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authorIngo Molnar <mingo@elte.hu>2009-02-11 09:22:04 +0100
committerIngo Molnar <mingo@elte.hu>2009-02-11 09:22:04 +0100
commit95fd4845ed0ffcab305b4f30ce1c12dc34f1b56c (patch)
treeaa2aac22a5b329b778a6771a87bbf1945ad49bbd /kernel/dma-coherent.c
parentd278c48435625cb6b7edcf6a547620768b175709 (diff)
parent8e4921515c1a379539607eb443d51c30f4f7f338 (diff)
downloadlinux-next-95fd4845ed0ffcab305b4f30ce1c12dc34f1b56c.tar.gz
Merge commit 'v2.6.29-rc4' into perfcounters/core
Conflicts: arch/x86/kernel/setup_percpu.c arch/x86/mm/fault.c drivers/acpi/processor_idle.c kernel/irq/handle.c
Diffstat (limited to 'kernel/dma-coherent.c')
-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 038707404b76..962a3b574f21 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);