diff options
Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
| -rw-r--r-- | arch/arm/mm/dma-mapping.c | 55 |
1 files changed, 44 insertions, 11 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 1272ed202dde..f61a5707823a 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -9,6 +9,7 @@ * * DMA uncached mapping support. */ +#include <linux/bootmem.h> #include <linux/module.h> #include <linux/mm.h> #include <linux/gfp.h> @@ -157,9 +158,47 @@ 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)arm_dma_limit; + u64 mask = (u64)DMA_BIT_MASK(32); if (dev) { mask = dev->coherent_dma_mask; @@ -173,12 +212,8 @@ 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 (!__dma_supported(dev, mask, true)) return 0; - } } return mask; @@ -687,7 +722,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs) { - pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel); + pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL); void *memory; if (dma_alloc_from_coherent(dev, size, handle, &memory)) @@ -700,7 +735,7 @@ void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, static void *arm_coherent_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs) { - pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel); + pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL); void *memory; if (dma_alloc_from_coherent(dev, size, handle, &memory)) @@ -1007,9 +1042,7 @@ 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) - return 0; - return 1; + return __dma_supported(dev, mask, false); } EXPORT_SYMBOL(dma_supported); |