Messages in this thread Patch in this message | | | From | Konrad Rzeszutek Wilk <> | Subject | [PATCH 06/19] swiotlb-xen: Copied swiotlb.c in, added xen_ prefix. | Date | Tue, 22 Jun 2010 15:42:39 -0400 |
| |
Furthemore converted all of the EXPORT_SYMBOL to EXPORT_SYMBOL_GPL, ran checkpatch and fixed the outstanding issues. Lastly added temporary function decleration and macro defines which will be removed in later commits.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- lib/swiotlb-xen.c | 349 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 349 insertions(+), 0 deletions(-)
diff --git a/lib/swiotlb-xen.c b/lib/swiotlb-xen.c index 11207e0..c177f32 100644 --- a/lib/swiotlb-xen.c +++ b/lib/swiotlb-xen.c @@ -44,6 +44,14 @@ static char *xen_io_tlb_start, *xen_io_tlb_end; +/* Temporary scaffolding. Will be removed later. */ +void +xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, + int nelems, enum dma_data_direction dir, + struct dma_attrs *attrs); +#define swiotlb_full(dev, size, dir, panic) +#define io_tlb_overflow_buffer DMA_ERROR_CODE + static dma_addr_t xen_phys_to_bus(struct device *hwdev, phys_addr_t paddr) { return phys_to_machine(XPADDR(paddr)).maddr;; @@ -116,3 +124,344 @@ xen_map_single(struct device *hwdev, phys_addr_t phys, size_t size, return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir); } + +void * +xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, + dma_addr_t *dma_handle, gfp_t flags) +{ + dma_addr_t dev_addr; + void *ret; + int order = get_order(size); + u64 dma_mask = DMA_BIT_MASK(32); + + if (hwdev && hwdev->coherent_dma_mask) + dma_mask = hwdev->coherent_dma_mask; + + ret = (void *)__get_free_pages(flags, order); + if (ret && xen_virt_to_bus(hwdev, ret) + size - 1 > dma_mask) { + /* + * The allocated memory isn't reachable by the device. + */ + free_pages((unsigned long) ret, order); + ret = NULL; + } + if (!ret) { + /* + * We are either out of memory or the device can't DMA to + * GFP_DMA memory; fall back on map_single(), which + * will grab memory from the lowest available address range. + */ + ret = xen_map_single(hwdev, 0, size, DMA_FROM_DEVICE); + if (!ret) + return NULL; + } + + memset(ret, 0, size); + dev_addr = xen_virt_to_bus(hwdev, ret); + + /* Confirm address can be DMA'd by device */ + if (dev_addr + size - 1 > dma_mask) { + printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n", + (unsigned long long)dma_mask, + (unsigned long long)dev_addr); + + /* DMA_TO_DEVICE to avoid memcpy in unmap_single */ + swiotlb_tbl_unmap_single(hwdev, ret, size, DMA_TO_DEVICE); + return NULL; + } + *dma_handle = dev_addr; + return ret; +} +EXPORT_SYMBOL_GPL(xen_swiotlb_alloc_coherent); + +void +xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, + dma_addr_t dev_addr) +{ + phys_addr_t paddr = dma_to_phys(hwdev, dev_addr); + + WARN_ON(irqs_disabled()); + if (!is_xen_swiotlb_buffer(paddr)) + free_pages((unsigned long)vaddr, get_order(size)); + else + /* DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single */ + swiotlb_tbl_unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_free_coherent); + +/* + * Map a single buffer of the indicated size for DMA in streaming mode. The + * physical address to use is returned. + * + * Once the device is given the dma address, the device owns this memory until + * either xen_swiotlb_unmap_page or xen_swiotlb_dma_sync_single is performed. + */ +dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + phys_addr_t phys = page_to_phys(page) + offset; + dma_addr_t dev_addr = phys_to_dma(dev, phys); + void *map; + + BUG_ON(dir == DMA_NONE); + /* + * If the address happens to be in the device's DMA window, + * we can safely return the device addr and not worry about bounce + * buffering it. + */ + if (dma_capable(dev, dev_addr, size) && !swiotlb_force) + return dev_addr; + + /* + * Oh well, have to allocate and map a bounce buffer. + */ + map = xen_map_single(dev, phys, size, dir); + if (!map) { + swiotlb_full(dev, size, dir, 1); + map = io_tlb_overflow_buffer; + } + + dev_addr = xen_virt_to_bus(dev, map); + + /* + * Ensure that the address returned is DMA'ble + */ + if (!dma_capable(dev, dev_addr, size)) + panic("map_single: bounce buffer is not DMA'ble"); + + return dev_addr; +} +EXPORT_SYMBOL_GPL(xen_swiotlb_map_page); + +/* + * Unmap a single streaming mode DMA translation. The dma_addr and size must + * match what was provided for in a previous xen_swiotlb_map_page call. All + * other usages are undefined. + * + * After this call, reads by the cpu to the buffer are guaranteed to see + * whatever the device wrote there. + */ +static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir) +{ + phys_addr_t paddr = dma_to_phys(hwdev, dev_addr); + + BUG_ON(dir == DMA_NONE); + + if (is_xen_swiotlb_buffer(paddr)) { + swiotlb_tbl_unmap_single(hwdev, phys_to_virt(paddr), size, dir); + return; + } + + if (dir != DMA_FROM_DEVICE) + return; + + /* + * phys_to_virt doesn't work with hihgmem page but we could + * call dma_mark_clean() with hihgmem page here. However, we + * are fine since dma_mark_clean() is null on POWERPC. We can + * make dma_mark_clean() take a physical address if necessary. + */ + dma_mark_clean(phys_to_virt(paddr), size); +} + +void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + xen_unmap_single(hwdev, dev_addr, size, dir); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_page); + +/* + * Make physical memory consistent for a single streaming mode DMA translation + * after a transfer. + * + * If you perform a xen_swiotlb_map_page() but wish to interrogate the buffer + * using the cpu, yet do not wish to teardown the dma mapping, you must + * call this function before doing so. At the next point you give the dma + * address back to the card, you must first perform a + * xen_swiotlb_dma_sync_for_device, and then the device again owns the buffer + */ +static void +xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir, + enum dma_sync_target target) +{ + phys_addr_t paddr = dma_to_phys(hwdev, dev_addr); + + BUG_ON(dir == DMA_NONE); + + if (is_xen_swiotlb_buffer(paddr)) { + swiotlb_tbl_sync_single(hwdev, phys_to_virt(paddr), size, dir, + target); + return; + } + + if (dir != DMA_FROM_DEVICE) + return; + + dma_mark_clean(phys_to_virt(paddr), size); +} + +void +xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir) +{ + xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_cpu); + +void +xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir) +{ + xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_device); + +/* + * Map a set of buffers described by scatterlist in streaming mode for DMA. + * This is the scatter-gather version of the above xen_swiotlb_map_page + * interface. Here the scatter gather list elements are each tagged with the + * appropriate dma address and length. They are obtained via + * sg_dma_{address,length}(SG). + * + * NOTE: An implementation may be able to use a smaller number of + * DMA address/length pairs than there are SG table elements. + * (for example via virtual mapping capabilities) + * The routine returns the number of addr/length pairs actually + * used, at most nents. + * + * Device ownership issues as mentioned above for xen_swiotlb_map_page are the + * same here. + */ +int +xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, + int nelems, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i; + + BUG_ON(dir == DMA_NONE); + + for_each_sg(sgl, sg, nelems, i) { + phys_addr_t paddr = sg_phys(sg); + dma_addr_t dev_addr = phys_to_dma(hwdev, paddr); + + if (swiotlb_force || + !dma_capable(hwdev, dev_addr, sg->length)) { + void *map = xen_map_single(hwdev, sg_phys(sg), + sg->length, dir); + if (!map) { + /* Don't panic here, we expect map_sg users + to do proper error handling. */ + swiotlb_full(hwdev, sg->length, dir, 0); + xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir, + attrs); + sgl[0].dma_length = 0; + return 0; + } + sg->dma_address = xen_virt_to_bus(hwdev, map); + } else + sg->dma_address = dev_addr; + sg->dma_length = sg->length; + } + return nelems; +} +EXPORT_SYMBOL_GPL(xen_swiotlb_map_sg_attrs); + +int +xen_swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems, + enum dma_data_direction dir) +{ + return xen_swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_map_sg); + +/* + * Unmap a set of streaming mode DMA translations. Again, cpu read rules + * concerning calls here are the same as for swiotlb_unmap_page() above. + */ +void +xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, + int nelems, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i; + + BUG_ON(dir == DMA_NONE); + + for_each_sg(sgl, sg, nelems, i) + xen_unmap_single(hwdev, sg->dma_address, sg->dma_length, dir); + +} +EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg_attrs); + +void +xen_swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems, + enum dma_data_direction dir) +{ + return xen_swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg); + +/* + * Make physical memory consistent for a set of streaming mode DMA translations + * after a transfer. + * + * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules + * and usage. + */ +static void +xen_swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl, + int nelems, enum dma_data_direction dir, + enum dma_sync_target target) +{ + struct scatterlist *sg; + int i; + + for_each_sg(sgl, sg, nelems, i) + xen_swiotlb_sync_single(hwdev, sg->dma_address, + sg->dma_length, dir, target); +} + +void +xen_swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, + int nelems, enum dma_data_direction dir) +{ + xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_cpu); + +void +xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, + int nelems, enum dma_data_direction dir) +{ + xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_device); + +int +xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) +{ + return (dma_addr == xen_virt_to_bus(hwdev, io_tlb_overflow_buffer)); +} +EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mapping_error); + +/* + * 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 +xen_swiotlb_dma_supported(struct device *hwdev, u64 mask) +{ + return xen_virt_to_bus(hwdev, xen_io_tlb_end - 1) <= mask; +} +EXPORT_SYMBOL_GPL(xen_swiotlb_dma_supported); -- 1.7.0.1
| |