diff options
Diffstat (limited to 'arch/openrisc/kernel/dma.c')
| -rw-r--r-- | arch/openrisc/kernel/dma.c | 55 |
1 files changed, 10 insertions, 45 deletions
diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c index adec711ad39d..c152a68811dd 100644 --- a/arch/openrisc/kernel/dma.c +++ b/arch/openrisc/kernel/dma.c @@ -11,8 +11,6 @@ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> * * DMA mapping callbacks... - * As alloc_coherent is the only DMA callback being used currently, that's - * the only thing implemented properly. The rest need looking into... */ #include <linux/dma-noncoherent.h> @@ -67,62 +65,29 @@ static const struct mm_walk_ops clear_nocache_walk_ops = { .pte_entry = page_clear_nocache, }; -/* - * Alloc "coherent" memory, which for OpenRISC means simply uncached. - * - * This function effectively just calls __get_free_pages, sets the - * cache-inhibit bit on those pages, and makes sure that the pages are - * flushed out of the cache before they are used. - * - * If the NON_CONSISTENT attribute is set, then this function just - * returns "normal", cachable memory. - * - * There are additional flags WEAK_ORDERING and WRITE_COMBINE to take - * into consideration here, too. All current known implementations of - * the OR1K support only strongly ordered memory accesses, so that flag - * is being ignored for now; uncached but write-combined memory is a - * missing feature of the OR1K. - */ -void * -arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, - gfp_t gfp, unsigned long attrs) +void *arch_dma_set_uncached(void *cpu_addr, size_t size) { - unsigned long va; - void *page; - - page = alloc_pages_exact(size, gfp | __GFP_ZERO); - if (!page) - return NULL; - - /* This gives us the real physical address of the first page. */ - *dma_handle = __pa(page); - - va = (unsigned long)page; + unsigned long va = (unsigned long)cpu_addr; + int error; /* * We need to iterate through the pages, clearing the dcache for * them and setting the cache-inhibit bit. */ - if (walk_page_range(&init_mm, va, va + size, &set_nocache_walk_ops, - NULL)) { - free_pages_exact(page, size); - return NULL; - } - - return (void *)va; + error = walk_page_range(&init_mm, va, va + size, &set_nocache_walk_ops, + NULL); + if (error) + return ERR_PTR(error); + return cpu_addr; } -void -arch_dma_free(struct device *dev, size_t size, void *vaddr, - dma_addr_t dma_handle, unsigned long attrs) +void arch_dma_clear_uncached(void *cpu_addr, size_t size) { - unsigned long va = (unsigned long)vaddr; + unsigned long va = (unsigned long)cpu_addr; /* walk_page_range shouldn't be able to fail here */ WARN_ON(walk_page_range(&init_mm, va, va + size, &clear_nocache_walk_ops, NULL)); - - free_pages_exact(vaddr, size); } void arch_sync_dma_for_device(phys_addr_t addr, size_t size, |