2 * arch/sh/mm/consistent.c
4 * Copyright (C) 2004 - 2007 Paul Mundt
6 * Declared coherent memory functions based on arch/x86/kernel/pci-dma_32.c
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
13 #include <linux/init.h>
14 #include <linux/platform_device.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/dma-debug.h>
18 #include <linux/module.h>
19 #include <linux/gfp.h>
20 #include <asm/cacheflush.h>
21 #include <asm/addrspace.h>
23 #define PREALLOC_DMA_DEBUG_ENTRIES 4096
25 struct dma_map_ops *dma_ops;
26 EXPORT_SYMBOL(dma_ops);
28 static int __init dma_init(void)
30 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
33 fs_initcall(dma_init);
35 void *dma_generic_alloc_coherent(struct device *dev, size_t size,
36 dma_addr_t *dma_handle, gfp_t gfp)
38 void *ret, *ret_nocache;
39 int order = get_order(size);
43 ret = (void *)__get_free_pages(gfp, order);
48 * Pages from the page allocator may have data present in
49 * cache. So flush the cache before using uncached memory.
51 dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);
53 ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size);
55 free_pages((unsigned long)ret, order);
59 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
61 *dma_handle = virt_to_phys(ret);
66 void dma_generic_free_coherent(struct device *dev, size_t size,
67 void *vaddr, dma_addr_t dma_handle)
69 int order = get_order(size);
70 unsigned long pfn = dma_handle >> PAGE_SHIFT;
73 for (k = 0; k < (1 << order); k++)
74 __free_pages(pfn_to_page(pfn + k), 0);
79 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
80 enum dma_data_direction direction)
82 #if defined(CONFIG_CPU_SH5) || defined(CONFIG_PMB)
85 void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
89 case DMA_FROM_DEVICE: /* invalidate only */
90 __flush_invalidate_region(p1addr, size);
92 case DMA_TO_DEVICE: /* writeback only */
93 __flush_wback_region(p1addr, size);
95 case DMA_BIDIRECTIONAL: /* writeback and invalidate */
96 __flush_purge_region(p1addr, size);
102 EXPORT_SYMBOL(dma_cache_sync);
104 static int __init memchunk_setup(char *str)
106 return 1; /* accept anything that begins with "memchunk." */
108 __setup("memchunk.", memchunk_setup);
110 static void __init memchunk_cmdline_override(char *name, unsigned long *sizep)
112 char *p = boot_command_line;
113 int k = strlen(name);
115 while ((p = strstr(p, "memchunk."))) {
116 p += 9; /* strlen("memchunk.") */
117 if (!strncmp(name, p, k) && p[k] == '=') {
119 *sizep = memparse(p, NULL);
120 pr_info("%s: forcing memory chunk size to 0x%08lx\n",
127 int __init platform_resource_setup_memory(struct platform_device *pdev,
128 char *name, unsigned long memsize)
131 dma_addr_t dma_handle;
134 r = pdev->resource + pdev->num_resources - 1;
136 pr_warning("%s: unable to find empty space for resource\n",
141 memchunk_cmdline_override(name, &memsize);
145 buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
147 pr_warning("%s: unable to allocate memory\n", name);
151 memset(buf, 0, memsize);
153 r->flags = IORESOURCE_MEM;
154 r->start = dma_handle;
155 r->end = r->start + memsize - 1;