diff options
Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
| -rw-r--r-- | arch/arm/mm/dma-mapping.c | 49 |
1 files changed, 44 insertions, 5 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 7f9b1798c6cf..ef0efabb63cb 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -173,10 +173,30 @@ static u64 get_coherent_dma_mask(struct device *dev) return 0; } - if ((~mask) & (u64)arm_dma_limit) { - dev_warn(dev, "coherent DMA mask %#llx is smaller " - "than system GFP_DMA mask %#llx\n", - mask, (u64)arm_dma_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) > arm_dma_pfn_limit) { + 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) < arm_dma_pfn_limit) { + 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); return 0; } } @@ -1008,8 +1028,27 @@ void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, */ int dma_supported(struct device *dev, u64 mask) { - if (mask < (u64)arm_dma_limit) + 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; } EXPORT_SYMBOL(dma_supported); |