diff options
Diffstat (limited to 'kernel/dma/coherent.c')
| -rw-r--r-- | kernel/dma/coherent.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 2a0c4985f38e..5b5b6c7ec7f2 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -7,7 +7,8 @@ #include <linux/slab.h> #include <linux/kernel.h> #include <linux/module.h> -#include <linux/dma-mapping.h> +#include <linux/dma-direct.h> +#include <linux/dma-map-ops.h> struct dma_coherent_mem { void *virt_base; @@ -32,9 +33,8 @@ static inline dma_addr_t dma_get_device_base(struct device *dev, struct dma_coherent_mem * mem) { if (mem->use_dev_dma_pfn_offset) - return (mem->pfn_base - dev->dma_pfn_offset) << PAGE_SHIFT; - else - return mem->device_base; + return phys_to_dma(dev, PFN_PHYS(mem->pfn_base)); + return mem->device_base; } static int dma_init_coherent_memory(phys_addr_t phys_addr, @@ -107,6 +107,23 @@ static int dma_assign_coherent_memory(struct device *dev, return 0; } +/* + * Declare a region of memory to be handed out by dma_alloc_coherent() when it + * is asked for coherent memory for this device. This shall only be used + * from platform code, usually based on the device tree description. + * + * phys_addr is the CPU physical address to which the memory is currently + * assigned (this will be ioremapped so the CPU can access the region). + * + * device_addr is the DMA address the device needs to be programmed with to + * actually address this memory (this will be handed out as the dma_addr_t in + * dma_alloc_coherent()). + * + * size is the size of the area (must be a multiple of PAGE_SIZE). + * + * As a simplification for the platforms, only *one* such region of memory may + * be declared per device. + */ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, dma_addr_t device_addr, size_t size) { |