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Linux kernel mirror (for testing)
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1/*
2 * arch/sh/mm/consistent.c
3 *
4 * Copyright (C) 2004 - 2007 Paul Mundt
5 *
6 * Declared coherent memory functions based on arch/x86/kernel/pci-dma_32.c
7 *
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
10 * for more details.
11 */
12#include <linux/mm.h>
13#include <linux/init.h>
14#include <linux/platform_device.h>
15#include <linux/dma-mapping.h>
16#include <linux/dma-debug.h>
17#include <linux/io.h>
18#include <asm/cacheflush.h>
19#include <asm/addrspace.h>
20
21#define PREALLOC_DMA_DEBUG_ENTRIES 4096
22
23static int __init dma_init(void)
24{
25 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
26 return 0;
27}
28fs_initcall(dma_init);
29
30void *dma_alloc_coherent(struct device *dev, size_t size,
31 dma_addr_t *dma_handle, gfp_t gfp)
32{
33 void *ret, *ret_nocache;
34 int order = get_order(size);
35
36 if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
37 return ret;
38
39 ret = (void *)__get_free_pages(gfp, order);
40 if (!ret)
41 return NULL;
42
43 memset(ret, 0, size);
44 /*
45 * Pages from the page allocator may have data present in
46 * cache. So flush the cache before using uncached memory.
47 */
48 dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);
49
50 ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size);
51 if (!ret_nocache) {
52 free_pages((unsigned long)ret, order);
53 return NULL;
54 }
55
56 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
57
58 *dma_handle = virt_to_phys(ret);
59
60 debug_dma_alloc_coherent(dev, size, *dma_handle, ret_nocache);
61
62 return ret_nocache;
63}
64EXPORT_SYMBOL(dma_alloc_coherent);
65
66void dma_free_coherent(struct device *dev, size_t size,
67 void *vaddr, dma_addr_t dma_handle)
68{
69 int order = get_order(size);
70 unsigned long pfn = dma_handle >> PAGE_SHIFT;
71 int k;
72
73 WARN_ON(irqs_disabled()); /* for portability */
74
75 if (dma_release_from_coherent(dev, order, vaddr))
76 return;
77
78 debug_dma_free_coherent(dev, size, vaddr, dma_handle);
79 for (k = 0; k < (1 << order); k++)
80 __free_pages(pfn_to_page(pfn + k), 0);
81 iounmap(vaddr);
82}
83EXPORT_SYMBOL(dma_free_coherent);
84
85void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
86 enum dma_data_direction direction)
87{
88#ifdef CONFIG_CPU_SH5
89 void *p1addr = vaddr;
90#else
91 void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
92#endif
93
94 switch (direction) {
95 case DMA_FROM_DEVICE: /* invalidate only */
96 __flush_invalidate_region(p1addr, size);
97 break;
98 case DMA_TO_DEVICE: /* writeback only */
99 __flush_wback_region(p1addr, size);
100 break;
101 case DMA_BIDIRECTIONAL: /* writeback and invalidate */
102 __flush_purge_region(p1addr, size);
103 break;
104 default:
105 BUG();
106 }
107}
108EXPORT_SYMBOL(dma_cache_sync);
109
110static int __init memchunk_setup(char *str)
111{
112 return 1; /* accept anything that begins with "memchunk." */
113}
114__setup("memchunk.", memchunk_setup);
115
116static void __init memchunk_cmdline_override(char *name, unsigned long *sizep)
117{
118 char *p = boot_command_line;
119 int k = strlen(name);
120
121 while ((p = strstr(p, "memchunk."))) {
122 p += 9; /* strlen("memchunk.") */
123 if (!strncmp(name, p, k) && p[k] == '=') {
124 p += k + 1;
125 *sizep = memparse(p, NULL);
126 pr_info("%s: forcing memory chunk size to 0x%08lx\n",
127 name, *sizep);
128 break;
129 }
130 }
131}
132
133int __init platform_resource_setup_memory(struct platform_device *pdev,
134 char *name, unsigned long memsize)
135{
136 struct resource *r;
137 dma_addr_t dma_handle;
138 void *buf;
139
140 r = pdev->resource + pdev->num_resources - 1;
141 if (r->flags) {
142 pr_warning("%s: unable to find empty space for resource\n",
143 name);
144 return -EINVAL;
145 }
146
147 memchunk_cmdline_override(name, &memsize);
148 if (!memsize)
149 return 0;
150
151 buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
152 if (!buf) {
153 pr_warning("%s: unable to allocate memory\n", name);
154 return -ENOMEM;
155 }
156
157 memset(buf, 0, memsize);
158
159 r->flags = IORESOURCE_MEM;
160 r->start = dma_handle;
161 r->end = r->start + memsize - 1;
162 r->name = name;
163 return 0;
164}