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