diff options
Diffstat (limited to 'drivers/tty/hvc/hvc_xen.c')
| -rw-r--r-- | drivers/tty/hvc/hvc_xen.c | 62 |
1 files changed, 40 insertions, 22 deletions
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c index 98764e740c07..388a71afd6ef 100644 --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -84,13 +84,13 @@ static inline void notify_daemon(struct xencons_info *cons) notify_remote_via_evtchn(cons->evtchn); } -static int __write_console(struct xencons_info *xencons, - const char *data, int len) +static ssize_t __write_console(struct xencons_info *xencons, + const u8 *data, size_t len) { XENCONS_RING_IDX cons, prod; struct xencons_interface *intf = xencons->intf; - int sent = 0; unsigned long flags; + size_t sent = 0; spin_lock_irqsave(&xencons->ring_lock, flags); cons = intf->out_cons; @@ -115,10 +115,11 @@ static int __write_console(struct xencons_info *xencons, return sent; } -static int domU_write_console(uint32_t vtermno, const char *data, int len) +static ssize_t domU_write_console(uint32_t vtermno, const u8 *data, size_t len) { - int ret = len; struct xencons_info *cons = vtermno_to_xencons(vtermno); + size_t ret = len; + if (cons == NULL) return -EINVAL; @@ -129,7 +130,7 @@ static int domU_write_console(uint32_t vtermno, const char *data, int len) * kernel is crippled. */ while (len) { - int sent = __write_console(cons, data, len); + ssize_t sent = __write_console(cons, data, len); if (sent < 0) return sent; @@ -144,14 +145,14 @@ static int domU_write_console(uint32_t vtermno, const char *data, int len) return ret; } -static int domU_read_console(uint32_t vtermno, char *buf, int len) +static ssize_t domU_read_console(uint32_t vtermno, u8 *buf, size_t len) { struct xencons_interface *intf; XENCONS_RING_IDX cons, prod; - int recv = 0; struct xencons_info *xencons = vtermno_to_xencons(vtermno); unsigned int eoiflag = 0; unsigned long flags; + size_t recv = 0; if (xencons == NULL) return -EINVAL; @@ -209,7 +210,7 @@ static const struct hv_ops domU_hvc_ops = { .notifier_hangup = notifier_hangup_irq, }; -static int dom0_read_console(uint32_t vtermno, char *buf, int len) +static ssize_t dom0_read_console(uint32_t vtermno, u8 *buf, size_t len) { return HYPERVISOR_console_io(CONSOLEIO_read, len, buf); } @@ -218,9 +219,9 @@ static int dom0_read_console(uint32_t vtermno, char *buf, int len) * Either for a dom0 to write to the system console, or a domU with a * debug version of Xen */ -static int dom0_write_console(uint32_t vtermno, const char *str, int len) +static ssize_t dom0_write_console(uint32_t vtermno, const u8 *str, size_t len) { - int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str); + int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (u8 *)str); if (rc < 0) return rc; @@ -377,18 +378,21 @@ void xen_console_resume(void) #ifdef CONFIG_HVC_XEN_FRONTEND static void xencons_disconnect_backend(struct xencons_info *info) { - if (info->irq > 0) - unbind_from_irqhandler(info->irq, NULL); - info->irq = 0; + if (info->hvc != NULL) + hvc_remove(info->hvc); + info->hvc = NULL; + if (info->irq > 0) { + evtchn_put(info->evtchn); + info->irq = 0; + info->evtchn = 0; + } + /* evtchn_put() will also close it so this is only an error path */ if (info->evtchn > 0) xenbus_free_evtchn(info->xbdev, info->evtchn); info->evtchn = 0; if (info->gntref > 0) gnttab_free_grant_references(info->gntref); info->gntref = 0; - if (info->hvc != NULL) - hvc_remove(info->hvc); - info->hvc = NULL; } static void xencons_free(struct xencons_info *info) @@ -433,7 +437,7 @@ static int xencons_connect_backend(struct xenbus_device *dev, if (ret) return ret; info->evtchn = evtchn; - irq = bind_interdomain_evtchn_to_irq_lateeoi(dev, evtchn); + irq = bind_evtchn_to_irq_lateeoi(evtchn); if (irq < 0) return irq; info->irq = irq; @@ -553,10 +557,23 @@ static void xencons_backend_changed(struct xenbus_device *dev, if (dev->state == XenbusStateClosed) break; fallthrough; /* Missed the backend's CLOSING state */ - case XenbusStateClosing: + case XenbusStateClosing: { + struct xencons_info *info = dev_get_drvdata(&dev->dev); + + /* + * Don't tear down the evtchn and grant ref before the other + * end has disconnected, but do stop userspace from trying + * to use the device before we allow the backend to close. + */ + if (info->hvc) { + hvc_remove(info->hvc); + info->hvc = NULL; + } + xenbus_frontend_closed(dev); break; } + } } static const struct xenbus_device_id xencons_ids[] = { @@ -588,7 +605,7 @@ 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; @@ -597,7 +614,7 @@ 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); @@ -616,12 +633,13 @@ static int __init xen_hvc_init(void) list_del(&info->list); spin_unlock_irqrestore(&xencons_lock, flags); if (info->irq) - unbind_from_irqhandler(info->irq, NULL); + evtchn_put(info->evtchn); kfree(info); return r; } r = 0; + register_fe: #ifdef CONFIG_HVC_XEN_FRONTEND r = xenbus_register_frontend(&xencons_driver); #endif |