Merge branch 's3c-moves2' of git://aeryn.fluff.org.uk/bjdooks/linux into devel
[linux-2.6] / arch / sh / mm / consistent.c
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/platform_device.h>
14 #include <linux/dma-mapping.h>
15 #include <asm/cacheflush.h>
16 #include <asm/addrspace.h>
17 #include <asm/io.h>
18
19 void *dma_alloc_coherent(struct device *dev, size_t size,
20                            dma_addr_t *dma_handle, gfp_t gfp)
21 {
22         void *ret, *ret_nocache;
23         int order = get_order(size);
24
25         if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
26                 return ret;
27
28         ret = (void *)__get_free_pages(gfp, order);
29         if (!ret)
30                 return NULL;
31
32         memset(ret, 0, size);
33         /*
34          * Pages from the page allocator may have data present in
35          * cache. So flush the cache before using uncached memory.
36          */
37         dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);
38
39         ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size);
40         if (!ret_nocache) {
41                 free_pages((unsigned long)ret, order);
42                 return NULL;
43         }
44
45         *dma_handle = virt_to_phys(ret);
46         return ret_nocache;
47 }
48 EXPORT_SYMBOL(dma_alloc_coherent);
49
50 void dma_free_coherent(struct device *dev, size_t size,
51                          void *vaddr, dma_addr_t dma_handle)
52 {
53         int order = get_order(size);
54
55         if (!dma_release_from_coherent(dev, order, vaddr)) {
56                 WARN_ON(irqs_disabled());       /* for portability */
57                 free_pages((unsigned long)phys_to_virt(dma_handle), order);
58                 iounmap(vaddr);
59         }
60 }
61 EXPORT_SYMBOL(dma_free_coherent);
62
63 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
64                     enum dma_data_direction direction)
65 {
66 #ifdef CONFIG_CPU_SH5
67         void *p1addr = vaddr;
68 #else
69         void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
70 #endif
71
72         switch (direction) {
73         case DMA_FROM_DEVICE:           /* invalidate only */
74                 __flush_invalidate_region(p1addr, size);
75                 break;
76         case DMA_TO_DEVICE:             /* writeback only */
77                 __flush_wback_region(p1addr, size);
78                 break;
79         case DMA_BIDIRECTIONAL:         /* writeback and invalidate */
80                 __flush_purge_region(p1addr, size);
81                 break;
82         default:
83                 BUG();
84         }
85 }
86 EXPORT_SYMBOL(dma_cache_sync);
87
88 static int __init memchunk_setup(char *str)
89 {
90         return 1; /* accept anything that begins with "memchunk." */
91 }
92 __setup("memchunk.", memchunk_setup);
93
94 static void __init memchunk_cmdline_override(char *name, unsigned long *sizep)
95 {
96         char *p = boot_command_line;
97         int k = strlen(name);
98
99         while ((p = strstr(p, "memchunk."))) {
100                 p += 9; /* strlen("memchunk.") */
101                 if (!strncmp(name, p, k) && p[k] == '=') {
102                         p += k + 1;
103                         *sizep = memparse(p, NULL);
104                         pr_info("%s: forcing memory chunk size to 0x%08lx\n",
105                                 name, *sizep);
106                         break;
107                 }
108         }
109 }
110
111 int __init platform_resource_setup_memory(struct platform_device *pdev,
112                                           char *name, unsigned long memsize)
113 {
114         struct resource *r;
115         dma_addr_t dma_handle;
116         void *buf;
117
118         r = pdev->resource + pdev->num_resources - 1;
119         if (r->flags) {
120                 pr_warning("%s: unable to find empty space for resource\n",
121                         name);
122                 return -EINVAL;
123         }
124
125         memchunk_cmdline_override(name, &memsize);
126         if (!memsize)
127                 return 0;
128
129         buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
130         if (!buf) {
131                 pr_warning("%s: unable to allocate memory\n", name);
132                 return -ENOMEM;
133         }
134
135         memset(buf, 0, memsize);
136
137         r->flags = IORESOURCE_MEM;
138         r->start = dma_handle;
139         r->end = r->start + memsize - 1;
140         r->name = name;
141         return 0;
142 }