_interval;
extern int xpc_hb_check_interval;
extern struct xpc_vars *xpc_vars;
extern struct xpc_rsvd_page *xpc_rsvd_page;
extern struct xpc_vars_part *xpc_vars_part;
extern struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
extern char xpc_remote_copy_buffer[];
extern struct xpc_rsvd_page *xpc_rsvd_page_init(void);
extern void xpc_allow_IPI_ops(void);
extern void xpc_restrict_IPI_ops(void);
extern int xpc_identify_act_IRQ_sender(void);
extern enum xpc_retval xpc_mark_partition_active(struct xpc_partition *);
extern void xpc_mark_partition_inactive(struct xpc_partition *);
extern void xpc_discovery(void);
extern void xpc_check_remote_hb(void);
extern void xpc_deactivate_partition(const int, struct xpc_partition *,
enum xpc_retval);
extern enum xpc_retval xpc_initiate_partid_to_nasids(partid_t, void *);
/* found in xpc_channel.c */
extern void xpc_initiate_connect(int);
extern void xpc_initiate_disconnect(int);
extern enum xpc_retval xpc_initiate_allocate(partid_t, int, u32, void **);
extern enum xpc_retval xpc_initiate_send(partid_t, int, void *);
extern enum xpc_retval xpc_initiate_send_notify(partid_t, int, void *,
xpc_notify_func, void *);
extern void xpc_initiate_received(partid_t, int, void *);
extern enum xpc_retval xpc_setup_infrastructure(struct xpc_partition *);
extern enum xpc_retval xpc_pull_remote_vars_part(struct xpc_partition *);
extern void xpc_process_channel_activity(struct xpc_partition *);
extern void xpc_connected_callout(struct xpc_channel *);
extern void xpc_deliver_msg(struct xpc_channel *);
extern void xpc_disconnect_channel(const int, struct xpc_channel *,
enum xpc_retval, unsigned long *);
extern void xpc_disconnected_callout(struct xpc_channel *);
extern void xpc_partition_down(struct xpc_partition *, enum xpc_retval);
extern void xpc_teardown_infrastructure(struct xpc_partition *);
static inline void
xpc_wakeup_channel_mgr(struct xpc_partition *part)
{
if (atomic_inc_return(&part->channel_mgr_requests) == 1) {
wake_up(&part->channel_mgr_wq);
}
}
/*
* These next two inlines are used to keep us from tearing down a channel's
* msg queues while a thread may be referencing them.
*/
static inline void
xpc_msgqueue_ref(struct xpc_channel *ch)
{
atomic_inc(&ch->references);
}
static inline void
xpc_msgqueue_deref(struct xpc_channel *ch)
{
s32 refs = atomic_dec_return(&ch->references);
DBUG_ON(refs < 0);
if (refs == 0) {
xpc_wakeup_channel_mgr(&xpc_partitions[ch->partid]);
}
}
#define XPC_DISCONNECT_CHANNEL(_ch, _reason, _irqflgs) \
xpc_disconnect_channel(__LINE__, _ch, _reason, _irqflgs)
/*
* These two inlines are used to keep us from tearing down a partition's
* setup infrastructure while a thread may be referencing it.
*/
static inline void
xpc_part_deref(struct xpc_partition *part)
{
s32 refs = atomic_dec_return(&part->references);
DBUG_ON(refs < 0);
if (refs == 0 && part->setup_state == XPC_P_WTEARDOWN) {
wake_up(&part->teardown_wq);
}
}
static inline int
xpc_part_ref(struct xpc_partition *part)
{
int setup;
atomic_inc(&part->references);
setup = (part->setup_state == XPC_P_SETUP);
if (!setup) {
xpc_part_deref(part);
}
return setup;
}
/*
* The following macro is to be used for the setting of the reason and
* reason_line fields in both the struct xpc_channel and struct xpc_partition
* structures.
*/
#define XPC_SET_REASON(_p, _reason, _line) \
{ \
(_p)->reason = _reason; \
(_p)->reason_line = _line; \
}
/*
* The following set of macros and inlines are used for the sending and
* receiving of IPIs (also known as IRQs). There are two flavors of IPIs,
* one that is associated with partition activity (SGI_XPC_ACTIVATE) and
* the other that is associated with channel activity (SGI_XPC_NOTIFY).
*/
static inline u64
xpc_IPI_receive(AMO_t *amo)
{
return FETCHOP_LOAD_OP(TO_AMO((u64) &amo->variable), FETCHOP_CLEAR);
}
static inline enum xpc_retval
xpc_IPI_send(AMO_t *amo, u64 flag, int nasid, int phys_cpuid, int vector)
{
int ret = 0;
unsigned long irq_flags;
local_irq_save(irq_flags);
FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_OR, flag);
sn_send_IPI_phys(nasid, phys_cpuid, vector, 0);
/*
* We must always use the nofault function regardless of whether we
* are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
* didn't, we'd never know that the other partition is down and would
* keep sending IPIs and AMOs to it until the heartbeat times out.
*/
ret = xp_nofault_PIOR((u64 *) GLOBAL_MMR_ADDR(NASID_GET(&amo->variable),
xp_nofault_PIOR_target));
local_irq_restore(irq_flags);
return ((ret == 0) ? xpcSuccess : xpcPioReadError);
}
/*
* IPIs associated with SGI_XPC_ACTIVATE IRQ.
*/
/*
* Flag the appropriate AMO variable and send an IPI to the specified node.
*/
static inline void
xpc_activate_IRQ_send(u64 amos_page, int from_nasid, int to_nasid,
int to_phys_cpuid)
{
int w_index = XPC_NASID_W_INDEX(from_nasid);
int b_index = XPC_NASID_B_INDEX(from_nasid);
AMO_t *amos = (AMO_t *) __va(amos_page +
(XP_MAX_PARTITIONS * sizeof(AMO_t)));
(void) xpc_IPI_send(&amos[w_index], (1UL << b_index), to_nasid,
to_phys_cpuid, SGI_XPC_ACTIVATE);
}
static inline void
xpc_IPI_send_activate(struct xpc_vars *vars)
{
xpc_activate_IRQ_send(vars->amos_page_pa, cnodeid_to_nasid(0),
vars->act_nasid, vars->act_phys_cpuid);
}
static inline void
xpc_IPI_send_activated(struct xpc_partition *part)
{
xpc_activate_IRQ_send(part->remote_amos_page_pa, cnodeid_to_nasid(0),
part->remote_act_nasid, part->remote_act_phys_cpuid);
}
static inline void
xpc_IPI_send_reactivate(struct xpc_partition *part)
{
xpc_activate_IRQ_send(xpc_vars->amos_page_pa, part->reactivate_nasid,
xpc_vars->act_nasid, xpc_vars->act_phys_cpuid);
}
/*
* IPIs associated with SGI_XPC_NOTIFY IRQ.
*/
/*
* Send an IPI to the remote partition that is associated with the
* specified channel.
*/
#define XPC_NOTIFY_IRQ_SEND(_ch, _ipi_f, _irq_f) \
xpc_notify_IRQ_send(_ch, _ipi_f, #_ipi_f, _irq_f)
static inline void
xpc_notify_IRQ_send(struct xpc_channel *ch, u8 ipi_flag, char *ipi_flag_string,
unsigned long *irq_flags)
{
struct xpc_partition *part = &xpc_partitions[ch->partid];
enum xpc_retval ret;
if (likely(part->act_state != XPC_P_DEACTIVATING)) {
ret = xpc_IPI_send(part->remote_IPI_amo_va,
(u64) ipi_flag << (ch->number * 8),
part->remote_IPI_nasid,
part->remote_IPI_phys_cpuid,
SGI_XPC_NOTIFY);
dev_dbg(xpc_chan, "%s sent to partid=%d, channel=%d, ret=%d\n",
ipi_flag_string, ch->partid, ch->number, ret);
if (unlikely(ret != xpcSuccess)) {
if (irq_flags != NULL) {
spin_unlock_irqrestore(&ch->lock, *irq_flags);
}
XPC_DEACTIVATE_PARTITION(part, ret);
if (irq_flags != NULL) {
spin_lock_irqsave(&ch->lock, *irq_flags);
}
}
}
}
/*
* Make it look like the remote partition, which is associated with the
* specified channel, sent us an IPI. This faked IPI will be handled
* by xpc_dropped_IPI_check().
*/
#define XPC_NOTIFY_IRQ_SEND_LOCAL(_ch, _ipi_f) \
xpc_notify_IRQ_send_local(_ch, _ipi_f, #_ipi_f)
static inline void
xpc_notify_IRQ_send_local(struct xpc_channel *ch, u8 ipi_flag,
char *ipi_flag_string)
{
struct xpc_partition *part = &xpc_partitions[ch->partid];
FETCHOP_STORE_OP(TO_AMO((u64) &part->local_IPI_amo_va->variable),
FETCHOP_OR, ((u64) ipi_flag << (ch->number * 8)));
dev_dbg(xpc_chan, "%s sent local from partid=%d, channel=%d\n",
ipi_flag_string, ch->partid, ch->number);
}
/*
* The sending and receiving of IPIs includes the setting of an AMO variable
* to indicate the reason the IPI was sent. The 64-bit variable is divided
* up into eight bytes, ordered from right to left. Byte zero pertains to
* channel 0, byte one to channel 1, and so on. Each byte is described by
* the following IPI flags.
*/
#define XPC_IPI_CLOSEREQUEST 0x01
#define XPC_IPI_CLOSEREPLY 0x02
#define XPC_IPI_OPENREQUEST 0x04
#define XPC_IPI_OPENREPLY 0x08
#define XPC_IPI_MSGREQUEST 0x10
/* given an AMO variable and a channel#, get its associated IPI flags */
#define XPC_GET_IPI_FLAGS(_amo, _c) ((u8) (((_amo) >> ((_c) * 8)) & 0xff))
#define XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(_amo) ((_amo) & 0x0f0f0f0f0f0f0f0f)
#define XPC_ANY_MSG_IPI_FLAGS_SET(_amo) ((_amo) & 0x1010101010101010)
static inline void
xpc_IPI_send_closerequest(struct xpc_channel *ch, unsigned long *irq_flags)
{
struct xpc_openclose_args *args = ch->local_openclose_args;
args->reason = ch->reason;
XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_CLOSEREQUEST, irq_flags);
}
static inline void
xpc_IPI_send_closereply(struct xpc_channel *ch, unsigned long *irq_flags)
{
XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_CLOSEREPLY, irq_flags);
}
static inline void
xpc_IPI_send_openrequest(struct xpc_channel *ch, unsigned long *irq_flags)
{
struct xpc_openclose_args *args = ch->local_openclose_args;
args->msg_size = ch->msg_size;
args->local_nentries = ch->local_nentries;
XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_OPENREQUEST, irq_flags);
}
static inline void
xpc_IPI_send_openreply(struct xpc_channel *ch, unsigned long *irq_flags)
{
struct xpc_openclose_args *args = ch->local_openclose_args;
args->remote_nentries = ch->remote_nentries;
args->local_nentries = ch->local_nentries;
args->local_msgqueue_pa = __pa(ch->local_msgqueue);
XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_OPENREPLY, irq_flags);
}
static inline void
xpc_IPI_send_msgrequest(struct xpc_channel *ch)
{
XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_MSGREQUEST, NULL);
}
static inline void
xpc_IPI_send_local_msgrequest(struct xpc_channel *ch)
{
XPC_NOTIFY_IRQ_SEND_LOCAL(ch, XPC_IPI_MSGREQUEST);
}
/*
* Memory for XPC's AMO variables is allocated by the MSPEC driver. These
* pages are located in the lowest granule. The lowest granule uses 4k pages
* for cached references and an alternate TLB handler to never provide a
* cacheable mapping for the entire region. This will prevent speculative
* reading of cached copies of our lines from being issued which will cause
* a PI FSB Protocol error to be generated by the SHUB. For XPC, we need 64
* (XP_MAX_PARTITIONS) AMO variables for message notification (xpc_main.c)
* and an additional 16 AMO variables for partition activation (xpc_hb.c).
*/
static inline AMO_t *
xpc_IPI_init(partid_t partid)
{
AMO_t *part_amo = xpc_vars->amos_page + partid;
xpc_IPI_receive(part_amo);
return part_amo;
}
static inline enum xpc_retval
xpc_map_bte_errors(bte_result_t error)
{
switch (error) {
case BTE_SUCCESS: return xpcSuccess;
case BTEFAIL_DIR: return xpcBteDirectoryError;
case BTEFAIL_POISON: return xpcBtePoisonError;
case BTEFAIL_WERR: return xpcBteWriteError;
case BTEFAIL_ACCESS: return xpcBteAccessError;
case BTEFAIL_PWERR: return xpcBtePWriteError;
case BTEFAIL_PRERR: return xpcBtePReadError;
case BTEFAIL_TOUT: return xpcBteTimeOutError;
case BTEFAIL_XTERR: return xpcBteXtalkError;
case BTEFAIL_NOTAVAIL: return xpcBteNotAvailable;
default: return xpcBteUnmappedError;
}
}
static inline void *
xpc_kmalloc_cacheline_aligned(size_t size, int flags, void **base)
{
/* see if kmalloc will give us cachline aligned memory by default */
*base = kmalloc(size, flags);
if (*base == NULL) {
return NULL;
}
if ((u64) *base == L1_CACHE_ALIGN((u64) *base)) {
return *base;
}
kfree(*base);
/* nope, we'll have to do it ourselves */
*base = kmalloc(size + L1_CACHE_BYTES, flags);
if (*base == NULL) {
return NULL;
}
return (void *) L1_CACHE_ALIGN((u64) *base);
}
/*
* Check to see if there is any channel activity to/from the specified
* partition.
*/
static inline void
xpc_check_for_channel_activity(struct xpc_partition *part)
{
u64 IPI_amo;
unsigned long irq_flags;
IPI_amo = xpc_IPI_receive(part->local_IPI_amo_va);
if (IPI_amo == 0) {
return;
}
spin_lock_irqsave(&part->IPI_lock, irq_flags);
part->local_IPI_amo |= IPI_amo;
spin_unlock_irqrestore(&part->IPI_lock, irq_flags);
dev_dbg(xpc_chan, "received IPI from partid=%d, IPI_amo=0x%lx\n",
XPC_PARTID(part), IPI_amo);
xpc_wakeup_channel_mgr(part);
}
#endif /* _IA64_SN_KERNEL_XPC_H */
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2004-2005 Silicon Graphics, Inc. All Rights Reserved.
*/
/*
* Cross Partition Communication (XPC) channel support.
*
* This is the part of XPC that manages the channels and
* sends/receives messages across them to/from other partitions.
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/cache.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <asm/sn/bte.h>
#include <asm/sn/sn_sal.h>
#include "xpc.h"
/*
* Set up the initial values for the XPartition Communication channels.
*/
static void
xpc_initialize_channels(struct xpc_partition *part, partid_t partid)
{
int ch_number;
struct xpc_channel *ch;
for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
ch = &part->channels[ch_number];
ch->partid = partid;
ch->number = ch_number;
ch->flags = XPC_C_DISCONNECTED;
ch->local_GP = &part->local_GPs[ch_number];
ch->local_openclose_args =
&part->local_openclose_args[ch_number];
atomic_set(&ch->kthreads_assigned, 0);
atomic_set(&ch->kthreads_idle, 0);
atomic_set(&ch->kthreads_active, 0);
atomic_set(&ch->references, 0);
atomic_set(&ch->n_to_notify, 0);
spin_lock_init(&ch->lock);
sema_init(&ch->msg_to_pull_sema, 1); /* mutex */
atomic_set(&ch->n_on_msg_allocate_wq, 0);
init_waitqueue_head(&ch->msg_allocate_wq);
init_waitqueue_head(&ch->idle_wq);
}
}
/*
* Setup the infrastructure necessary to support XPartition Communication
* between the specified remote partition and the local one.
*/
enum xpc_retval
xpc_setup_infrastructure(struct xpc_partition *part)
{
int ret;
struct timer_list *timer;
partid_t partid = XPC_PARTID(part);
/*
* Zero out MOST of the entry for this partition. Only the fields
* starting with `nchannels' will be zeroed. The preceding fields must
* remain `viable' across partition ups and downs, since they may be
* referenced during this memset() operation.
*/
memset(&part->nchannels, 0, sizeof(struct xpc_partition) -
offsetof(struct xpc_partition, nchannels));
/*
* Allocate all of the channel structures as a contiguous chunk of
* memory.
*/
part->channels = kmalloc(sizeof(struct xpc_channel) * XPC_NCHANNELS,
GFP_KERNEL);
if (part->channels == NULL) {
dev_err(xpc_chan, "can't get memory for channels\n");
return xpcNoMemory;
}
memset(part->channels, 0, sizeof(struct xpc_channel) * XPC_NCHANNELS);
part->nchannels = XPC_NCHANNELS;
/* allocate all the required GET/PUT values */
part->local_GPs = xpc_kmalloc_cacheline_aligned(XPC_GP_SIZE,
GFP_KERNEL, &part->local_GPs_base);
if (part->local_GPs == NULL) {
kfree(part->channels);
part->channels = NULL;
dev_err(xpc_chan, "can't get memory for local get/put "
"values\n");
return xpcNoMemory;
}
memset(part->local_GPs, 0, XPC_GP_SIZE);
part->remote_GPs = xpc_kmalloc_cacheline_aligned(XPC_GP_SIZE,
GFP_KERNEL, &part->remote_GPs_base);
if (part->remote_GPs == NULL) {
kfree(part->channels);
part->channels = NULL;
kfree(part->local_GPs_base);
part->local_GPs = NULL;
dev_err(xpc_chan, "can't get memory for remote get/put "
"values\n");
return xpcNoMemory;
}
memset(part->remote_GPs, 0, XPC_GP_SIZE);
/* allocate all the required open and close args */
part->local_openclose_args = xpc_kmalloc_cacheline_aligned(
XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL,
&part->local_openclose_args_base);
if (part->local_openclose_args == NULL) {
kfree(part->channels);
part->channels = NULL;
kfree(part->local_GPs_base);
part->local_GPs = NULL;
kfree(part->remote_GPs_base);
part->remote_GPs = NULL;
dev_err(xpc_chan, "can't get memory for local connect args\n");
return xpcNoMemory;
}
memset(part->local_openclose_args, 0, XPC_OPENCLOSE_ARGS_SIZE);
part->remote_openclose_args = xpc_kmalloc_cacheline_aligned(
XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL,
&part->remote_openclose_args_base);
if (part->remote_openclose_args == NULL) {
kfree(part->channels);
part->channels = NULL;
kfree(part->local_GPs_base);
part->local_GPs = NULL;
kfree(part->remote_GPs_base);
part->remote_GPs = NULL;
kfree(part->local_openclose_args_base);
part->local_openclose_args = NULL;
dev_err(xpc_chan, "can't get memory for remote connect args\n");
return xpcNoMemory;
}
memset(part->remote_openclose_args, 0, XPC_OPENCLOSE_ARGS_SIZE);
xpc_initialize_channels(part, partid);
atomic_set(&part->nchannels_active, 0);
/* local_IPI_amo were set to 0 by an earlier memset() */
/* Initialize this partitions AMO_t structure */
part->local_IPI_amo_va = xpc_IPI_init(partid);
spin_lock_init(&part->IPI_lock);
atomic_set(&part->channel_mgr_requests, 1);
init_waitqueue_head(&part->channel_mgr_wq);
sprintf(part->IPI_owner, "xpc%02d", partid);
ret = request_irq(SGI_XPC_NOTIFY, xpc_notify_IRQ_handler, SA_SHIRQ,
part->IPI_owner, (void *) (u64) partid);
if (ret != 0) {
kfree(part->channels);
part->channels = NULL;
kfree(part->local_GPs_base);
part->local_GPs = NULL;
kfree(part->remote_GPs_base);
part->remote_GPs = NULL;
kfree(part->local_openclose_args_base);
part->local_openclose_args = NULL;
kfree(part->remote_openclose_args_base);
part->remote_openclose_args = NULL;
dev_err(xpc_chan, "can't register NOTIFY IRQ handler, "
"errno=%d\n", -ret);
return xpcLackOfResources;
}
/* Setup a timer to check for dropped IPIs */
timer = &part->dropped_IPI_timer;
init_timer(timer);
timer->function = (void (*)(unsigned long)) xpc_dropped_IPI_check;
timer->data = (unsigned long) part;
timer->expires = jiffies + XPC_P_DROPPED_IPI_WAIT;
add_timer(timer);
/*
* With the setting of the partition setup_state to XPC_P_SETUP, we're
* declaring that this partition is ready to go.
*/
(volatile u8) part->setup_state = XPC_P_SETUP;
/*
* Setup the per partition specific variables required by the
* remote partition to establish channel connections with us.
*
* The setting of the magic # indicates that these per partition
* specific variables are ready to be used.
*/
xpc_vars_part[partid].GPs_pa = __pa(part->local_GPs);
xpc_vars_part[partid].openclose_args_pa =
__pa(part->local_openclose_args);
xpc_vars_part[partid].IPI_amo_pa = __pa(part->local_IPI_amo_va);
xpc_vars_part[partid].IPI_nasid = cpuid_to_nasid(smp_processor_id());
xpc_vars_part[partid].IPI_phys_cpuid =
cpu_physical_id(smp_processor_id());
xpc_vars_part[partid].nchannels = part->nchannels;
(volatile u64) xpc_vars_part[partid].magic = XPC_VP_MAGIC1;
return xpcSuccess;
}
/*
* Create a wrapper that hides the underlying mechanism for pulling a cacheline
* (or multiple cachelines) from a remote partition.
*
* src must be a cacheline aligned physical address on the remote partition.
* dst must be a cacheline aligned virtual address on this partition.
* cnt must be an cacheline sized
*/
static enum xpc_retval
xpc_pull_remote_cachelines(struct xpc_partition *part, void *dst,
const void *src, size_t cnt)
{
bte_result_t bte_ret;
DBUG_ON((u64) src != L1_CACHE_ALIGN((u64) src));
DBUG_ON((u64) dst != L1_CACHE_ALIGN((u64) dst));
DBUG_ON(cnt != L1_CACHE_ALIGN(cnt));
if (part->act_state == XPC_P_DEACTIVATING) {
return part->reason;
}
bte_ret = xp_bte_copy((u64) src, (u64) ia64_tpa((u64) dst),
(u64) cnt, (BTE_NORMAL | BTE_WACQUIRE), NULL);
if (bte_ret == BTE_SUCCESS) {
return xpcSuccess;
}
dev_dbg(xpc_chan, "xp_bte_copy() from partition %d failed, ret=%d\n",
XPC_PARTID(part), bte_ret);
return xpc_map_bte_errors(bte_ret);
}
/*
* Pull the remote per partititon specific variables from the specified
* partition.
*/
enum xpc_retval
xpc_pull_remote_vars_part(struct xpc_partition *part)
{
u8 buffer[L1_CACHE_BYTES * 2];
struct xpc_vars_part *pulled_entry_cacheline =
(struct xpc_vars_part *) L1_CACHE_ALIGN((u64) buffer);
struct xpc_vars_part *pulled_entry;
u64 remote_entry_cacheline_pa, remote_entry_pa;
partid_t partid = XPC_PARTID(part);
enum xpc_retval ret;
/* pull the cacheline that contains the variables we're interested in */
DBUG_ON(part->remote_vars_part_pa !=
L1_CACHE_ALIGN(part->remote_vars_part_pa));
DBUG_ON(sizeof(struct xpc_vars_part) != L1_CACHE_BYTES / 2);
remote_entry_pa = part->remote_vars_part_pa +
sn_partition_id * sizeof(struct xpc_vars_part);
remote_entry_cacheline_pa = (remote_entry_pa & ~(L1_CACHE_BYTES - 1));
pulled_entry = (struct xpc_vars_part *) ((u64) pulled_entry_cacheline +
(remote_entry_pa & (L1_CACHE_BYTES - 1)));
ret = xpc_pull_remote_cachelines(part, pulled_entry_cacheline,
(void *) remote_entry_cacheline_pa,
L1_CACHE_BYTES);
if (ret != xpcSuccess) {
dev_dbg(xpc_chan, "failed to pull XPC vars_part from "
"partition %d, ret=%d\n", partid, ret);
return ret;
}
/* see if they've been set up yet */
if (pulled_entry->magic != XPC_VP_MAGIC1 &&
pulled_entry->magic != XPC_VP_MAGIC2) {
if (pulled_entry->magic != 0) {
dev_dbg(xpc_chan, "partition %d's XPC vars_part for "
"partition %d has bad magic value (=0x%lx)\n",
partid, sn_partition_id, pulled_entry->magic);
return xpcBadMagic;
}
/* they've not been initialized yet */
return xpcRetry;
}
if (xpc_vars_part[partid].magic == XPC_VP_MAGIC1) {
/* validate the variables */
if (pulled_entry->GPs_pa == 0 ||
pulled_entry->openclose_args_pa == 0 ||
pulled_entry->IPI_amo_pa == 0) {
dev_err(xpc_chan, "partition %d's XPC vars_part for "
"partition %d are not valid\n", partid,
sn_partition_id);
return xpcInvalidAddress;
}
/* the variables we imported look to be valid */
part->remote_GPs_pa = pulled_entry->GPs_pa;
part->remote_openclose_args_pa =
pulled_entry->openclose_args_pa;
part->remote_IPI_amo_va =
(AMO_t *) __va(pulled_entry->IPI_amo_pa);
part->remote_IPI_nasid = pulled_entry->IPI_nasid;
part->remote_IPI_phys_cpuid = pulled_entry->IPI_phys_cpuid;
if (part->nchannels > pulled_entry->nchannels) {
part->nchannels = pulled_entry->nchannels;
}
/* let the other side know that we've pulled their variables */
(volatile u64) xpc_vars_part[partid].magic = XPC_VP_MAGIC2;
}
if (pulled_entry->magic == XPC_VP_MAGIC1) {
return xpcRetry;
}
return xpcSuccess;
}
/*
* Get the IPI flags and pull the openclose args and/or remote GPs as needed.
*/
static u64
xpc_get_IPI_flags(struct xpc_partition *part)
{
unsigned long irq_flags;
u64 IPI_amo;
enum xpc_retval ret;
/*
* See if there are any IPI flags to be handled.
*/
spin_lock_irqsave(&part->IPI_lock, irq_flags);
if ((IPI_amo = part->local_IPI_amo) != 0) {
part->local_IPI_amo = 0;
}
spin_unlock_irqrestore(&part->IPI_lock, irq_flags);
if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_amo)) {
ret = xpc_pull_remote_cachelines(part,
part->remote_openclose_args,
(void *) part->remote_openclose_args_pa,
XPC_OPENCLOSE_ARGS_SIZE);
if (ret != xpcSuccess) {
XPC_DEACTIVATE_PARTITION(part, ret);
dev_dbg(xpc_chan, "failed to pull openclose args from "
"partition %d, ret=%d\n", XPC_PARTID(part),
ret);
/* don't bother processing IPIs anymore */
IPI_amo = 0;
}
}
if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_amo)) {
ret = xpc_pull_remote_cachelines(part, part->remote_GPs,
(void *) part->remote_GPs_pa,
XPC_GP_SIZE);
if (ret != xpcSuccess) {
XPC_DEACTIVATE_PARTITION(part, ret);
dev_dbg(xpc_chan, "failed to pull GPs from partition "
"%d, ret=%d\n", XPC_PARTID(part), ret);
/* don't bother processing IPIs anymore */
IPI_amo = 0;
}
}
return IPI_amo;
}
/*
* Allocate the local message queue and the notify queue.
*/
static enum xpc_retval
xpc_allocate_local_msgqueue(struct xpc_channel *ch)
{
unsigned long irq_flags;
int nentries;
size_t nbytes;
// >>> may want to check for ch->flags & XPC_C_DISCONNECTING between
// >>> iterations of the for-loop, bail if set?
// >>> should we impose a minumum #of entries? like 4 or 8?
for (nentries = ch->local_nentries; nentries > 0; nentries--) {
nbytes = nentries * ch->msg_size;
ch->local_msgqueue = xpc_kmalloc_cacheline_aligned(nbytes,
(GFP_KERNEL | GFP_DMA),
&ch->local_msgqueue_base);
if (ch->local_msgqueue == NULL) {
continue;
}
memset(ch->local_msgqueue, 0, nbytes);
nbytes = nentries * sizeof(struct xpc_notify);
ch->notify_queue = kmalloc(nbytes, (GFP_KERNEL | GFP_DMA));
if (ch->notify_queue == NULL) {
kfree(ch->local_msgqueue_base);
ch->local_msgqueue = NULL;
continue;
}
memset(ch->notify_queue, 0, nbytes);
spin_lock_irqsave(&ch->lock, irq_flags);
if (nentries < ch->local_nentries) {
dev_dbg(xpc_chan, "nentries=%d local_nentries=%d, "
"partid=%d, channel=%d\n", nentries,
ch->local_nentries, ch->partid, ch->number);
ch->local_nentries = nentries;
}
spin_unlock_irqrestore(&ch->lock, irq_flags);
return xpcSuccess;
}
dev_dbg(xpc_chan, "can't get memory for local message queue and notify "
"queue, partid=%d, channel=%d\n", ch->partid, ch->number);
return xpcNoMemory;
}
/*
* Allocate the cached remote message queue.
*/
static enum xpc_retval
xpc_allocate_remote_msgqueue(struct xpc_channel *ch)
{
unsigned long irq_flags;
int nentries;
size_t nbytes;
DBUG_ON(ch->remote_nentries <= 0);
// >>> may want to check for ch->flags & XPC_C_DISCONNECTING between
// >>> iterations of the for-loop, bail if set?
// >>> should we impose a minumum #of entries? like 4 or 8?
for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
nbytes = nentries * ch->msg_size;
ch->remote_msgqueue = xpc_kmalloc_cacheline_aligned(nbytes,
(GFP_KERNEL | GFP_DMA),
&ch->remote_msgqueue_base);
if (ch->remote_msgqueue == NULL) {
continue;
}
memset(ch->remote_msgqueue, 0, nbytes);
spin_lock_irqsave(&ch->lock, irq_flags);
if (nentries < ch->remote_nentries) {
dev_dbg(xpc_chan, "nentries=%d remote_nentries=%d, "
"partid=%d, channel=%d\n", nentries,
ch->remote_nentries, ch->partid, ch->number);
ch->remote_nentries = nentries;
}
spin_unlock_irqrestore(&ch->lock, irq_flags);
return xpcSuccess;
}
dev_dbg(xpc_chan, "can't get memory for cached remote message queue, "
"partid=%d, channel=%d\n", ch->partid, ch->number);
return xpcNoMemory;
}
/*
* Allocate message queues and other stuff associated with a channel.
*
* Note: Assumes all of the channel sizes are filled in.
*/
static enum xpc_retval
xpc_allocate_msgqueues(struct xpc_channel *ch)
{
unsigned long irq_flags;
int i;
enum xpc_retval ret;
DBUG_ON(ch->flags & XPC_C_SETUP);
if ((ret = xpc_allocate_local_msgqueue(ch)) != xpcSuccess) {
return ret;
}
if ((ret = xpc_allocate_remote_msgqueue(ch)) != xpcSuccess) {
kfree(ch->local_msgqueue_base);
ch->local_msgqueue = NULL;
kfree(ch->notify_queue);
ch->notify_queue = NULL;
return ret;
}
for (i = 0; i < ch->local_nentries; i++) {
/* use a semaphore as an event wait queue */
sema_init(&ch->notify_queue[i].sema, 0);
}
sema_init(&ch->teardown_sema, 0); /* event wait */
spin_lock_irqsave(&ch->lock, irq_flags);
ch->flags |= XPC_C_SETUP;
spin_unlock_irqrestore(&ch->lock, irq_flags);
return xpcSuccess;
}
/*
* Process a connect message from a remote partition.
*
* Note: xpc_process_connect() is expecting to be called with the
* spin_lock_irqsave held and will leave it locked upon return.
*/
static void
xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
{
enum xpc_retval ret;
DBUG_ON(!spin_is_locked(&ch->lock));
if (!(ch->flags & XPC_C_OPENREQUEST) ||
!(ch->flags & XPC_C_ROPENREQUEST)) {
/* nothing more to do for now */
return;
}
DBUG_ON(!(ch->flags & XPC_C_CONNECTING));
if (!(ch->flags & XPC_C_SETUP)) {
spin_unlock_irqrestore(&ch->lock, *irq_flags);
ret = xpc_allocate_msgqueues(ch);
spin_lock_irqsave(&ch->lock, *irq_flags);
if (ret != xpcSuccess) {
XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags);
}
if (ch->flags & (XPC_C_CONNECTED | XPC_C_DISCONNECTING)) {
return;
}
DBUG_ON(!(ch->flags & XPC_C_SETUP));
DBUG_ON(ch->local_msgqueue == NULL);
DBUG_ON(ch->remote_msgqueue == NULL);
}
if (!(ch->flags & XPC_C_OPENREPLY)) {
ch->flags |= XPC_C_OPENREPLY;
xpc_IPI_send_openreply(ch, irq_flags);
}
if (!(ch->flags & XPC_C_ROPENREPLY)) {
return;
}
DBUG_ON(ch->remote_msgqueue_pa == 0);
ch->flags = (XPC_C_CONNECTED | XPC_C_SETUP); /* clear all else */
dev_info(xpc_chan, "channel %d to partition %d connected\n",
ch->number, ch->partid);
spin_unlock_irqrestore(&ch->lock, *irq_flags);
xpc_create_kthreads(ch, 1);
spin_lock_irqsave(&ch->lock, *irq_flags);
}
/*
* Free up message queues and other stuff that were allocated for the specified
* channel.
*
* Note: ch->reason and ch->reason_line are left set for debugging purposes,
* they're cleared when XPC_C_DISCONNECTED is cleared.
*/
static void
xpc_free_msgqueues(struct xpc_channel *ch)
{
DBUG_ON(!spin_is_locked(&ch->lock));
DBUG_ON(atomic_read(&ch->n_to_notify) != 0);
ch->remote_msgqueue_pa = 0;
ch->func = NULL;
ch->key = NULL;
ch->msg_size = 0;
ch->local_nentries = 0;
ch->remote_nentries = 0;
ch->kthreads_assigned_limit = 0;
ch->kthreads_idle_limit = 0;
ch->local_GP->get = 0;
ch->local_GP->put = 0;
ch->remote_GP.get = 0;
ch->remote_GP.put = 0;
ch->w_local_GP.get = 0;
ch->w_local_GP.put = 0;
ch->w_remote_GP.get = 0;
ch->w_remote_GP.put = 0;
ch->next_msg_to_pull = 0;
if (ch->flags & XPC_C_SETUP) {
ch->flags &= ~XPC_C_SETUP;
dev_dbg(xpc_chan, "ch->flags=0x%x, partid=%d, channel=%d\n",
ch->flags, ch->partid, ch->number);
kfree(ch->local_msgqueue_base);
ch->local_msgqueue = NULL;
kfree(ch->remote_msgqueue_base);
ch->remote_msgqueue = NULL;
kfree(ch->notify_queue);
ch->notify_queue = NULL;
/* in case someone is waiting for the teardown to complete */
up(&ch->teardown_sema);
}
}
/*
* spin_lock_irqsave() is expected to be held on entry.
*/
static void
xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
{
struct xpc_partition *part = &xpc_partitions[ch->partid];
u32 ch_flags = ch->flags;
DBUG_ON(!spin_is_locked(&ch->lock));
if (!(ch->flags & XPC_C_DISCONNECTING)) {
return;
}
DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
/* make sure all activity has settled down first */
if (atomic_read(&ch->references) > 0) {
return;
}
DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0);
/* it's now safe to free the channel's message queues */
xpc_free_msgqueues(ch);
DBUG_ON(ch->flags & XPC_C_SETUP);
if (part->act_state != XPC_P_DEACTIVATING) {
/* as long as the other side is up do the full protocol */
if (!(ch->flags & XPC_C_RCLOSEREQUEST)) {
return;
}
if (!(ch->flags & XPC_C_CLOSEREPLY)) {
ch->flags |= XPC_C_CLOSEREPLY;
xpc_IPI_send_closereply(ch, irq_flags);
}
if (!(ch->flags & XPC_C_RCLOSEREPLY)) {
return;
}
}
/* both sides are disconnected now */
ch->flags = XPC_C_DISCONNECTED; /* clear all flags, but this one */
atomic_dec(&part->nchannels_active);
if (ch_flags & XPC_C_WASCONNECTED) {
dev_info(xpc_chan, "channel %d to partition %d disconnected, "
"reason=%d\n", ch->number, ch->partid, ch->reason);
}
}
/*
* Process a change in the channel's remote connection state.
*/
static void
xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
u8 IPI_flags)
{
unsigned long irq_flags;
struct xpc_openclose_args *args =
&part->remote_openclose_args[ch_number];
struct xpc_channel *ch = &part->channels[ch_number];
enum xpc_retval reason;
spin_lock_irqsave(&ch->lock, irq_flags);
if (IPI_flags & XPC_IPI_CLOSEREQUEST) {
dev_dbg(xpc_chan, "XPC_IPI_CLOSEREQUEST (reason=%d) received "
"from partid=%d, channel=%d\n", args->reason,
ch->partid, ch->number);
/*
* If RCLOSEREQUEST is set, we're probably waiting for
* RCLOSEREPLY. We should find it and a ROPENREQUEST packed
* with this RCLOSEQREUQEST in the IPI_flags.
*/
if (ch->flags & XPC_C_RCLOSEREQUEST) {
DBUG_ON(!(ch->flags & XPC_C_DISCONNECTING));
DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
DBUG_ON(!(ch->flags & XPC_C_CLOSEREPLY));
DBUG_ON(ch->flags & XPC_C_RCLOSEREPLY);
DBUG_ON(!(IPI_flags & XPC_IPI_CLOSEREPLY));
IPI_flags &= ~XPC_IPI_CLOSEREPLY;
ch->flags |= XPC_C_RCLOSEREPLY;
/* both sides have finished disconnecting */
xpc_process_disconnect(ch, &irq_flags);
}
if (ch->flags & XPC_C_DISCONNECTED) {
// >>> explain this section
if (!(IPI_flags & XPC_IPI_OPENREQUEST)) {
DBUG_ON(part->act_state !=
XPC_P_DEACTIVATING);
spin_unlock_irqrestore(&ch->lock, irq_flags);
return;
}
XPC_SET_REASON(ch, 0, 0);
ch->flags &= ~XPC_C_DISCONNECTED;
atomic_inc(&part->nchannels_active);
ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST);
}
IPI_flags &= ~(XPC_IPI_OPENREQUEST | XPC_IPI_OPENREPLY);
/*
* The meaningful CLOSEREQUEST connection state fields are:
* reason = reason connection is to be closed
*/
ch->flags |= XPC_C_RCLOSEREQUEST;
if (!(ch->flags & XPC_C_DISCONNECTING)) {
reason = args->reason;
if (reason <= xpcSuccess || reason > xpcUnknownReason) {
reason = xpcUnknownReason;
} else if (reason == xpcUnregistering) {
reason = xpcOtherUnregistering;
}
XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
} else {
xpc_process_disconnect(ch, &irq_flags);
}
}
if (IPI_flags & XPC_IPI_CLOSEREPLY) {
dev_dbg(xpc_chan, "XPC_IPI_CLOSEREPLY received from partid=%d,"
" channel=%d\n", ch->partid, ch->number);
if (ch->flags & XPC_C_DISCONNECTED) {
DBUG_ON(part->act_state != XPC_P_DEACTIVATING);
spin_unlock_irqrestore(&ch->lock, irq_flags);
return;
}
DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
DBUG_ON(!(ch->flags & XPC_C_RCLOSEREQUEST));
ch->flags |= XPC_C_RCLOSEREPLY;
if (ch->flags & XPC_C_CLOSEREPLY) {
/* both sides have finished disconnecting */
xpc_process_disconnect(ch, &irq_flags);
}
}
if (IPI_flags & XPC_IPI_OPENREQUEST) {
dev_dbg(xpc_chan, "XPC_IPI_OPENREQUEST (msg_size=%d, "
"local_nentries=%d) received from partid=%d, "
"channel=%d\n", args->msg_size, args->local_nentries,
ch->partid, ch->number);
if ((ch->flags & XPC_C_DISCONNECTING) ||
part->act_state == XPC_P_DEACTIVATING) {
spin_unlock_irqrestore(&ch->lock, irq_flags);
return;
}
DBUG_ON(!(ch->flags & (XPC_C_DISCONNECTED |
XPC_C_OPENREQUEST)));
DBUG_ON(ch->flags & (XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY |
XPC_C_OPENREPLY | XPC_C_CONNECTED));
/*
* The meaningful OPENREQUEST connection state fields are:
* msg_size = size of channel's messages in bytes
* local_nentries = remote partition's local_nentries
*/
DBUG_ON(args->msg_size == 0);
DBUG_ON(args->local_nentries == 0);
ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING);
ch->remote_nentries = args->local_nentries;
if (ch->flags & XPC_C_OPENREQUEST) {
if (args->msg_size != ch->msg_size) {
XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes,
&irq_flags);
spin_unlock_irqrestore(&ch->lock, irq_flags);
return;
}
} else {
ch->msg_size = args->msg_size;
XPC_SET_REASON(ch, 0, 0);
ch->flags &= ~XPC_C_DISCONNECTED;
atomic_inc(&part->nchannels_active);
}
xpc_process_connect(ch, &irq_flags);
}
if (IPI_flags & XPC_IPI_OPENREPLY) {
dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY (local_msgqueue_pa=0x%lx, "
"local_nentries=%d, remote_nentries=%d) received from "
"partid=%d, channel=%d\n", args->local_msgqueue_pa,
args->local_nentries, args->remote_nentries,
ch->partid, ch->number);
if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) {
spin_unlock_irqrestore(&ch->lock, irq_flags);
return;
}
DBUG_ON(!(ch->flags & XPC_C_OPENREQUEST));
DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST));
DBUG_ON(ch->flags & XPC_C_CONNECTED);
/*
* The meaningful OPENREPLY connection state fields are:
* local_msgqueue_pa = physical address of remote
* partition's local_msgqueue
* local_nentries = remote partition's local_nentries
* remote_nentries = remote partition's remote_nentries
*/
DBUG_ON(args->local_msgqueue_pa == 0);
DBUG_ON(args->local_nentries == 0);
DBUG_ON(args->remote_nentries == 0);
ch->flags |= XPC_C_ROPENREPLY;
ch->remote_msgqueue_pa = args->local_msgqueue_pa;
if (args->local_nentries < ch->remote_nentries) {
dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new "
"remote_nentries=%d, old remote_nentries=%d, "
"partid=%d, channel=%d\n",
args->local_nentries, ch->remote_nentries,
ch->partid, ch->number);
ch->remote_nentries = args->local_nentries;
}
if (args->remote_nentries < ch->local_nentries) {
dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new "
"local_nentries=%d, old local_nentries=%d, "
"partid=%d, channel=%d\n",
args->remote_nentries, ch->local_nentries,
ch->partid, ch->number);
ch->local_nentries = args->remote_nentries;
}
xpc_process_connect(ch, &irq_flags);
}
spin_unlock_irqrestore(&ch->lock, irq_flags);
}
/*
* Attempt to establish a channel connection to a remote partition.
*/
static enum xpc_retval
xpc_connect_channel(struct xpc_channel *ch)
{
unsigned long irq_flags;
struct xpc_registration *registration = &xpc_registrations[ch->number];
if (down_interruptible(&registration->sema) != 0) {
return xpcInterrupted;
}
if (!XPC_CHANNEL_REGISTERED(ch->number)) {
up(&registration->sema);
return xpcUnregistered;
}
spin_lock_irqsave(&ch->lock, irq_flags);
DBUG_ON(ch->flags & XPC_C_CONNECTED);
DBUG_ON(ch->flags & XPC_C_OPENREQUEST);
if (ch->flags & XPC_C_DISCONNECTING) {
spin_unlock_irqrestore(&ch->lock, irq_flags);
up(&registration->sema);
return ch->reason;
}
/* add info from the channel connect registration to the channel */
ch->kthreads_assigned_limit = registration->assigned_limit;
ch->kthreads_idle_limit = registration->idle_limit;
DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0);
DBUG_ON(atomic_read(&ch->kthreads_idle) != 0);
DBUG_ON(atomic_read(&ch->kthreads_active) != 0);
ch->func = registration->func;
DBUG_ON(registration->func == NULL);
ch->key = registration->key;
ch->local_nentries = registration->nentries;
if (ch->flags & XPC_C_ROPENREQUEST) {
if (registration->msg_size != ch->msg_size) {
/* the local and remote sides aren't the same */
/*
* Because XPC_DISCONNECT_CHANNEL() can block we're
* forced to up the registration sema before we unlock
* the channel lock. But that's okay here because we're
* done with the part that required the registration
* sema. XPC_DISCONNECT_CHANNEL() requires that the
* channel lock be locked and will unlock and relock
* the channel lock as needed.
*/
up(&registration->sema);
XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes,
&irq_flags);
spin_unlock_irqrestore(&ch->lock, irq_flags);
return xpcUnequalMsgSizes;
}
} else {
ch->msg_size = registration->msg_size;
XPC_SET_REASON(ch, 0, 0);
ch->flags &= ~XPC_C_DISCONNECTED;
atomic_inc(&xpc_partitions[ch->partid].nchannels_active);
}
up(&registration->sema);
/* initiate the connection */
ch->flags |= (XPC_C_OPENREQUEST | XPC_C_CONNECTING);
xpc_IPI_send_openrequest(ch, &irq_flags);
xpc_process_connect(ch, &irq_flags);
spin_unlock_irqrestore(&ch->lock, irq_flags);
return xpcSuccess;
}
/*
* Notify those who wanted to be notified upon delivery of their message.
*/
static void
xpc_notify_senders(struct xpc_channel *ch, enum xpc_retval reason, s64 put)
{
struct xpc_notify *notify;
u8 notify_type;
s64 get = ch->w_remote_GP.get - 1;
while (++get < put && atomic_read(&ch->n_to_notify) > 0) {
notify = &ch->notify_queue[get % ch->local_nentries];
/*
* See if the notify entry indicates it was associated with
* a message who's sender wants to be notified. It is possible
* that it is, but someone else is doing or has done the
* notification.
*/
notify_type = notify->type;
if (notify_type == 0 ||
cmpxchg(&notify->type, notify_type, 0) !=
notify_type) {
continue;
}
DBUG_ON(notify_type != XPC_N_CALL);
atomic_dec(&ch->n_to_notify);
if (notify->func != NULL) {
dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, "
"msg_number=%ld, partid=%d, channel=%d\n",
(void *) notify, get, ch->partid, ch->number);
notify->func(reason, ch->partid, ch->number,
notify->key);
dev_dbg(xpc_chan, "notify->func() returned, "
"notify=0x%p, msg_number=%ld, partid=%d, "
"channel=%d\n", (void *) notify, get,
ch->partid, ch->number);
}
}
}
/*
* Clear some of the msg flags in the local message queue.
*/
static inline void
xpc_clear_local_msgqueue_flags(struct xpc_channel *ch)
{
struct xpc_msg *msg;
s64 get;
get = ch->w_remote_GP.get;
do {
msg = (struct xpc_msg *) ((u64) ch->local_msgqueue +
(get % ch->local_nentries) * ch->msg_size);
msg->flags = 0;
} while (++get < (volatile s64) ch->remote_GP.get);
}
/*
* Clear some of the msg flags in the remote message queue.
*/
static inline void
xpc_clear_remote_msgqueue_flags(struct xpc_channel *ch)
{
struct xpc_msg *msg;
s64 put;
put = ch->w_remote_GP.put;
do {
msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue +
(put % ch->remote_nentries) * ch->msg_size);
msg->flags = 0;
} while (++put < (volatile s64) ch->remote_GP.put);
}
static void
xpc_process_msg_IPI(struct xpc_partition *part, int ch_number)
{
struct xpc_channel *ch = &part->channels[ch_number];
int nmsgs_sent;
ch->remote_GP = part->remote_GPs[ch_number];
/* See what, if anything, has changed for each connected channel */
xpc_msgqueue_ref(ch);
if (ch->w_remote_GP.get == ch->remote_GP.get &&
ch->w_remote_GP.put == ch->remote_GP.put) {
/* nothing changed since GPs were last pulled */
xpc_msgqueue_deref(ch);
return;
}
if (!(ch->flags & XPC_C_CONNECTED)){
xpc_msgqueue_deref(ch);
return;
}
/*
* First check to see if messages recently sent by us have been
* received by the other side. (The remote GET value will have
* changed since we last looked at it.)
*/
if (ch->w_remote_GP.get != ch->remote_GP.get) {
/*
* We need to notify any senders that want to be notified
* that their sent messages have been received by their
* intended recipients. We need to do this before updating
* w_remote_GP.get so that we don't allocate the same message
* queue entries prematurely (see xpc_allocate_msg()).
*/
if (atomic_read(&ch->n_to_notify) > 0) {
/*
* Notify senders that messages sent have been
* received and delivered by the other side.
*/
xpc_notify_senders(ch, xpcMsgDelivered,
ch->remote_GP.get);
}
/*
* Clear msg->flags in previously sent messages, so that
* they're ready for xpc_allocate_msg().
*/
xpc_clear_local_msgqueue_flags(ch);
(volatile s64) ch->w_remote_GP.get = ch->remote_GP.get;
dev_dbg(xpc_chan, "w_remote_GP.get changed to %ld, partid=%d, "
"channel=%d\n", ch->w_remote_GP.get, ch->partid,
ch->number);
/*
* If anyone was waiting for message queue entries to become
* available, wake them up.
*/
if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) {
wake_up(&ch->msg_allocate_wq);
}
}
/*
* Now check for newly sent messages by the other side. (The remote
* PUT value will have changed since we last looked at it.)
*/
if (ch->w_remote_GP.put != ch->remote_GP.put) {
/*
* Clear msg->flags in previously received messages, so that
* they're ready for xpc_get_deliverable_msg().
*/
xpc_clear_remote_msgqueue_flags(ch);
(volatile s64) ch->w_remote_GP.put = ch->remote_GP.put;
dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, "
"channel=%d\n", ch->w_remote_GP.put, ch->partid,
ch->number);
nmsgs_sent = ch->w_remote_GP.put - ch->w_local_GP.get;
if (nmsgs_sent > 0) {
dev_dbg(xpc_chan, "msgs waiting to be copied and "
"delivered=%d, partid=%d, channel=%d\n",
nmsgs_sent, ch->partid, ch->number);
if (ch->flags & XPC_C_CONNECTCALLOUT) {
xpc_activate_kthreads(ch, nmsgs_sent);
}
}
}
xpc_msgqueue_deref(ch);
}
void
xpc_process_channel_activity(struct xpc_partition *part)
{
unsigned long irq_flags;
u64 IPI_amo, IPI_flags;
struct xpc_channel *ch;
int ch_number;
IPI_amo = xpc_get_IPI_flags(part);
/*
* Initiate channel connections for registered channels.
*
* For each connected channel that has pending messages activate idle
* kthreads and/or create new kthreads as needed.
*/
for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
ch = &part->channels[ch_number];
/*
* Process any open or close related IPI flags, and then deal
* with connecting or disconnecting the channel as required.
*/
IPI_flags = XPC_GET_IPI_FLAGS(IPI_amo, ch_number);
if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_flags)) {
xpc_process_openclose_IPI(part, ch_number, IPI_flags);
}
if (ch->flags & XPC_C_DISCONNECTING) {
spin_lock_irqsave(&ch->lock, irq_flags);
xpc_process_disconnect(ch, &irq_flags);
spin_unlock_irqrestore(&ch->lock, irq_flags);
continue;
}
if (part->act_state == XPC_P_DEACTIVATING) {
continue;
}
if (!(ch->flags & XPC_C_CONNECTED)) {
if (!(ch->flags & XPC_C_OPENREQUEST)) {
DBUG_ON(ch->flags & XPC_C_SETUP);
(void) xpc_connect_channel(ch);
} else {
spin_lock_irqsave(&ch->lock, irq_flags);
xpc_process_connect(ch, &irq_flags);
spin_unlock_irqrestore(&ch->lock, irq_flags);
}
continue;
}
/*
* Process any message related IPI flags, this may involve the
* activation of kthreads to deliver any pending messages sent
* from the other partition.
*/
if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_flags)) {
xpc_process_msg_IPI(part, ch_number);
}
}
}
/*
* XPC's heartbeat code calls this function to inform XPC that a partition has
* gone down. XPC responds by tearing down the XPartition Communication
* infrastructure used for the just downed partition.
*
* XPC's heartbeat code will never call this function and xpc_partition_up()
* at the same time. Nor will it ever make multiple calls to either function
* at the same time.
*/
void
xpc_partition_down(struct xpc_partition *part, enum xpc_retval reason)
{
unsigned long irq_flags;
int ch_number;
struct xpc_channel *ch;
dev_dbg(xpc_chan, "deactivating partition %d, reason=%d\n",
XPC_PARTID(part), reason);
if (!xpc_part_ref(part)) {
/* infrastructure for this partition isn't currently set up */
return;
}
/* disconnect all channels associated with the downed partition */
for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
ch = &part->channels[ch_number];
xpc_msgqueue_ref(ch);
spin_lock_irqsave(&ch->lock, irq_flags);
XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
spin_unlock_irqrestore(&ch->lock, irq_flags);
xpc_msgqueue_deref(ch);
}
xpc_wakeup_channel_mgr(part);
xpc_part_deref(part);
}
/*
* Teardown the infrastructure necessary to support XPartition Communication
* between the specified remote partition and the local one.
*/
void
xpc_teardown_infrastructure(struct xpc_partition *part)
{
partid_t partid = XPC_PARTID(part);
/*
* We start off by making this partition inaccessible to local
* processes by marking it as no longer setup. Then we make it
* inaccessible to remote processes by clearing the XPC per partition
* specific variable's magic # (which indicates that these variables
* are no longer valid) and by ignoring all XPC notify IPIs sent to
* this partition.
*/
DBUG_ON(atomic_read(&part->nchannels_active) != 0);
DBUG_ON(part->setup_state != XPC_P_SETUP);
part->setup_state = XPC_P_WTEARDOWN;
xpc_vars_part[partid].magic = 0;
free_irq(SGI_XPC_NOTIFY, (void *) (u64) partid);
/*
* Before proceding with the teardown we have to wait until all
* existing references cease.
*/
wait_event(part->teardown_wq, (atomic_read(&part->references) == 0));
/* now we can begin tearing down the infrastructure */
part->setup_state = XPC_P_TORNDOWN;
/* in case we've still got outstanding timers registered... */
del_timer_sync(&part->dropped_IPI_timer);
kfree(part->remote_openclose_args_base);
part->remote_openclose_args = NULL;
kfree(part->local_openclose_args_base);
part->local_openclose_args = NULL;
kfree(part->remote_GPs_base);
part->remote_GPs = NULL;
kfree(part->local_GPs_base);
part->local_GPs = NULL;
kfree(part->channels);
part->channels = NULL;
part->local_IPI_amo_va = NULL;
}
/*
* Called by XP at the time of channel connection registration to cause
* XPC to establish connections to all currently active partitions.
*/
void
xpc_initiate_connect(int ch_number)
{
partid_t partid;
struct xpc_partition *part;
struct xpc_channel *ch;
DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
part = &xpc_partitions[partid];
if (xpc_part_ref(part)) {
ch = &part->channels[ch_number];
if (!(ch->flags & XPC_C_DISCONNECTING)) {
DBUG_ON(ch->flags & XPC_C_OPENREQUEST);
DBUG_ON(ch->flags & XPC_C_CONNECTED);
DBUG_ON(ch->flags & XPC_C_SETUP);
/*
* Initiate the establishment of a connection
* on the newly registered channel to the
* remote partition.
*/
xpc_wakeup_channel_mgr(part);
}
xpc_part_deref(part);
}
}
}
void
xpc_connected_callout(struct xpc_channel *ch)
{
unsigned long irq_flags;
/* let the registerer know that a connection has been established */
if (ch->func != NULL) {
dev_dbg(xpc_chan, "ch->func() called, reason=xpcConnected, "
"partid=%d, channel=%d\n", ch->partid, ch->number);
ch->func(xpcConnected, ch->partid, ch->number,
(void *) (u64) ch->local_nentries, ch->key);
dev_dbg(xpc_chan, "ch->func() returned, reason=xpcConnected, "
"partid=%d, channel=%d\n", ch->partid, ch->number);
}
spin_lock_irqsave(&ch->lock, irq_flags);
ch->flags |= XPC_C_CONNECTCALLOUT;
spin_unlock_irqrestore(&ch->lock, irq_flags);
}
/*
* Called by XP at the time of channel connection unregistration to cause
* XPC to teardown all current connections for the specified channel.
*
* Before returning xpc_initiate_disconnect() will wait until all connections
* on the specified channel have been closed/torndown. So the caller can be
* assured that they will not be receiving any more callouts from XPC to the
* function they registered via xpc_connect().
*
* Arguments:
*
* ch_number - channel # to unregister.
*/
void
xpc_initiate_disconnect(int ch_number)
{
unsigned long irq_flags;
partid_t partid;
struct xpc_partition *part;
struct xpc_channel *ch;
DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
/* initiate the channel disconnect for every active partition */
for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
part = &xpc_partitions[partid];
if (xpc_part_ref(part)) {
ch = &part->channels[ch_number];
xpc_msgqueue_ref(ch);
spin_lock_irqsave(&ch->lock, irq_flags);
XPC_DISCONNECT_CHANNEL(ch, xpcUnregistering,
&irq_flags);
spin_unlock_irqrestore(&ch->lock, irq_flags);
xpc_msgqueue_deref(ch);
xpc_part_deref(part);
}
}
xpc_disconnect_wait(ch_number);
}
/*
* To disconnect a channel, and reflect it back to all who may be waiting.
*
* >>> An OPEN is not allowed until XPC_C_DISCONNECTING is cleared by
* >>> xpc_free_msgqueues().
*
* THE CHANNEL IS TO BE LOCKED BY THE CALLER AND WILL REMAIN LOCKED UPON RETURN.
*/
void
xpc_disconnect_channel(const int line, struct xpc_channel *ch,
enum xpc_retval reason, unsigned long *irq_flags)
{
u32 flags;
DBUG_ON(!spin_is_locked(&ch->lock));
if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) {
return;
}
DBUG_ON(!(ch->flags & (XPC_C_CONNECTING | XPC_C_CONNECTED)));
dev_dbg(xpc_chan, "reason=%d, line=%d, partid=%d, channel=%d\n",
reason, line, ch->partid, ch->number);
XPC_SET_REASON(ch, reason, line);
flags = ch->flags;
/* some of these may not have been set */
ch->flags &= ~(XPC_C_OPENREQUEST | XPC_C_OPENREPLY |
XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY |
XPC_C_CONNECTING | XPC_C_CONNECTED);
ch->flags |= (XPC_C_CLOSEREQUEST | XPC_C_DISCONNECTING);
xpc_IPI_send_closerequest(ch, irq_flags);
if (flags & XPC_C_CONNECTED) {
ch->flags |= XPC_C_WASCONNECTED;
}
if (atomic_read(&ch->kthreads_idle) > 0) {
/* wake all idle kthreads so they can exit */
wake_up_all(&ch->idle_wq);
}
spin_unlock_irqrestore(&ch->lock, *irq_flags);
/* wake those waiting to allocate an entry from the local msg queue */
if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) {
wake_up(&ch->msg_allocate_wq);
}
/* wake those waiting for notify completion */
if (atomic_read(&ch->n_to_notify) > 0) {
xpc_notify_senders(ch, reason, ch->w_local_GP.put);
}
spin_lock_irqsave(&ch->lock, *irq_flags);
}
void
xpc_disconnected_callout(struct xpc_channel *ch)
{
/*
* Let the channel's registerer know that the channel is now
* disconnected. We don't want to do this if the registerer was never
* informed of a connection being made, unless the disconnect was for
* abnormal reasons.
*/
if (ch->func != NULL) {
dev_dbg(xpc_chan, "ch->func() called, reason=%d, partid=%d, "
"channel=%d\n", ch->reason, ch->partid, ch->number);
ch->func(ch->reason, ch->partid, ch->number, NULL, ch->key);
dev_dbg(xpc_chan, "ch->func() returned, reason=%d, partid=%d, "
"channel=%d\n", ch->reason, ch->partid, ch->number);
}
}
/*
* Wait for a message entry to become available for the specified channel,
* but don't wait any longer than 1 jiffy.
*/
static enum xpc_retval
xpc_allocate_msg_wait(struct xpc_channel *ch)
{
enum xpc_retval ret;
if (ch->flags & XPC_C_DISCONNECTING) {
DBUG_ON(ch->reason == xpcInterrupted); // >>> Is this true?
return ch->reason;
}
atomic_inc(&ch->n_on_msg_allocate_wq);
ret = interruptible_sleep_on_timeout(&ch->msg_allocate_wq, 1);
atomic_dec(&ch->n_on_msg_allocate_wq);
if (ch->flags & XPC_C_DISCONNECTING) {
ret = ch->reason;
DBUG_ON(ch->reason == xpcInterrupted); // >>> Is this true?
} else if (ret == 0) {
ret = xpcTimeout;
} else {
ret = xpcInterrupted;
}
return ret;
}
/*
* Allocate an entry for a message from the message queue associated with the
* specified channel.
*/
static enum xpc_retval
xpc_allocate_msg(struct xpc_channel *ch, u32 flags,
struct xpc_msg **address_of_msg)
{
struct xpc_msg *msg;
enum xpc_retval ret;
s64 put;
/* this reference will be dropped in xpc_send_msg() */
xpc_msgqueue_ref(ch);
if (ch->flags & XPC_C_DISCONNECTING) {
xpc_msgqueue_deref(ch);
return ch->reason;
}
if (!(ch->flags & XPC_C_CONNECTED)) {
xpc_msgqueue_deref(ch);
return xpcNotConnected;
}
/*
* Get the next available message entry from the local message queue.
* If none are available, we'll make sure that we grab the latest
* GP values.
*/
ret = xpcTimeout;
while (1) {
put = (volatile s64) ch->w_local_GP.put;
if (put - (volatile s64) ch->w_remote_GP.get <
ch->local_nentries) {
/* There are available message entries. We need to try
* to secure one for ourselves. We'll do this by trying
* to increment w_local_GP.put as long as someone else
* doesn't beat us to it. If they do, we'll have to
* try again.
*/
if (cmpxchg(&ch->w_local_GP.put, put, put + 1) ==
put) {
/* we got the entry referenced by put */
break;
}
continue; /* try again */
}
/*
* There aren't any available msg entries at this time.
*
* In waiting for a message entry to become available,
* we set a timeout in case the other side is not
* sending completion IPIs. This lets us fake an IPI
* that will cause the IPI handler to fetch the latest
* GP values as if an IPI was sent by the other side.
*/
if (ret == xpcTimeout) {
xpc_IPI_send_local_msgrequest(ch);
}
if (flags & XPC_NOWAIT) {
xpc_msgqueue_deref(ch);
return xpcNoWait;
}
ret = xpc_allocate_msg_wait(ch);
if (ret != xpcInterrupted && ret != xpcTimeout) {
xpc_msgqueue_deref(ch);
return ret;
}
}
/* get the message's address and initialize it */
msg = (struct xpc_msg *) ((u64) ch->local_msgqueue +
(put % ch->local_nentries) * ch->msg_size);
DBUG_ON(msg->flags != 0);
msg->number = put;
dev_dbg(xpc_chan, "w_local_GP.put changed to %ld; msg=0x%p, "
"msg_number=%ld, partid=%d, channel=%d\n", put + 1,
(void *) msg, msg->number, ch->partid, ch->number);
*address_of_msg = msg;
return xpcSuccess;
}
/*
* Allocate an entry for a message from the message queue associated with the
* specified channel. NOTE that this routine can sleep waiting for a message
* entry to become available. To not sleep, pass in the XPC_NOWAIT flag.
*
* Arguments:
*
* partid - ID of partition to which the channel is connected.
* ch_number - channel #.
* flags - see xpc.h for valid flags.
* payload - address of the allocated payload area pointer (filled in on
* return) in which the user-defined message is constructed.
*/
enum xpc_retval
xpc_initiate_allocate(partid_t partid, int ch_number, u32 flags, void **payload)
{
struct xpc_partition *part = &xpc_partitions[partid];
enum xpc_retval ret = xpcUnknownReason;
struct xpc_msg *msg;
DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
*payload = NULL;
if (xpc_part_ref(part)) {
ret = xpc_allocate_msg(&part->channels[ch_number], flags, &msg);
xpc_part_deref(part);
if (msg != NULL) {
*payload = &msg->payload;
}
}
return ret;
}
/*
* Now we actually send the messages that are ready to be sent by advancing
* the local message queue's Put value and then send an IPI to the recipient
* partition.
*/
static void
xpc_send_msgs(struct xpc_channel *ch, s64 initial_put)
{
struct xpc_msg *msg;
s64 put = initial_put + 1;
int send_IPI = 0;
while (1) {
while (1) {
if (put == (volatile s64) ch->w_local_GP.put) {
break;
}
msg = (struct xpc_msg *) ((u64) ch->local_msgqueue +
(put % ch->local_nentries) * ch->msg_size);
if (!(msg->flags & XPC_M_READY)) {
break;
}
put++;
}
if (put == initial_put) {
/* nothing's changed */
break;
}
if (cmpxchg_rel(&ch->local_GP->put, initial_put, put) !=
initial_put) {
/* someone else beat us to it */
DBUG_ON((volatile s64) ch->local_GP->put < initial_put);
break;
}
/* we just set the new value of local_GP->put */
dev_dbg(xpc_chan, "local_GP->put changed to %ld, partid=%d, "
"channel=%d\n", put, ch->partid, ch->number);
send_IPI = 1;
/*
* We need to ensure that the message referenced by
* local_GP->put is not XPC_M_READY or that local_GP->put
* equals w_local_GP.put, so we'll go have a look.
*/
initial_put = put;
}
if (send_IPI) {
xpc_IPI_send_msgrequest(ch);
}
}
/*
* Common code that does the actual sending of the message by advancing the
* local message queue's Put value and sends an IPI to the partition the
* message is being sent to.
*/
static enum xpc_retval
xpc_send_msg(struct xpc_channel *ch, struct xpc_msg *msg, u8 notify_type,
xpc_notify_func func, void *key)
{
enum xpc_retval ret = xpcSuccess;
struct xpc_notify *notify = NULL; // >>> to keep the compiler happy!!
s64 put, msg_number = msg->number;
DBUG_ON(notify_type == XPC_N_CALL && func == NULL);
DBUG_ON((((u64) msg - (u64) ch->local_msgqueue) / ch->msg_size) !=
msg_number % ch->local_nentries);
DBUG_ON(msg->flags & XPC_M_READY);
if (ch->flags & XPC_C_DISCONNECTING) {
/* drop the reference grabbed in xpc_allocate_msg() */
xpc_msgqueue_deref(ch);
return ch->reason;
}
if (notify_type != 0) {
/*
* Tell the remote side to send an ACK interrupt when the
* message has been delivered.
*/
msg->flags |= XPC_M_INTERRUPT;
atomic_inc(&ch->n_to_notify);
notify = &ch->notify_queue[msg_number % ch->local_nentries];
notify->func = func;
notify->key = key;
(volatile u8) notify->type = notify_type;
// >>> is a mb() needed here?
if (ch->flags & XPC_C_DISCONNECTING) {
/*
* An error occurred between our last error check and
* this one. We will try to clear the type field from
* the notify entry. If we succeed then
* xpc_disconnect_channel() didn't already process
* the notify entry.
*/
if (cmpxchg(&notify->type, notify_type, 0) ==
notify_type) {
atomic_dec(&ch->n_to_notify);
ret = ch->reason;
}
/* drop the reference grabbed in xpc_allocate_msg() */
xpc_msgqueue_deref(ch);
return ret;
}
}
msg->flags |= XPC_M_READY;
/*
* The preceding store of msg->flags must occur before the following
* load of ch->local_GP->put.
*/
mb();
/* see if the message is next in line to be sent, if so send it */
put = ch->local_GP->put;
if (put == msg_number) {
xpc_send_msgs(ch, put);
}
/* drop the reference grabbed in xpc_allocate_msg() */
xpc_msgqueue_deref(ch);
return ret;
}
/*
* Send a message previously allocated using xpc_initiate_allocate() on the
* specified channel connected to the specified partition.
*
* This routine will not wait for the message to be received, nor will
* notification be given when it does happen. Once this routine has returned
* the message entry allocated via xpc_initiate_allocate() is no longer
* accessable to the caller.
*
* This routine, although called by users, does not call xpc_part_ref() to
* ensure that the partition infrastructure is in place. It relies on the
* fact that we called xpc_msgqueue_ref() in xpc_allocate_msg().
*
* Arguments:
*
* partid - ID of partition to which the channel is connected.
* ch_number - channel # to send message on.
* payload - pointer to the payload area allocated via
* xpc_initiate_allocate().
*/
enum xpc_retval
xpc_initiate_send(partid_t partid, int ch_number, void *payload)
{
struct xpc_partition *part = &xpc_partitions[partid];
struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
enum xpc_retval ret;
dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *) msg,
partid, ch_number);
DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
DBUG_ON(msg == NULL);
ret = xpc_send_msg(&part->channels[ch_number], msg, 0, NULL, NULL);
return ret;
}
/*
* Send a message previously allocated using xpc_initiate_allocate on the
* specified channel connected to the specified partition.
*
* This routine will not wait for the message to be sent. Once this routine
* has returned the message entry allocated via xpc_initiate_allocate() is no
* longer accessable to the caller.
*
* Once the remote end of the channel has received the message, the function
* passed as an argument to xpc_initiate_send_notify() will be called. This
* allows the sender to free up or re-use any buffers referenced by the
* message, but does NOT mean the message has been processed at the remote
* end by a receiver.
*
* If this routine returns an error, the caller's function will NOT be called.
*
* This routine, although called by users, does not call xpc_part_ref() to
* ensure that the partition infrastructure is in place. It relies on the
* fact that we called xpc_msgqueue_ref() in xpc_allocate_msg().
*
* Arguments:
*
* partid - ID of partition to which the channel is connected.
* ch_number - channel # to send message on.
* payload - pointer to the payload area allocated via
* xpc_initiate_allocate().
* func - function to call with asynchronous notification of message
* receipt. THIS FUNCTION MUST BE NON-BLOCKING.
* key - user-defined key to be passed to the function when it's called.
*/
enum xpc_retval
xpc_initiate_send_notify(partid_t partid, int ch_number, void *payload,
xpc_notify_func func, void *key)
{
struct xpc_partition *part = &xpc_partitions[partid];
struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
enum xpc_retval ret;
dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *) msg,
partid, ch_number);
DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
DBUG_ON(msg == NULL);
DBUG_ON(func == NULL);
ret = xpc_send_msg(&part->channels[ch_number], msg, XPC_N_CALL,
func, key);
return ret;
}
static struct xpc_msg *
xpc_pull_remote_msg(struct xpc_channel *ch, s64 get)
{
struct xpc_partition *part = &xpc_partitions[ch->partid];
struct xpc_msg *remote_msg, *msg;
u32 msg_index, nmsgs;
u64 msg_offset;
enum xpc_retval ret;
if (down_interruptible(&ch->msg_to_pull_sema) != 0) {
/* we were interrupted by a signal */
return NULL;
}
while (get >= ch->next_msg_to_pull) {
/* pull as many messages as are ready and able to be pulled */
msg_index = ch->next_msg_to_pull % ch->remote_nentries;
DBUG_ON(ch->next_msg_to_pull >=
(volatile s64) ch->w_remote_GP.put);
nmsgs = (volatile s64) ch->w_remote_GP.put -
ch->next_msg_to_pull;
if (msg_index + nmsgs > ch->remote_nentries) {
/* ignore the ones that wrap the msg queue for now */
nmsgs = ch->remote_nentries - msg_index;
}
msg_offset = msg_index * ch->msg_size;
msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue +
msg_offset);
remote_msg = (struct xpc_msg *) (ch->remote_msgqueue_pa +
msg_offset);
if ((ret = xpc_pull_remote_cachelines(part, msg, remote_msg,
nmsgs * ch->msg_size)) != xpcSuccess) {
dev_dbg(xpc_chan, "failed to pull %d msgs starting with"
" msg %ld from partition %d, channel=%d, "
"ret=%d\n", nmsgs, ch->next_msg_to_pull,
ch->partid, ch->number, ret);
XPC_DEACTIVATE_PARTITION(part, ret);
up(&ch->msg_to_pull_sema);
return NULL;
}
mb(); /* >>> this may not be needed, we're not sure */
ch->next_msg_to_pull += nmsgs;
}
up(&ch->msg_to_pull_sema);
/* return the message we were looking for */
msg_offset = (get % ch->remote_nentries) * ch->msg_size;
msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue + msg_offset);
return msg;
}
/*
* Get a message to be delivered.
*/
static struct xpc_msg *
xpc_get_deliverable_msg(struct xpc_channel *ch)
{
struct xpc_msg *msg = NULL;
s64 get;
do {
if ((volatile u32) ch->flags & XPC_C_DISCONNECTING) {
break;
}
get = (volatile s64) ch->w_local_GP.get;
if (get == (volatile s64) ch->w_remote_GP.put) {
break;
}
/* There are messages waiting to be pulled and delivered.
* We need to try to secure one for ourselves. We'll do this
* by trying to increment w_local_GP.get and hope that no one
* else beats us to it. If they do, we'll we'll simply have
* to try again for the next one.
*/
if (cmpxchg(&ch->w_local_GP.get, get, get + 1) == get) {
/* we got the entry referenced by get */
dev_dbg(xpc_chan, "w_local_GP.get changed to %ld, "
"partid=%d, channel=%d\n", get + 1,
ch->partid, ch->number);
/* pull the message from the remote partition */
msg = xpc_pull_remote_msg(ch, get);
DBUG_ON(msg != NULL && msg->number != get);
DBUG_ON(msg != NULL && (msg->flags & XPC_M_DONE));
DBUG_ON(msg != NULL && !(msg->flags & XPC_M_READY));
break;
}
} while (1);
return msg;
}
/*
* Deliver a message to its intended recipient.
*/
void
xpc_deliver_msg(struct xpc_channel *ch)
{
struct xpc_msg *msg;
if ((msg = xpc_get_deliverable_msg(ch)) != NULL) {
/*
* This ref is taken to protect the payload itself from being
* freed before the user is finished with it, which the user
* indicates by calling xpc_initiate_received().
*/
xpc_msgqueue_ref(ch);
atomic_inc(&ch->kthreads_active);
if (ch->func != NULL) {
dev_dbg(xpc_chan, "ch->func() called, msg=0x%p, "
"msg_number=%ld, partid=%d, channel=%d\n",
(void *) msg, msg->number, ch->partid,
ch->number);
/* deliver the message to its intended recipient */
ch->func(xpcMsgReceived, ch->partid, ch->number,
&msg->payload, ch->key);
dev_dbg(xpc_chan, "ch->func() returned, msg=0x%p, "
"msg_number=%ld, partid=%d, channel=%d\n",
(void *) msg, msg->number, ch->partid,
ch->number);
}
atomic_dec(&ch->kthreads_active);
}
}
/*
* Now we actually acknowledge the messages that have been delivered and ack'd
* by advancing the cached remote message queue's Get value and if requested
* send an IPI to the message sender's partition.
*/
static void
xpc_acknowledge_msgs(struct xpc_channel *ch, s64 initial_get, u8 msg_flags)
{
struct xpc_msg *msg;
s64 get = initial_get + 1;
int send_IPI = 0;
while (1) {
while (1) {
if (get == (volatile s64) ch->w_local_GP.get) {
break;
}
msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue +
(get % ch->remote_nentries) * ch->msg_size);
if (!(msg->flags & XPC_M_DONE)) {
break;
}
msg_flags |= msg->flags;
get++;
}
if (get == initial_get) {
/* nothing's changed */
break;
}
if (cmpxchg_rel(&ch->local_GP->get, initial_get, get) !=
initial_get) {
/* someone else beat us to it */
DBUG_ON((volatile s64) ch->local_GP->get <=
initial_get);
break;
}
/* we just set the new value of local_GP->get */
dev_dbg(xpc_chan, "local_GP->get changed to %ld, partid=%d, "
"channel=%d\n", get, ch->partid, ch->number);
send_IPI = (msg_flags & XPC_M_INTERRUPT);
/*
* We need to ensure that the message referenced by
* local_GP->get is not XPC_M_DONE or that local_GP->get
* equals w_local_GP.get, so we'll go have a look.
*/
initial_get = get;
}
if (send_IPI) {
xpc_IPI_send_msgrequest(ch);
}
}
/*
* Acknowledge receipt of a delivered message.
*
* If a message has XPC_M_INTERRUPT set, send an interrupt to the partition
* that sent the message.
*
* This function, although called by users, does not call xpc_part_ref() to
* ensure that the partition infrastructure is in place. It relies on the
* fact that we called xpc_msgqueue_ref() in xpc_deliver_msg().
*
* Arguments:
*
* partid - ID of partition to which the channel is connected.
* ch_number - channel # message received on.
* payload - pointer to the payload area allocated via
* xpc_initiate_allocate().
*/
void
xpc_initiate_received(partid_t partid, int ch_number, void *payload)
{
struct xpc_partition *part = &xpc_partitions[partid];
struct xpc_channel *ch;
struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
s64 get, msg_number = msg->number;
DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
ch = &part->channels[ch_number];
dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n",
(void *) msg, msg_number, ch->partid, ch->number);
DBUG_ON((((u64) msg - (u64) ch->remote_msgqueue) / ch->msg_size) !=
msg_number % ch->remote_nentries);
DBUG_ON(msg->flags & XPC_M_DONE);
msg->flags |= XPC_M_DONE;
/*
* The preceding store of msg->flags must occur before the following
* load of ch->local_GP->get.
*/
mb();
/*
* See if this message is next in line to be acknowledged as having
* been delivered.
*/
get = ch->local_GP->get;
if (get == msg_number) {
xpc_acknowledge_msgs(ch, get, msg->flags);
}
/* the call to xpc_msgqueue_ref() was done by xpc_deliver_msg() */
xpc_msgqueue_deref(ch);
}
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2004-2005 Silicon Graphics, Inc. All Rights Reserved.
*/
/*
* Cross Partition Communication (XPC) support - standard version.
*
* XPC provides a message passing capability that crosses partition
* boundaries. This module is made up of two parts:
*
* partition This part detects the presence/absence of other
* partitions. It provides a heartbeat and monitors
* the heartbeats of other partitions.
*
* channel This part manages the channels and sends/receives
* messages across them to/from other partitions.
*
* There are a couple of additional functions residing in XP, which
* provide an interface to XPC for its users.
*
*
* Caveats:
*
* . We currently have no way to determine which nasid an IPI came
* from. Thus, xpc_IPI_send() does a remote AMO write followed by
* an IPI. The AMO indicates where data is to be pulled from, so
* after the IPI arrives, the remote partition checks the AMO word.
* The IPI can actually arrive before the AMO however, so other code
* must periodically check for this case. Also, remote AMO operations
* do not reliably time out. Thus we do a remote PIO read solely to
* know whether the remote partition is down and whether we should
* stop sending IPIs to it. This remote PIO read operation is set up
* in a special nofault region so SAL knows to ignore (and cleanup)
* any errors due to the remote AMO write, PIO read, and/or PIO
* write operations.
*
* If/when new hardware solves this IPI problem, we should abandon
* the current approach.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/syscalls.h>
#include <linux/cache.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <asm/sn/intr.h>
#include <asm/sn/sn_sal.h>
#include <asm/uaccess.h>
#include "xpc.h"
/* define two XPC debug device structures to be used with dev_dbg() et al */
struct device_driver xpc_dbg_name = {
.name = "xpc"
};
struct device xpc_part_dbg_subname = {
.bus_id = {0}, /* set to "part" at xpc_init() time */
.driver = &xpc_dbg_name
};
struct device xpc_chan_dbg_subname = {
.bus_id = {0}, /* set to "chan" at xpc_init() time */
.driver = &xpc_dbg_name
};
struct device *xpc_part = &xpc_part_dbg_subname;
struct device *xpc_chan = &xpc_chan_dbg_subname;
/* systune related variables for /proc/sys directories */
static int xpc_hb_min = 1;
static int xpc_hb_max = 10;
static int xpc_hb_check_min = 10;
static int xpc_hb_check_max = 120;
static ctl_table xpc_sys_xpc_hb_dir[] = {
{
1,
"hb_interval",
&xpc_hb_interval,
sizeof(int),
0644,
NULL,
&proc_dointvec_minmax,
&sysctl_intvec,
NULL,
&xpc_hb_min, &xpc_hb_max
},
{
2,
"hb_check_interval",
&xpc_hb_check_interval,
sizeof(int),
0644,
NULL,
&proc_dointvec_minmax,
&sysctl_intvec,
NULL,
&xpc_hb_check_min, &xpc_hb_check_max
},
{0}
};
static ctl_table xpc_sys_xpc_dir[] = {
{
1,
"hb",
NULL,
0,
0555,
xpc_sys_xpc_hb_dir
},
{0}
};
static ctl_table xpc_sys_dir[] = {
{
1,
"xpc",
NULL,
0,
0555,
xpc_sys_xpc_dir
},
{0}
};
static struct ctl_table_header *xpc_sysctl;
/* #of IRQs received */
static atomic_t xpc_act_IRQ_rcvd;
/* IRQ handler notifies this wait queue on receipt of an IRQ */
static DECLARE_WAIT_QUEUE_HEAD(xpc_act_IRQ_wq);
static unsigned long xpc_hb_check_timeout;
/* xpc_hb_checker thread exited notification */
static DECLARE_MUTEX_LOCKED(xpc_hb_checker_exited);
/* xpc_discovery thread exited notification */
static DECLARE_MUTEX_LOCKED(xpc_discovery_exited);
static struct timer_list xpc_hb_timer;
static void xpc_kthread_waitmsgs(struct xpc_partition *, struct xpc_channel *);
/*
* Notify the heartbeat check thread that an IRQ has been received.
*/
static irqreturn_t
xpc_act_IRQ_handler(int irq, void *dev_id, struct pt_regs *regs)
{
atomic_inc(&xpc_act_IRQ_rcvd);
wake_up_interruptible(&xpc_act_IRQ_wq);
return IRQ_HANDLED;
}
/*
* Timer to produce the heartbeat. The timer structures function is
* already set when this is initially called. A tunable is used to
* specify when the next timeout should occur.
*/
static void
xpc_hb_beater(unsigned long dummy)
{
xpc_vars->heartbeat++;
if (jiffies >= xpc_hb_check_timeout) {
wake_up_interruptible(&xpc_act_IRQ_wq);
}
xpc_hb_timer.expires = jiffies + (xpc_hb_interval * HZ);
add_timer(&xpc_hb_timer);
}
/*
* This thread is responsible for nearly all of the partition
* activation/deactivation.
*/
static int
xpc_hb_checker(void *ignore)
{
int last_IRQ_count = 0;
int new_IRQ_count;
int force_IRQ=0;
/* this thread was marked active by xpc_hb_init() */
daemonize(XPC_HB_CHECK_THREAD_NAME);
set_cpus_allowed(current, cpumask_of_cpu(XPC_HB_CHECK_CPU));
xpc_hb_check_timeout = jiffies + (xpc_hb_check_interval * HZ);
while (!(volatile int) xpc_exiting) {
/* wait for IRQ or timeout */
(void) wait_event_interruptible(xpc_act_IRQ_wq,
(last_IRQ_count < atomic_read(&xpc_act_IRQ_rcvd) ||
jiffies >= xpc_hb_check_timeout ||
(volatile int) xpc_exiting));
dev_dbg(xpc_part, "woke up with %d ticks rem; %d IRQs have "
"been received\n",
(int) (xpc_hb_check_timeout - jiffies),
atomic_read(&xpc_act_IRQ_rcvd) - last_IRQ_count);
/* checking of remote heartbeats is skewed by IRQ handling */
if (jiffies >= xpc_hb_check_timeout) {
dev_dbg(xpc_part, "checking remote heartbeats\n");
xpc_check_remote_hb();
/*
* We need to periodically recheck to ensure no
* IPI/AMO pairs have been missed. That check
* must always reset xpc_hb_check_timeout.
*/
force_IRQ = 1;
}
new_IRQ_count = atomic_read(&xpc_act_IRQ_rcvd);
if (last_IRQ_count < new_IRQ_count || force_IRQ != 0) {
force_IRQ = 0;
dev_dbg(xpc_part, "found an IRQ to process; will be "
"resetting xpc_hb_check_timeout\n");
last_IRQ_count += xpc_identify_act_IRQ_sender();
if (last_IRQ_count < new_IRQ_count) {
/* retry once to help avoid missing AMO */
(void) xpc_identify_act_IRQ_sender();
}
last_IRQ_count = new_IRQ_count;
xpc_hb_check_timeout = jiffies +
(xpc_hb_check_interval * HZ);
}
}
dev_dbg(xpc_part, "heartbeat checker is exiting\n");
/* mark this thread as inactive */
up(&xpc_hb_checker_exited);
return 0;
}
/*
* This thread will attempt to discover other partitions to activate
* based on info provided by SAL. This new thread is short lived and
* will exit once discovery is complete.
*/
static int
xpc_initiate_discovery(void *ignore)
{
daemonize(XPC_DISCOVERY_THREAD_NAME);
xpc_discovery();
dev_dbg(xpc_part, "discovery thread is exiting\n");
/* mark this thread as inactive */
up(&xpc_discovery_exited);
return 0;
}
/*
* Establish first contact with the remote partititon. This involves pulling
* the XPC per partition variables from the remote partition and waiting for
* the remote partition to pull ours.
*/
static enum xpc_retval
xpc_make_first_contact(struct xpc_partition *part)
{
enum xpc_retval ret;
while ((ret = xpc_pull_remote_vars_part(part)) != xpcSuccess) {
if (ret != xpcRetry) {
XPC_DEACTIVATE_PARTITION(part, ret);
return ret;
}
dev_dbg(xpc_chan, "waiting to make first contact with "
"partition %d\n", XPC_PARTID(part));
/* wait a 1/4 of a second or so */
set_current_state(TASK_INTERRUPTIBLE);
(void) schedule_timeout(0.25 * HZ);
if (part->act_state == XPC_P_DEACTIVATING) {
return part->reason;
}
}
return xpc_mark_partition_active(part);
}
/*
* The first kthread assigned to a newly activated partition is the one
* created by XPC HB with which it calls xpc_partition_up(). XPC hangs on to
* that kthread until the partition is brought down, at which time that kthread
* returns back to XPC HB. (The return of that kthread will signify to XPC HB
* that XPC has dismantled all communication infrastructure for the associated
* partition.) This kthread becomes the channel manager for that partition.
*
* Each active partition has a channel manager, who, besides connecting and
* disconnecting channels, will ensure that each of the partition's connected
* channels has the required number of assigned kthreads to get the work done.
*/
static void
xpc_channel_mgr(struct xpc_partition *part)
{
while (part->act_state != XPC_P_DEACTIVATING ||
atomic_read(&part->nchannels_active) > 0) {
xpc_process_channel_activity(part);
/*
* Wait until we've been requested to activate kthreads or
* all of the channel's message queues have been torn down or
* a signal is pending.
*
* The channel_mgr_requests is set to 1 after being awakened,
* This is done to prevent the channel mgr from making one pass
* through the loop for each request, since he will
* be servicing all the requests in one pass. The reason it's
* set to 1 instead of 0 is so that other kthreads will know
* that the channel mgr is running and won't bother trying to
* wake him up.
*/
atomic_dec(&part->channel_mgr_requests);
(void) wait_event_interruptible(part->channel_mgr_wq,
(atomic_read(&part->channel_mgr_requests) > 0 ||
(volatile u64) part->local_IPI_amo != 0 ||
((volatile u8) part->act_state ==
XPC_P_DEACTIVATING &&
atomic_read(&part->nchannels_active) == 0)));
atomic_set(&part->channel_mgr_requests, 1);
// >>> Does it need to wakeup periodically as well? In case we
// >>> miscalculated the #of kthreads to wakeup or create?
}
}
/*
* When XPC HB determines that a partition has come up, it will create a new
* kthread and that kthread will call this function to attempt to set up the
* basic infrastructure used for Cross Partition Communication with the newly
* upped partition.
*
* The kthread that was created by XPC HB and which setup the XPC
* infrastructure will remain assigned to the partition until the partition
* goes down. At which time the kthread will teardown the XPC infrastructure
* and then exit.
*
* XPC HB will put the remote partition's XPC per partition specific variables
* physical address into xpc_partitions[partid].remote_vars_part_pa prior to
* calling xpc_partition_up().
*/
static void
xpc_partition_up(struct xpc_partition *part)
{
DBUG_ON(part->channels != NULL);
dev_dbg(xpc_chan, "activating partition %d\n", XPC_PARTID(part));
if (xpc_setup_infrastructure(part) != xpcSuccess) {
return;
}
/*
* The kthread that XPC HB called us with will become the
* channel manager for this partition. It will not return
* back to XPC HB until the partition's XPC infrastructure
* has been dismantled.
*/
(void) xpc_part_ref(part); /* this will always succeed */
if (xpc_make_first_contact(part) == xpcSuccess) {
xpc_channel_mgr(part);
}
xpc_part_deref(part);
xpc_teardown_infrastructure(part);
}
static int
xpc_activating(void *__partid)
{
partid_t partid = (u64) __partid;
struct xpc_partition *part = &xpc_partitions[partid];
unsigned long irq_flags;
struct sched_param param = { sched_priority: MAX_USER_RT_PRIO - 1 };
int ret;
DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
spin_lock_irqsave(&part->act_lock, irq_flags);
if (part->act_state == XPC_P_DEACTIVATING) {
part->act_state = XPC_P_INACTIVE;
spin_unlock_irqrestore(&part->act_lock, irq_flags);
part->remote_rp_pa = 0;
return 0;
}
/* indicate the thread is activating */
DBUG_ON(part->act_state != XPC_P_ACTIVATION_REQ);
part->act_state = XPC_P_ACTIVATING;
XPC_SET_REASON(part, 0, 0);
spin_unlock_irqrestore(&part->act_lock, irq_flags);
dev_dbg(xpc_part, "bringing partition %d up\n", partid);
daemonize("xpc%02d", partid);
/*
* This thread needs to run at a realtime priority to prevent a
* significant performance degradation.
*/
ret = sched_setscheduler(current, SCHED_FIFO, &param);
if (ret != 0) {
dev_warn(xpc_part, "unable to set pid %d to a realtime "
"priority, ret=%d\n", current->pid, ret);
}
/* allow this thread and its children to run on any CPU */
set_cpus_allowed(current, CPU_MASK_ALL);
/*
* Register the remote partition's AMOs with SAL so it can handle
* and cleanup errors within that address range should the remote
* partition go down. We don't unregister this range because it is
* difficult to tell when outstanding writes to the remote partition
* are finished and thus when it is safe to unregister. This should
* not result in wasted space in the SAL xp_addr_region table because
* we should get the same page for remote_amos_page_pa after module
* reloads and system reboots.
*/
if (sn_register_xp_addr_region(part->remote_amos_page_pa,
PAGE_SIZE, 1) < 0) {
dev_warn(xpc_part, "xpc_partition_up(%d) failed to register "
"xp_addr region\n", partid);
spin_lock_irqsave(&part->act_lock, irq_flags);
part->act_state = XPC_P_INACTIVE;
XPC_SET_REASON(part, xpcPhysAddrRegFailed, __LINE__);
spin_unlock_irqrestore(&part->act_lock, irq_flags);
part->remote_rp_pa = 0;
return 0;
}
XPC_ALLOW_HB(partid, xpc_vars);
xpc_IPI_send_activated(part);
/*
* xpc_partition_up() holds this thread and marks this partition as
* XPC_P_ACTIVE by calling xpc_hb_mark_active().
*/
(void) xpc_partition_up(part);
xpc_mark_partition_inactive(part);
if (part->reason == xpcReactivating) {
/* interrupting ourselves results in activating partition */
xpc_IPI_send_reactivate(part);
}
return 0;
}
void
xpc_activate_partition(struct xpc_partition *part)
{
partid_t partid = XPC_PARTID(part);
unsigned long irq_flags;
pid_t pid;
spin_lock_irqsave(&part->act_lock, irq_flags);
pid = kernel_thread(xpc_activating, (void *) ((u64) partid), 0);
DBUG_ON(part->act_state != XPC_P_INACTIVE);
if (pid > 0) {
part->act_state = XPC_P_ACTIVATION_REQ;
XPC_SET_REASON(part, xpcCloneKThread, __LINE__);
} else {
XPC_SET_REASON(part, xpcCloneKThreadFailed, __LINE__);
}
spin_unlock_irqrestore(&part->act_lock, irq_flags);
}
/*
* Handle the receipt of a SGI_XPC_NOTIFY IRQ by seeing whether the specified
* partition actually sent it. Since SGI_XPC_NOTIFY IRQs may be shared by more
* than one partition, we use an AMO_t structure per partition to indicate
* whether a partition has sent an IPI or not. >>> If it has, then wake up the
* associated kthread to handle it.
*
* All SGI_XPC_NOTIFY IRQs received by XPC are the result of IPIs sent by XPC
* running on other partitions.
*
* Noteworthy Arguments:
*
* irq - Interrupt ReQuest number. NOT USED.
*
* dev_id - partid of IPI's potential sender.
*
* regs - processor's context before the processor entered
* interrupt code. NOT USED.
*/
irqreturn_t
xpc_notify_IRQ_handler(int irq, void *dev_id, struct pt_regs *regs)
{
partid_t partid = (partid_t) (u64) dev_id;
struct xpc_partition *part = &xpc_partitions[partid];
DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
if (xpc_part_ref(part)) {
xpc_check_for_channel_activity(part);
xpc_part_deref(part);
}
return IRQ_HANDLED;
}
/*
* Check to see if xpc_notify_IRQ_handler() dropped any IPIs on the floor
* because the write to their associated IPI amo completed after the IRQ/IPI
* was received.
*/
void
xpc_dropped_IPI_check(struct xpc_partition *part)
{
if (xpc_part_ref(part)) {
xpc_check_for_channel_activity(part);
part->dropped_IPI_timer.expires = jiffies +
XPC_P_DROPPED_IPI_WAIT;
add_timer(&part->dropped_IPI_timer);
xpc_part_deref(part);
}
}
void
xpc_activate_kthreads(struct xpc_channel *ch, int needed)
{
int idle = atomic_read(&ch->kthreads_idle);
int assigned = atomic_read(&ch->kthreads_assigned);
int wakeup;
DBUG_ON(needed <= 0);
if (idle > 0) {
wakeup = (needed > idle) ? idle : needed;
needed -= wakeup;
dev_dbg(xpc_chan, "wakeup %d idle kthreads, partid=%d, "
"channel=%d\n", wakeup, ch->partid, ch->number);
/* only wakeup the requested number of kthreads */
wake_up_nr(&ch->idle_wq, wakeup);
}
if (needed <= 0) {
return;
}
if (needed + assigned > ch->kthreads_assigned_limit) {
needed = ch->kthreads_assigned_limit - assigned;
// >>>should never be less than 0
if (needed <= 0) {
return;
}
}
dev_dbg(xpc_chan, "create %d new kthreads, partid=%d, channel=%d\n",
needed, ch->partid, ch->number);
xpc_create_kthreads(ch, needed);
}
/*
* This function is where XPC's kthreads wait for messages to deliver.
*/
static void
xpc_kthread_waitmsgs(struct xpc_partition *part, struct xpc_channel *ch)
{
do {
/* deliver messages to their intended recipients */
while ((volatile s64) ch->w_local_GP.get <
(volatile s64) ch->w_remote_GP.put &&
!((volatile u32) ch->flags &
XPC_C_DISCONNECTING)) {
xpc_deliver_msg(ch);
}
if (atomic_inc_return(&ch->kthreads_idle) >
ch->kthreads_idle_limit) {
/* too many idle kthreads on this channel */
atomic_dec(&ch->kthreads_idle);
break;
}
dev_dbg(xpc_chan, "idle kthread calling "
"wait_event_interruptible_exclusive()\n");
(void) wait_event_interruptible_exclusive(ch->idle_wq,
((volatile s64) ch->w_local_GP.get <
(volatile s64) ch->w_remote_GP.put ||
((volatile u32) ch->flags &
XPC_C_DISCONNECTING)));
atomic_dec(&ch->kthreads_idle);
} while (!((volatile u32) ch->flags & XPC_C_DISCONNECTING));
}
static int
xpc_daemonize_kthread(void *args)
{
partid_t partid = XPC_UNPACK_ARG1(args);
u16 ch_number = XPC_UNPACK_ARG2(args);
struct xpc_partition *part = &xpc_partitions[partid];
struct xpc_channel *ch;
int n_needed;
daemonize("xpc%02dc%d", partid, ch_number);
dev_dbg(xpc_chan, "kthread starting, partid=%d, channel=%d\n",
partid, ch_number);
ch = &part->channels[ch_number];
if (!(ch->flags & XPC_C_DISCONNECTING)) {
DBUG_ON(!(ch->flags & XPC_C_CONNECTED));
/* let registerer know that connection has been established */
if (atomic_read(&ch->kthreads_assigned) == 1) {
xpc_connected_callout(ch);
/*
* It is possible that while the callout was being
* made that the remote partition sent some messages.
* If that is the case, we may need to activate
* additional kthreads to help deliver them. We only
* need one less than total #of messages to deliver.
*/
n_needed = ch->w_remote_GP.put - ch->w_local_GP.get - 1;
if (n_needed > 0 &&
!(ch->flags & XPC_C_DISCONNECTING)) {
xpc_activate_kthreads(ch, n_needed);
}
}
xpc_kthread_waitmsgs(part, ch);
}
if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
((ch->flags & XPC_C_CONNECTCALLOUT) ||
(ch->reason != xpcUnregistering &&
ch->reason != xpcOtherUnregistering))) {
xpc_disconnected_callout(ch);
}
xpc_msgqueue_deref(ch);
dev_dbg(xpc_chan, "kthread exiting, partid=%d, channel=%d\n",
partid, ch_number);
xpc_part_deref(part);
return 0;
}
/*
* For each partition that XPC has established communications with, there is
* a minimum of one kernel thread assigned to perform any operation that
* may potentially sleep or block (basically the callouts to the asynchronous
* functions registered via xpc_connect()).
*
* Additional kthreads are created and destroyed by XPC as the workload
* demands.
*
* A kthread is assigned to one of the active channels that exists for a given
* partition.
*/
void
xpc_create_kthreads(struct xpc_channel *ch, int needed)
{
unsigned long irq_flags;
pid_t pid;
u64 args = XPC_PACK_ARGS(ch->partid, ch->number);
while (needed-- > 0) {
pid = kernel_thread(xpc_daemonize_kthread, (void *) args, 0);
if (pid < 0) {
/* the fork failed */
if (atomic_read(&ch->kthreads_assigned) <
ch->kthreads_idle_limit) {
/*
* Flag this as an error only if we have an
* insufficient #of kthreads for the channel
* to function.
*
* No xpc_msgqueue_ref() is needed here since
* the channel mgr is doing this.
*/
spin_lock_irqsave(&ch->lock, irq_flags);
XPC_DISCONNECT_CHANNEL(ch, xpcLackOfResources,
&irq_flags);
spin_unlock_irqrestore(&ch->lock, irq_flags);
}
break;
}
/*
* The following is done on behalf of the newly created
* kthread. That kthread is responsible for doing the
* counterpart to the following before it exits.
*/
(void) xpc_part_ref(&xpc_partitions[ch->partid]);
xpc_msgqueue_ref(ch);
atomic_inc(&ch->kthreads_assigned);
ch->kthreads_created++; // >>> temporary debug only!!!
}
}
void
xpc_disconnect_wait(int ch_number)
{
partid_t partid;
struct xpc_partition *part;
struct xpc_channel *ch;
/* now wait for all callouts to the caller's function to cease */
for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
part = &xpc_partitions[partid];
if (xpc_part_ref(part)) {
ch = &part->channels[ch_number];
// >>> how do we keep from falling into the window between our check and going
// >>> down and coming back up where sema is re-inited?
if (ch->flags & XPC_C_SETUP) {
(void) down(&ch->teardown_sema);
}
xpc_part_deref(part);
}
}
}
static void
xpc_do_exit(void)
{
partid_t partid;
int active_part_count;
struct xpc_partition *part;
/* now it's time to eliminate our heartbeat */
del_timer_sync(&xpc_hb_timer);
xpc_vars->heartbeating_to_mask = 0;
/* indicate to others that our reserved page is uninitialized */
xpc_rsvd_page->vars_pa = 0;
/*
* Ignore all incoming interrupts. Without interupts the heartbeat
* checker won't activate any new partitions that may come up.
*/
free_irq(SGI_XPC_ACTIVATE, NULL);
/*
* Cause the heartbeat checker and the discovery threads to exit.
* We don't want them attempting to activate new partitions as we
* try to deactivate the existing ones.
*/
xpc_exiting = 1;
wake_up_interruptible(&xpc_act_IRQ_wq);
/* wait for the heartbeat checker thread to mark itself inactive */
down(&xpc_hb_checker_exited);
/* wait for the discovery thread to mark itself inactive */
down(&xpc_discovery_exited);
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(0.3 * HZ);
set_current_state(TASK_RUNNING);
/* wait for all partitions to become inactive */
do {
active_part_count = 0;
for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
part = &xpc_partitions[partid];
if (part->act_state != XPC_P_INACTIVE) {
active_part_count++;
XPC_DEACTIVATE_PARTITION(part, xpcUnloading);
}
}
if (active_part_count) {
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(0.3 * HZ);
set_current_state(TASK_RUNNING);
}
} while (active_part_count > 0);
/* close down protections for IPI operations */
xpc_restrict_IPI_ops();
/* clear the interface to XPC's functions */
xpc_clear_interface();
if (xpc_sysctl) {
unregister_sysctl_table(xpc_sysctl);
}
}
int __init
xpc_init(void)
{
int ret;
partid_t partid;
struct xpc_partition *part;
pid_t pid;
/*
* xpc_remote_copy_buffer is used as a temporary buffer for bte_copy'ng
* both a partition's reserved page and its XPC variables. Its size was
* based on the size of a reserved page. So we need to ensure that the
* XPC variables will fit as well.
*/
if (XPC_VARS_ALIGNED_SIZE > XPC_RSVD_PAGE_ALIGNED_SIZE) {
dev_err(xpc_part, "xpc_remote_copy_buffer is not big enough\n");
return -EPERM;
}
DBUG_ON((u64) xpc_remote_copy_buffer !=
L1_CACHE_ALIGN((u64) xpc_remote_copy_buffer));
snprintf(xpc_part->bus_id, BUS_ID_SIZE, "part");
snprintf(xpc_chan->bus_id, BUS_ID_SIZE, "chan");
xpc_sysctl = register_sysctl_table(xpc_sys_dir, 1);
/*
* The first few fields of each entry of xpc_partitions[] need to
* be initialized now so that calls to xpc_connect() and
* xpc_disconnect() can be made prior to the activation of any remote
* partition. NOTE THAT NONE OF THE OTHER FIELDS BELONGING TO THESE
* ENTRIES ARE MEANINGFUL UNTIL AFTER AN ENTRY'S CORRESPONDING
* PARTITION HAS BEEN ACTIVATED.
*/
for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
part = &xpc_partitions[partid];
DBUG_ON((u64) part != L1_CACHE_ALIGN((u64) part));
part->act_IRQ_rcvd = 0;
spin_lock_init(&part->act_lock);
part->act_state = XPC_P_INACTIVE;
XPC_SET_REASON(part, 0, 0);
part->setup_state = XPC_P_UNSET;
init_waitqueue_head(&part->teardown_wq);
atomic_set(&part->references, 0);
}
/*
* Open up protections for IPI operations (and AMO operations on
* Shub 1.1 systems).
*/
xpc_allow_IPI_ops();
/*
* Interrupts being processed will increment this atomic variable and
* awaken the heartbeat thread which will process the interrupts.
*/
atomic_set(&xpc_act_IRQ_rcvd, 0);
/*
* This is safe to do before the xpc_hb_checker thread has started
* because the handler releases a wait queue. If an interrupt is
* received before the thread is waiting, it will not go to sleep,
* but rather immediately process the interrupt.
*/
ret = request_irq(SGI_XPC_ACTIVATE, xpc_act_IRQ_handler, 0,
"xpc hb", NULL);
if (ret != 0) {
dev_err(xpc_part, "can't register ACTIVATE IRQ handler, "
"errno=%d\n", -ret);
xpc_restrict_IPI_ops();
if (xpc_sysctl) {
unregister_sysctl_table(xpc_sysctl);
}
return -EBUSY;
}
/*
* Fill the partition reserved page with the information needed by
* other partitions to discover we are alive and establish initial
* communications.
*/
xpc_rsvd_page = xpc_rsvd_page_init();
if (xpc_rsvd_page == NULL) {
dev_err(xpc_part, "could not setup our reserved page\n");
free_irq(SGI_XPC_ACTIVATE, NULL);
xpc_restrict_IPI_ops();
if (xpc_sysctl) {
unregister_sysctl_table(xpc_sysctl);
}
return -EBUSY;
}
/*
* Set the beating to other partitions into motion. This is
* the last requirement for other partitions' discovery to
* initiate communications with us.
*/
init_timer(&xpc_hb_timer);
xpc_hb_timer.function = xpc_hb_beater;
xpc_hb_beater(0);
/*
* The real work-horse behind xpc. This processes incoming
* interrupts and monitors remote heartbeats.
*/
pid = kernel_thread(xpc_hb_checker, NULL, 0);
if (pid < 0) {
dev_err(xpc_part, "failed while forking hb check thread\n");
/* indicate to others that our reserved page is uninitialized */
xpc_rsvd_page->vars_pa = 0;
del_timer_sync(&xpc_hb_timer);
free_irq(SGI_XPC_ACTIVATE, NULL);
xpc_restrict_IPI_ops();
if (xpc_sysctl) {
unregister_sysctl_table(xpc_sysctl);
}
return -EBUSY;
}
/*
* Startup a thread that will attempt to discover other partitions to
* activate based on info provided by SAL. This new thread is short
* lived and will exit once discovery is complete.
*/
pid = kernel_thread(xpc_initiate_discovery, NULL, 0);
if (pid < 0) {
dev_err(xpc_part, "failed while forking discovery thread\n");
/* mark this new thread as a non-starter */
up(&xpc_discovery_exited);
xpc_do_exit();
return -EBUSY;
}
/* set the interface to point at XPC's functions */
xpc_set_interface(xpc_initiate_connect, xpc_initiate_disconnect,
xpc_initiate_allocate, xpc_initiate_send,
xpc_initiate_send_notify, xpc_initiate_received,
xpc_initiate_partid_to_nasids);
return 0;
}
module_init(xpc_init);
void __exit
xpc_exit(void)
{
xpc_do_exit();
}
module_exit(xpc_exit);
MODULE_AUTHOR("Silicon Graphics, Inc.");
MODULE_DESCRIPTION("Cross Partition Communication (XPC) support");
MODULE_LICENSE("GPL");
module_param(xpc_hb_interval, int, 0);
MODULE_PARM_DESC(xpc_hb_interval, "Number of seconds between "
"heartbeat increments.");
module_param(xpc_hb_check_interval, int, 0);
MODULE_PARM_DESC(xpc_hb_check_interval, "Number of seconds between "
"heartbeat checks.");
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2004-2005 Silicon Graphics, Inc. All Rights Reserved.
*/
/*
* Cross Partition Communication (XPC) partition support.
*
* This is the part of XPC that detects the presence/absence of
* other partitions. It provides a heartbeat and monitors the
* heartbeats of other partitions.
*
*/
#include <linux/kernel.h>
#include <linux/sysctl.h>
#include <linux/cache.h>
#include <linux/mmzone.h>
#include <linux/nodemask.h>
#include <asm/sn/bte.h>
#include <asm/sn/intr.h>
#include <asm/sn/sn_sal.h>
#include <asm/sn/nodepda.h>
#include <asm/sn/addrs.h>
#include "xpc.h"
/* XPC is exiting flag */
int xpc_exiting;
/* SH_IPI_ACCESS shub register value on startup */
static u64 xpc_sh1_IPI_access;
static u64 xpc_sh2_IPI_access0;
static u64 xpc_sh2_IPI_access1;
static u64 xpc_sh2_IPI_access2;
static u64 xpc_sh2_IPI_access3;
/* original protection values for each node */
u64 xpc_prot_vec[MAX_COMPACT_NODES];
/* this partition's reserved page */
struct xpc_rsvd_page *xpc_rsvd_page;
/* this partition's XPC variables (within the reserved page) */
struct xpc_vars *xpc_vars;
struct xpc_vars_part *xpc_vars_part;
/*
* For performance reasons, each entry of xpc_partitions[] is cacheline
* aligned. And xpc_partitions[] is padded with an additional entry at the
* end so that the last legitimate entry doesn't share its cacheline with
* another variable.
*/
struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
/*
* Generic buffer used to store a local copy of the remote partitions
* reserved page or XPC variables.
*
* xpc_discovery runs only once and is a seperate thread that is
* very likely going to be processing in parallel with receiving
* interrupts.
*/
char ____cacheline_aligned
xpc_remote_copy_buffer[XPC_RSVD_PAGE_ALIGNED_SIZE];
/* systune related variables */
int xpc_hb_interval = XPC_HB_DEFAULT_INTERVAL;
int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_TIMEOUT;
/*
* Given a nasid, get the physical address of the partition's reserved page
* for that nasid. This function returns 0 on any error.
*/
static u64
xpc_get_rsvd_page_pa(int nasid, u64 buf, u64 buf_size)
{
bte_result_t bte_res;
s64 status;
u64 cookie = 0;
u64 rp_pa = nasid; /* seed with nasid */
u64 len = 0;
while (1) {
status = sn_partition_reserved_page_pa(buf, &cookie, &rp_pa,
&len);
dev_dbg(xpc_part, "SAL returned with status=%li, cookie="
"0x%016lx, address=0x%016lx, len=0x%016lx\n",
status, cookie, rp_pa, len);
if (status != SALRET_MORE_PASSES) {
break;
}
if (len > buf_size) {
dev_err(xpc_part, "len (=0x%016lx) > buf_size\n", len);
status = SALRET_ERROR;
break;
}
bte_res = xp_bte_copy(rp_pa, ia64_tpa(buf), buf_size,
(BTE_NOTIFY | BTE_WACQUIRE), NULL);
if (bte_res != BTE_SUCCESS) {
dev_dbg(xpc_part, "xp_bte_copy failed %i\n", bte_res);
status = SALRET_ERROR;
break;
}
}
if (status != SALRET_OK) {
rp_pa = 0;
}
dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
return rp_pa;
}
/*
* Fill the partition reserved page with the information needed by
* other partitions to discover we are alive and establish initial
* communications.
*/
struct xpc_rsvd_page *
xpc_rsvd_page_init(void)
{
struct xpc_rsvd_page *rp;
AMO_t *amos_page;
u64 rp_pa, next_cl, nasid_array = 0;
int i, ret;
/* get the local reserved page's address */
rp_pa = xpc_get_rsvd_page_pa(cnodeid_to_nasid(0),
(u64) xpc_remote_copy_buffer,
XPC_RSVD_PAGE_ALIGNED_SIZE);
if (rp_pa == 0) {
dev_err(xpc_part, "SAL failed to locate the reserved page\n");
return NULL;
}
rp = (struct xpc_rsvd_page *) __va(rp_pa);
if (rp->partid != sn_partition_id) {
dev_err(xpc_part, "the reserved page's partid of %d should be "
"%d\n", rp->partid, sn_partition_id);
return NULL;
}
rp->version = XPC_RP_VERSION;
/*
* Place the XPC variables on the cache line following the
* reserved page structure.
*/
next_cl = (u64) rp + XPC_RSVD_PAGE_ALIGNED_SIZE;
xpc_vars = (struct xpc_vars *) next_cl;
/*
* Before clearing xpc_vars, see if a page of AMOs had been previously
* allocated. If not we'll need to allocate one and set permissions
* so that cross-partition AMOs are allowed.
*
* The allocated AMO page needs MCA reporting to remain disabled after
* XPC has unloaded. To make this work, we keep a copy of the pointer
* to this page (i.e., amos_page) in the struct xpc_vars structure,
* which is pointed to by the reserved page, and re-use that saved copy
* on subsequent loads of XPC. This AMO page is never freed, and its
* memory protections are never restricted.
*/
if ((amos_page = xpc_vars->amos_page) == NULL) {
amos_page = (AMO_t *) mspec_kalloc_page(0);
if (amos_page == NULL) {
dev_err(xpc_part, "can't allocate page of AMOs\n");
return NULL;
}
/*
* Open up AMO-R/W to cpu. This is done for Shub 1.1 systems
* when xpc_allow_IPI_ops() is called via xpc_hb_init().
*/
if (!enable_shub_wars_1_1()) {
ret = sn_change_memprotect(ia64_tpa((u64) amos_page),
PAGE_SIZE, SN_MEMPROT_ACCESS_CLASS_1,
&nasid_array);
if (ret != 0) {
dev_err(xpc_part, "can't change memory "
"protections\n");
mspec_kfree_page((unsigned long) amos_page);
return NULL;
}
}
}
memset(xpc_vars, 0, sizeof(struct xpc_vars));
/*
* Place the XPC per partition specific variables on the cache line
* following the XPC variables structure.
*/
next_cl += XPC_VARS_ALIGNED_SIZE;
memset((u64 *) next_cl, 0, sizeof(struct xpc_vars_part) *
XP_MAX_PARTITIONS);
xpc_vars_part = (struct xpc_vars_part *) next_cl;
xpc_vars->vars_part_pa = __pa(next_cl);
xpc_vars->version = XPC_V_VERSION;
xpc_vars->act_nasid = cpuid_to_nasid(0);
xpc_vars->act_phys_cpuid = cpu_physical_id(0);
xpc_vars->amos_page = amos_page; /* save for next load of XPC */
/*
* Initialize the activation related AMO variables.
*/
xpc_vars->act_amos = xpc_IPI_init(XP_MAX_PARTITIONS);
for (i = 1; i < XP_NASID_MASK_WORDS; i++) {
xpc_IPI_init(i + XP_MAX_PARTITIONS);
}
/* export AMO page's physical address to other partitions */
xpc_vars->amos_page_pa = ia64_tpa((u64) xpc_vars->amos_page);
/*
* This signifies to the remote partition that our reserved
* page is initialized.
*/
(volatile u64) rp->vars_pa = __pa(xpc_vars);
return rp;
}
/*
* Change protections to allow IPI operations (and AMO operations on
* Shub 1.1 systems).
*/
void
xpc_allow_IPI_ops(void)
{
int node;
int nasid;
// >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
if (is_shub2()) {
xpc_sh2_IPI_access0 =
(u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
xpc_sh2_IPI_access1 =
(u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
xpc_sh2_IPI_access2 =
(u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
xpc_sh2_IPI_access3 =
(u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
for_each_online_node(node) {
nasid = cnodeid_to_nasid(node);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
-1UL);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
-1UL);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
-1UL);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
-1UL);
}
} else {
xpc_sh1_IPI_access =
(u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
for_each_online_node(node) {
nasid = cnodeid_to_nasid(node);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
-1UL);
/*
* Since the BIST collides with memory operations on
* SHUB 1.1 sn_change_memprotect() cannot be used.
*/
if (enable_shub_wars_1_1()) {
/* open up everything */
xpc_prot_vec[node] = (u64) HUB_L((u64 *)
GLOBAL_MMR_ADDR(nasid,
SH1_MD_DQLP_MMR_DIR_PRIVEC0));
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
SH1_MD_DQLP_MMR_DIR_PRIVEC0),
-1UL);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
SH1_MD_DQRP_MMR_DIR_PRIVEC0),
-1UL);
}
}
}
}
/*
* Restrict protections to disallow IPI operations (and AMO operations on
* Shub 1.1 systems).
*/
void
xpc_restrict_IPI_ops(void)
{
int node;
int nasid;
// >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
if (is_shub2()) {
for_each_online_node(node) {
nasid = cnodeid_to_nasid(node);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
xpc_sh2_IPI_access0);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
xpc_sh2_IPI_access1);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
xpc_sh2_IPI_access2);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
xpc_sh2_IPI_access3);
}
} else {
for_each_online_node(node) {
nasid = cnodeid_to_nasid(node);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
xpc_sh1_IPI_access);
if (enable_shub_wars_1_1()) {
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
SH1_MD_DQLP_MMR_DIR_PRIVEC0),
xpc_prot_vec[node]);
HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
SH1_MD_DQRP_MMR_DIR_PRIVEC0),
xpc_prot_vec[node]);
}
}
}
}
/*
* At periodic intervals, scan through all active partitions and ensure
* their heartbeat is still active. If not, the partition is deactivated.
*/
void
xpc_check_remote_hb(void)
{
struct xpc_vars *remote_vars;
struct xpc_partition *part;
partid_t partid;
bte_result_t bres;
remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
if (partid == sn_partition_id) {
continue;
}
part = &xpc_partitions[partid];
if (part->act_state == XPC_P_INACTIVE ||
part->act_state == XPC_P_DEACTIVATING) {
continue;
}
/* pull the remote_hb cache line */
bres = xp_bte_copy(part->remote_vars_pa,
ia64_tpa((u64) remote_vars),
XPC_VARS_ALIGNED_SIZE,
(BTE_NOTIFY | BTE_WACQUIRE), NULL);
if (bres != BTE_SUCCESS) {
XPC_DEACTIVATE_PARTITION(part,
xpc_map_bte_errors(bres));
continue;
}
dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
" = %ld, kdb_status = %ld, HB_mask = 0x%lx\n", partid,
remote_vars->heartbeat, part->last_heartbeat,
remote_vars->kdb_status,
remote_vars->heartbeating_to_mask);
if (((remote_vars->heartbeat == part->last_heartbeat) &&
(remote_vars->kdb_status == 0)) ||
!XPC_HB_ALLOWED(sn_partition_id, remote_vars)) {
XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);
continue;
}
part->last_heartbeat = remote_vars->heartbeat;
}
}
/*
* Get a copy of the remote partition's rsvd page.
*
* remote_rp points to a buffer that is cacheline aligned for BTE copies and
* assumed to be of size XPC_RSVD_PAGE_ALIGNED_SIZE.
*/
static enum xpc_retval
xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
struct xpc_rsvd_page *remote_rp, u64 *remote_rsvd_page_pa)
{
int bres, i;
/* get the reserved page's physical address */
*remote_rsvd_page_pa = xpc_get_rsvd_page_pa(nasid, (u64) remote_rp,
XPC_RSVD_PAGE_ALIGNED_SIZE);
if (*remote_rsvd_page_pa == 0) {
return xpcNoRsvdPageAddr;
}
/* pull over the reserved page structure */
bres = xp_bte_copy(*remote_rsvd_page_pa, ia64_tpa((u64) remote_rp),
XPC_RSVD_PAGE_ALIGNED_SIZE,
(BTE_NOTIFY | BTE_WACQUIRE), NULL);
if (bres != BTE_SUCCESS) {
return xpc_map_bte_errors(bres);
}
if (discovered_nasids != NULL) {
for (i = 0; i < XP_NASID_MASK_WORDS; i++) {
discovered_nasids[i] |= remote_rp->part_nasids[i];
}
}
/* check that the partid is for another partition */
if (remote_rp->partid < 1 ||
remote_rp->partid > (XP_MAX_PARTITIONS - 1)) {
return xpcInvalidPartid;
}
if (remote_rp->partid == sn_partition_id) {
return xpcLocalPartid;
}
if (XPC_VERSION_MAJOR(remote_rp->version) !=
XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
return xpcBadVersion;
}
return xpcSuccess;
}
/*
* Get a copy of the remote partition's XPC variables.
*
* remote_vars points to a buffer that is cacheline aligned for BTE copies and
* assumed to be of size XPC_VARS_ALIGNED_SIZE.
*/
static enum xpc_retval
xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
{
int bres;
if (remote_vars_pa == 0) {
return xpcVarsNotSet;
}
/* pull over the cross partition variables */
bres = xp_bte_copy(remote_vars_pa, ia64_tpa((u64) remote_vars),
XPC_VARS_ALIGNED_SIZE,
(BTE_NOTIFY | BTE_WACQUIRE), NULL);
if (bres != BTE_SUCCESS) {
return xpc_map_bte_errors(bres);
}
if (XPC_VERSION_MAJOR(remote_vars->version) !=
XPC_VERSION_MAJOR(XPC_V_VERSION)) {
return xpcBadVersion;
}
return xpcSuccess;
}
/*
* Prior code has determine the nasid which generated an IPI. Inspect
* that nasid to determine if its partition needs to be activated or
* deactivated.
*
* A partition is consider "awaiting activation" if our partition
* flags indicate it is not active and it has a heartbeat. A
* partition is considered "awaiting deactivation" if our partition
* flags indicate it is active but it has no heartbeat or it is not
* sending its heartbeat to us.
*
* To determine the heartbeat, the remote nasid must have a properly
* initialized reserved page.
*/
static void
xpc_identify_act_IRQ_req(int nasid)
{
struct xpc_rsvd_page *remote_rp;
struct xpc_vars *remote_vars;
u64 remote_rsvd_page_pa;
u64 remote_vars_pa;
partid_t partid;
struct xpc_partition *part;
enum xpc_retval ret;
/* pull over the reserved page structure */
remote_rp = (struct xpc_rsvd_page *) xpc_remote_copy_buffer;
ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rsvd_page_pa);
if (ret != xpcSuccess) {
dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
"which sent interrupt, reason=%d\n", nasid, ret);
return;
}
remote_vars_pa = remote_rp->vars_pa;
partid = remote_rp->partid;
part = &xpc_partitions[partid];
/* pull over the cross partition variables */
remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
if (ret != xpcSuccess) {
dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
"which sent interrupt, reason=%d\n", nasid, ret);
XPC_DEACTIVATE_PARTITION(part, ret);
return;
}
part->act_IRQ_rcvd++;
dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
"%ld:0x%lx\n", (int) nasid, (int) partid, part->act_IRQ_rcvd,
remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
if (part->act_state == XPC_P_INACTIVE) {
part->remote_rp_pa = remote_rsvd_page_pa;
dev_dbg(xpc_part, " remote_rp_pa = 0x%016lx\n",
part->remote_rp_pa);
part->remote_vars_pa = remote_vars_pa;
dev_dbg(xpc_part, " remote_vars_pa = 0x%016lx\n",
part->remote_vars_pa);
part->last_heartbeat = remote_vars->heartbeat;
dev_dbg(xpc_part, " last_heartbeat = 0x%016lx\n",
part->last_heartbeat);
part->remote_vars_part_pa = remote_vars->vars_part_pa;
dev_dbg(xpc_part, " remote_vars_part_pa = 0x%016lx\n",
part->remote_vars_part_pa);
part->remote_act_nasid = remote_vars->act_nasid;
dev_dbg(xpc_part, " remote_act_nasid = 0x%x\n",
part->remote_act_nasid);
part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
dev_dbg(xpc_part, " remote_act_phys_cpuid = 0x%x\n",
part->remote_act_phys_cpuid);
part->remote_amos_page_pa = remote_vars->amos_page_pa;
dev_dbg(xpc_part, " remote_amos_page_pa = 0x%lx\n",
part->remote_amos_page_pa);
xpc_activate_partition(part);
} else if (part->remote_amos_page_pa != remote_vars->amos_page_pa ||
!XPC_HB_ALLOWED(sn_partition_id, remote_vars)) {
part->reactivate_nasid = nasid;
XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
}
}
/*
* Loop through the activation AMO variables and process any bits
* which are set. Each bit indicates a nasid sending a partition
* activation or deactivation request.
*
* Return #of IRQs detected.
*/
int
xpc_identify_act_IRQ_sender(void)
{
int word, bit;
u64 nasid_mask;
u64 nasid; /* remote nasid */
int n_IRQs_detected = 0;
AMO_t *act_amos;
struct xpc_rsvd_page *rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
act_amos = xpc_vars->act_amos;
/* scan through act AMO variable looking for non-zero entries */
for (word = 0; word < XP_NASID_MASK_WORDS; word++) {
nasid_mask = xpc_IPI_receive(&act_amos[word]);
if (nasid_mask == 0) {
/* no IRQs from nasids in this variable */
continue;
}
dev_dbg(xpc_part, "AMO[%d] gave back 0x%lx\n", word,
nasid_mask);
/*
* If this nasid has been added to the machine since
* our partition was reset, this will retain the
* remote nasid in our reserved pages machine mask.
* This is used in the event of module reload.
*/
rp->mach_nasids[word] |= nasid_mask;
/* locate the nasid(s) which sent interrupts */
for (bit = 0; bit < (8 * sizeof(u64)); bit++) {
if (nasid_mask & (1UL << bit)) {
n_IRQs_detected++;
nasid = XPC_NASID_FROM_W_B(word, bit);
dev_dbg(xpc_part, "interrupt from nasid %ld\n",
nasid);
xpc_identify_act_IRQ_req(nasid);
}
}
}
return n_IRQs_detected;
}
/*
* Mark specified partition as active.
*/
enum xpc_retval
xpc_mark_partition_active(struct xpc_partition *part)
{
unsigned long irq_flags;
enum xpc_retval ret;
dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
spin_lock_irqsave(&part->act_lock, irq_flags);
if (part->act_state == XPC_P_ACTIVATING) {
part->act_state = XPC_P_ACTIVE;
ret = xpcSuccess;
} else {
DBUG_ON(part->reason == xpcSuccess);
ret = part->reason;
}
spin_unlock_irqrestore(&part->act_lock, irq_flags);
return ret;
}
/*
* Notify XPC that the partition is down.
*/
void
xpc_deactivate_partition(const int line, struct xpc_partition *part,
enum xpc_retval reason)
{
unsigned long irq_flags;
partid_t partid = XPC_PARTID(part);
spin_lock_irqsave(&part->act_lock, irq_flags);
if (part->act_state == XPC_P_INACTIVE) {
XPC_SET_REASON(part, reason, line);
spin_unlock_irqrestore(&part->act_lock, irq_flags);
if (reason == xpcReactivating) {
/* we interrupt ourselves to reactivate partition */
xpc_IPI_send_reactivate(part);
}
return;
}
if (part->act_state == XPC_P_DEACTIVATING) {
if ((part->reason == xpcUnloading && reason != xpcUnloading) ||
reason == xpcReactivating) {
XPC_SET_REASON(part, reason, line);
}
spin_unlock_irqrestore(&part->act_lock, irq_flags);
return;
}
part->act_state = XPC_P_DEACTIVATING;
XPC_SET_REASON(part, reason, line);
spin_unlock_irqrestore(&part->act_lock, irq_flags);
XPC_DISALLOW_HB(partid, xpc_vars);
dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n", partid,
reason);
xpc_partition_down(part, reason);
}
/*
* Mark specified partition as active.
*/
void
xpc_mark_partition_inactive(struct xpc_partition *part)
{
unsigned long irq_flags;
dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
XPC_PARTID(part));
spin_lock_irqsave(&part->act_lock, irq_flags);
part->act_state = XPC_P_INACTIVE;
spin_unlock_irqrestore(&part->act_lock, irq_flags);
part->remote_rp_pa = 0;
}
/*
* SAL has provided a partition and machine mask. The partition mask
* contains a bit for each even nasid in our partition. The machine
* mask contains a bit for each even nasid in the entire machine.
*
* Using those two bit arrays, we can determine which nasids are
* known in the machine. Each should also have a reserved page
* initialized if they are available for partitioning.
*/
void
xpc_discovery(void)
{
void *remote_rp_base;
struct xpc_rsvd_page *remote_rp;
struct xpc_vars *remote_vars;
u64 remote_rsvd_page_pa;
u64 remote_vars_pa;
int region;
int max_regions;
int nasid;
struct xpc_rsvd_page *rp;
partid_t partid;
struct xpc_partition *part;
u64 *discovered_nasids;
enum xpc_retval ret;
remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RSVD_PAGE_ALIGNED_SIZE,
GFP_KERNEL, &remote_rp_base);
if (remote_rp == NULL) {
return;
}
remote_vars = (struct xpc_vars *) remote_rp;
discovered_nasids = kmalloc(sizeof(u64) * XP_NASID_MASK_WORDS,
GFP_KERNEL);
if (discovered_nasids == NULL) {
kfree(remote_rp_base);
return;
}
memset(discovered_nasids, 0, sizeof(u64) * XP_NASID_MASK_WORDS);
rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
/*
* The term 'region' in this context refers to the minimum number of
* nodes that can comprise an access protection grouping. The access
* protection is in regards to memory, IOI and IPI.
*/
//>>> move the next two #defines into either include/asm-ia64/sn/arch.h or
//>>> include/asm-ia64/sn/addrs.h
#define SH1_MAX_REGIONS 64
#define SH2_MAX_REGIONS 256
max_regions = is_shub2() ? SH2_MAX_REGIONS : SH1_MAX_REGIONS;
for (region = 0; region < max_regions; region++) {
if ((volatile int) xpc_exiting) {
break;
}
dev_dbg(xpc_part, "searching region %d\n", region);
for (nasid = (region * sn_region_size * 2);
nasid < ((region + 1) * sn_region_size * 2);
nasid += 2) {
if ((volatile int) xpc_exiting) {
break;
}
dev_dbg(xpc_part, "checking nasid %d\n", nasid);
if (XPC_NASID_IN_ARRAY(nasid, rp->part_nasids)) {
dev_dbg(xpc_part, "PROM indicates Nasid %d is "
"part of the local partition; skipping "
"region\n", nasid);
break;
}
if (!(XPC_NASID_IN_ARRAY(nasid, rp->mach_nasids))) {
dev_dbg(xpc_part, "PROM indicates Nasid %d was "
"not on Numa-Link network at reset\n",
nasid);
continue;
}
if (XPC_NASID_IN_ARRAY(nasid, discovered_nasids)) {
dev_dbg(xpc_part, "Nasid %d is part of a "
"partition which was previously "
"discovered\n", nasid);
continue;
}
/* pull over the reserved page structure */
ret = xpc_get_remote_rp(nasid, discovered_nasids,
remote_rp, &remote_rsvd_page_pa);
if (ret != xpcSuccess) {
dev_dbg(xpc_part, "unable to get reserved page "
"from nasid %d, reason=%d\n", nasid,
ret);
if (ret == xpcLocalPartid) {
break;
}
continue;
}
remote_vars_pa = remote_rp->vars_pa;
partid = remote_rp->partid;
part = &xpc_partitions[partid];
/* pull over the cross partition variables */
ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
if (ret != xpcSuccess) {
dev_dbg(xpc_part, "unable to get XPC variables "
"from nasid %d, reason=%d\n", nasid,
ret);
XPC_DEACTIVATE_PARTITION(part, ret);
continue;
}
if (part->act_state != XPC_P_INACTIVE) {
dev_dbg(xpc_part, "partition %d on nasid %d is "
"already activating\n", partid, nasid);
break;
}
/*
* Register the remote partition's AMOs with SAL so it
* can handle and cleanup errors within that address
* range should the remote partition go down. We don't
* unregister this range because it is difficult to
* tell when outstanding writes to the remote partition
* are finished and thus when it is thus safe to
* unregister. This should not result in wasted space
* in the SAL xp_addr_region table because we should
* get the same page for remote_act_amos_pa after
* module reloads and system reboots.
*/
if (sn_register_xp_addr_region(
remote_vars->amos_page_pa,
PAGE_SIZE, 1) < 0) {
dev_dbg(xpc_part, "partition %d failed to "
"register xp_addr region 0x%016lx\n",
partid, remote_vars->amos_page_pa);
XPC_SET_REASON(part, xpcPhysAddrRegFailed,
__LINE__);
break;
}
/*
* The remote nasid is valid and available.
* Send an interrupt to that nasid to notify
* it that we are ready to begin activation.
*/
dev_dbg(xpc_part, "sending an interrupt to AMO 0x%lx, "
"nasid %d, phys_cpuid 0x%x\n",
remote_vars->amos_page_pa,
remote_vars->act_nasid,
remote_vars->act_phys_cpuid);
xpc_IPI_send_activate(remote_vars);
}
}
kfree(discovered_nasids);
kfree(remote_rp_base);
}
/*
* Given a partid, get the nasids owned by that partition from the
* remote partitions reserved page.
*/
enum xpc_retval
xpc_initiate_partid_to_nasids(partid_t partid, void *nasid_mask)
{
struct xpc_partition *part;
u64 part_nasid_pa;
int bte_res;
part = &xpc_partitions[partid];
if (part->remote_rp_pa == 0) {
return xpcPartitionDown;
}
part_nasid_pa = part->remote_rp_pa +
(u64) &((struct xpc_rsvd_page *) 0)->part_nasids;
bte_res = xp_bte_copy(part_nasid_pa, ia64_tpa((u64) nasid_mask),
L1_CACHE_ALIGN(XP_NASID_MASK_BYTES),
(BTE_NOTIFY | BTE_WACQUIRE), NULL);
return xpc_map_bte_errors(bte_res);
}
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