diff options
Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
| -rw-r--r-- | arch/arm/mm/dma-mapping.c | 35 |
1 files changed, 32 insertions, 3 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 82a093cee09..0a0a1e7c20d 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -25,9 +25,11 @@ #include <asm/tlbflush.h> #include <asm/sizes.h> +#include "mm.h" + static u64 get_coherent_dma_mask(struct device *dev) { - u64 mask = ISA_DMA_THRESHOLD; + u64 mask = (u64)arm_dma_limit; if (dev) { mask = dev->coherent_dma_mask; @@ -41,10 +43,10 @@ static u64 get_coherent_dma_mask(struct device *dev) return 0; } - if ((~mask) & ISA_DMA_THRESHOLD) { + if ((~mask) & (u64)arm_dma_limit) { dev_warn(dev, "coherent DMA mask %#llx is smaller " "than system GFP_DMA mask %#llx\n", - mask, (unsigned long long)ISA_DMA_THRESHOLD); + mask, (u64)arm_dma_limit); return 0; } } @@ -657,6 +659,33 @@ void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, } EXPORT_SYMBOL(dma_sync_sg_for_device); +/* + * Return whether the given device DMA address mask can be supported + * properly. For example, if your device can only drive the low 24-bits + * during bus mastering, then you would pass 0x00ffffff as the mask + * to this function. + */ +int dma_supported(struct device *dev, u64 mask) +{ + if (mask < (u64)arm_dma_limit) + return 0; + return 1; +} +EXPORT_SYMBOL(dma_supported); + +int dma_set_mask(struct device *dev, u64 dma_mask) +{ + if (!dev->dma_mask || !dma_supported(dev, dma_mask)) + return -EIO; + +#ifndef CONFIG_DMABOUNCE + *dev->dma_mask = dma_mask; +#endif + + return 0; +} +EXPORT_SYMBOL(dma_set_mask); + #define PREALLOC_DMA_DEBUG_ENTRIES 4096 static int __init dma_debug_do_init(void) |