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
dma_alloc_coherent(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t gfp)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 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
46
47 *dma_handle = virt_to_phys(ret);
48 return ret_nocache;
49 }
50 EXPORT_SYMBOL(dma_alloc_coherent);
51
dma_free_coherent(struct device * dev,size_t size,void * vaddr,dma_addr_t dma_handle)52 void dma_free_coherent(struct device *dev, size_t size,
53 void *vaddr, dma_addr_t dma_handle)
54 {
55 int order = get_order(size);
56 unsigned long pfn = dma_handle >> PAGE_SHIFT;
57 int k;
58
59 if (!dma_release_from_coherent(dev, order, vaddr)) {
60 WARN_ON(irqs_disabled()); /* for portability */
61 for (k = 0; k < (1 << order); k++)
62 __free_pages(pfn_to_page(pfn + k), 0);
63 iounmap(vaddr);
64 }
65 }
66 EXPORT_SYMBOL(dma_free_coherent);
67
dma_cache_sync(struct device * dev,void * vaddr,size_t size,enum dma_data_direction direction)68 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
69 enum dma_data_direction direction)
70 {
71 #ifdef CONFIG_CPU_SH5
72 void *p1addr = vaddr;
73 #else
74 void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
75 #endif
76
77 switch (direction) {
78 case DMA_FROM_DEVICE: /* invalidate only */
79 __flush_invalidate_region(p1addr, size);
80 break;
81 case DMA_TO_DEVICE: /* writeback only */
82 __flush_wback_region(p1addr, size);
83 break;
84 case DMA_BIDIRECTIONAL: /* writeback and invalidate */
85 __flush_purge_region(p1addr, size);
86 break;
87 default:
88 BUG();
89 }
90 }
91 EXPORT_SYMBOL(dma_cache_sync);
92
memchunk_setup(char * str)93 static int __init memchunk_setup(char *str)
94 {
95 return 1; /* accept anything that begins with "memchunk." */
96 }
97 __setup("memchunk.", memchunk_setup);
98
memchunk_cmdline_override(char * name,unsigned long * sizep)99 static void __init memchunk_cmdline_override(char *name, unsigned long *sizep)
100 {
101 char *p = boot_command_line;
102 int k = strlen(name);
103
104 while ((p = strstr(p, "memchunk."))) {
105 p += 9; /* strlen("memchunk.") */
106 if (!strncmp(name, p, k) && p[k] == '=') {
107 p += k + 1;
108 *sizep = memparse(p, NULL);
109 pr_info("%s: forcing memory chunk size to 0x%08lx\n",
110 name, *sizep);
111 break;
112 }
113 }
114 }
115
platform_resource_setup_memory(struct platform_device * pdev,char * name,unsigned long memsize)116 int __init platform_resource_setup_memory(struct platform_device *pdev,
117 char *name, unsigned long memsize)
118 {
119 struct resource *r;
120 dma_addr_t dma_handle;
121 void *buf;
122
123 r = pdev->resource + pdev->num_resources - 1;
124 if (r->flags) {
125 pr_warning("%s: unable to find empty space for resource\n",
126 name);
127 return -EINVAL;
128 }
129
130 memchunk_cmdline_override(name, &memsize);
131 if (!memsize)
132 return 0;
133
134 buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
135 if (!buf) {
136 pr_warning("%s: unable to allocate memory\n", name);
137 return -ENOMEM;
138 }
139
140 memset(buf, 0, memsize);
141
142 r->flags = IORESOURCE_MEM;
143 r->start = dma_handle;
144 r->end = r->start + memsize - 1;
145 r->name = name;
146 return 0;
147 }
148