The WHCI HCD will also support urbs with scatter-gather lists. Add a
usb_bus field to indicated how many sg list elements are supported by
the HCD.
Save space in struct urb by adding a URB_HAS_SG flag and reusing
transfer_buffer to point to a struct sg_table.
Split usb_sg_init() into usb_sg_init_with_sg() and
usb_sg_init_without_sg().
Signed-off-by: David Vrabel <david.vrabel@xxxxxxx>
---
drivers/usb/core/message.c | 289 +++++++++++++++++++++++-------------------
drivers/usb/host/xhci-ring.c | 15 ++-
drivers/usb/storage/usb.c | 10 ++
include/linux/usb.h | 9 +-
4 files changed, 184 insertions(+), 139 deletions(-)
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 9720e69..a39765c 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -332,6 +332,158 @@ static void sg_complete(struct urb *urb)
spin_unlock(&io->lock);
}
+static int
+usb_sg_init_without_sg(struct usb_sg_request *io, struct usb_device *dev,
+ unsigned pipe, unsigned period, struct scatterlist *sg,
+ size_t length, gfp_t mem_flags)
+{
+ int i;
+ int urb_flags;
+ int dma;
+
+ /* not all host controllers use DMA (like the mainstream pci ones);
+ * they can use PIO (sl811) or be software over another transport.
+ */
+ dma = (dev->dev.dma_mask != NULL);
+ if (dma)
+ io->entries = usb_buffer_map_sg(dev, usb_pipein(pipe),
+ sg, io->nents);
+ else
+ io->entries = io->nents;
+
+ /* initialize all the urbs we'll use */
+ if (io->entries <= 0)
+ return io->entries;
+
+ io->urbs = kmalloc(io->entries * sizeof *io->urbs, mem_flags);
+ if (!io->urbs)
+ goto nomem;
+
+ urb_flags = URB_NO_INTERRUPT;
+ if (dma)
+ urb_flags |= URB_NO_TRANSFER_DMA_MAP;
+ 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;
+ 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;
+#else
+ 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;
+ }
+
+ 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_flags &= ~URB_NO_INTERRUPT;
+
+ return 0;
+
+nomem:
+ sg_clean(io);
+ return -ENOMEM;
+}
+
+static int
+usb_sg_init_with_sg(struct usb_sg_request *io, struct usb_device *dev,
+ unsigned pipe, unsigned period, struct scatterlist *sg,
+ size_t length, gfp_t mem_flags)
+{
+ struct sg_table *sgt;
+
+ if (length == 0) {
+ struct scatterlist *s;
+ int i;
+ for_each_sg(sg, s, io->nents, i) {
+ length += s->length;
+ }
+ }
+
+ /* initialize one urb with transfer_buffer pointing to a new sg_table */
+ io->urbs = kmalloc(sizeof(struct urb *) + sizeof(struct sg_table), mem_flags);
+ if (!io->urbs)
+ return -ENOMEM;
+
+ sgt = (struct sg_table *)&io->urbs[1];
+ sgt->sgl = sg;
+ sgt->orig_nents = io->nents;
+
+ /* not all host controllers use DMA (like the mainstream pci ones);
+ * they can use PIO (sl811) or be software over another transport.
+ */
+ if (dev->dev.dma_mask != NULL)
+ sgt->nents = usb_buffer_map_sg(dev, usb_pipein(pipe), sg, io->nents);
+ else
+ sgt->nents = sgt->orig_nents;
+ if (sgt->nents <= 0)
+ return sgt->nents;
+
+ io->urbs[0] = usb_alloc_urb(0, mem_flags);
+ if (!io->urbs[0])
+ return -ENOMEM;
+ io->entries = 1;
+
+ io->urbs[0]->dev = NULL;
+ io->urbs[0]->pipe = pipe;
+ io->urbs[0]->interval = period;
+ io->urbs[0]->transfer_flags = URB_HAS_SG;
+
+ io->urbs[0]->complete = sg_complete;
+ io->urbs[0]->context = io;
+
+ io->urbs[0]->transfer_buffer = sgt;
+ io->urbs[0]->transfer_buffer_length = length;
+
+ return 0;
+}
/**
* usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
@@ -362,10 +514,7 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
unsigned pipe, unsigned period, struct scatterlist *sg,
int nents, size_t length, gfp_t mem_flags)
{
- int i;
- int urb_flags;
- int dma;
- int use_sg;
+ int ret;
if (!io || !dev || !sg
|| usb_pipecontrol(pipe)
@@ -378,128 +527,15 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
io->pipe = pipe;
io->sg = sg;
io->nents = nents;
+ io->entries = 0;
- /* not all host controllers use DMA (like the mainstream pci ones);
- * they can use PIO (sl811) or be software over another transport.
- */
- dma = (dev->dev.dma_mask != NULL);
- if (dma)
- io->entries = usb_buffer_map_sg(dev, usb_pipein(pipe),
- sg, nents);
+ if (dev->bus->sg_tablesize)
+ ret = usb_sg_init_with_sg(io, dev, pipe, period, sg, length, mem_flags);
else
- io->entries = nents;
-
- /* initialize all the urbs we'll use */
- if (io->entries <= 0)
- return io->entries;
-
- /* 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;
-
- urb_flags = URB_NO_INTERRUPT;
- if (dma)
- urb_flags |= URB_NO_TRANSFER_DMA_MAP;
- if (usb_pipein(pipe))
- urb_flags |= URB_SHORT_NOT_OK;
-
- if (use_sg) {
- io->urbs[0] = usb_alloc_urb(0, mem_flags);
- if (!io->urbs[0]) {
- io->entries = 0;
- goto nomem;
- }
-
- 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;
-#else
- 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;
- }
-
- 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_flags &= ~URB_NO_INTERRUPT;
+ ret = usb_sg_init_without_sg(io, dev, pipe, period, sg, length, mem_flags);
+ if (ret < 0) {
+ sg_clean(io);
+ return ret;
}
/* transaction state */
@@ -507,11 +543,8 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
io->status = 0;
io->bytes = 0;
init_completion(&io->complete);
- return 0;
-nomem:
- sg_clean(io);
- return -ENOMEM;
+ return 0;
}
EXPORT_SYMBOL_GPL(usb_sg_init);
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index aa88a06..bd5a96e 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1265,15 +1265,16 @@ static int prepare_transfer(struct xhci_hcd *xhci,
static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb)
{
int num_sgs, num_trbs, running_total, temp, i;
+ struct sg_table *sg_table;
struct scatterlist *sg;
- sg = NULL;
- num_sgs = urb->num_sgs;
+ sg_table = urb->transfer_buffer;
+ num_sgs = sg_table->nents;
temp = urb->transfer_buffer_length;
xhci_dbg(xhci, "count sg list trbs: \n");
num_trbs = 0;
- for_each_sg(urb->sg->sg, sg, num_sgs, i) {
+ for_each_sg(sg_table->sgl, sg, num_sgs, i) {
unsigned int previous_total_trbs = num_trbs;
unsigned int len = sg_dma_len(sg);
@@ -1341,6 +1342,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
struct xhci_ring *ep_ring;
unsigned int num_trbs;
struct xhci_td *td;
+ struct sg_table *sg_table;
struct scatterlist *sg;
int num_sgs;
int trb_buff_len, this_sg_len, running_total;
@@ -1352,7 +1354,8 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
ep_ring = xhci->devs[slot_id]->ep_rings[ep_index];
num_trbs = count_sg_trbs_needed(xhci, urb);
- num_sgs = urb->num_sgs;
+ sg_table = urb->transfer_buffer;
+ num_sgs = sg_table->nents;
trb_buff_len = prepare_transfer(xhci, xhci->devs[slot_id],
ep_index, num_trbs, urb, &td, mem_flags);
@@ -1376,7 +1379,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
* the amount of memory allocated for this scatter-gather list.
* 3. TRBs buffers can't cross 64KB boundaries.
*/
- sg = urb->sg->sg;
+ sg = sg_table->sgl;
addr = (u64) sg_dma_address(sg);
this_sg_len = sg_dma_len(sg);
trb_buff_len = TRB_MAX_BUFF_SIZE -
@@ -1480,7 +1483,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
int running_total, trb_buff_len, ret;
u64 addr;
- if (urb->sg)
+ if (urb->transfer_flags & URB_HAS_SG)
return queue_bulk_sg_tx(xhci, mem_flags, urb, slot_id, ep_index);
ep_ring = xhci->devs[slot_id]->ep_rings[ep_index];
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index 8060b85..964d8ee 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -840,6 +840,15 @@ static int usb_stor_scan_thread(void * __us)
complete_and_exit(&us->scanning_done, 0);
}
+static unsigned int usb_stor_sg_tablesize(struct usb_interface *intf)
+{
+ struct usb_device *usb_dev = interface_to_usbdev(intf);
+
+ if (usb_dev->bus->sg_tablesize) {
+ return usb_dev->bus->sg_tablesize;
+ }
+ return SG_ALL;
+}
/* First part of general USB mass-storage probing */
int usb_stor_probe1(struct us_data **pus,
@@ -868,6 +877,7 @@ int usb_stor_probe1(struct us_data **pus,
* Allow 16-byte CDBs and thus > 2TB
*/
host->max_cmd_len = 16;
+ host->sg_tablesize = usb_stor_sg_tablesize(intf);
*pus = us = host_to_us(host);
memset(us, 0, sizeof(struct us_data));
mutex_init(&(us->dev_mutex));
diff --git a/include/linux/usb.h b/include/linux/usb.h
index b1e3c2f..b96e7d8 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -331,6 +331,7 @@ struct usb_bus {
u8 otg_port; /* 0, or number of OTG/HNP port */
unsigned is_b_host:1; /* true during some HNP roleswitches */
unsigned b_hnp_enable:1; /* OTG: did A-Host enable HNP? */
+ int sg_tablesize; /* 0 or largest number of sg list entries */
int devnum_next; /* Next open device number in
* round-robin allocation */
@@ -977,6 +978,7 @@ extern int usb_disabled(void);
* ignored */
#define URB_NO_TRANSFER_DMA_MAP 0x0004 /* urb->transfer_dma valid on submit */
#define URB_NO_SETUP_DMA_MAP 0x0008 /* urb->setup_dma valid on submit */
+#define URB_HAS_SG 0x0010 /* urb->transfer_buffer points to a struct sg_table */
#define URB_NO_FSBR 0x0020 /* UHCI-specific */
#define URB_ZERO_PACKET 0x0040 /* Finish bulk OUT with short packet */
#define URB_NO_INTERRUPT 0x0080 /* HINT: no non-error interrupt
@@ -1041,13 +1043,12 @@ typedef void (*usb_complete_t)(struct urb *);
* is set). This buffer must be suitable for DMA; allocate it with
* kmalloc() or equivalent. For transfers to "in" endpoints, contents
* of this buffer will be modified. This buffer is used for the data
- * stage of control transfers.
+ * stage of control transfers. If @transfer_flags & URB_HAS_SG then
+ * this points to a struct sg_table instead.
* @transfer_dma: When transfer_flags includes URB_NO_TRANSFER_DMA_MAP,
* the device driver is saying that it provided this DMA address,
* which the host controller driver should use in preference to the
* transfer_buffer.
- * @sg: scatter gather buffer list
- * @num_sgs: number of entries in the sg list
* @transfer_buffer_length: How big is transfer_buffer. The transfer may
* be broken up into chunks according to the current maximum packet
* size for the endpoint, which is a function of the configuration
@@ -1203,8 +1204,6 @@ 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) */
--
1.6.3.3
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