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
25struct dma_map_ops *dma_ops;
26EXPORT_SYMBOL(dma_ops);
27
28static int __init dma_init(void)
29{
30	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
31	return 0;
32}
33fs_initcall(dma_init);
34
35void *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
67void 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
81void 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}
103EXPORT_SYMBOL(dma_cache_sync);
104
105static int __init memchunk_setup(char *str)
106{
107	return 1; /* accept anything that begins with "memchunk." */
108}
109__setup("memchunk.", memchunk_setup);
110
111static 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
128int __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