diff options
| -rw-r--r-- | arch/arm/xen/mm.c | 61 |
1 files changed, 21 insertions, 40 deletions
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index 90574d89d0d4..2fde161733b0 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -35,64 +35,45 @@ unsigned long xen_get_swiotlb_free_pages(unsigned int order) return __get_free_pages(flags, order); } -enum dma_cache_op { - DMA_UNMAP, - DMA_MAP, -}; static bool hypercall_cflush = false; -/* functions called by SWIOTLB */ - -static void dma_cache_maint(dma_addr_t handle, unsigned long offset, - size_t size, enum dma_data_direction dir, enum dma_cache_op op) +/* buffers in highmem or foreign pages cannot cross page boundaries */ +static void dma_cache_maint(dma_addr_t handle, size_t size, u32 op) { struct gnttab_cache_flush cflush; - unsigned long xen_pfn; - size_t left = size; - xen_pfn = (handle >> XEN_PAGE_SHIFT) + offset / XEN_PAGE_SIZE; - offset %= XEN_PAGE_SIZE; + cflush.a.dev_bus_addr = handle & XEN_PAGE_MASK; + cflush.offset = xen_offset_in_page(handle); + cflush.op = op; do { - size_t len = left; - - /* buffers in highmem or foreign pages cannot cross page - * boundaries */ - if (len + offset > XEN_PAGE_SIZE) - len = XEN_PAGE_SIZE - offset; - - cflush.op = 0; - cflush.a.dev_bus_addr = xen_pfn << XEN_PAGE_SHIFT; - cflush.offset = offset; - cflush.length = len; - - if (op == DMA_UNMAP && dir != DMA_TO_DEVICE) - cflush.op = GNTTAB_CACHE_INVAL; - if (op == DMA_MAP) { - if (dir == DMA_FROM_DEVICE) - cflush.op = GNTTAB_CACHE_INVAL; - else - cflush.op = GNTTAB_CACHE_CLEAN; - } - if (cflush.op) - HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1); + if (size + cflush.offset > XEN_PAGE_SIZE) + cflush.length = XEN_PAGE_SIZE - cflush.offset; + else + cflush.length = size; + + HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1); - offset = 0; - xen_pfn++; - left -= len; - } while (left); + cflush.offset = 0; + cflush.a.dev_bus_addr += cflush.length; + size -= cflush.length; + } while (size); } static void __xen_dma_page_dev_to_cpu(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_UNMAP); + if (dir != DMA_TO_DEVICE) + dma_cache_maint(handle, size, GNTTAB_CACHE_INVAL); } static void __xen_dma_page_cpu_to_dev(struct device *hwdev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_MAP); + if (dir == DMA_FROM_DEVICE) + dma_cache_maint(handle, size, GNTTAB_CACHE_INVAL); + else + dma_cache_maint(handle, size, GNTTAB_CACHE_CLEAN); } void __xen_dma_map_page(struct device *hwdev, struct page *page, |