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path: root/drivers/tty/hvc/hvc_xen.c
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Diffstat (limited to 'drivers/tty/hvc/hvc_xen.c')
-rw-r--r--drivers/tty/hvc/hvc_xen.c70
1 files changed, 49 insertions, 21 deletions
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 080adf7bcae4..c89f93ff07c5 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -43,6 +43,7 @@ struct xencons_info {
int irq;
int vtermno;
grant_ref_t gntref;
+ spinlock_t ring_lock;
};
static LIST_HEAD(xenconsoles);
@@ -52,17 +53,22 @@ static DEFINE_SPINLOCK(xencons_lock);
static struct xencons_info *vtermno_to_xencons(int vtermno)
{
- struct xencons_info *entry, *n, *ret = NULL;
+ struct xencons_info *entry, *ret = NULL;
+ unsigned long flags;
- if (list_empty(&xenconsoles))
- return NULL;
+ spin_lock_irqsave(&xencons_lock, flags);
+ if (list_empty(&xenconsoles)) {
+ spin_unlock_irqrestore(&xencons_lock, flags);
+ return NULL;
+ }
- list_for_each_entry_safe(entry, n, &xenconsoles, list) {
+ list_for_each_entry(entry, &xenconsoles, list) {
if (entry->vtermno == vtermno) {
ret = entry;
break;
}
}
+ spin_unlock_irqrestore(&xencons_lock, flags);
return ret;
}
@@ -84,12 +90,15 @@ static int __write_console(struct xencons_info *xencons,
XENCONS_RING_IDX cons, prod;
struct xencons_interface *intf = xencons->intf;
int sent = 0;
+ unsigned long flags;
+ spin_lock_irqsave(&xencons->ring_lock, flags);
cons = intf->out_cons;
prod = intf->out_prod;
mb(); /* update queue values before going on */
if ((prod - cons) > sizeof(intf->out)) {
+ spin_unlock_irqrestore(&xencons->ring_lock, flags);
pr_err_once("xencons: Illegal ring page indices");
return -EINVAL;
}
@@ -99,6 +108,7 @@ static int __write_console(struct xencons_info *xencons,
wmb(); /* write ring before updating pointer */
intf->out_prod = prod;
+ spin_unlock_irqrestore(&xencons->ring_lock, flags);
if (sent)
notify_daemon(xencons);
@@ -141,16 +151,19 @@ static int domU_read_console(uint32_t vtermno, char *buf, int len)
int recv = 0;
struct xencons_info *xencons = vtermno_to_xencons(vtermno);
unsigned int eoiflag = 0;
+ unsigned long flags;
if (xencons == NULL)
return -EINVAL;
intf = xencons->intf;
+ spin_lock_irqsave(&xencons->ring_lock, flags);
cons = intf->in_cons;
prod = intf->in_prod;
mb(); /* get pointers before reading ring */
if ((prod - cons) > sizeof(intf->in)) {
+ spin_unlock_irqrestore(&xencons->ring_lock, flags);
pr_err_once("xencons: Illegal ring page indices");
return -EINVAL;
}
@@ -174,10 +187,13 @@ static int domU_read_console(uint32_t vtermno, char *buf, int len)
xencons->out_cons = intf->out_cons;
xencons->out_cons_same = 0;
}
+ if (!recv && xencons->out_cons_same++ > 1) {
+ eoiflag = XEN_EOI_FLAG_SPURIOUS;
+ }
+ spin_unlock_irqrestore(&xencons->ring_lock, flags);
+
if (recv) {
notify_daemon(xencons);
- } else if (xencons->out_cons_same++ > 1) {
- eoiflag = XEN_EOI_FLAG_SPURIOUS;
}
xen_irq_lateeoi(xencons->irq, eoiflag);
@@ -223,7 +239,7 @@ static int xen_hvm_console_init(void)
{
int r;
uint64_t v = 0;
- unsigned long gfn;
+ unsigned long gfn, flags;
struct xencons_info *info;
if (!xen_hvm_domain())
@@ -234,6 +250,7 @@ static int xen_hvm_console_init(void)
info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
if (!info)
return -ENOMEM;
+ spin_lock_init(&info->ring_lock);
} else if (info->intf != NULL) {
/* already configured */
return 0;
@@ -258,9 +275,9 @@ static int xen_hvm_console_init(void)
goto err;
info->vtermno = HVC_COOKIE;
- spin_lock(&xencons_lock);
+ spin_lock_irqsave(&xencons_lock, flags);
list_add_tail(&info->list, &xenconsoles);
- spin_unlock(&xencons_lock);
+ spin_unlock_irqrestore(&xencons_lock, flags);
return 0;
err:
@@ -270,6 +287,7 @@ err:
static int xencons_info_pv_init(struct xencons_info *info, int vtermno)
{
+ spin_lock_init(&info->ring_lock);
info->evtchn = xen_start_info->console.domU.evtchn;
/* GFN == MFN for PV guest */
info->intf = gfn_to_virt(xen_start_info->console.domU.mfn);
@@ -283,6 +301,7 @@ static int xencons_info_pv_init(struct xencons_info *info, int vtermno)
static int xen_pv_console_init(void)
{
struct xencons_info *info;
+ unsigned long flags;
if (!xen_pv_domain())
return -ENODEV;
@@ -299,9 +318,9 @@ static int xen_pv_console_init(void)
/* already configured */
return 0;
}
- spin_lock(&xencons_lock);
+ spin_lock_irqsave(&xencons_lock, flags);
xencons_info_pv_init(info, HVC_COOKIE);
- spin_unlock(&xencons_lock);
+ spin_unlock_irqrestore(&xencons_lock, flags);
return 0;
}
@@ -309,6 +328,7 @@ static int xen_pv_console_init(void)
static int xen_initial_domain_console_init(void)
{
struct xencons_info *info;
+ unsigned long flags;
if (!xen_initial_domain())
return -ENODEV;
@@ -318,14 +338,15 @@ static int xen_initial_domain_console_init(void)
info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
if (!info)
return -ENOMEM;
+ spin_lock_init(&info->ring_lock);
}
info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0, false);
info->vtermno = HVC_COOKIE;
- spin_lock(&xencons_lock);
+ spin_lock_irqsave(&xencons_lock, flags);
list_add_tail(&info->list, &xenconsoles);
- spin_unlock(&xencons_lock);
+ spin_unlock_irqrestore(&xencons_lock, flags);
return 0;
}
@@ -380,10 +401,12 @@ static void xencons_free(struct xencons_info *info)
static int xen_console_remove(struct xencons_info *info)
{
+ unsigned long flags;
+
xencons_disconnect_backend(info);
- spin_lock(&xencons_lock);
+ spin_lock_irqsave(&xencons_lock, flags);
list_del(&info->list);
- spin_unlock(&xencons_lock);
+ spin_unlock_irqrestore(&xencons_lock, flags);
if (info->xbdev != NULL)
xencons_free(info);
else {
@@ -464,6 +487,7 @@ static int xencons_probe(struct xenbus_device *dev,
{
int ret, devid;
struct xencons_info *info;
+ unsigned long flags;
devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
if (devid == 0)
@@ -472,6 +496,7 @@ static int xencons_probe(struct xenbus_device *dev,
info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
if (!info)
return -ENOMEM;
+ spin_lock_init(&info->ring_lock);
dev_set_drvdata(&dev->dev, info);
info->xbdev = dev;
info->vtermno = xenbus_devid_to_vtermno(devid);
@@ -482,9 +507,9 @@ static int xencons_probe(struct xenbus_device *dev,
ret = xencons_connect_backend(dev, info);
if (ret < 0)
goto error;
- spin_lock(&xencons_lock);
+ spin_lock_irqsave(&xencons_lock, flags);
list_add_tail(&info->list, &xenconsoles);
- spin_unlock(&xencons_lock);
+ spin_unlock_irqrestore(&xencons_lock, flags);
return 0;
@@ -562,7 +587,7 @@ static int __init xen_hvc_init(void)
ops = &dom0_hvc_ops;
r = xen_initial_domain_console_init();
if (r < 0)
- return r;
+ goto register_fe;
info = vtermno_to_xencons(HVC_COOKIE);
} else {
ops = &domU_hvc_ops;
@@ -571,7 +596,7 @@ static int __init xen_hvc_init(void)
else
r = xen_pv_console_init();
if (r < 0)
- return r;
+ goto register_fe;
info = vtermno_to_xencons(HVC_COOKIE);
info->irq = bind_evtchn_to_irq_lateeoi(info->evtchn);
@@ -583,10 +608,12 @@ static int __init xen_hvc_init(void)
info->hvc = hvc_alloc(HVC_COOKIE, info->irq, ops, 256);
if (IS_ERR(info->hvc)) {
+ unsigned long flags;
+
r = PTR_ERR(info->hvc);
- spin_lock(&xencons_lock);
+ spin_lock_irqsave(&xencons_lock, flags);
list_del(&info->list);
- spin_unlock(&xencons_lock);
+ spin_unlock_irqrestore(&xencons_lock, flags);
if (info->irq)
unbind_from_irqhandler(info->irq, NULL);
kfree(info);
@@ -594,6 +621,7 @@ static int __init xen_hvc_init(void)
}
r = 0;
+ register_fe:
#ifdef CONFIG_HVC_XEN_FRONTEND
r = xenbus_register_frontend(&xencons_driver);
#endif
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-04-19 22:58:00 +0000