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authorLinus Torvalds <torvalds@linux-foundation.org>2009-01-26 10:12:08 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-26 10:12:08 -0800
commit37f5fed55559a030c430550bcacec75e6a833f1b (patch)
treeef20187783d784a1106d287bb4bb7805bf3a6ca3 /kernel
parenta1c70a756f8d756668acdbfd61dfc14de12fbaea (diff)
parent0609697eab9775564845d4c94f9e3780fb791ffd (diff)
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Merge branch 'sh/for-2.6.29' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6
* 'sh/for-2.6.29' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (22 commits) dma-coherent: Restore dma_alloc_from_coherent() large alloc fall back policy. dma-coherent: per-device coherent area is in pages, not bytes. sh: fix unaligned and nonexistent address handling nommu: Stub in vm_map_ram()/vm_unmap_ram()/vm_unmap_aliases(). sh: fix sh-sci / early printk build on sh7723 sh: export the sh7343 JPU to user space sh: update defconfigs. serial: sh-sci: Fix up SH7720/SH7721 SCI build. sh: Kill off obsolete busses from arch/sh/Kconfig. sh: sh7785lcr/highlander/hp6xx need linux/irq.h. sh: Migo-R MMC support using spi_gpio and mmc_spi. sh: ap325rxa MMC support using spi_gpio and mmc_spi sh: mach-x3proto: needs linux/irq.h. sh: Drop the BKL from sys_execve() on SH-5. sh: convert rsk7203 to use smsc911x. sh: convert magicpanelr2 platform to use smsc911x. sh: convert ap325rxa platform to use smsc911x. sh: mach-migor: Add tw9910 support. sh: mach-migor: Delete soc_camera_platform setup. sh: mach-migor: Add ov772x support. ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/dma-coherent.c47
1 files changed, 24 insertions, 23 deletions
diff --git a/kernel/dma-coherent.c b/kernel/dma-coherent.c
index 0387074..962a3b5 100644
--- a/kernel/dma-coherent.c
+++ b/kernel/dma-coherent.c
@@ -98,7 +98,7 @@ EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
* @size: size of requested memory area
* @dma_handle: This will be filled with the correct dma handle
* @ret: This pointer will be filled with the virtual address
- * to allocated area.
+ * to allocated area.
*
* This function should be only called from per-arch dma_alloc_coherent()
* to support allocation from per-device coherent memory pools.
@@ -118,31 +118,32 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size,
mem = dev->dma_mem;
if (!mem)
return 0;
- if (unlikely(size > mem->size))
- return 0;
+
+ *ret = NULL;
+
+ if (unlikely(size > (mem->size << PAGE_SHIFT)))
+ goto err;
pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
- if (pageno >= 0) {
- /*
- * Memory was found in the per-device arena.
- */
- *dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
- *ret = mem->virt_base + (pageno << PAGE_SHIFT);
- memset(*ret, 0, size);
- } else if (mem->flags & DMA_MEMORY_EXCLUSIVE) {
- /*
- * The per-device arena is exhausted and we are not
- * permitted to fall back to generic memory.
- */
- *ret = NULL;
- } else {
- /*
- * The per-device arena is exhausted and we are
- * permitted to fall back to generic memory.
- */
- return 0;
- }
+ if (unlikely(pageno < 0))
+ goto err;
+
+ /*
+ * Memory was found in the per-device area.
+ */
+ *dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
+ *ret = mem->virt_base + (pageno << PAGE_SHIFT);
+ memset(*ret, 0, size);
+
return 1;
+
+err:
+ /*
+ * In the case where the allocation can not be satisfied from the
+ * per-device area, try to fall back to generic memory if the
+ * constraints allow it.
+ */
+ return mem->flags & DMA_MEMORY_EXCLUSIVE;
}
EXPORT_SYMBOL(dma_alloc_from_coherent);