allow coexistance of N build and AC build.
[tomato.git] / release / src-rt-6.x / linux / linux-2.6 / arch / i386 / kernel / pci-dma.c
blob048f09b62553e638ecb6c0ba89528a4f9665b014
1 /*
2 * Dynamic DMA mapping support.
4 * On i386 there is no hardware dynamic DMA address translation,
5 * so consistent alloc/free are merely page allocation/freeing.
6 * The rest of the dynamic DMA mapping interface is implemented
7 * in asm/pci.h.
8 */
10 #include <linux/types.h>
11 #include <linux/mm.h>
12 #include <linux/string.h>
13 #include <linux/pci.h>
14 #include <linux/module.h>
15 #include <linux/pci.h>
16 #include <asm/io.h>
18 struct dma_coherent_mem {
19 void *virt_base;
20 u32 device_base;
21 int size;
22 int flags;
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;
30 struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
31 int order = get_order(size);
32 /* ignore region specifiers */
33 gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
35 if (mem) {
36 int page = bitmap_find_free_region(mem->bitmap, mem->size,
37 order);
38 if (page >= 0) {
39 *dma_handle = mem->device_base + (page << PAGE_SHIFT);
40 ret = mem->virt_base + (page << PAGE_SHIFT);
41 memset(ret, 0, size);
42 return ret;
44 if (mem->flags & DMA_MEMORY_EXCLUSIVE)
45 return NULL;
48 if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
49 gfp |= GFP_DMA;
51 ret = (void *)__get_free_pages(gfp, order);
53 if (ret != NULL) {
54 memset(ret, 0, size);
55 *dma_handle = virt_to_phys(ret);
57 return ret;
59 EXPORT_SYMBOL(dma_alloc_coherent);
61 void dma_free_coherent(struct device *dev, size_t size,
62 void *vaddr, dma_addr_t dma_handle)
64 struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
65 int order = get_order(size);
67 if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
68 int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
70 bitmap_release_region(mem->bitmap, page, order);
71 } else
72 free_pages((unsigned long)vaddr, order);
74 EXPORT_SYMBOL(dma_free_coherent);
76 int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
77 dma_addr_t device_addr, size_t size, int flags)
79 void __iomem *mem_base = NULL;
80 int pages = size >> PAGE_SHIFT;
81 int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
83 if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
84 goto out;
85 if (!size)
86 goto out;
87 if (dev->dma_mem)
88 goto out;
90 /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
92 mem_base = ioremap(bus_addr, size);
93 if (!mem_base)
94 goto out;
96 dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
97 if (!dev->dma_mem)
98 goto out;
99 dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
100 if (!dev->dma_mem->bitmap)
101 goto free1_out;
103 dev->dma_mem->virt_base = mem_base;
104 dev->dma_mem->device_base = device_addr;
105 dev->dma_mem->size = pages;
106 dev->dma_mem->flags = flags;
108 if (flags & DMA_MEMORY_MAP)
109 return DMA_MEMORY_MAP;
111 return DMA_MEMORY_IO;
113 free1_out:
114 kfree(dev->dma_mem);
115 out:
116 if (mem_base)
117 iounmap(mem_base);
118 return 0;
120 EXPORT_SYMBOL(dma_declare_coherent_memory);
122 void dma_release_declared_memory(struct device *dev)
124 struct dma_coherent_mem *mem = dev->dma_mem;
126 if(!mem)
127 return;
128 dev->dma_mem = NULL;
129 iounmap(mem->virt_base);
130 kfree(mem->bitmap);
131 kfree(mem);
133 EXPORT_SYMBOL(dma_release_declared_memory);
135 void *dma_mark_declared_memory_occupied(struct device *dev,
136 dma_addr_t device_addr, size_t size)
138 struct dma_coherent_mem *mem = dev->dma_mem;
139 int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1) >> PAGE_SHIFT;
140 int pos, err;
142 if (!mem)
143 return ERR_PTR(-EINVAL);
145 pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
146 err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
147 if (err != 0)
148 return ERR_PTR(err);
149 return mem->virt_base + (pos << PAGE_SHIFT);
151 EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
153 #ifdef CONFIG_PCI
154 /* Many VIA bridges seem to corrupt data for DAC. Disable it here */
156 int forbid_dac;
157 EXPORT_SYMBOL(forbid_dac);
159 static __devinit void via_no_dac(struct pci_dev *dev)
161 if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI && forbid_dac == 0) {
162 printk(KERN_INFO "PCI: VIA PCI bridge detected. Disabling DAC.\n");
163 forbid_dac = 1;
166 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID, via_no_dac);
168 static int check_iommu(char *s)
170 if (!strcmp(s, "usedac")) {
171 forbid_dac = -1;
172 return 1;
174 return 0;
176 __setup("iommu=", check_iommu);
177 #endif