diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index b2da4753b12e168e9548d0f8b8ad309a042decee..1609623ec829d43ba7f5903de249f7749943e094 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1239,7 +1239,8 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
/* Map the URB's buffers for DMA access.
* Lower level HCD code should use *_dma exclusively,
- * unless it uses pio or talks to another transport.
+ * unless it uses pio or talks to another transport,
+ * or uses the provided scatter gather list for bulk.
*/
if (is_root_hub(urb->dev))
return 0;
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 3a2e69ec2f2946b56031c3b9c2ed2db49b4eac1d..2bed83caacb1a0c714a2e05af21242bbb504dcad 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -365,6 +365,7 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
int i;
int urb_flags;
int dma;
+ int use_sg;
if (!io || !dev || !sg
|| usb_pipecontrol(pipe)
@@ -392,7 +393,19 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
if (io->entries <= 0)
return io->entries;
- io->urbs = kmalloc(io->entries * sizeof *io->urbs, mem_flags);
+ /* If we're running on an xHCI host controller, queue the whole scatter
+ * gather list with one call to urb_enqueue(). This is only for bulk,
+ * as that endpoint type does not care how the data gets broken up
+ * across frames.
+ */
+ if (usb_pipebulk(pipe) &&
+ bus_to_hcd(dev->bus)->driver->flags & HCD_USB3) {
+ io->urbs = kmalloc(sizeof *io->urbs, mem_flags);
+ use_sg = true;
+ } else {
+ io->urbs = kmalloc(io->entries * sizeof *io->urbs, mem_flags);
+ use_sg = false;
+ }
if (!io->urbs)
goto nomem;
@@ -402,62 +415,92 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
if (usb_pipein(pipe))
urb_flags |= URB_SHORT_NOT_OK;
- for_each_sg(sg, sg, io->entries, i) {
- unsigned len;
-
- io->urbs[i] = usb_alloc_urb(0, mem_flags);
- if (!io->urbs[i]) {
- io->entries = i;
+ if (use_sg) {
+ io->urbs[0] = usb_alloc_urb(0, mem_flags);
+ if (!io->urbs[0]) {
+ io->entries = 0;
goto nomem;
}
- io->urbs[i]->dev = NULL;
- io->urbs[i]->pipe = pipe;
- io->urbs[i]->interval = period;
- io->urbs[i]->transfer_flags = urb_flags;
-
- io->urbs[i]->complete = sg_complete;
- io->urbs[i]->context = io;
-
- /*
- * Some systems need to revert to PIO when DMA is temporarily
- * unavailable. For their sakes, both transfer_buffer and
- * transfer_dma are set when possible. However this can only
- * work on systems without:
- *
- * - HIGHMEM, since DMA buffers located in high memory are
- * not directly addressable by the CPU for PIO;
- *
- * - IOMMU, since dma_map_sg() is allowed to use an IOMMU to
- * make virtually discontiguous buffers be "dma-contiguous"
- * so that PIO and DMA need diferent numbers of URBs.
- *
- * So when HIGHMEM or IOMMU are in use, transfer_buffer is NULL
- * to prevent stale pointers and to help spot bugs.
- */
- if (dma) {
- io->urbs[i]->transfer_dma = sg_dma_address(sg);
- len = sg_dma_len(sg);
+ io->urbs[0]->dev = NULL;
+ io->urbs[0]->pipe = pipe;
+ io->urbs[0]->interval = period;
+ io->urbs[0]->transfer_flags = urb_flags;
+
+ io->urbs[0]->complete = sg_complete;
+ io->urbs[0]->context = io;
+ /* A length of zero means transfer the whole sg list */
+ io->urbs[0]->transfer_buffer_length = length;
+ if (length == 0) {
+ for_each_sg(sg, sg, io->entries, i) {
+ io->urbs[0]->transfer_buffer_length +=
+ sg_dma_len(sg);
+ }
+ }
+ io->urbs[0]->sg = io;
+ io->urbs[0]->num_sgs = io->entries;
+ io->entries = 1;
+ } else {
+ for_each_sg(sg, sg, io->entries, i) {
+ unsigned len;
+
+ io->urbs[i] = usb_alloc_urb(0, mem_flags);
+ if (!io->urbs[i]) {
+ io->entries = i;
+ goto nomem;
+ }
+
+ io->urbs[i]->dev = NULL;
+ io->urbs[i]->pipe = pipe;
+ io->urbs[i]->interval = period;
+ io->urbs[i]->transfer_flags = urb_flags;
+
+ io->urbs[i]->complete = sg_complete;
+ io->urbs[i]->context = io;
+
+ /*
+ * Some systems need to revert to PIO when DMA is
+ * temporarily unavailable. For their sakes, both
+ * transfer_buffer and transfer_dma are set when
+ * possible. However this can only work on systems
+ * without:
+ *
+ * - HIGHMEM, since DMA buffers located in high memory
+ * are not directly addressable by the CPU for PIO;
+ *
+ * - IOMMU, since dma_map_sg() is allowed to use an
+ * IOMMU to make virtually discontiguous buffers be
+ * "dma-contiguous" so that PIO and DMA need diferent
+ * numbers of URBs.
+ *
+ * So when HIGHMEM or IOMMU are in use, transfer_buffer
+ * is NULL to prevent stale pointers and to help spot
+ * bugs.
+ */
+ if (dma) {
+ io->urbs[i]->transfer_dma = sg_dma_address(sg);
+ len = sg_dma_len(sg);
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_GART_IOMMU)
- io->urbs[i]->transfer_buffer = NULL;
+ io->urbs[i]->transfer_buffer = NULL;
#else
- io->urbs[i]->transfer_buffer = sg_virt(sg);
+ io->urbs[i]->transfer_buffer = sg_virt(sg);
#endif
- } else {
- /* hc may use _only_ transfer_buffer */
- io->urbs[i]->transfer_buffer = sg_virt(sg);
- len = sg->length;
- }
+ } else {
+ /* hc may use _only_ transfer_buffer */
+ io->urbs[i]->transfer_buffer = sg_virt(sg);
+ len = sg->length;
+ }
- if (length) {
- len = min_t(unsigned, len, length);
- length -= len;
- if (length == 0)
- io->entries = i + 1;
+ if (length) {
+ len = min_t(unsigned, len, length);
+ length -= len;
+ if (length == 0)
+ io->entries = i + 1;
+ }
+ io->urbs[i]->transfer_buffer_length = len;
}
- io->urbs[i]->transfer_buffer_length = len;
+ io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
}
- io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
/* transaction state */
io->count = io->entries;
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 13bced521b83ff77bf8d3ab8f1eeee6e5e47f137..0a1819a64974fd7e2c0c268525661569b35fb0f6 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1198,6 +1198,8 @@ struct urb {
unsigned int transfer_flags; /* (in) URB_SHORT_NOT_OK | ...*/
void *transfer_buffer; /* (in) associated data buffer */
dma_addr_t transfer_dma; /* (in) dma addr for transfer_buffer */
+ struct usb_sg_request *sg; /* (in) scatter gather buffer list */
+ int num_sgs; /* (in) number of entries in the sg list */
u32 transfer_buffer_length; /* (in) data buffer length */
u32 actual_length; /* (return) actual transfer length */
unsigned char *setup_packet; /* (in) setup packet (control only) */