Commit c7754d46 authored by David S. Miller's avatar David S. Miller

[SPARC64]: Add hypervisor API negotiation and fix console bugs.

Hypervisor interfaces need to be negotiated in order to use
some API calls reliably.  So add a small set of interfaces
to request API versions and query current settings.

This allows us to fix some bugs in the hypervisor console:

1) If we can negotiate API group CORE of at least major 1
   minor 1 we can use con_read and con_write which can improve
   console performance quite a bit.

2) When we do a console write request, we should hold the
   spinlock around the whole request, not a byte at a time.
   What would happen is that it's easy for output from
   different cpus to get mixed with each other.

3) Use consistent udelay() based polling, udelay(1) each
   loop with a limit of 1000 polls to handle stuck hypervisor
   console.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7b104bcb
......@@ -12,7 +12,7 @@ obj-y := process.o setup.o cpu.o idprom.o \
irq.o ptrace.o time.o sys_sparc.o signal.o \
unaligned.o central.o pci.o starfire.o semaphore.o \
power.o sbus.o iommu_common.o sparc64_ksyms.o chmc.o \
visemul.o prom.o of_device.o
visemul.o prom.o of_device.o hvapi.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-$(CONFIG_PCI) += ebus.o isa.o pci_common.o pci_iommu.o \
......
......@@ -1843,3 +1843,97 @@ sun4v_cpu_state:
mov %o1, %o0
1: retl
nop
/* %o0: API group number
* %o1: pointer to unsigned long major number storage
* %o2: pointer to unsigned long minor number storage
*
* returns %o0: status
*/
.globl sun4v_get_version
sun4v_get_version:
mov HV_CORE_GET_VER, %o5
mov %o1, %o3
mov %o2, %o4
ta HV_CORE_TRAP
stx %o1, [%o3]
retl
stx %o2, [%o4]
/* %o0: API group number
* %o1: desired major number
* %o2: desired minor number
* %o3: pointer to unsigned long actual minor number storage
*
* returns %o0: status
*/
.globl sun4v_set_version
sun4v_set_version:
mov HV_CORE_SET_VER, %o5
mov %o3, %o4
ta HV_CORE_TRAP
retl
stx %o1, [%o4]
/* %o0: pointer to unsigned long status
*
* returns %o0: signed character
*/
.globl sun4v_con_getchar
sun4v_con_getchar:
mov %o0, %o4
mov HV_FAST_CONS_GETCHAR, %o5
clr %o0
clr %o1
ta HV_FAST_TRAP
stx %o0, [%o4]
retl
sra %o1, 0, %o0
/* %o0: signed long character
*
* returns %o0: status
*/
.globl sun4v_con_putchar
sun4v_con_putchar:
mov HV_FAST_CONS_PUTCHAR, %o5
ta HV_FAST_TRAP
retl
sra %o0, 0, %o0
/* %o0: buffer real address
* %o1: buffer size
* %o2: pointer to unsigned long bytes_read
*
* returns %o0: status
*/
.globl sun4v_con_read
sun4v_con_read:
mov %o2, %o4
mov HV_FAST_CONS_READ, %o5
ta HV_FAST_TRAP
brnz %o0, 1f
cmp %o1, -1 /* break */
be,a,pn %icc, 1f
mov %o1, %o0
cmp %o1, -2 /* hup */
be,a,pn %icc, 1f
mov %o1, %o0
stx %o1, [%o4]
1: retl
nop
/* %o0: buffer real address
* %o1: buffer size
* %o2: pointer to unsigned long bytes_written
*
* returns %o0: status
*/
.globl sun4v_con_write
sun4v_con_write:
mov %o2, %o4
mov HV_FAST_CONS_WRITE, %o5
ta HV_FAST_TRAP
stx %o1, [%o4]
retl
nop
/* hvapi.c: Hypervisor API management.
*
* Copyright (C) 2007 David S. Miller <davem@davemloft.net>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <asm/hypervisor.h>
#include <asm/oplib.h>
/* If the hypervisor indicates that the API setting
* calls are unsupported, by returning HV_EBADTRAP or
* HV_ENOTSUPPORTED, we assume that API groups with the
* PRE_API flag set are major 1 minor 0.
*/
struct api_info {
unsigned long group;
unsigned long major;
unsigned long minor;
unsigned int refcnt;
unsigned int flags;
#define FLAG_PRE_API 0x00000001
};
static struct api_info api_table[] = {
{ .group = HV_GRP_SUN4V, .flags = FLAG_PRE_API },
{ .group = HV_GRP_CORE, .flags = FLAG_PRE_API },
{ .group = HV_GRP_INTR, },
{ .group = HV_GRP_SOFT_STATE, },
{ .group = HV_GRP_PCI, .flags = FLAG_PRE_API },
{ .group = HV_GRP_LDOM, },
{ .group = HV_GRP_SVC_CHAN, .flags = FLAG_PRE_API },
{ .group = HV_GRP_NCS, .flags = FLAG_PRE_API },
{ .group = HV_GRP_NIAG_PERF, .flags = FLAG_PRE_API },
{ .group = HV_GRP_FIRE_PERF, },
{ .group = HV_GRP_DIAG, .flags = FLAG_PRE_API },
};
static DEFINE_SPINLOCK(hvapi_lock);
static struct api_info *__get_info(unsigned long group)
{
int i;
for (i = 0; i < ARRAY_SIZE(api_table); i++) {
if (api_table[i].group == group)
return &api_table[i];
}
return NULL;
}
static void __get_ref(struct api_info *p)
{
p->refcnt++;
}
static void __put_ref(struct api_info *p)
{
if (--p->refcnt == 0) {
unsigned long ignore;
sun4v_set_version(p->group, 0, 0, &ignore);
p->major = p->minor = 0;
}
}
/* Register a hypervisor API specification. It indicates the
* API group and desired major+minor.
*
* If an existing API registration exists '0' (success) will
* be returned if it is compatible with the one being registered.
* Otherwise a negative error code will be returned.
*
* Otherwise an attempt will be made to negotiate the requested
* API group/major/minor with the hypervisor, and errors returned
* if that does not succeed.
*/
int sun4v_hvapi_register(unsigned long group, unsigned long major,
unsigned long *minor)
{
struct api_info *p;
unsigned long flags;
int ret;
spin_lock_irqsave(&hvapi_lock, flags);
p = __get_info(group);
ret = -EINVAL;
if (p) {
if (p->refcnt) {
ret = -EINVAL;
if (p->major == major) {
*minor = p->minor;
ret = 0;
}
} else {
unsigned long actual_minor;
unsigned long hv_ret;
hv_ret = sun4v_set_version(group, major, *minor,
&actual_minor);
ret = -EINVAL;
if (hv_ret == HV_EOK) {
*minor = actual_minor;
p->major = major;
p->minor = actual_minor;
ret = 0;
} else if (hv_ret == HV_EBADTRAP ||
HV_ENOTSUPPORTED) {
if (p->flags & FLAG_PRE_API) {
if (major == 1) {
p->major = 1;
p->minor = 0;
*minor = 0;
ret = 0;
}
}
}
}
if (ret == 0)
__get_ref(p);
}
spin_unlock_irqrestore(&hvapi_lock, flags);
return ret;
}
EXPORT_SYMBOL(sun4v_hvapi_register);
void sun4v_hvapi_unregister(unsigned long group)
{
struct api_info *p;
unsigned long flags;
spin_lock_irqsave(&hvapi_lock, flags);
p = __get_info(group);
if (p)
__put_ref(p);
spin_unlock_irqrestore(&hvapi_lock, flags);
}
EXPORT_SYMBOL(sun4v_hvapi_unregister);
int sun4v_hvapi_get(unsigned long group,
unsigned long *major,
unsigned long *minor)
{
struct api_info *p;
unsigned long flags;
int ret;
spin_lock_irqsave(&hvapi_lock, flags);
ret = -EINVAL;
p = __get_info(group);
if (p && p->refcnt) {
*major = p->major;
*minor = p->minor;
ret = 0;
}
spin_unlock_irqrestore(&hvapi_lock, flags);
return ret;
}
EXPORT_SYMBOL(sun4v_hvapi_get);
void __init sun4v_hvapi_init(void)
{
unsigned long group, major, minor;
group = HV_GRP_SUN4V;
major = 1;
minor = 0;
if (sun4v_hvapi_register(group, major, &minor))
goto bad;
group = HV_GRP_CORE;
major = 1;
minor = 1;
if (sun4v_hvapi_register(group, major, &minor))
goto bad;
return;
bad:
prom_printf("HVAPI: Cannot register API group "
"%lx with major(%u) minor(%u)\n",
group, major, minor);
prom_halt();
}
......@@ -269,6 +269,7 @@ void __init per_cpu_patch(void)
void __init sun4v_patch(void)
{
extern void sun4v_hvapi_init(void);
struct sun4v_1insn_patch_entry *p1;
struct sun4v_2insn_patch_entry *p2;
......@@ -300,6 +301,8 @@ void __init sun4v_patch(void)
p2++;
}
sun4v_hvapi_init();
}
#ifdef CONFIG_SMP
......
/* sunhv.c: Serial driver for SUN4V hypervisor console.
*
* Copyright (C) 2006 David S. Miller (davem@davemloft.net)
* Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net)
*/
#include <linux/module.h>
......@@ -35,57 +35,51 @@
#define CON_BREAK ((long)-1)
#define CON_HUP ((long)-2)
static inline long hypervisor_con_getchar(long *status)
{
register unsigned long func asm("%o5");
register unsigned long arg0 asm("%o0");
register unsigned long arg1 asm("%o1");
func = HV_FAST_CONS_GETCHAR;
arg0 = 0;
arg1 = 0;
__asm__ __volatile__("ta %6"
: "=&r" (func), "=&r" (arg0), "=&r" (arg1)
: "0" (func), "1" (arg0), "2" (arg1),
"i" (HV_FAST_TRAP));
#define IGNORE_BREAK 0x1
#define IGNORE_ALL 0x2
*status = arg0;
static char *con_write_page;
static char *con_read_page;
return (long) arg1;
}
static int hung_up = 0;
static inline long hypervisor_con_putchar(long ch)
static void transmit_chars_putchar(struct uart_port *port, struct circ_buf *xmit)
{
register unsigned long func asm("%o5");
register unsigned long arg0 asm("%o0");
while (!uart_circ_empty(xmit)) {
long status = sun4v_con_putchar(xmit->buf[xmit->tail]);
func = HV_FAST_CONS_PUTCHAR;
arg0 = ch;
__asm__ __volatile__("ta %4"
: "=&r" (func), "=&r" (arg0)
: "0" (func), "1" (arg0), "i" (HV_FAST_TRAP));
if (status != HV_EOK)
break;
return (long) arg0;
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
}
}
#define IGNORE_BREAK 0x1
#define IGNORE_ALL 0x2
static void transmit_chars_write(struct uart_port *port, struct circ_buf *xmit)
{
while (!uart_circ_empty(xmit)) {
unsigned long ra = __pa(xmit->buf + xmit->tail);
unsigned long len, status, sent;
static int hung_up = 0;
len = CIRC_CNT_TO_END(xmit->head, xmit->tail,
UART_XMIT_SIZE);
status = sun4v_con_write(ra, len, &sent);
if (status != HV_EOK)
break;
xmit->tail = (xmit->tail + sent) & (UART_XMIT_SIZE - 1);
port->icount.tx += sent;
}
}
static struct tty_struct *receive_chars(struct uart_port *port)
static int receive_chars_getchar(struct uart_port *port, struct tty_struct *tty)
{
struct tty_struct *tty = NULL;
int saw_console_brk = 0;
int limit = 10000;
if (port->info != NULL) /* Unopened serial console */
tty = port->info->tty;
while (limit-- > 0) {
long status;
long c = hypervisor_con_getchar(&status);
unsigned char flag;
long c = sun4v_con_getchar(&status);
if (status == HV_EWOULDBLOCK)
break;
......@@ -110,27 +104,90 @@ static struct tty_struct *receive_chars(struct uart_port *port)
continue;
}
flag = TTY_NORMAL;
port->icount.rx++;
if (c == CON_BREAK) {
port->icount.brk++;
if (uart_handle_break(port))
continue;
flag = TTY_BREAK;
}
if (uart_handle_sysrq_char(port, c))
continue;
if ((port->ignore_status_mask & IGNORE_ALL) ||
((port->ignore_status_mask & IGNORE_BREAK) &&
(c == CON_BREAK)))
tty_insert_flip_char(tty, c, TTY_NORMAL);
}
return saw_console_brk;
}
static int receive_chars_read(struct uart_port *port, struct tty_struct *tty)
{
int saw_console_brk = 0;
int limit = 10000;
while (limit-- > 0) {
unsigned long ra = __pa(con_read_page);
unsigned long bytes_read, i;
long stat = sun4v_con_read(ra, PAGE_SIZE, &bytes_read);
if (stat != HV_EOK) {
bytes_read = 0;
if (stat == CON_BREAK) {
if (uart_handle_break(port))
continue;
saw_console_brk = 1;
*con_read_page = 0;
bytes_read = 1;
} else if (stat == CON_HUP) {
hung_up = 1;
uart_handle_dcd_change(port, 0);
continue;
} else {
/* HV_EWOULDBLOCK, etc. */
break;
}
}
if (hung_up) {
hung_up = 0;
uart_handle_dcd_change(port, 1);
}
for (i = 0; i < bytes_read; i++)
uart_handle_sysrq_char(port, con_read_page[i]);
if (tty == NULL)
continue;
tty_insert_flip_char(tty, c, flag);
port->icount.rx += bytes_read;
tty_insert_flip_string(tty, con_read_page, bytes_read);
}
if (saw_console_brk)
return saw_console_brk;
}
struct sunhv_ops {
void (*transmit_chars)(struct uart_port *port, struct circ_buf *xmit);
int (*receive_chars)(struct uart_port *port, struct tty_struct *tty);
};
static struct sunhv_ops bychar_ops = {
.transmit_chars = transmit_chars_putchar,
.receive_chars = receive_chars_getchar,
};
static struct sunhv_ops bywrite_ops = {
.transmit_chars = transmit_chars_write,
.receive_chars = receive_chars_read,
};
static struct sunhv_ops *sunhv_ops = &bychar_ops;
static struct tty_struct *receive_chars(struct uart_port *port)
{
struct tty_struct *tty = NULL;
if (port->info != NULL) /* Unopened serial console */
tty = port->info->tty;
if (sunhv_ops->receive_chars(port, tty))
sun_do_break();
return tty;
......@@ -147,15 +204,7 @@ static void transmit_chars(struct uart_port *port)
if (uart_circ_empty(xmit) || uart_tx_stopped(port))
return;
while (!uart_circ_empty(xmit)) {
long status = hypervisor_con_putchar(xmit->buf[xmit->tail]);
if (status != HV_EOK)
break;
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
}
sunhv_ops->transmit_chars(port, xmit);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
......@@ -212,7 +261,7 @@ static void sunhv_start_tx(struct uart_port *port)
struct circ_buf *xmit = &port->info->xmit;
while (!uart_circ_empty(xmit)) {
long status = hypervisor_con_putchar(xmit->buf[xmit->tail]);
long status = sun4v_con_putchar(xmit->buf[xmit->tail]);
if (status != HV_EOK)
break;
......@@ -231,9 +280,10 @@ static void sunhv_send_xchar(struct uart_port *port, char ch)
spin_lock_irqsave(&port->lock, flags);
while (limit-- > 0) {
long status = hypervisor_con_putchar(ch);
long status = sun4v_con_putchar(ch);
if (status == HV_EOK)
break;
udelay(1);
}
spin_unlock_irqrestore(&port->lock, flags);
......@@ -254,15 +304,15 @@ static void sunhv_break_ctl(struct uart_port *port, int break_state)
{
if (break_state) {
unsigned long flags;
int limit = 1000000;
int limit = 10000;
spin_lock_irqsave(&port->lock, flags);
while (limit-- > 0) {
long status = hypervisor_con_putchar(CON_BREAK);
long status = sun4v_con_putchar(CON_BREAK);
if (status == HV_EOK)
break;
udelay(2);
udelay(1);
}
spin_unlock_irqrestore(&port->lock, flags);
......@@ -359,38 +409,99 @@ static struct uart_driver sunhv_reg = {
static struct uart_port *sunhv_port;
static inline void sunhv_console_putchar(struct uart_port *port, char c)
/* Copy 's' into the con_write_page, decoding "\n" into
* "\r\n" along the way. We have to return two lengths
* because the caller needs to know how much to advance
* 's' and also how many bytes to output via con_write_page.
*/
static int fill_con_write_page(const char *s, unsigned int n,
unsigned long *page_bytes)
{
const char *orig_s = s;
char *p = con_write_page;
int left = PAGE_SIZE;
while (n--) {
if (*s == '\n') {
if (left < 2)
break;
*p++ = '\r';
left--;
} else if (left < 1)
break;
*p++ = *s++;
left--;
}
*page_bytes = p - con_write_page;
return s - orig_s;
}
static void sunhv_console_write_paged(struct console *con, const char *s, unsigned n)
{
struct uart_port *port = sunhv_port;
unsigned long flags;
int limit = 1000000;
spin_lock_irqsave(&port->lock, flags);
while (n > 0) {
unsigned long ra = __pa(con_write_page);
unsigned long page_bytes;
unsigned int cpy = fill_con_write_page(s, n,
&page_bytes);
n -= cpy;
s += cpy;
while (page_bytes > 0) {
unsigned long written;
int limit = 1000000;
while (limit--) {
unsigned long stat;
stat = sun4v_con_write(ra, page_bytes,
&written);
if (stat == HV_EOK)
break;
udelay(1);
}
if (limit <= 0)
break;
page_bytes -= written;
ra += written;
}
}
spin_unlock_irqrestore(&port->lock, flags);
}
static inline void sunhv_console_putchar(struct uart_port *port, char c)
{
int limit = 1000000;
while (limit-- > 0) {
long status = hypervisor_con_putchar(c);
long status = sun4v_con_putchar(c);
if (status == HV_EOK)
break;
udelay(2);
udelay(1);
}
spin_unlock_irqrestore(&port->lock, flags);
}
static void sunhv_console_write(struct console *con, const char *s, unsigned n)
static void sunhv_console_write_bychar(struct console *con, const char *s, unsigned n)
{
struct uart_port *port = sunhv_port;
unsigned long flags;
int i;
spin_lock_irqsave(&port->lock, flags);
for (i = 0; i < n; i++) {
if (*s == '\n')
sunhv_console_putchar(port, '\r');
sunhv_console_putchar(port, *s++);
}
spin_unlock_irqrestore(&port->lock, flags);
}
static struct console sunhv_console = {
.name = "ttyHV",
.write = sunhv_console_write,
.write = sunhv_console_write_bychar,
.device = uart_console_device,
.flags = CON_PRINTBUFFER,
.index = -1,
......@@ -410,6 +521,7 @@ static inline struct console *SUNHV_CONSOLE(void)
static int __devinit hv_probe(struct of_device *op, const struct of_device_id *match)
{
struct uart_port *port;
unsigned long minor;
int err;
if (op->irqs[0] == 0xffffffff)
......@@ -419,6 +531,22 @@ static int __devinit hv_probe(struct of_device *op, const struct of_device_id *m
if (unlikely(!port))
return -ENOMEM;
minor = 1;
if (sun4v_hvapi_register(HV_GRP_CORE, 1, &minor) == 0 &&
minor >= 1) {
err = -ENOMEM;
con_write_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!con_write_page)
goto out_free_port;
con_read_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!con_read_page)
goto out_free_con_write_page;
sunhv_console.write = sunhv_console_write_paged;
sunhv_ops = &bywrite_ops;
}
sunhv_port = port;
port->line = 0;
......@@ -437,7 +565,7 @@ static int __devinit hv_probe(struct of_device *op, const struct of_device_id *m
err = uart_register_driver(&sunhv_reg);
if (err)
goto out_free_port;
goto out_free_con_read_page;
sunhv_reg.tty_driver->name_base = sunhv_reg.minor - 64;
sunserial_current_minor += 1;
......@@ -463,6 +591,12 @@ static int __devinit hv_probe(struct of_device *op, const struct of_device_id *m
sunserial_current_minor -= 1;
uart_unregister_driver(&sunhv_reg);
out_free_con_read_page:
kfree(con_read_page);
out_free_con_write_page:
kfree(con_write_page);
out_free_port:
kfree(port);
sunhv_port = NULL;
......
......@@ -940,6 +940,54 @@ struct hv_fault_status {
*/
#define HV_FAST_CONS_PUTCHAR 0x61
/* con_read()
* TRAP: HV_FAST_TRAP
* FUNCTION: HV_FAST_CONS_READ
* ARG0: buffer real address
* ARG1: buffer size in bytes
* RET0: status
* RET1: bytes read or BREAK or HUP
* ERRORS: EWOULDBLOCK No character available.
*
* Reads characters into a buffer from the console device. If no
* character is available then an EWOULDBLOCK error is returned.
* If a character is available, then the returned status is EOK
* and the number of bytes read into the given buffer is provided
* in RET1.
*
* A virtual BREAK is represented by the 64-bit RET1 value -1.
*
* A virtual HUP signal is represented by the 64-bit RET1 value -2.
*
* If BREAK or HUP are indicated, no bytes were read into buffer.
*/
#define HV_FAST_CONS_READ 0x62
/* con_write()
* TRAP: HV_FAST_TRAP
* FUNCTION: HV_FAST_CONS_WRITE
* ARG0: buffer real address
* ARG1: buffer size in bytes
* RET0: status
* RET1: bytes written
* ERRORS: EWOULDBLOCK Output buffer currently full, would block
*
* Send a characters in buffer to the console device. Breaks must be
* sent using con_putchar().
*/
#define HV_FAST_CONS_WRITE 0x63
#ifndef __ASSEMBLY__
extern long sun4v_con_getchar(long *status);
extern long sun4v_con_putchar(long c);
extern long sun4v_con_read(unsigned long buffer,
unsigned long size,
unsigned long *bytes_read);
extern unsigned long sun4v_con_write(unsigned long buffer,
unsigned long size,
unsigned long *bytes_written);
#endif
/* Trap trace services.
*
* The hypervisor provides a trap tracing capability for privileged
......@@ -2121,8 +2169,41 @@ struct hv_mmu_statistics {
#define HV_FAST_MMUSTAT_INFO 0x103
/* Function numbers for HV_CORE_TRAP. */
#define HV_CORE_VER 0x00
#define HV_CORE_SET_VER 0x00
#define HV_CORE_PUTCHAR 0x01
#define HV_CORE_EXIT 0x02
#define HV_CORE_GET_VER 0x03
/* Hypervisor API groups for use with HV_CORE_SET_VER and
* HV_CORE_GET_VER.
*/
#define HV_GRP_SUN4V 0x0000
#define HV_GRP_CORE 0x0001
#define HV_GRP_INTR 0x0002
#define HV_GRP_SOFT_STATE 0x0003
#define HV_GRP_PCI 0x0100
#define HV_GRP_LDOM 0x0101
#define HV_GRP_SVC_CHAN 0x0102
#define HV_GRP_NCS 0x0103
#define HV_GRP_NIAG_PERF 0x0200
#define HV_GRP_FIRE_PERF 0x0201
#define HV_GRP_DIAG 0x0300
#ifndef __ASSEMBLY__
extern unsigned long sun4v_get_version(unsigned long group,
unsigned long *major,
unsigned long *minor);
extern unsigned long sun4v_set_version(unsigned long group,
unsigned long major,
unsigned long minor,
unsigned long *actual_minor);
extern int sun4v_hvapi_register(unsigned long group, unsigned long major,
unsigned long *minor);
extern void sun4v_hvapi_unregister(unsigned long group);
extern int sun4v_hvapi_get(unsigned long group,
unsigned long *major,
unsigned long *minor);
#endif
#endif /* !(_SPARC64_HYPERVISOR_H) */
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