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-rw-r--r--Documentation/DMA-API.txt3
-rw-r--r--arch/x86/kernel/pci-dma_32.c3
-rw-r--r--arch/x86/kernel/pci-dma_64.c1
-rw-r--r--lib/swiotlb.c1
4 files changed, 7 insertions, 1 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index cc7a8c39fb6..b939ebb6287 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -68,6 +68,9 @@ size and dma_handle must all be the same as those passed into the
consistent allocate. cpu_addr must be the virtual address returned by
the consistent allocate.
+Note that unlike their sibling allocation calls, these routines
+may only be called with IRQs enabled.
+
Part Ib - Using small dma-coherent buffers
------------------------------------------
diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c
index 048f09b6255..0aae2f3847a 100644
--- a/arch/x86/kernel/pci-dma_32.c
+++ b/arch/x86/kernel/pci-dma_32.c
@@ -63,7 +63,8 @@ void dma_free_coherent(struct device *dev, size_t size,
{
struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
int order = get_order(size);
-
+
+ WARN_ON(irqs_disabled()); /* for portability */
if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
diff --git a/arch/x86/kernel/pci-dma_64.c b/arch/x86/kernel/pci-dma_64.c
index 29711445c81..9576a2eb375 100644
--- a/arch/x86/kernel/pci-dma_64.c
+++ b/arch/x86/kernel/pci-dma_64.c
@@ -167,6 +167,7 @@ EXPORT_SYMBOL(dma_alloc_coherent);
void dma_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t bus)
{
+ WARN_ON(irqs_disabled()); /* for portability */
if (dma_ops->unmap_single)
dma_ops->unmap_single(dev, bus, size, 0);
free_pages((unsigned long)vaddr, get_order(size));
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index a7381d55663..30c1400e749 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -497,6 +497,7 @@ void
swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
dma_addr_t dma_handle)
{
+ WARN_ON(irqs_disabled());
if (!(vaddr >= (void *)io_tlb_start
&& vaddr < (void *)io_tlb_end))
free_pages((unsigned long) vaddr, get_order(size));