The patch titled
usb: dma bounce buffer support
has been added to the -mm tree. Its filename is
usb-dma-bounce-buffer-support-v3.patch
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------------------------------------------------------
Subject: usb: dma bounce buffer support
From: Magnus Damm <magnus.damm@xxxxxxxxx>
The sm501 usb host controller is a regular ohci implementation but with the
exception that it can only do dma to a certain area of memory. This memory is
sm501 specific and the mfd driver for sm501 currently divides this memory
between the framebuffer and the usb host controller.
To support the sm501 usb host controller we need to allocate all usb data from
this sm501 memory. The function dma_declare_coherent_memory() helps us with
that - all dma_alloc_coherent() calls will end up allocating such memory.
The USB core does however allocate data using kmalloc, so to fully support
such a behaviour we need dma bounce buffer support. These bounce buffers can
be requested using the flag HCD_LOCAL_MEM.
This patch:
Add dma bounce buffer support to the usb core. These buffers can be
enabled with the HCD_LOCAL_MEM flag, and they make sure that all data
passed to the host controller is allocated using dma_alloc_coherent().
Signed-off-by: Magnus Damm <damm@xxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/usb/core/buffer.c | 9 +-
drivers/usb/core/hcd.c | 134 ++++++++++++++++++++++++++++++------
drivers/usb/core/hcd.h | 1
3 files changed, 122 insertions(+), 22 deletions(-)
diff -puN drivers/usb/core/buffer.c~usb-dma-bounce-buffer-support-v3 drivers/usb/core/buffer.c
--- a/drivers/usb/core/buffer.c~usb-dma-bounce-buffer-support-v3
+++ a/drivers/usb/core/buffer.c
@@ -53,7 +53,8 @@ int hcd_buffer_create(struct usb_hcd *hc
char name[16];
int i, size;
- if (!hcd->self.controller->dma_mask)
+ if (!hcd->self.controller->dma_mask &&
+ !(hcd->driver->flags & HCD_LOCAL_MEM))
return 0;
for (i = 0; i < HCD_BUFFER_POOLS; i++) {
@@ -107,7 +108,8 @@ void *hcd_buffer_alloc(
int i;
/* some USB hosts just use PIO */
- if (!bus->controller->dma_mask) {
+ if (!bus->controller->dma_mask &&
+ !(hcd->driver->flags & HCD_LOCAL_MEM)) {
*dma = ~(dma_addr_t) 0;
return kmalloc(size, mem_flags);
}
@@ -132,7 +134,8 @@ void hcd_buffer_free(
if (!addr)
return;
- if (!bus->controller->dma_mask) {
+ if (!bus->controller->dma_mask &&
+ !(hcd->driver->flags & HCD_LOCAL_MEM)) {
kfree(addr);
return;
}
diff -puN drivers/usb/core/hcd.c~usb-dma-bounce-buffer-support-v3 drivers/usb/core/hcd.c
--- a/drivers/usb/core/hcd.c~usb-dma-bounce-buffer-support-v3
+++ a/drivers/usb/core/hcd.c
@@ -35,6 +35,7 @@
#include <linux/mutex.h>
#include <asm/irq.h>
#include <asm/byteorder.h>
+#include <asm/unaligned.h>
#include <linux/platform_device.h>
#include <linux/workqueue.h>
@@ -1112,48 +1113,137 @@ void usb_hcd_unlink_urb_from_ep(struct u
}
EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
-static void map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
+static int hcd_alloc_coherent(struct usb_bus *bus,
+ gfp_t mem_flags, dma_addr_t *dma_handle,
+ void **vaddr_handle, size_t size,
+ enum dma_data_direction dir)
{
+ unsigned char *vaddr;
+
+ vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
+ mem_flags, dma_handle);
+ if (!vaddr)
+ return -ENOMEM;
+
+ put_unaligned((unsigned long)*vaddr_handle,
+ (unsigned long *)(vaddr + size));
+
+ if (dir == DMA_TO_DEVICE)
+ memcpy(vaddr, *vaddr_handle, size);
+
+ *vaddr_handle = vaddr;
+ return 0;
+}
+
+static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
+ void **vaddr_handle, size_t size,
+ enum dma_data_direction dir)
+{
+ unsigned char *vaddr = *vaddr_handle;
+
+ vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
+
+ if (dir == DMA_FROM_DEVICE)
+ memcpy(vaddr, *vaddr_handle, size);
+
+ hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
+
+ *vaddr_handle = vaddr;
+ *dma_handle = 0;
+}
+
+static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
+ gfp_t mem_flags)
+{
+ enum dma_data_direction dir;
+ int ret = 0;
+
/* 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.
*/
- if (hcd->self.uses_dma && !is_root_hub(urb->dev)) {
- if (usb_endpoint_xfer_control(&urb->ep->desc)
- && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
- urb->setup_dma = dma_map_single (
+ if (is_root_hub(urb->dev))
+ return 0;
+
+ if (usb_endpoint_xfer_control(&urb->ep->desc)
+ && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) {
+ if (hcd->self.uses_dma)
+ urb->setup_dma = dma_map_single(
hcd->self.controller,
urb->setup_packet,
sizeof (struct usb_ctrlrequest),
DMA_TO_DEVICE);
- if (urb->transfer_buffer_length != 0
- && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP))
+ else if (hcd->driver->flags & HCD_LOCAL_MEM)
+ ret = hcd_alloc_coherent(
+ urb->dev->bus, mem_flags,
+ &urb->setup_dma,
+ (void **)&urb->setup_packet,
+ sizeof (struct usb_ctrlrequest),
+ DMA_TO_DEVICE);
+ }
+
+ dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+ if (ret == 0 && urb->transfer_buffer_length != 0
+ && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
+ if (hcd->self.uses_dma)
urb->transfer_dma = dma_map_single (
hcd->self.controller,
urb->transfer_buffer,
urb->transfer_buffer_length,
- usb_urb_dir_in(urb)
- ? DMA_FROM_DEVICE
- : DMA_TO_DEVICE);
+ dir);
+ else if (hcd->driver->flags & HCD_LOCAL_MEM) {
+ ret = hcd_alloc_coherent(
+ urb->dev->bus, mem_flags,
+ &urb->transfer_dma,
+ &urb->transfer_buffer,
+ urb->transfer_buffer_length,
+ dir);
+
+ if (ret && usb_endpoint_xfer_control(&urb->ep->desc)
+ && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
+ hcd_free_coherent(urb->dev->bus,
+ &urb->setup_dma,
+ (void **)&urb->setup_packet,
+ sizeof (struct usb_ctrlrequest),
+ DMA_TO_DEVICE);
+ }
}
+ return ret;
}
static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
{
- if (hcd->self.uses_dma && !is_root_hub(urb->dev)) {
- if (usb_endpoint_xfer_control(&urb->ep->desc)
- && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
+ enum dma_data_direction dir;
+
+ if (is_root_hub(urb->dev))
+ return;
+
+ if (usb_endpoint_xfer_control(&urb->ep->desc)
+ && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) {
+ if (hcd->self.uses_dma)
dma_unmap_single(hcd->self.controller, urb->setup_dma,
sizeof(struct usb_ctrlrequest),
DMA_TO_DEVICE);
- if (urb->transfer_buffer_length != 0
- && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP))
+ else if (hcd->driver->flags & HCD_LOCAL_MEM)
+ hcd_free_coherent(urb->dev->bus, &urb->setup_dma,
+ (void **)&urb->setup_packet,
+ sizeof (struct usb_ctrlrequest),
+ DMA_TO_DEVICE);
+ }
+
+ dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+ if (urb->transfer_buffer_length != 0
+ && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
+ if (hcd->self.uses_dma)
dma_unmap_single(hcd->self.controller,
urb->transfer_dma,
urb->transfer_buffer_length,
- usb_urb_dir_in(urb)
- ? DMA_FROM_DEVICE
- : DMA_TO_DEVICE);
+ dir);
+ else if (hcd->driver->flags & HCD_LOCAL_MEM)
+ hcd_free_coherent(urb->dev->bus, &urb->transfer_dma,
+ &urb->transfer_buffer,
+ urb->transfer_buffer_length,
+ dir);
}
}
@@ -1185,7 +1275,12 @@ int usb_hcd_submit_urb (struct urb *urb,
* URBs must be submitted in process context with interrupts
* enabled.
*/
- map_urb_for_dma(hcd, urb);
+ status = map_urb_for_dma(hcd, urb, mem_flags);
+ if (unlikely(status)) {
+ usbmon_urb_submit_error(&hcd->self, urb, status);
+ goto error;
+ }
+
if (is_root_hub(urb->dev))
status = rh_urb_enqueue(hcd, urb);
else
@@ -1194,6 +1289,7 @@ int usb_hcd_submit_urb (struct urb *urb,
if (unlikely(status)) {
usbmon_urb_submit_error(&hcd->self, urb, status);
unmap_urb_for_dma(hcd, urb);
+ error:
urb->hcpriv = NULL;
INIT_LIST_HEAD(&urb->urb_list);
atomic_dec(&urb->use_count);
diff -puN drivers/usb/core/hcd.h~usb-dma-bounce-buffer-support-v3 drivers/usb/core/hcd.h
--- a/drivers/usb/core/hcd.h~usb-dma-bounce-buffer-support-v3
+++ a/drivers/usb/core/hcd.h
@@ -165,6 +165,7 @@ struct hc_driver {
int flags;
#define HCD_MEMORY 0x0001 /* HC regs use memory (else I/O) */
+#define HCD_LOCAL_MEM 0x0002 /* HC needs dma_alloc_coherent() */
#define HCD_USB11 0x0010 /* USB 1.1 */
#define HCD_USB2 0x0020 /* USB 2.0 */
_
Patches currently in -mm which might be from magnus.damm@xxxxxxxxx are
usb-dma-bounce-buffer-support-v3.patch
usb-dma-bounce-buffer-support-v3-checkpatch-fixes.patch
usb-ohci-sm501-driver-v2.patch
usb-ohci-sm501-driver-v2-fix.patch
sm501fb-control-panel-pin-usage-with-platform-data-flags.patch
sm501fb-clear-framebuffer-memory-and-palette.patch
-
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