1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2004 - 2007 Paul Mundt
6 #include <linux/init.h>
7 #include <linux/dma-noncoherent.h>
8 #include <linux/module.h>
9 #include <asm/cacheflush.h>
10 #include <asm/addrspace.h>
12 void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
13 gfp_t gfp, unsigned long attrs)
15 void *ret, *ret_nocache;
16 int order = get_order(size);
20 ret = (void *)__get_free_pages(gfp, order);
25 * Pages from the page allocator may have data present in
26 * cache. So flush the cache before using uncached memory.
28 arch_sync_dma_for_device(dev, virt_to_phys(ret), size,
31 ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size);
33 free_pages((unsigned long)ret, order);
37 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
39 *dma_handle = virt_to_phys(ret);
41 *dma_handle -= PFN_PHYS(dev->dma_pfn_offset);
46 void arch_dma_free(struct device *dev, size_t size, void *vaddr,
47 dma_addr_t dma_handle, unsigned long attrs)
49 int order = get_order(size);
50 unsigned long pfn = (dma_handle >> PAGE_SHIFT);
54 pfn += dev->dma_pfn_offset;
56 for (k = 0; k < (1 << order); k++)
57 __free_pages(pfn_to_page(pfn + k), 0);
62 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
63 size_t size, enum dma_data_direction dir)
65 void *addr = sh_cacheop_vaddr(phys_to_virt(paddr));
68 case DMA_FROM_DEVICE: /* invalidate only */
69 __flush_invalidate_region(addr, size);
71 case DMA_TO_DEVICE: /* writeback only */
72 __flush_wback_region(addr, size);
74 case DMA_BIDIRECTIONAL: /* writeback and invalidate */
75 __flush_purge_region(addr, size);