diff options
Diffstat (limited to 'lib/swiotlb.c')
| -rw-r--r-- | lib/swiotlb.c | 68 |
1 files changed, 51 insertions, 17 deletions
diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 98a7a4450e0..785046e4c3a 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -14,6 +14,7 @@ * 04/07/.. ak Better overflow handling. Assorted fixes. * 05/09/10 linville Add support for syncing ranges, support syncing for * DMA_BIDIRECTIONAL mappings, miscellaneous cleanup. + * 08/12/11 beckyb Add highmem support */ #include <linux/cache.h> @@ -24,6 +25,7 @@ #include <linux/swiotlb.h> #include <linux/string.h> #include <linux/swiotlb.h> +#include <linux/pfn.h> #include <linux/types.h> #include <linux/ctype.h> #include <linux/highmem.h> @@ -149,11 +151,6 @@ int __weak swiotlb_arch_range_needs_mapping(void *ptr, size_t size) return 0; } -static dma_addr_t swiotlb_sg_to_bus(struct device *hwdev, struct scatterlist *sg) -{ - return swiotlb_phys_to_bus(hwdev, page_to_phys(sg_page(sg)) + sg->offset); -} - static void swiotlb_print_info(unsigned long bytes) { phys_addr_t pstart, pend; @@ -330,6 +327,47 @@ static int is_swiotlb_buffer(char *addr) } /* + * Bounce: copy the swiotlb buffer back to the original dma location + */ +static void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size, + enum dma_data_direction dir) +{ + unsigned long pfn = PFN_DOWN(phys); + + if (PageHighMem(pfn_to_page(pfn))) { + /* The buffer does not have a mapping. Map it in and copy */ + unsigned int offset = phys & ~PAGE_MASK; + char *buffer; + unsigned int sz = 0; + unsigned long flags; + + while (size) { + sz = min(PAGE_SIZE - offset, size); + + local_irq_save(flags); + buffer = kmap_atomic(pfn_to_page(pfn), + KM_BOUNCE_READ); + if (dir == DMA_TO_DEVICE) + memcpy(dma_addr, buffer + offset, sz); + else + memcpy(buffer + offset, dma_addr, sz); + kunmap_atomic(buffer, KM_BOUNCE_READ); + local_irq_restore(flags); + + size -= sz; + pfn++; + dma_addr += sz; + offset = 0; + } + } else { + if (dir == DMA_TO_DEVICE) + memcpy(dma_addr, phys_to_virt(phys), size); + else + memcpy(phys_to_virt(phys), dma_addr, size); + } +} + +/* * Allocates bounce buffer and returns its kernel virtual address. */ static void * @@ -430,7 +468,7 @@ found: for (i = 0; i < nslots; i++) io_tlb_orig_addr[index+i] = phys + (i << IO_TLB_SHIFT); if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) - memcpy(dma_addr, phys_to_virt(phys), size); + swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE); return dma_addr; } @@ -450,11 +488,7 @@ unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir) * First, sync the memory before unmapping the entry */ if (phys && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL))) - /* - * bounce... copy the data back into the original buffer * and - * delete the bounce buffer. - */ - memcpy(phys_to_virt(phys), dma_addr, size); + swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE); /* * Return the buffer to the free list by setting the corresponding @@ -494,13 +528,13 @@ sync_single(struct device *hwdev, char *dma_addr, size_t size, switch (target) { case SYNC_FOR_CPU: if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)) - memcpy(phys_to_virt(phys), dma_addr, size); + swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE); else BUG_ON(dir != DMA_TO_DEVICE); break; case SYNC_FOR_DEVICE: if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) - memcpy(dma_addr, phys_to_virt(phys), size); + swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE); else BUG_ON(dir != DMA_FROM_DEVICE); break; @@ -817,11 +851,11 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, BUG_ON(dir == DMA_NONE); for_each_sg(sgl, sg, nelems, i) { - if (sg->dma_address != swiotlb_sg_to_bus(hwdev, sg)) + if (sg->dma_address != swiotlb_virt_to_bus(hwdev, sg_virt(sg))) unmap_single(hwdev, swiotlb_bus_to_virt(sg->dma_address), sg->dma_length, dir); else if (dir == DMA_FROM_DEVICE) - dma_mark_clean(swiotlb_bus_to_virt(sg->dma_address), sg->dma_length); + dma_mark_clean(sg_virt(sg), sg->dma_length); } } EXPORT_SYMBOL(swiotlb_unmap_sg_attrs); @@ -850,11 +884,11 @@ swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl, BUG_ON(dir == DMA_NONE); for_each_sg(sgl, sg, nelems, i) { - if (sg->dma_address != swiotlb_sg_to_bus(hwdev, sg)) + if (sg->dma_address != swiotlb_virt_to_bus(hwdev, sg_virt(sg))) sync_single(hwdev, swiotlb_bus_to_virt(sg->dma_address), sg->dma_length, dir, target); else if (dir == DMA_FROM_DEVICE) - dma_mark_clean(swiotlb_bus_to_virt(sg->dma_address), sg->dma_length); + dma_mark_clean(sg_virt(sg), sg->dma_length); } } |