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authorRussell King <rmk+kernel@arm.linux.org.uk>2013-07-09 12:14:49 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-10-31 14:49:21 +0000
commit4dcfa60071b3d23f0181f27d8519f12e37cefbb9 (patch)
treea3c568b34226152a8f825c7ce1cff8a8bf1a20c2 /arch/arm/mm/mm.h
parent42536b9f9ce38b07ac213c5f4550301f9a0d251d (diff)
ARM: DMA-API: better handing of DMA masks for coherent allocations
We need to start treating DMA masks as something which is specific to the bus that the device resides on, otherwise we're going to hit all sorts of nasty issues with LPAE and 32-bit DMA controllers in >32-bit systems, where memory is offset from PFN 0. In order to start doing this, we convert the DMA mask to a PFN using the device specific dma_to_pfn() macro. This is the reverse of the pfn_to_dma() macro which is used to get the DMA address for the device. This gives us a PFN mask, which we can then check against the PFN limit of the DMA zone. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/mm.h')
-rw-r--r--arch/arm/mm/mm.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index d5a4e9ad8f0..d5a982d15a8 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -81,8 +81,10 @@ extern __init void add_static_vm_early(struct static_vm *svm);
#ifdef CONFIG_ZONE_DMA
extern phys_addr_t arm_dma_limit;
+extern unsigned long arm_dma_pfn_limit;
#else
#define arm_dma_limit ((phys_addr_t)~0)
+#define arm_dma_pfn_limit (~0ul >> PAGE_SHIFT)
#endif
extern phys_addr_t arm_lowmem_limit;