From 11a5aa32562e1e90ab2d0278748fe0fbecda1cbe Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 25 Nov 2013 21:52:25 +0000 Subject: [PATCH] ARM: dma-mapping: check DMA mask against available memory Some buses have negative offsets, which causes the DMA mask checks to falsely fail. Fix this by using the actual amount of memory fitted in the system. Signed-off-by: Russell King --- arch/arm/mm/dma-mapping.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 79f8b39..f6b6bfa 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -9,6 +9,7 @@ * * DMA uncached mapping support. */ +#include #include #include #include @@ -162,6 +163,8 @@ static u64 get_coherent_dma_mask(struct device *dev) u64 mask = (u64)DMA_BIT_MASK(32); if (dev) { + unsigned long max_dma_pfn; + mask = dev->coherent_dma_mask; /* @@ -173,6 +176,8 @@ static u64 get_coherent_dma_mask(struct device *dev) return 0; } + max_dma_pfn = min(max_pfn, arm_dma_pfn_limit); + /* * If the mask allows for more memory than we can address, * and we actually have that much memory, then fail the @@ -180,7 +185,7 @@ static u64 get_coherent_dma_mask(struct device *dev) */ if (sizeof(mask) != sizeof(dma_addr_t) && mask > (dma_addr_t)~0 && - dma_to_pfn(dev, ~0) > arm_dma_pfn_limit) { + dma_to_pfn(dev, ~0) > max_dma_pfn) { dev_warn(dev, "Coherent DMA mask %#llx is larger than dma_addr_t allows\n", mask); dev_warn(dev, "Driver did not use or check the return value from dma_set_coherent_mask()?\n"); @@ -192,7 +197,7 @@ static u64 get_coherent_dma_mask(struct device *dev) * fits within the allowable addresses which we can * allocate. */ - if (dma_to_pfn(dev, mask) < arm_dma_pfn_limit) { + if (dma_to_pfn(dev, mask) < max_dma_pfn) { dev_warn(dev, "Coherent DMA mask %#llx (pfn %#lx-%#lx) covers a smaller range of system memory than the DMA zone pfn 0x0-%#lx\n", mask, dma_to_pfn(dev, 0), dma_to_pfn(dev, mask) + 1, -- 2.7.4