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authorSarah Sharp <sarah.a.sharp@linux.intel.com>2010-04-05 10:55:58 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2010-05-20 13:21:38 -0700
commiteab1cafc3b524b714b0567ab98fc75ace09db98c (patch)
tree854ed5c4cba741efabec933714dac5c68bcbb452 /include
parente9df17eb1408cfafa3d1844bfc7f22c7237b31b8 (diff)
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USB: Support for allocating USB 3.0 streams.
Bulk endpoint streams were added in the USB 3.0 specification. Streams allow a device driver to overload a bulk endpoint so that multiple transfers can be queued at once. The device then decides which transfer it wants to work on first, and can queue part of a transfer before it switches to a new stream. All this switching is invisible to the device driver, which just gets a completion for the URB. Drivers that use streams must be able to handle URBs completing in a different order than they were submitted to the endpoint. This requires adding new API to set up xHCI data structures to support multiple queues ("stream rings") per endpoint. Drivers will allocate a number of stream IDs before enqueueing URBs to the bulk endpoints of the device, and free the stream IDs in their disconnect function. See Documentation/usb/bulk-streams.txt for details. The new mass storage device class, USB Attached SCSI Protocol (UASP), uses these streams API. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include')
-rw-r--r--include/linux/usb.h10
-rw-r--r--include/linux/usb/hcd.h10
2 files changed, 20 insertions, 0 deletions
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 191af49..1ea2537 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -570,6 +570,16 @@ static inline void usb_mark_last_busy(struct usb_device *udev)
/* for drivers using iso endpoints */
extern int usb_get_current_frame_number(struct usb_device *usb_dev);
+/* Sets up a group of bulk endpoints to support multiple stream IDs. */
+extern int usb_alloc_streams(struct usb_interface *interface,
+ struct usb_host_endpoint **eps, unsigned int num_eps,
+ unsigned int num_streams, gfp_t mem_flags);
+
+/* Reverts a group of bulk endpoints back to not using stream IDs. */
+extern void usb_free_streams(struct usb_interface *interface,
+ struct usb_host_endpoint **eps, unsigned int num_eps,
+ gfp_t mem_flags);
+
/* used these for multi-interface device registration */
extern int usb_driver_claim_interface(struct usb_driver *driver,
struct usb_interface *iface, void *priv);
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index d268415..aca73a5 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -250,6 +250,16 @@ struct hc_driver {
int (*alloc_dev)(struct usb_hcd *, struct usb_device *);
/* Called by usb_disconnect to free HC device structures */
void (*free_dev)(struct usb_hcd *, struct usb_device *);
+ /* Change a group of bulk endpoints to support multiple stream IDs */
+ int (*alloc_streams)(struct usb_hcd *hcd, struct usb_device *udev,
+ struct usb_host_endpoint **eps, unsigned int num_eps,
+ unsigned int num_streams, gfp_t mem_flags);
+ /* Reverts a group of bulk endpoints back to not using stream IDs.
+ * Can fail if we run out of memory.
+ */
+ int (*free_streams)(struct usb_hcd *hcd, struct usb_device *udev,
+ struct usb_host_endpoint **eps, unsigned int num_eps,
+ gfp_t mem_flags);
/* Bandwidth computation functions */
/* Note that add_endpoint() can only be called once per endpoint before
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