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 <linux/module.h>
19 #include <linux/gfp.h>
20 #include <asm/cacheflush.h>
21 #include <asm/addrspace.h>
22
23 #define PREALLOC_DMA_DEBUG_ENTRIES 4096
24
25 struct dma_map_ops *dma_ops;
26 EXPORT_SYMBOL(dma_ops);
27
dma_init(void)28 static int __init dma_init(void)
29 {
30 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
31 return 0;
32 }
33 fs_initcall(dma_init);
34
dma_generic_alloc_coherent(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t gfp,struct dma_attrs * attrs)35 void *dma_generic_alloc_coherent(struct device *dev, size_t size,
36 dma_addr_t *dma_handle, gfp_t gfp,
37 struct dma_attrs *attrs)
38 {
39 void *ret, *ret_nocache;
40 int order = get_order(size);
41
42 gfp |= __GFP_ZERO;
43
44 ret = (void *)__get_free_pages(gfp, order);
45 if (!ret)
46 return NULL;
47
48 /*
49 * Pages from the page allocator may have data present in
50 * cache. So flush the cache before using uncached memory.
51 */
52 dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);
53
54 ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size);
55 if (!ret_nocache) {
56 free_pages((unsigned long)ret, order);
57 return NULL;
58 }
59
60 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
61
62 *dma_handle = virt_to_phys(ret);
63
64 return ret_nocache;
65 }
66
dma_generic_free_coherent(struct device * dev,size_t size,void * vaddr,dma_addr_t dma_handle,struct dma_attrs * attrs)67 void dma_generic_free_coherent(struct device *dev, size_t size,
68 void *vaddr, dma_addr_t dma_handle,
69 struct dma_attrs *attrs)
70 {
71 int order = get_order(size);
72 unsigned long pfn = dma_handle >> PAGE_SHIFT;
73 int k;
74
75 for (k = 0; k < (1 << order); k++)
76 __free_pages(pfn_to_page(pfn + k), 0);
77
78 iounmap(vaddr);
79 }
80
dma_cache_sync(struct device * dev,void * vaddr,size_t size,enum dma_data_direction direction)81 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
82 enum dma_data_direction direction)
83 {
84 void *addr;
85
86 addr = __in_29bit_mode() ?
87 (void *)CAC_ADDR((unsigned long)vaddr) : vaddr;
88
89 switch (direction) {
90 case DMA_FROM_DEVICE: /* invalidate only */
91 __flush_invalidate_region(addr, size);
92 break;
93 case DMA_TO_DEVICE: /* writeback only */
94 __flush_wback_region(addr, size);
95 break;
96 case DMA_BIDIRECTIONAL: /* writeback and invalidate */
97 __flush_purge_region(addr, size);
98 break;
99 default:
100 BUG();
101 }
102 }
103 EXPORT_SYMBOL(dma_cache_sync);
104
memchunk_setup(char * str)105 static int __init memchunk_setup(char *str)
106 {
107 return 1; /* accept anything that begins with "memchunk." */
108 }
109 __setup("memchunk.", memchunk_setup);
110
memchunk_cmdline_override(char * name,unsigned long * sizep)111 static void __init memchunk_cmdline_override(char *name, unsigned long *sizep)
112 {
113 char *p = boot_command_line;
114 int k = strlen(name);
115
116 while ((p = strstr(p, "memchunk."))) {
117 p += 9; /* strlen("memchunk.") */
118 if (!strncmp(name, p, k) && p[k] == '=') {
119 p += k + 1;
120 *sizep = memparse(p, NULL);
121 pr_info("%s: forcing memory chunk size to 0x%08lx\n",
122 name, *sizep);
123 break;
124 }
125 }
126 }
127
platform_resource_setup_memory(struct platform_device * pdev,char * name,unsigned long memsize)128 int __init platform_resource_setup_memory(struct platform_device *pdev,
129 char *name, unsigned long memsize)
130 {
131 struct resource *r;
132 dma_addr_t dma_handle;
133 void *buf;
134
135 r = pdev->resource + pdev->num_resources - 1;
136 if (r->flags) {
137 pr_warning("%s: unable to find empty space for resource\n",
138 name);
139 return -EINVAL;
140 }
141
142 memchunk_cmdline_override(name, &memsize);
143 if (!memsize)
144 return 0;
145
146 buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
147 if (!buf) {
148 pr_warning("%s: unable to allocate memory\n", name);
149 return -ENOMEM;
150 }
151
152 memset(buf, 0, memsize);
153
154 r->flags = IORESOURCE_MEM;
155 r->start = dma_handle;
156 r->end = r->start + memsize - 1;
157 r->name = name;
158 return 0;
159 }
160