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authorDavid Brownell <david-b@pacbell.net>2007-08-10 16:10:27 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2007-10-12 18:03:15 -0400
commitaa24886e379d2b641c5117e178b15ce1d5d366ba (patch)
treec0934ff01f7c7a18ec5f86896735286f413cd06e
parentfa007d8bebc5d812a445c48664b5bcad81f1351c (diff)
dma_free_coherent() needs irqs enabled (sigh)
On at least ARM (and I'm told MIPS too) dma_free_coherent() has a newish call context requirement: unlike its dma_alloc_coherent() sibling, it may not be called with IRQs disabled. (This was new behavior on ARM as of late 2005, caused by ARM SMP updates.) This little surprise can be annoyingly driver-visible. Since it looks like that restriction won't be removed, this patch changes the definition of the API to include that requirement. Also, to help catch nonportable drivers, it updates the x86 and swiotlb versions to include the relevant warnings. (I already observed that it trips on the bus_reset_tasklet of the new firewire_ohci driver.) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: David Miller <davem@davemloft.net> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-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 cc7a8c39fb6f..b939ebb62871 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
68consistent allocate. cpu_addr must be the virtual address returned by 68consistent allocate. cpu_addr must be the virtual address returned by
69the consistent allocate. 69the consistent allocate.
70 70
71Note that unlike their sibling allocation calls, these routines
72may only be called with IRQs enabled.
73
71 74
72Part Ib - Using small dma-coherent buffers 75Part Ib - Using small dma-coherent buffers
73------------------------------------------ 76------------------------------------------
diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c
index 048f09b62553..0aae2f3847a5 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,
63{ 63{
64 struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; 64 struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
65 int order = get_order(size); 65 int order = get_order(size);
66 66
67 WARN_ON(irqs_disabled()); /* for portability */
67 if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) { 68 if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
68 int page = (vaddr - mem->virt_base) >> PAGE_SHIFT; 69 int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
69 70
diff --git a/arch/x86/kernel/pci-dma_64.c b/arch/x86/kernel/pci-dma_64.c
index 29711445c818..9576a2eb375e 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);
167void dma_free_coherent(struct device *dev, size_t size, 167void dma_free_coherent(struct device *dev, size_t size,
168 void *vaddr, dma_addr_t bus) 168 void *vaddr, dma_addr_t bus)
169{ 169{
170 WARN_ON(irqs_disabled()); /* for portability */
170 if (dma_ops->unmap_single) 171 if (dma_ops->unmap_single)
171 dma_ops->unmap_single(dev, bus, size, 0); 172 dma_ops->unmap_single(dev, bus, size, 0);
172 free_pages((unsigned long)vaddr, get_order(size)); 173 free_pages((unsigned long)vaddr, get_order(size));
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index a7381d55663a..30c1400e749e 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -497,6 +497,7 @@ void
497swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, 497swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
498 dma_addr_t dma_handle) 498 dma_addr_t dma_handle)
499{ 499{
500 WARN_ON(irqs_disabled());
500 if (!(vaddr >= (void *)io_tlb_start 501 if (!(vaddr >= (void *)io_tlb_start
501 && vaddr < (void *)io_tlb_end)) 502 && vaddr < (void *)io_tlb_end))
502 free_pages((unsigned long) vaddr, get_order(size)); 503 free_pages((unsigned long) vaddr, get_order(size));