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 24 struct dma_map_ops *dma_ops; 25 EXPORT_SYMBOL(dma_ops); 26 27 static int __init dma_init(void) 28 { 29 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); 30 return 0; 31 } 32 fs_initcall(dma_init); 33 34 void *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 64 void 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 77 void 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 } 100 EXPORT_SYMBOL(dma_cache_sync); 101 102 static int __init memchunk_setup(char *str) 103 { 104 return 1; /* accept anything that begins with "memchunk." */ 105 } 106 __setup("memchunk.", memchunk_setup); 107 108 static 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 } 124 125 int __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 } 157