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authorRussell King <rmk+kernel@arm.linux.org.uk>2011-07-03 22:39:43 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-07-03 23:28:31 +0100
commitdd3641fc3cf6d10b7cf4e266c2f651517779e727 (patch)
tree2f6a90b735f26aeaea94ace887f8576bebbb2b30 /arch/arm/common/dmabounce.c
parent23bc9873ba60ee661d8e9f3a6b22fc3bcc4b7015 (diff)
downloadlinux-dd3641fc3cf6d10b7cf4e266c2f651517779e727.tar.bz2
ARM: dmabounce: move decision for bouncing into __dma_map_page()
Move the decision whether to bounce into __dma_map_page(), before the check for high pages. This avoids triggering the high page check for devices which aren't using dmabounce. Fix the unmap path to cope too. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/common/dmabounce.c')
-rw-r--r--arch/arm/common/dmabounce.c124
1 files changed, 58 insertions, 66 deletions
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
index 643e1d660677..6ae292cc43bf 100644
--- a/arch/arm/common/dmabounce.c
+++ b/arch/arm/common/dmabounce.c
@@ -246,88 +246,58 @@ static inline dma_addr_t map_single(struct device *dev, void *ptr, size_t size,
enum dma_data_direction dir)
{
struct dmabounce_device_info *device_info = dev->archdata.dmabounce;
- dma_addr_t dma_addr;
- int ret;
+ struct safe_buffer *buf;
if (device_info)
DO_STATS ( device_info->map_op_count++ );
- dma_addr = virt_to_dma(dev, ptr);
-
- ret = needs_bounce(dev, dma_addr, size);
- if (ret < 0)
+ buf = alloc_safe_buffer(device_info, ptr, size, dir);
+ if (buf == 0) {
+ dev_err(dev, "%s: unable to map unsafe buffer %p!\n",
+ __func__, ptr);
return ~0;
+ }
- if (ret > 0) {
- struct safe_buffer *buf;
-
- buf = alloc_safe_buffer(device_info, ptr, size, dir);
- if (buf == 0) {
- dev_err(dev, "%s: unable to map unsafe buffer %p!\n",
- __func__, ptr);
- return ~0;
- }
-
- dev_dbg(dev,
- "%s: unsafe buffer %p (dma=%#x) mapped to %p (dma=%#x)\n",
- __func__, buf->ptr, virt_to_dma(dev, buf->ptr),
- buf->safe, buf->safe_dma_addr);
-
- if ((dir == DMA_TO_DEVICE) ||
- (dir == DMA_BIDIRECTIONAL)) {
- dev_dbg(dev, "%s: copy unsafe %p to safe %p, size %d\n",
- __func__, ptr, buf->safe, size);
- memcpy(buf->safe, ptr, size);
- }
- ptr = buf->safe;
+ dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped to %p (dma=%#x)\n",
+ __func__, buf->ptr, virt_to_dma(dev, buf->ptr),
+ buf->safe, buf->safe_dma_addr);
- dma_addr = buf->safe_dma_addr;
- } else {
- /*
- * We don't need to sync the DMA buffer since
- * it was allocated via the coherent allocators.
- */
- __dma_single_cpu_to_dev(ptr, size, dir);
+ if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) {
+ dev_dbg(dev, "%s: copy unsafe %p to safe %p, size %d\n",
+ __func__, ptr, buf->safe, size);
+ memcpy(buf->safe, ptr, size);
}
- return dma_addr;
+ return buf->safe_dma_addr;
}
-static inline void unmap_single(struct device *dev, dma_addr_t dma_addr,
+static inline void unmap_single(struct device *dev, struct safe_buffer *buf,
size_t size, enum dma_data_direction dir)
{
- struct safe_buffer *buf = find_safe_buffer_dev(dev, dma_addr, "unmap");
-
- if (buf) {
- BUG_ON(buf->size != size);
- BUG_ON(buf->direction != dir);
+ BUG_ON(buf->size != size);
+ BUG_ON(buf->direction != dir);
- dev_dbg(dev,
- "%s: unsafe buffer %p (dma=%#x) mapped to %p (dma=%#x)\n",
- __func__, buf->ptr, virt_to_dma(dev, buf->ptr),
- buf->safe, buf->safe_dma_addr);
+ dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped to %p (dma=%#x)\n",
+ __func__, buf->ptr, virt_to_dma(dev, buf->ptr),
+ buf->safe, buf->safe_dma_addr);
- DO_STATS(dev->archdata.dmabounce->bounce_count++);
+ DO_STATS(dev->archdata.dmabounce->bounce_count++);
- if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) {
- void *ptr = buf->ptr;
+ if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) {
+ void *ptr = buf->ptr;
- dev_dbg(dev,
- "%s: copy back safe %p to unsafe %p size %d\n",
- __func__, buf->safe, ptr, size);
- memcpy(ptr, buf->safe, size);
+ dev_dbg(dev, "%s: copy back safe %p to unsafe %p size %d\n",
+ __func__, buf->safe, ptr, size);
+ memcpy(ptr, buf->safe, size);
- /*
- * Since we may have written to a page cache page,
- * we need to ensure that the data will be coherent
- * with user mappings.
- */
- __cpuc_flush_dcache_area(ptr, size);
- }
- free_safe_buffer(dev->archdata.dmabounce, buf);
- } else {
- __dma_single_dev_to_cpu(dma_to_virt(dev, dma_addr), size, dir);
+ /*
+ * Since we may have written to a page cache page,
+ * we need to ensure that the data will be coherent
+ * with user mappings.
+ */
+ __cpuc_flush_dcache_area(ptr, size);
}
+ free_safe_buffer(dev->archdata.dmabounce, buf);
}
/* ************************************************** */
@@ -341,12 +311,25 @@ static inline void unmap_single(struct device *dev, dma_addr_t dma_addr,
dma_addr_t __dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir)
{
+ dma_addr_t dma_addr;
+ int ret;
+
dev_dbg(dev, "%s(page=%p,off=%#lx,size=%zx,dir=%x)\n",
__func__, page, offset, size, dir);
+ dma_addr = pfn_to_dma(dev, page_to_pfn(page)) + offset;
+
+ ret = needs_bounce(dev, dma_addr, size);
+ if (ret < 0)
+ return ~0;
+
+ if (ret == 0) {
+ __dma_page_cpu_to_dev(page, offset, size, dir);
+ return dma_addr;
+ }
+
if (PageHighMem(page)) {
- dev_err(dev, "DMA buffer bouncing of HIGHMEM pages "
- "is not supported\n");
+ dev_err(dev, "DMA buffer bouncing of HIGHMEM pages is not supported\n");
return ~0;
}
@@ -363,10 +346,19 @@ EXPORT_SYMBOL(__dma_map_page);
void __dma_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
enum dma_data_direction dir)
{
+ struct safe_buffer *buf;
+
dev_dbg(dev, "%s(ptr=%p,size=%d,dir=%x)\n",
__func__, (void *) dma_addr, size, dir);
- unmap_single(dev, dma_addr, size, dir);
+ buf = find_safe_buffer_dev(dev, dma_addr, __func__);
+ if (!buf) {
+ __dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, dma_addr)),
+ dma_addr & ~PAGE_MASK, size, dir);
+ return;
+ }
+
+ unmap_single(dev, buf, size, dir);
}
EXPORT_SYMBOL(__dma_unmap_page);