Commit 5d171050 authored by Jag Raman's avatar Jag Raman Committed by David S. Miller

sparc64: vcc: Enable VCC port probe and removal

Enables VCC port probe and removal to initialize and terminate
VCC ports respectively. When a device/port matching the VCC driver
is added, the probe function is invoked along with a reference
to the device. remove function is called when the device is
removed.

Also add APIs to cache and retrieve VCC ports from a VCC table
Signed-off-by: default avatarJagannathan Raman <jag.raman@oracle.com>
Reviewed-by: default avatarLiam Merwick <liam.merwick@oracle.com>
Reviewed-by: default avatarShannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ce808b74
......@@ -52,6 +52,7 @@ struct vio_ver_info {
#define VDEV_NETWORK_SWITCH 0x02
#define VDEV_DISK 0x03
#define VDEV_DISK_SERVER 0x04
#define VDEV_CONSOLE_CON 0x05
u8 resv1[3];
u64 resv2[5];
......@@ -282,6 +283,14 @@ struct vio_dring_state {
struct ldc_trans_cookie cookies[VIO_MAX_RING_COOKIES];
};
#define VIO_TAG_SIZE ((int)sizeof(struct vio_msg_tag))
#define VIO_VCC_MTU_SIZE (LDC_PACKET_SIZE - VIO_TAG_SIZE)
struct vio_vcc {
struct vio_msg_tag tag;
char data[VIO_VCC_MTU_SIZE];
};
static inline void *vio_dring_cur(struct vio_dring_state *dr)
{
return dr->base + (dr->entry_size * dr->prod);
......
......@@ -246,6 +246,7 @@ u64 vio_vdev_node(struct mdesc_handle *hp, struct vio_dev *vdev)
return node;
}
EXPORT_SYMBOL(vio_vdev_node);
static void vio_fill_channel_info(struct mdesc_handle *hp, u64 mp,
struct vio_dev *vdev)
......
......@@ -814,15 +814,21 @@ int vio_driver_init(struct vio_driver_state *vio, struct vio_dev *vdev,
case VDEV_NETWORK_SWITCH:
case VDEV_DISK:
case VDEV_DISK_SERVER:
case VDEV_CONSOLE_CON:
break;
default:
return -EINVAL;
}
if (!ops || !ops->send_attr || !ops->handle_attr ||
!ops->handshake_complete)
return -EINVAL;
if (dev_class == VDEV_NETWORK ||
dev_class == VDEV_NETWORK_SWITCH ||
dev_class == VDEV_DISK ||
dev_class == VDEV_DISK_SERVER) {
if (!ops || !ops->send_attr || !ops->handle_attr ||
!ops->handshake_complete)
return -EINVAL;
}
if (!ver_table || ver_table_size < 0)
return -EINVAL;
......
......@@ -3,8 +3,13 @@
* Copyright (C) 2017 Oracle. All rights reserved.
*/
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <asm/vio.h>
#include <asm/ldc.h>
#define DRV_MODULE_NAME "vcc"
#define DRV_MODULE_VERSION "1.1"
......@@ -17,6 +22,33 @@ MODULE_DESCRIPTION("Sun LDOM virtual console concentrator driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_MODULE_VERSION);
struct vcc_port {
struct vio_driver_state vio;
spinlock_t lock;
char *domain;
struct tty_struct *tty; /* only populated while dev is open */
unsigned long index; /* index into the vcc_table */
u64 refcnt;
bool excl_locked;
bool removed;
/* This buffer is required to support the tty write_room interface
* and guarantee that any characters that the driver accepts will
* be eventually sent, either immediately or later.
*/
int chars_in_buffer;
struct vio_vcc buffer;
struct timer_list rx_timer;
struct timer_list tx_timer;
};
/* Microseconds that thread will delay waiting for a vcc port ref */
#define VCC_REF_DELAY 100
#define VCC_MAX_PORTS 1024
#define VCC_MINOR_START 0 /* must be zero */
......@@ -24,6 +56,9 @@ static const char vcc_driver_name[] = "vcc";
static const char vcc_device_node[] = "vcc";
static struct tty_driver *vcc_tty_driver;
static struct vcc_port *vcc_table[VCC_MAX_PORTS];
static DEFINE_SPINLOCK(vcc_table_lock);
int vcc_dbg;
int vcc_dbg_ldc;
int vcc_dbg_vio;
......@@ -70,6 +105,340 @@ static struct ktermios vcc_tty_termios = {
.c_ospeed = 38400
};
/**
* vcc_table_add() - Add VCC port to the VCC table
* @port: pointer to the VCC port
*
* Return: index of the port in the VCC table on success,
* -1 on failure
*/
static int vcc_table_add(struct vcc_port *port)
{
unsigned long flags;
int i;
spin_lock_irqsave(&vcc_table_lock, flags);
for (i = VCC_MINOR_START; i < VCC_MAX_PORTS; i++) {
if (!vcc_table[i]) {
vcc_table[i] = port;
break;
}
}
spin_unlock_irqrestore(&vcc_table_lock, flags);
if (i < VCC_MAX_PORTS)
return i;
else
return -1;
}
/**
* vcc_table_remove() - Removes a VCC port from the VCC table
* @index: Index into the VCC table
*/
static void vcc_table_remove(unsigned long index)
{
unsigned long flags;
if (WARN_ON(index >= VCC_MAX_PORTS))
return;
spin_lock_irqsave(&vcc_table_lock, flags);
vcc_table[index] = NULL;
spin_unlock_irqrestore(&vcc_table_lock, flags);
}
/**
* vcc_get() - Gets a reference to VCC port
* @index: Index into the VCC table
* @excl: Indicates if an exclusive access is requested
*
* Return: reference to the VCC port, if found
* NULL, if port not found
*/
static struct vcc_port *vcc_get(unsigned long index, bool excl)
{
struct vcc_port *port;
unsigned long flags;
try_again:
spin_lock_irqsave(&vcc_table_lock, flags);
port = vcc_table[index];
if (!port) {
spin_unlock_irqrestore(&vcc_table_lock, flags);
return NULL;
}
if (!excl) {
if (port->excl_locked) {
spin_unlock_irqrestore(&vcc_table_lock, flags);
udelay(VCC_REF_DELAY);
goto try_again;
}
port->refcnt++;
spin_unlock_irqrestore(&vcc_table_lock, flags);
return port;
}
if (port->refcnt) {
spin_unlock_irqrestore(&vcc_table_lock, flags);
/* Threads wanting exclusive access will wait half the time,
* probably giving them higher priority in the case of
* multiple waiters.
*/
udelay(VCC_REF_DELAY/2);
goto try_again;
}
port->refcnt++;
port->excl_locked = true;
spin_unlock_irqrestore(&vcc_table_lock, flags);
return port;
}
/**
* vcc_put() - Returns a reference to VCC port
* @port: pointer to VCC port
* @excl: Indicates if the returned reference is an exclusive reference
*
* Note: It's the caller's responsibility to ensure the correct value
* for the excl flag
*/
static void vcc_put(struct vcc_port *port, bool excl)
{
unsigned long flags;
if (!port)
return;
spin_lock_irqsave(&vcc_table_lock, flags);
/* check if caller attempted to put with the wrong flags */
if (WARN_ON((excl && !port->excl_locked) ||
(!excl && port->excl_locked)))
goto done;
port->refcnt--;
if (excl)
port->excl_locked = false;
done:
spin_unlock_irqrestore(&vcc_table_lock, flags);
}
/**
* vcc_get_ne() - Get a non-exclusive reference to VCC port
* @index: Index into the VCC table
*
* Gets a non-exclusive reference to VCC port, if it's not removed
*
* Return: pointer to the VCC port, if found
* NULL, if port not found
*/
static struct vcc_port *vcc_get_ne(unsigned long index)
{
struct vcc_port *port;
port = vcc_get(index, false);
if (port && port->removed) {
vcc_put(port, false);
return NULL;
}
return port;
}
static void vcc_event(void *arg, int event)
{
}
static struct ldc_channel_config vcc_ldc_cfg = {
.event = vcc_event,
.mtu = VIO_VCC_MTU_SIZE,
.mode = LDC_MODE_RAW,
.debug = 0,
};
/* Ordered from largest major to lowest */
static struct vio_version vcc_versions[] = {
{ .major = 1, .minor = 0 },
};
/**
* vcc_probe() - Initialize VCC port
* @vdev: Pointer to VIO device of the new VCC port
* @id: VIO device ID
*
* Initializes a VCC port to receive serial console data from
* the guest domain. Sets up a TTY end point on the control
* domain. Sets up VIO/LDC link between the guest & control
* domain endpoints.
*
* Return: status of the probe
*/
static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
{
struct mdesc_handle *hp;
struct vcc_port *port;
struct device *dev;
const char *domain;
char *name;
u64 node;
int rv;
vccdbg("VCC: name=%s\n", dev_name(&vdev->dev));
if (!vcc_tty_driver) {
pr_err("VCC: TTY driver not registered\n");
return -ENODEV;
}
port = kzalloc(sizeof(struct vcc_port), GFP_KERNEL);
if (!port)
return -ENOMEM;
name = kstrdup(dev_name(&vdev->dev), GFP_KERNEL);
rv = vio_driver_init(&port->vio, vdev, VDEV_CONSOLE_CON, vcc_versions,
ARRAY_SIZE(vcc_versions), NULL, name);
if (rv)
goto free_port;
port->vio.debug = vcc_dbg_vio;
vcc_ldc_cfg.debug = vcc_dbg_ldc;
rv = vio_ldc_alloc(&port->vio, &vcc_ldc_cfg, port);
if (rv)
goto free_port;
spin_lock_init(&port->lock);
port->index = vcc_table_add(port);
if (port->index == -1) {
pr_err("VCC: no more TTY indices left for allocation\n");
goto free_ldc;
}
/* Register the device using VCC table index as TTY index */
dev = tty_register_device(vcc_tty_driver, port->index, &vdev->dev);
if (IS_ERR(dev)) {
rv = PTR_ERR(dev);
goto free_table;
}
hp = mdesc_grab();
node = vio_vdev_node(hp, vdev);
if (node == MDESC_NODE_NULL) {
rv = -ENXIO;
mdesc_release(hp);
goto unreg_tty;
}
domain = mdesc_get_property(hp, node, "vcc-domain-name", NULL);
if (!domain) {
rv = -ENXIO;
mdesc_release(hp);
goto unreg_tty;
}
port->domain = kstrdup(domain, GFP_KERNEL);
mdesc_release(hp);
dev_set_drvdata(&vdev->dev, port);
/* It's possible to receive IRQs in the middle of vio_port_up. Disable
* IRQs until the port is up.
*/
disable_irq_nosync(vdev->rx_irq);
vio_port_up(&port->vio);
enable_irq(vdev->rx_irq);
return 0;
unreg_tty:
tty_unregister_device(vcc_tty_driver, port->index);
free_table:
vcc_table_remove(port->index);
free_ldc:
vio_ldc_free(&port->vio);
free_port:
kfree(name);
kfree(port);
return rv;
}
/**
* vcc_remove() - Terminate a VCC port
* @vdev: Pointer to VIO device of the VCC port
*
* Terminates a VCC port. Sets up the teardown of TTY and
* VIO/LDC link between guest and primary domains.
*
* Return: status of removal
*/
static int vcc_remove(struct vio_dev *vdev)
{
struct vcc_port *port = dev_get_drvdata(&vdev->dev);
if (!port)
return -ENODEV;
/* If there's a process with the device open, do a synchronous
* hangup of the TTY. This *may* cause the process to call close
* asynchronously, but it's not guaranteed.
*/
if (port->tty)
tty_vhangup(port->tty);
/* Get exclusive reference to VCC, ensures that there are no other
* clients to this port
*/
port = vcc_get(port->index, true);
if (WARN_ON(!port))
return -ENODEV;
tty_unregister_device(vcc_tty_driver, port->index);
del_timer_sync(&port->vio.timer);
vio_ldc_free(&port->vio);
dev_set_drvdata(&vdev->dev, NULL);
if (port->tty) {
port->removed = true;
vcc_put(port, true);
} else {
vcc_table_remove(port->index);
kfree(port->vio.name);
kfree(port->domain);
kfree(port);
}
return 0;
}
static const struct vio_device_id vcc_match[] = {
{
.type = "vcc-port",
},
{},
};
MODULE_DEVICE_TABLE(vio, vcc_match);
static struct vio_driver vcc_driver = {
.id_table = vcc_match,
.probe = vcc_probe,
.remove = vcc_remove,
.name = "vcc",
};
static const struct tty_operations vcc_ops;
#define VCC_TTY_FLAGS (TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_REAL_RAW)
......@@ -127,11 +496,21 @@ static int __init vcc_init(void)
return rv;
}
rv = vio_register_driver(&vcc_driver);
if (rv) {
pr_err("VCC: VIO driver registration failed\n");
vcc_tty_exit();
} else {
vccdbg("VCC: VIO driver registered successfully\n");
}
return rv;
}
static void __exit vcc_exit(void)
{
vio_unregister_driver(&vcc_driver);
vccdbg("VCC: VIO driver unregistered\n");
vcc_tty_exit();
vccdbg("VCC: TTY driver unregistered\n");
}
......
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