2 * arch/sh/mm/consistent.c
4 * Copyright (C) 2004 - 2007 Paul Mundt
6 * Declared coherent memory functions based on arch/x86/kernel/pci-dma_32.c
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
13 #include <linux/dma-mapping.h>
14 #include <asm/cacheflush.h>
15 #include <asm/addrspace.h>
18 struct dma_coherent_mem {
23 unsigned long *bitmap;
26 void *dma_alloc_coherent(struct device *dev, size_t size,
27 dma_addr_t *dma_handle, gfp_t gfp)
29 void *ret, *ret_nocache;
30 struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
31 int order = get_order(size);
34 int page = bitmap_find_free_region(mem->bitmap, mem->size,
37 *dma_handle = mem->device_base + (page << PAGE_SHIFT);
38 ret = mem->virt_base + (page << PAGE_SHIFT);
42 if (mem->flags & DMA_MEMORY_EXCLUSIVE)
46 ret = (void *)__get_free_pages(gfp, order);
52 * Pages from the page allocator may have data present in
53 * cache. So flush the cache before using uncached memory.
55 dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);
57 ret_nocache = ioremap_nocache(virt_to_phys(ret), size);
59 free_pages((unsigned long)ret, order);
63 *dma_handle = virt_to_phys(ret);
66 EXPORT_SYMBOL(dma_alloc_coherent);
68 void dma_free_coherent(struct device *dev, size_t size,
69 void *vaddr, dma_addr_t dma_handle)
71 struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
72 int order = get_order(size);
74 if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
75 int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
77 bitmap_release_region(mem->bitmap, page, order);
79 WARN_ON(irqs_disabled()); /* for portability */
80 BUG_ON(mem && mem->flags & DMA_MEMORY_EXCLUSIVE);
81 free_pages((unsigned long)phys_to_virt(dma_handle), order);
85 EXPORT_SYMBOL(dma_free_coherent);
87 int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
88 dma_addr_t device_addr, size_t size, int flags)
90 void __iomem *mem_base = NULL;
91 int pages = size >> PAGE_SHIFT;
92 int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
94 if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
101 /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
103 mem_base = ioremap_nocache(bus_addr, size);
107 dev->dma_mem = kmalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
110 dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
111 if (!dev->dma_mem->bitmap)
114 dev->dma_mem->virt_base = mem_base;
115 dev->dma_mem->device_base = device_addr;
116 dev->dma_mem->size = pages;
117 dev->dma_mem->flags = flags;
119 if (flags & DMA_MEMORY_MAP)
120 return DMA_MEMORY_MAP;
122 return DMA_MEMORY_IO;
131 EXPORT_SYMBOL(dma_declare_coherent_memory);
133 void dma_release_declared_memory(struct device *dev)
135 struct dma_coherent_mem *mem = dev->dma_mem;
140 iounmap(mem->virt_base);
144 EXPORT_SYMBOL(dma_release_declared_memory);
146 void *dma_mark_declared_memory_occupied(struct device *dev,
147 dma_addr_t device_addr, size_t size)
149 struct dma_coherent_mem *mem = dev->dma_mem;
150 int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1) >> PAGE_SHIFT;
154 return ERR_PTR(-EINVAL);
156 pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
157 err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
160 return mem->virt_base + (pos << PAGE_SHIFT);
162 EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
164 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
165 enum dma_data_direction direction)
167 #ifdef CONFIG_CPU_SH5
168 void *p1addr = vaddr;
170 void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
174 case DMA_FROM_DEVICE: /* invalidate only */
175 __flush_invalidate_region(p1addr, size);
177 case DMA_TO_DEVICE: /* writeback only */
178 __flush_wback_region(p1addr, size);
180 case DMA_BIDIRECTIONAL: /* writeback and invalidate */
181 __flush_purge_region(p1addr, size);
187 EXPORT_SYMBOL(dma_cache_sync);