diff options
| -rw-r--r-- | drivers/usb/core/hcd.c | 2 | ||||
| -rw-r--r-- | drivers/usb/core/urb.c | 102 | ||||
| -rw-r--r-- | include/linux/usb.h | 22 |
3 files changed, 123 insertions, 3 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index c5a2f83991dc..87d6edf11f92 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1410,6 +1410,8 @@ void usb_hcd_giveback_urb (struct usb_hcd *hcd, struct urb *urb) } usbmon_urb_complete (&hcd->self, urb); + usb_unanchor_urb(urb); + /* pass ownership to the completion handler */ urb->complete (urb); atomic_dec (&urb->use_count); diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 94ea9727ff55..ac4273dddf34 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -4,6 +4,7 @@ #include <linux/slab.h> #include <linux/init.h> #include <linux/usb.h> +#include <linux/wait.h> #include "hcd.h" #define to_urb(d) container_of(d, struct urb, kref) @@ -11,6 +12,7 @@ static void urb_destroy(struct kref *kref) { struct urb *urb = to_urb(kref); + kfree(urb); } @@ -34,6 +36,7 @@ void usb_init_urb(struct urb *urb) memset(urb, 0, sizeof(*urb)); kref_init(&urb->kref); spin_lock_init(&urb->lock); + INIT_LIST_HEAD(&urb->anchor_list); } } @@ -100,8 +103,60 @@ struct urb * usb_get_urb(struct urb *urb) kref_get(&urb->kref); return urb; } - - + +/** + * usb_anchor_urb - anchors an URB while it is processed + * @urb: pointer to the urb to anchor + * @anchor: pointer to the anchor + * + * This can be called to have access to URBs which are to be executed + * without bothering to track them + */ +void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor) +{ + unsigned long flags; + + spin_lock_irqsave(&anchor->lock, flags); + usb_get_urb(urb); + list_add_tail(&urb->anchor_list, &anchor->urb_list); + urb->anchor = anchor; + spin_unlock_irqrestore(&anchor->lock, flags); +} +EXPORT_SYMBOL_GPL(usb_anchor_urb); + +/** + * usb_unanchor_urb - unanchors an URB + * @urb: pointer to the urb to anchor + * + * Call this to stop the system keeping track of this URB + */ +void usb_unanchor_urb(struct urb *urb) +{ + unsigned long flags; + struct usb_anchor *anchor; + + if (!urb) + return; + + anchor = urb->anchor; + if (!anchor) + return; + + spin_lock_irqsave(&anchor->lock, flags); + if (unlikely(anchor != urb->anchor)) { + /* we've lost the race to another thread */ + spin_unlock_irqrestore(&anchor->lock, flags); + return; + } + urb->anchor = NULL; + list_del(&urb->anchor_list); + spin_unlock_irqrestore(&anchor->lock, flags); + usb_put_urb(urb); + if (list_empty(&anchor->urb_list)) + wake_up(&anchor->wait); +} +EXPORT_SYMBOL_GPL(usb_unanchor_urb); + /*-------------------------------------------------------------------*/ /** @@ -478,6 +533,48 @@ void usb_kill_urb(struct urb *urb) spin_unlock_irq(&urb->lock); } +/** + * usb_kill_anchored_urbs - cancel transfer requests en masse + * @anchor: anchor the requests are bound to + * + * this allows all outstanding URBs to be killed starting + * from the back of the queue + */ +void usb_kill_anchored_urbs(struct usb_anchor *anchor) +{ + struct urb *victim; + + spin_lock_irq(&anchor->lock); + while (!list_empty(&anchor->urb_list)) { + victim = list_entry(anchor->urb_list.prev, struct urb, anchor_list); + /* we must make sure the URB isn't freed before we kill it*/ + usb_get_urb(victim); + spin_unlock_irq(&anchor->lock); + /* this will unanchor the URB */ + usb_kill_urb(victim); + usb_put_urb(victim); + spin_lock_irq(&anchor->lock); + } + spin_unlock_irq(&anchor->lock); +} +EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs); + +/** + * usb_wait_anchor_empty_timeout - wait for an anchor to be unused + * @anchor: the anchor you want to become unused + * @timeout: how long you are willing to wait in milliseconds + * + * Call this is you want to be sure all an anchor's + * URBs have finished + */ +int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, + unsigned int timeout) +{ + return wait_event_timeout(anchor->wait, list_empty(&anchor->urb_list), + msecs_to_jiffies(timeout)); +} +EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); + EXPORT_SYMBOL(usb_init_urb); EXPORT_SYMBOL(usb_alloc_urb); EXPORT_SYMBOL(usb_free_urb); @@ -485,4 +582,3 @@ EXPORT_SYMBOL(usb_get_urb); EXPORT_SYMBOL(usb_submit_urb); EXPORT_SYMBOL(usb_unlink_urb); EXPORT_SYMBOL(usb_kill_urb); - diff --git a/include/linux/usb.h b/include/linux/usb.h index 98e0338664fb..0873c6219efc 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1000,11 +1000,26 @@ struct usb_iso_packet_descriptor { struct urb; +struct usb_anchor { + struct list_head urb_list; + wait_queue_head_t wait; + spinlock_t lock; +}; + +static inline void init_usb_anchor(struct usb_anchor *anchor) +{ + INIT_LIST_HEAD(&anchor->urb_list); + init_waitqueue_head(&anchor->wait); + spin_lock_init(&anchor->lock); +} + typedef void (*usb_complete_t)(struct urb *); /** * struct urb - USB Request Block * @urb_list: For use by current owner of the URB. + * @anchor_list: membership in the list of an anchor + * @anchor: to anchor URBs to a common mooring * @pipe: Holds endpoint number, direction, type, and more. * Create these values with the eight macros available; * usb_{snd,rcv}TYPEpipe(dev,endpoint), where the TYPE is "ctrl" @@ -1177,6 +1192,8 @@ struct urb /* public: documented fields in the urb that can be used by drivers */ struct list_head urb_list; /* list head for use by the urb's * current owner */ + struct list_head anchor_list; /* the URB may be anchored by the driver */ + struct usb_anchor *anchor; struct usb_device *dev; /* (in) pointer to associated device */ unsigned int pipe; /* (in) pipe information */ int status; /* (return) non-ISO status */ @@ -1312,6 +1329,11 @@ extern struct urb *usb_get_urb(struct urb *urb); extern int usb_submit_urb(struct urb *urb, gfp_t mem_flags); extern int usb_unlink_urb(struct urb *urb); extern void usb_kill_urb(struct urb *urb); +extern void usb_kill_anchored_urbs(struct usb_anchor *anchor); +extern void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor); +extern void usb_unanchor_urb(struct urb *urb); +extern int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, + unsigned int timeout); void *usb_buffer_alloc (struct usb_device *dev, size_t size, gfp_t mem_flags, dma_addr_t *dma); |