1/*
  2 * This file is subject to the terms and conditions of the GNU General Public
  3 * License.  See the file COPYING in the main directory of this archive
  4 * for more details.
  5 */
  6
  7#undef DEBUG
  8
  9#include <linux/dma-mapping.h>
 10#include <linux/device.h>
 11#include <linux/kernel.h>
 12#include <linux/scatterlist.h>
 13#include <linux/slab.h>
 14#include <linux/vmalloc.h>
 15#include <linux/export.h>
 16
 17#include <asm/pgalloc.h>
 18
 19#ifdef CONFIG_MMU
 20
 21void *dma_alloc_coherent(struct device *dev, size_t size,
 22			 dma_addr_t *handle, gfp_t flag)
 23{
 24	struct page *page, **map;
 25	pgprot_t pgprot;
 26	void *addr;
 27	int i, order;
 28
 29	pr_debug("dma_alloc_coherent: %d,%x\n", size, flag);
 30
 31	size = PAGE_ALIGN(size);
 32	order = get_order(size);
 33
 34	page = alloc_pages(flag, order);
 35	if (!page)
 36		return NULL;
 37
 38	*handle = page_to_phys(page);
 39	map = kmalloc(sizeof(struct page *) << order, flag & ~__GFP_DMA);
 40	if (!map) {
 41		__free_pages(page, order);
 42		return NULL;
 43	}
 44	split_page(page, order);
 45
 46	order = 1 << order;
 47	size >>= PAGE_SHIFT;
 48	map[0] = page;
 49	for (i = 1; i < size; i++)
 50		map[i] = page + i;
 51	for (; i < order; i++)
 52		__free_page(page + i);
 53	pgprot = __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
 54	if (CPU_IS_040_OR_060)
 55		pgprot_val(pgprot) |= _PAGE_GLOBAL040 | _PAGE_NOCACHE_S;
 56	else
 57		pgprot_val(pgprot) |= _PAGE_NOCACHE030;
 58	addr = vmap(map, size, VM_MAP, pgprot);
 59	kfree(map);
 60
 61	return addr;
 62}
 63
 64void dma_free_coherent(struct device *dev, size_t size,
 65		       void *addr, dma_addr_t handle)
 66{
 67	pr_debug("dma_free_coherent: %p, %x\n", addr, handle);
 68	vfree(addr);
 69}
 70
 71#else
 72
 73#include <asm/cacheflush.h>
 74
 75void *dma_alloc_coherent(struct device *dev, size_t size,
 76			   dma_addr_t *dma_handle, gfp_t gfp)
 77{
 78	void *ret;
 79	/* ignore region specifiers */
 80	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
 81
 82	if (dev == NULL || (*dev->dma_mask < 0xffffffff))
 83		gfp |= GFP_DMA;
 84	ret = (void *)__get_free_pages(gfp, get_order(size));
 85
 86	if (ret != NULL) {
 87		memset(ret, 0, size);
 88		*dma_handle = virt_to_phys(ret);
 89	}
 90	return ret;
 91}
 92
 93void dma_free_coherent(struct device *dev, size_t size,
 94			 void *vaddr, dma_addr_t dma_handle)
 95{
 96	free_pages((unsigned long)vaddr, get_order(size));
 97}
 98
 99#endif /* CONFIG_MMU */
100
101EXPORT_SYMBOL(dma_alloc_coherent);
102EXPORT_SYMBOL(dma_free_coherent);
103
104void dma_sync_single_for_device(struct device *dev, dma_addr_t handle,
105				size_t size, enum dma_data_direction dir)
106{
107	switch (dir) {
108	case DMA_TO_DEVICE:
109		cache_push(handle, size);
110		break;
111	case DMA_FROM_DEVICE:
112		cache_clear(handle, size);
113		break;
114	default:
115		if (printk_ratelimit())
116			printk("dma_sync_single_for_device: unsupported dir %u\n", dir);
117		break;
118	}
119}
120EXPORT_SYMBOL(dma_sync_single_for_device);
121
122void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
123			    enum dma_data_direction dir)
124{
125	int i;
126
127	for (i = 0; i < nents; sg++, i++)
128		dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir);
129}
130EXPORT_SYMBOL(dma_sync_sg_for_device);
131
132dma_addr_t dma_map_single(struct device *dev, void *addr, size_t size,
133			  enum dma_data_direction dir)
134{
135	dma_addr_t handle = virt_to_bus(addr);
136
137	dma_sync_single_for_device(dev, handle, size, dir);
138	return handle;
139}
140EXPORT_SYMBOL(dma_map_single);
141
142dma_addr_t dma_map_page(struct device *dev, struct page *page,
143			unsigned long offset, size_t size,
144			enum dma_data_direction dir)
145{
146	dma_addr_t handle = page_to_phys(page) + offset;
147
148	dma_sync_single_for_device(dev, handle, size, dir);
149	return handle;
150}
151EXPORT_SYMBOL(dma_map_page);
152
153int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
154	       enum dma_data_direction dir)
155{
156	int i;
157
158	for (i = 0; i < nents; sg++, i++) {
159		sg->dma_address = sg_phys(sg);
160		dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir);
161	}
162	return nents;
163}
164EXPORT_SYMBOL(dma_map_sg);