From 11a5aa32562e1e90ab2d0278748fe0fbecda1cbe Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 25 Nov 2013 21:52:25 +0000 Subject: 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(-) (limited to 'arch/arm/mm/dma-mapping.c') diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 79f8b39801a..f6b6bfa88ec 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, -- cgit v1.2.3-70-g09d2 From 9f28cde0bc643186d32744ce69d12222e8588fe7 Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 6 Dec 2013 12:30:42 +0000 Subject: ARM: another fix for the DMA mapping checks Peter reports that OMAP audio broke with the recent fix for these checks, caused by OMAP audio using a 64-bit DMA mask. We should allow 64-bit DMA masks even with 32-bit dma_addr_t if we can be sure the amount of RAM we have won't allow the 32-bit dma_addr_t to overflow. Unfortunately, the checks to detect overflow were not correct. Tested-by: Peter Ujfalusi Signed-off-by: Russell King --- arch/arm/mm/dma-mapping.c | 91 +++++++++++++++++++++-------------------------- 1 file changed, 40 insertions(+), 51 deletions(-) (limited to 'arch/arm/mm/dma-mapping.c') diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index f6b6bfa88ec..f61a5707823 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -158,13 +158,49 @@ struct dma_map_ops arm_coherent_dma_ops = { }; EXPORT_SYMBOL(arm_coherent_dma_ops); +static int __dma_supported(struct device *dev, u64 mask, bool warn) +{ + unsigned long max_dma_pfn; + + /* + * If the mask allows for more memory than we can address, + * and we actually have that much memory, then we must + * indicate that DMA to this device is not supported. + */ + if (sizeof(mask) != sizeof(dma_addr_t) && + mask > (dma_addr_t)~0 && + dma_to_pfn(dev, ~0) < max_pfn) { + if (warn) { + 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"); + } + return 0; + } + + max_dma_pfn = min(max_pfn, arm_dma_pfn_limit); + + /* + * Translate the device's DMA mask to a PFN limit. This + * PFN number includes the page which we can DMA to. + */ + if (dma_to_pfn(dev, mask) < max_dma_pfn) { + if (warn) + 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, + max_dma_pfn + 1); + return 0; + } + + return 1; +} + 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; /* @@ -176,34 +212,8 @@ 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 - * allocation. - */ - if (sizeof(mask) != sizeof(dma_addr_t) && - mask > (dma_addr_t)~0 && - 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"); - return 0; - } - - /* - * Now check that the mask, when translated to a PFN, - * fits within the allowable addresses which we can - * allocate. - */ - 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, - arm_dma_pfn_limit + 1); + if (!__dma_supported(dev, mask, true)) return 0; - } } return mask; @@ -1032,28 +1042,7 @@ void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, */ int dma_supported(struct device *dev, u64 mask) { - unsigned long limit; - - /* - * If the mask allows for more memory than we can address, - * and we actually have that much memory, then we must - * indicate that DMA to this device is not supported. - */ - if (sizeof(mask) != sizeof(dma_addr_t) && - mask > (dma_addr_t)~0 && - dma_to_pfn(dev, ~0) > arm_dma_pfn_limit) - return 0; - - /* - * Translate the device's DMA mask to a PFN limit. This - * PFN number includes the page which we can DMA to. - */ - limit = dma_to_pfn(dev, mask); - - if (limit < arm_dma_pfn_limit) - return 0; - - return 1; + return __dma_supported(dev, mask, false); } EXPORT_SYMBOL(dma_supported); -- cgit v1.2.3-70-g09d2