diff options
Diffstat (limited to 'arch/sh/kernel/dma-coherent.c')
-rw-r--r-- | arch/sh/kernel/dma-coherent.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/sh/kernel/dma-coherent.c b/arch/sh/kernel/dma-coherent.c new file mode 100644 index 000000000000..a0021eef956b --- /dev/null +++ b/arch/sh/kernel/dma-coherent.c @@ -0,0 +1,83 @@ +/* + * Copyright (C) 2004 - 2007 Paul Mundt + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/dma-noncoherent.h> +#include <linux/module.h> +#include <asm/cacheflush.h> +#include <asm/addrspace.h> + +void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, + gfp_t gfp, unsigned long attrs) +{ + void *ret, *ret_nocache; + int order = get_order(size); + + gfp |= __GFP_ZERO; + + ret = (void *)__get_free_pages(gfp, order); + if (!ret) + return NULL; + + /* + * Pages from the page allocator may have data present in + * cache. So flush the cache before using uncached memory. + */ + arch_sync_dma_for_device(dev, virt_to_phys(ret), size, + DMA_BIDIRECTIONAL); + + ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size); + if (!ret_nocache) { + free_pages((unsigned long)ret, order); + return NULL; + } + + split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order); + + *dma_handle = virt_to_phys(ret); + if (!WARN_ON(!dev)) + *dma_handle -= PFN_PHYS(dev->dma_pfn_offset); + + return ret_nocache; +} + +void arch_dma_free(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_handle, unsigned long attrs) +{ + int order = get_order(size); + unsigned long pfn = (dma_handle >> PAGE_SHIFT); + int k; + + if (!WARN_ON(!dev)) + pfn += dev->dma_pfn_offset; + + for (k = 0; k < (1 << order); k++) + __free_pages(pfn_to_page(pfn + k), 0); + + iounmap(vaddr); +} + +void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr, + size_t size, enum dma_data_direction dir) +{ + void *addr = sh_cacheop_vaddr(phys_to_virt(paddr)); + + switch (dir) { + case DMA_FROM_DEVICE: /* invalidate only */ + __flush_invalidate_region(addr, size); + break; + case DMA_TO_DEVICE: /* writeback only */ + __flush_wback_region(addr, size); + break; + case DMA_BIDIRECTIONAL: /* writeback and invalidate */ + __flush_purge_region(addr, size); + break; + default: + BUG(); + } +} |