diff options
Diffstat (limited to 'drivers/tty/hvc/hvc_xen.c')
| -rw-r--r-- | drivers/tty/hvc/hvc_xen.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c index 5bddb2f5e931..98764e740c07 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); @@ -89,12 +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; } @@ -104,6 +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); @@ -146,16 +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; } @@ -179,10 +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); @@ -239,6 +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; @@ -275,6 +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); @@ -325,6 +338,7 @@ 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); @@ -482,6 +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); |