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 25 struct dma_map_ops *dma_ops; 26 EXPORT_SYMBOL(dma_ops); 27 28 static int __init dma_init(void) 29 { 30 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); 31 return 0; 32 } 33 fs_initcall(dma_init); 34 35 void *dma_generic_alloc_coherent(struct device *dev, size_t size, 36 dma_addr_t *dma_handle, gfp_t gfp) 37 { 38 void *ret, *ret_nocache; 39 int order = get_order(size); 40 41 gfp |= __GFP_ZERO; 42 43 ret = (void *)__get_free_pages(gfp, order); 44 if (!ret) 45 return NULL; 46 47 /* 48 * Pages from the page allocator may have data present in 49 * cache. So flush the cache before using uncached memory. 50 */ 51 dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL); 52 53 ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size); 54 if (!ret_nocache) { 55 free_pages((unsigned long)ret, order); 56 return NULL; 57 } 58 59 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order); 60 61 *dma_handle = virt_to_phys(ret); 62 63 return ret_nocache; 64 } 65 66 void dma_generic_free_coherent(struct device *dev, size_t size, 67 void *vaddr, dma_addr_t dma_handle) 68 { 69 int order = get_order(size); 70 unsigned long pfn = dma_handle >> PAGE_SHIFT; 71 int k; 72 73 for (k = 0; k < (1 << order); k++) 74 __free_pages(pfn_to_page(pfn + k), 0); 75 76 iounmap(vaddr); 77 } 78 79 void dma_cache_sync(struct device *dev, void *vaddr, size_t size, 80 enum dma_data_direction direction) 81 { 82 #if defined(CONFIG_CPU_SH5) || defined(CONFIG_PMB) 83 void *p1addr = vaddr; 84 #else 85 void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr); 86 #endif 87 88 switch (direction) { 89 case DMA_FROM_DEVICE: /* invalidate only */ 90 __flush_invalidate_region(p1addr, size); 91 break; 92 case DMA_TO_DEVICE: /* writeback only */ 93 __flush_wback_region(p1addr, size); 94 break; 95 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 96 __flush_purge_region(p1addr, size); 97 break; 98 default: 99 BUG(); 100 } 101 } 102 EXPORT_SYMBOL(dma_cache_sync); 103 104 static int __init memchunk_setup(char *str) 105 { 106 return 1; /* accept anything that begins with "memchunk." */ 107 } 108 __setup("memchunk.", memchunk_setup); 109 110 static void __init memchunk_cmdline_override(char *name, unsigned long *sizep) 111 { 112 char *p = boot_command_line; 113 int k = strlen(name); 114 115 while ((p = strstr(p, "memchunk."))) { 116 p += 9; /* strlen("memchunk.") */ 117 if (!strncmp(name, p, k) && p[k] == '=') { 118 p += k + 1; 119 *sizep = memparse(p, NULL); 120 pr_info("%s: forcing memory chunk size to 0x%08lx\n", 121 name, *sizep); 122 break; 123 } 124 } 125 } 126 127 int __init platform_resource_setup_memory(struct platform_device *pdev, 128 char *name, unsigned long memsize) 129 { 130 struct resource *r; 131 dma_addr_t dma_handle; 132 void *buf; 133 134 r = pdev->resource + pdev->num_resources - 1; 135 if (r->flags) { 136 pr_warning("%s: unable to find empty space for resource\n", 137 name); 138 return -EINVAL; 139 } 140 141 memchunk_cmdline_override(name, &memsize); 142 if (!memsize) 143 return 0; 144 145 buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL); 146 if (!buf) { 147 pr_warning("%s: unable to allocate memory\n", name); 148 return -ENOMEM; 149 } 150 151 memset(buf, 0, memsize); 152 153 r->flags = IORESOURCE_MEM; 154 r->start = dma_handle; 155 r->end = r->start + memsize - 1; 156 r->name = name; 157 return 0; 158 } 159