diff options
Diffstat (limited to 'arch/tile/kernel/pci-dma.c')
| -rw-r--r-- | arch/tile/kernel/pci-dma.c | 586 |
1 files changed, 586 insertions, 0 deletions
diff --git a/arch/tile/kernel/pci-dma.c b/arch/tile/kernel/pci-dma.c new file mode 100644 index 000000000..b9fe80ec1 --- /dev/null +++ b/arch/tile/kernel/pci-dma.c @@ -0,0 +1,586 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#include <linux/mm.h> +#include <linux/dma-mapping.h> +#include <linux/swiotlb.h> +#include <linux/vmalloc.h> +#include <linux/export.h> +#include <asm/tlbflush.h> +#include <asm/homecache.h> + +/* Generic DMA mapping functions: */ + +/* + * Allocate what Linux calls "coherent" memory. On TILEPro this is + * uncached memory; on TILE-Gx it is hash-for-home memory. + */ +#ifdef __tilepro__ +#define PAGE_HOME_DMA PAGE_HOME_UNCACHED +#else +#define PAGE_HOME_DMA PAGE_HOME_HASH +#endif + +static void *tile_dma_alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t gfp, + struct dma_attrs *attrs) +{ + u64 dma_mask = dev->coherent_dma_mask ?: DMA_BIT_MASK(32); + int node = dev_to_node(dev); + int order = get_order(size); + struct page *pg; + dma_addr_t addr; + + gfp |= __GFP_ZERO; + + /* + * If the mask specifies that the memory be in the first 4 GB, then + * we force the allocation to come from the DMA zone. We also + * force the node to 0 since that's the only node where the DMA + * zone isn't empty. If the mask size is smaller than 32 bits, we + * may still not be able to guarantee a suitable memory address, in + * which case we will return NULL. But such devices are uncommon. + */ + if (dma_mask <= DMA_BIT_MASK(32)) { + gfp |= GFP_DMA; + node = 0; + } + + pg = homecache_alloc_pages_node(node, gfp, order, PAGE_HOME_DMA); + if (pg == NULL) + return NULL; + + addr = page_to_phys(pg); + if (addr + size > dma_mask) { + __homecache_free_pages(pg, order); + return NULL; + } + + *dma_handle = addr; + + return page_address(pg); +} + +/* + * Free memory that was allocated with tile_dma_alloc_coherent. + */ +static void tile_dma_free_coherent(struct device *dev, size_t size, + void *vaddr, dma_addr_t dma_handle, + struct dma_attrs *attrs) +{ + homecache_free_pages((unsigned long)vaddr, get_order(size)); +} + +/* + * The map routines "map" the specified address range for DMA + * accesses. The memory belongs to the device after this call is + * issued, until it is unmapped with dma_unmap_single. + * + * We don't need to do any mapping, we just flush the address range + * out of the cache and return a DMA address. + * + * The unmap routines do whatever is necessary before the processor + * accesses the memory again, and must be called before the driver + * touches the memory. We can get away with a cache invalidate if we + * can count on nothing having been touched. + */ + +/* Set up a single page for DMA access. */ +static void __dma_prep_page(struct page *page, unsigned long offset, + size_t size, enum dma_data_direction direction) +{ + /* + * Flush the page from cache if necessary. + * On tilegx, data is delivered to hash-for-home L3; on tilepro, + * data is delivered direct to memory. + * + * NOTE: If we were just doing DMA_TO_DEVICE we could optimize + * this to be a "flush" not a "finv" and keep some of the + * state in cache across the DMA operation, but it doesn't seem + * worth creating the necessary flush_buffer_xxx() infrastructure. + */ + int home = page_home(page); + switch (home) { + case PAGE_HOME_HASH: +#ifdef __tilegx__ + return; +#endif + break; + case PAGE_HOME_UNCACHED: +#ifdef __tilepro__ + return; +#endif + break; + case PAGE_HOME_IMMUTABLE: + /* Should be going to the device only. */ + BUG_ON(direction == DMA_FROM_DEVICE || + direction == DMA_BIDIRECTIONAL); + return; + case PAGE_HOME_INCOHERENT: + /* Incoherent anyway, so no need to work hard here. */ + return; + default: + BUG_ON(home < 0 || home >= NR_CPUS); + break; + } + homecache_finv_page(page); + +#ifdef DEBUG_ALIGNMENT + /* Warn if the region isn't cacheline aligned. */ + if (offset & (L2_CACHE_BYTES - 1) || (size & (L2_CACHE_BYTES - 1))) + pr_warn("Unaligned DMA to non-hfh memory: PA %#llx/%#lx\n", + PFN_PHYS(page_to_pfn(page)) + offset, size); +#endif +} + +/* Make the page ready to be read by the core. */ +static void __dma_complete_page(struct page *page, unsigned long offset, + size_t size, enum dma_data_direction direction) +{ +#ifdef __tilegx__ + switch (page_home(page)) { + case PAGE_HOME_HASH: + /* I/O device delivered data the way the cpu wanted it. */ + break; + case PAGE_HOME_INCOHERENT: + /* Incoherent anyway, so no need to work hard here. */ + break; + case PAGE_HOME_IMMUTABLE: + /* Extra read-only copies are not a problem. */ + break; + default: + /* Flush the bogus hash-for-home I/O entries to memory. */ + homecache_finv_map_page(page, PAGE_HOME_HASH); + break; + } +#endif +} + +static void __dma_prep_pa_range(dma_addr_t dma_addr, size_t size, + enum dma_data_direction direction) +{ + struct page *page = pfn_to_page(PFN_DOWN(dma_addr)); + unsigned long offset = dma_addr & (PAGE_SIZE - 1); + size_t bytes = min(size, (size_t)(PAGE_SIZE - offset)); + + while (size != 0) { + __dma_prep_page(page, offset, bytes, direction); + size -= bytes; + ++page; + offset = 0; + bytes = min((size_t)PAGE_SIZE, size); + } +} + +static void __dma_complete_pa_range(dma_addr_t dma_addr, size_t size, + enum dma_data_direction direction) +{ + struct page *page = pfn_to_page(PFN_DOWN(dma_addr)); + unsigned long offset = dma_addr & (PAGE_SIZE - 1); + size_t bytes = min(size, (size_t)(PAGE_SIZE - offset)); + + while (size != 0) { + __dma_complete_page(page, offset, bytes, direction); + size -= bytes; + ++page; + offset = 0; + bytes = min((size_t)PAGE_SIZE, size); + } +} + +static int tile_dma_map_sg(struct device *dev, struct scatterlist *sglist, + int nents, enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i; + + BUG_ON(!valid_dma_direction(direction)); + + WARN_ON(nents == 0 || sglist->length == 0); + + for_each_sg(sglist, sg, nents, i) { + sg->dma_address = sg_phys(sg); + __dma_prep_pa_range(sg->dma_address, sg->length, direction); +#ifdef CONFIG_NEED_SG_DMA_LENGTH + sg->dma_length = sg->length; +#endif + } + + return nents; +} + +static void tile_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, + int nents, enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i; + + BUG_ON(!valid_dma_direction(direction)); + for_each_sg(sglist, sg, nents, i) { + sg->dma_address = sg_phys(sg); + __dma_complete_pa_range(sg->dma_address, sg->length, + direction); + } +} + +static dma_addr_t tile_dma_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + BUG_ON(!valid_dma_direction(direction)); + + BUG_ON(offset + size > PAGE_SIZE); + __dma_prep_page(page, offset, size, direction); + + return page_to_pa(page) + offset; +} + +static void tile_dma_unmap_page(struct device *dev, dma_addr_t dma_address, + size_t size, enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + BUG_ON(!valid_dma_direction(direction)); + + __dma_complete_page(pfn_to_page(PFN_DOWN(dma_address)), + dma_address & PAGE_OFFSET, size, direction); +} + +static void tile_dma_sync_single_for_cpu(struct device *dev, + dma_addr_t dma_handle, + size_t size, + enum dma_data_direction direction) +{ + BUG_ON(!valid_dma_direction(direction)); + + __dma_complete_pa_range(dma_handle, size, direction); +} + +static void tile_dma_sync_single_for_device(struct device *dev, + dma_addr_t dma_handle, size_t size, + enum dma_data_direction direction) +{ + __dma_prep_pa_range(dma_handle, size, direction); +} + +static void tile_dma_sync_sg_for_cpu(struct device *dev, + struct scatterlist *sglist, int nelems, + enum dma_data_direction direction) +{ + struct scatterlist *sg; + int i; + + BUG_ON(!valid_dma_direction(direction)); + WARN_ON(nelems == 0 || sglist->length == 0); + + for_each_sg(sglist, sg, nelems, i) { + dma_sync_single_for_cpu(dev, sg->dma_address, + sg_dma_len(sg), direction); + } +} + +static void tile_dma_sync_sg_for_device(struct device *dev, + struct scatterlist *sglist, int nelems, + enum dma_data_direction direction) +{ + struct scatterlist *sg; + int i; + + BUG_ON(!valid_dma_direction(direction)); + WARN_ON(nelems == 0 || sglist->length == 0); + + for_each_sg(sglist, sg, nelems, i) { + dma_sync_single_for_device(dev, sg->dma_address, + sg_dma_len(sg), direction); + } +} + +static inline int +tile_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) +{ + return 0; +} + +static inline int +tile_dma_supported(struct device *dev, u64 mask) +{ + return 1; +} + +static struct dma_map_ops tile_default_dma_map_ops = { + .alloc = tile_dma_alloc_coherent, + .free = tile_dma_free_coherent, + .map_page = tile_dma_map_page, + .unmap_page = tile_dma_unmap_page, + .map_sg = tile_dma_map_sg, + .unmap_sg = tile_dma_unmap_sg, + .sync_single_for_cpu = tile_dma_sync_single_for_cpu, + .sync_single_for_device = tile_dma_sync_single_for_device, + .sync_sg_for_cpu = tile_dma_sync_sg_for_cpu, + .sync_sg_for_device = tile_dma_sync_sg_for_device, + .mapping_error = tile_dma_mapping_error, + .dma_supported = tile_dma_supported +}; + +struct dma_map_ops *tile_dma_map_ops = &tile_default_dma_map_ops; +EXPORT_SYMBOL(tile_dma_map_ops); + +/* Generic PCI DMA mapping functions */ + +static void *tile_pci_dma_alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t gfp, + struct dma_attrs *attrs) +{ + int node = dev_to_node(dev); + int order = get_order(size); + struct page *pg; + dma_addr_t addr; + + gfp |= __GFP_ZERO; + + pg = homecache_alloc_pages_node(node, gfp, order, PAGE_HOME_DMA); + if (pg == NULL) + return NULL; + + addr = page_to_phys(pg); + + *dma_handle = phys_to_dma(dev, addr); + + return page_address(pg); +} + +/* + * Free memory that was allocated with tile_pci_dma_alloc_coherent. + */ +static void tile_pci_dma_free_coherent(struct device *dev, size_t size, + void *vaddr, dma_addr_t dma_handle, + struct dma_attrs *attrs) +{ + homecache_free_pages((unsigned long)vaddr, get_order(size)); +} + +static int tile_pci_dma_map_sg(struct device *dev, struct scatterlist *sglist, + int nents, enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i; + + BUG_ON(!valid_dma_direction(direction)); + + WARN_ON(nents == 0 || sglist->length == 0); + + for_each_sg(sglist, sg, nents, i) { + sg->dma_address = sg_phys(sg); + __dma_prep_pa_range(sg->dma_address, sg->length, direction); + + sg->dma_address = phys_to_dma(dev, sg->dma_address); +#ifdef CONFIG_NEED_SG_DMA_LENGTH + sg->dma_length = sg->length; +#endif + } + + return nents; +} + +static void tile_pci_dma_unmap_sg(struct device *dev, + struct scatterlist *sglist, int nents, + enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i; + + BUG_ON(!valid_dma_direction(direction)); + for_each_sg(sglist, sg, nents, i) { + sg->dma_address = sg_phys(sg); + __dma_complete_pa_range(sg->dma_address, sg->length, + direction); + } +} + +static dma_addr_t tile_pci_dma_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + BUG_ON(!valid_dma_direction(direction)); + + BUG_ON(offset + size > PAGE_SIZE); + __dma_prep_page(page, offset, size, direction); + + return phys_to_dma(dev, page_to_pa(page) + offset); +} + +static void tile_pci_dma_unmap_page(struct device *dev, dma_addr_t dma_address, + size_t size, + enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + BUG_ON(!valid_dma_direction(direction)); + + dma_address = dma_to_phys(dev, dma_address); + + __dma_complete_page(pfn_to_page(PFN_DOWN(dma_address)), + dma_address & PAGE_OFFSET, size, direction); +} + +static void tile_pci_dma_sync_single_for_cpu(struct device *dev, + dma_addr_t dma_handle, + size_t size, + enum dma_data_direction direction) +{ + BUG_ON(!valid_dma_direction(direction)); + + dma_handle = dma_to_phys(dev, dma_handle); + + __dma_complete_pa_range(dma_handle, size, direction); +} + +static void tile_pci_dma_sync_single_for_device(struct device *dev, + dma_addr_t dma_handle, + size_t size, + enum dma_data_direction + direction) +{ + dma_handle = dma_to_phys(dev, dma_handle); + + __dma_prep_pa_range(dma_handle, size, direction); +} + +static void tile_pci_dma_sync_sg_for_cpu(struct device *dev, + struct scatterlist *sglist, + int nelems, + enum dma_data_direction direction) +{ + struct scatterlist *sg; + int i; + + BUG_ON(!valid_dma_direction(direction)); + WARN_ON(nelems == 0 || sglist->length == 0); + + for_each_sg(sglist, sg, nelems, i) { + dma_sync_single_for_cpu(dev, sg->dma_address, + sg_dma_len(sg), direction); + } +} + +static void tile_pci_dma_sync_sg_for_device(struct device *dev, + struct scatterlist *sglist, + int nelems, + enum dma_data_direction direction) +{ + struct scatterlist *sg; + int i; + + BUG_ON(!valid_dma_direction(direction)); + WARN_ON(nelems == 0 || sglist->length == 0); + + for_each_sg(sglist, sg, nelems, i) { + dma_sync_single_for_device(dev, sg->dma_address, + sg_dma_len(sg), direction); + } +} + +static inline int +tile_pci_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) +{ + return 0; +} + +static inline int +tile_pci_dma_supported(struct device *dev, u64 mask) +{ + return 1; +} + +static struct dma_map_ops tile_pci_default_dma_map_ops = { + .alloc = tile_pci_dma_alloc_coherent, + .free = tile_pci_dma_free_coherent, + .map_page = tile_pci_dma_map_page, + .unmap_page = tile_pci_dma_unmap_page, + .map_sg = tile_pci_dma_map_sg, + .unmap_sg = tile_pci_dma_unmap_sg, + .sync_single_for_cpu = tile_pci_dma_sync_single_for_cpu, + .sync_single_for_device = tile_pci_dma_sync_single_for_device, + .sync_sg_for_cpu = tile_pci_dma_sync_sg_for_cpu, + .sync_sg_for_device = tile_pci_dma_sync_sg_for_device, + .mapping_error = tile_pci_dma_mapping_error, + .dma_supported = tile_pci_dma_supported +}; + +struct dma_map_ops *gx_pci_dma_map_ops = &tile_pci_default_dma_map_ops; +EXPORT_SYMBOL(gx_pci_dma_map_ops); + +/* PCI DMA mapping functions for legacy PCI devices */ + +#ifdef CONFIG_SWIOTLB +static void *tile_swiotlb_alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t gfp, + struct dma_attrs *attrs) +{ + gfp |= GFP_DMA; + return swiotlb_alloc_coherent(dev, size, dma_handle, gfp); +} + +static void tile_swiotlb_free_coherent(struct device *dev, size_t size, + void *vaddr, dma_addr_t dma_addr, + struct dma_attrs *attrs) +{ + swiotlb_free_coherent(dev, size, vaddr, dma_addr); +} + +static struct dma_map_ops pci_swiotlb_dma_ops = { + .alloc = tile_swiotlb_alloc_coherent, + .free = tile_swiotlb_free_coherent, + .map_page = swiotlb_map_page, + .unmap_page = swiotlb_unmap_page, + .map_sg = swiotlb_map_sg_attrs, + .unmap_sg = swiotlb_unmap_sg_attrs, + .sync_single_for_cpu = swiotlb_sync_single_for_cpu, + .sync_single_for_device = swiotlb_sync_single_for_device, + .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = swiotlb_sync_sg_for_device, + .dma_supported = swiotlb_dma_supported, + .mapping_error = swiotlb_dma_mapping_error, +}; + +struct dma_map_ops *gx_legacy_pci_dma_map_ops = &pci_swiotlb_dma_ops; +#else +struct dma_map_ops *gx_legacy_pci_dma_map_ops; +#endif +EXPORT_SYMBOL(gx_legacy_pci_dma_map_ops); + +#ifdef CONFIG_ARCH_HAS_DMA_SET_COHERENT_MASK +int dma_set_coherent_mask(struct device *dev, u64 mask) +{ + struct dma_map_ops *dma_ops = get_dma_ops(dev); + + /* Handle legacy PCI devices with limited memory addressability. */ + if (((dma_ops == gx_pci_dma_map_ops) || + (dma_ops == gx_legacy_pci_dma_map_ops)) && + (mask <= DMA_BIT_MASK(32))) { + if (mask > dev->archdata.max_direct_dma_addr) + mask = dev->archdata.max_direct_dma_addr; + } + + if (!dma_supported(dev, mask)) + return -EIO; + dev->coherent_dma_mask = mask; + return 0; +} +EXPORT_SYMBOL(dma_set_coherent_mask); +#endif |