aboutsummaryrefslogtreecommitdiffstats
path: root/arch/sh/mm/consistent.c
blob: 895bb3f335c77f39481191e54739e8871674f7a1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
/*
 * arch/sh/mm/consistent.c
 *
 * Copyright (C) 2004 - 2007  Paul Mundt
 *
 * Declared coherent memory functions based on arch/x86/kernel/pci-dma_32.c
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/mm.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <asm/cacheflush.h>
#include <asm/addrspace.h>
#include <asm/io.h>

struct dma_coherent_mem {
	void		*virt_base;
	u32		device_base;
	int		size;
	int		flags;
	unsigned long	*bitmap;
};

void *dma_alloc_coherent(struct device *dev, size_t size,
			   dma_addr_t *dma_handle, gfp_t gfp)
{
	void *ret, *ret_nocache;
	int order = get_order(size);

	if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
		return ret;

	ret = (void *)__get_free_pages(gfp, order);
	if (!ret)
		return NULL;

	memset(ret, 0, size);
	/*
	 * Pages from the page allocator may have data present in
	 * cache. So flush the cache before using uncached memory.
	 */
	dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);

	ret_nocache = ioremap_nocache(virt_to_phys(ret), size);
	if (!ret_nocache) {
		free_pages((unsigned long)ret, order);
		return NULL;
	}

	*dma_handle = virt_to_phys(ret);
	return ret_nocache;
}
EXPORT_SYMBOL(dma_alloc_coherent);

void dma_free_coherent(struct device *dev, size_t size,
			 void *vaddr, dma_addr_t dma_handle)
{
	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
	int order = get_order(size);

	if (!dma_release_from_coherent(dev, order, vaddr)) {
		WARN_ON(irqs_disabled());	/* for portability */
		BUG_ON(mem && mem->flags & DMA_MEMORY_EXCLUSIVE);
		free_pages((unsigned long)phys_to_virt(dma_handle), order);
		iounmap(vaddr);
	}
}
EXPORT_SYMBOL(dma_free_coherent);

void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
		    enum dma_data_direction direction)
{
#ifdef CONFIG_CPU_SH5
	void *p1addr = vaddr;
#else
	void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
#endif

	switch (direction) {
	case DMA_FROM_DEVICE:		/* invalidate only */
		__flush_invalidate_region(p1addr, size);
		break;
	case DMA_TO_DEVICE:		/* writeback only */
		__flush_wback_region(p1addr, size);
		break;
	case DMA_BIDIRECTIONAL:		/* writeback and invalidate */
		__flush_purge_region(p1addr, size);
		break;
	default:
		BUG();
	}
}
EXPORT_SYMBOL(dma_cache_sync);

static int __init memchunk_setup(char *str)
{
	return 1; /* accept anything that begins with "memchunk." */
}
__setup("memchunk.", memchunk_setup);

static void memchunk_cmdline_override(char *name, unsigned long *sizep)
{
	char *p = boot_command_line;
	int k = strlen(name);

	while ((p = strstr(p, "memchunk."))) {
		p += 9; /* strlen("memchunk.") */
		if (!strncmp(name, p, k) && p[k] == '=') {
			p += k + 1;
			*sizep = memparse(p, NULL);
			pr_info("%s: forcing memory chunk size to 0x%08lx\n",
				name, *sizep);
			break;
		}
	}
}

int platform_resource_setup_memory(struct platform_device *pdev,
				   char *name, unsigned long memsize)
{
	struct resource *r;
	dma_addr_t dma_handle;
	void *buf;

	r = pdev->resource + pdev->num_resources - 1;
	if (r->flags) {
		pr_warning("%s: unable to find empty space for resource\n",
			name);
		return -EINVAL;
	}

	memchunk_cmdline_override(name, &memsize);
	if (!memsize)
		return 0;

	buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
	if (!buf) {
		pr_warning("%s: unable to allocate memory\n", name);
		return -ENOMEM;
	}

	memset(buf, 0, memsize);

	r->flags = IORESOURCE_MEM;
	r->start = dma_handle;
	r->end = r->start + memsize - 1;
	r->name = name;
	return 0;
}

Privacy Policy