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Diffstat (limited to 'arch/mn10300/mm/dma-alloc.c')
-rw-r--r-- | arch/mn10300/mm/dma-alloc.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/mn10300/mm/dma-alloc.c b/arch/mn10300/mm/dma-alloc.c new file mode 100644 index 000000000000..f3649d8f50e3 --- /dev/null +++ b/arch/mn10300/mm/dma-alloc.c @@ -0,0 +1,56 @@ +/* MN10300 Dynamic DMA mapping support + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * Derived from: arch/i386/kernel/pci-dma.c + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/pci.h> +#include <asm/io.h> + +void *dma_alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, int gfp) +{ + unsigned long addr; + void *ret; + + /* ignore region specifiers */ + gfp &= ~(__GFP_DMA | __GFP_HIGHMEM); + + if (dev == NULL || dev->coherent_dma_mask < 0xffffffff) + gfp |= GFP_DMA; + + addr = __get_free_pages(gfp, get_order(size)); + if (!addr) + return NULL; + + /* map the coherent memory through the uncached memory window */ + ret = (void *) (addr | 0x20000000); + + /* fill the memory with obvious rubbish */ + memset((void *) addr, 0xfb, size); + + /* write back and evict all cache lines covering this region */ + mn10300_dcache_flush_inv_range2(virt_to_phys((void *) addr), PAGE_SIZE); + + *dma_handle = virt_to_bus((void *) addr); + return ret; +} +EXPORT_SYMBOL(dma_alloc_coherent); + +void dma_free_coherent(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_handle) +{ + unsigned long addr = (unsigned long) vaddr & ~0x20000000; + + free_pages(addr, get_order(size)); +} +EXPORT_SYMBOL(dma_free_coherent); |