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 <asm/cacheflush.h> 19 #include <asm/addrspace.h> 20 21 #define PREALLOC_DMA_DEBUG_ENTRIES 4096 22 23 static int __init dma_init(void) 24 { 25 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); 26 return 0; 27 } 28 fs_initcall(dma_init); 29 30 void *dma_alloc_coherent(struct device *dev, size_t size, 31 dma_addr_t *dma_handle, gfp_t gfp) 32 { 33 void *ret, *ret_nocache; 34 int order = get_order(size); 35 36 if (dma_alloc_from_coherent(dev, size, dma_handle, &ret)) 37 return ret; 38 39 ret = (void *)__get_free_pages(gfp, order); 40 if (!ret) 41 return NULL; 42 43 memset(ret, 0, size); 44 /* 45 * Pages from the page allocator may have data present in 46 * cache. So flush the cache before using uncached memory. 47 */ 48 dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL); 49 50 ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size); 51 if (!ret_nocache) { 52 free_pages((unsigned long)ret, order); 53 return NULL; 54 } 55 56 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order); 57 58 *dma_handle = virt_to_phys(ret); 59 60 debug_dma_alloc_coherent(dev, size, *dma_handle, ret_nocache); 61 62 return ret_nocache; 63 } 64 EXPORT_SYMBOL(dma_alloc_coherent); 65 66 void dma_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 WARN_ON(irqs_disabled()); /* for portability */ 74 75 if (dma_release_from_coherent(dev, order, vaddr)) 76 return; 77 78 debug_dma_free_coherent(dev, size, vaddr, dma_handle); 79 for (k = 0; k < (1 << order); k++) 80 __free_pages(pfn_to_page(pfn + k), 0); 81 iounmap(vaddr); 82 } 83 EXPORT_SYMBOL(dma_free_coherent); 84 85 void dma_cache_sync(struct device *dev, void *vaddr, size_t size, 86 enum dma_data_direction direction) 87 { 88 #ifdef CONFIG_CPU_SH5 89 void *p1addr = vaddr; 90 #else 91 void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr); 92 #endif 93 94 switch (direction) { 95 case DMA_FROM_DEVICE: /* invalidate only */ 96 __flush_invalidate_region(p1addr, size); 97 break; 98 case DMA_TO_DEVICE: /* writeback only */ 99 __flush_wback_region(p1addr, size); 100 break; 101 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 102 __flush_purge_region(p1addr, size); 103 break; 104 default: 105 BUG(); 106 } 107 } 108 EXPORT_SYMBOL(dma_cache_sync); 109 110 static int __init memchunk_setup(char *str) 111 { 112 return 1; /* accept anything that begins with "memchunk." */ 113 } 114 __setup("memchunk.", memchunk_setup); 115 116 static void __init memchunk_cmdline_override(char *name, unsigned long *sizep) 117 { 118 char *p = boot_command_line; 119 int k = strlen(name); 120 121 while ((p = strstr(p, "memchunk."))) { 122 p += 9; /* strlen("memchunk.") */ 123 if (!strncmp(name, p, k) && p[k] == '=') { 124 p += k + 1; 125 *sizep = memparse(p, NULL); 126 pr_info("%s: forcing memory chunk size to 0x%08lx\n", 127 name, *sizep); 128 break; 129 } 130 } 131 } 132 133 int __init platform_resource_setup_memory(struct platform_device *pdev, 134 char *name, unsigned long memsize) 135 { 136 struct resource *r; 137 dma_addr_t dma_handle; 138 void *buf; 139 140 r = pdev->resource + pdev->num_resources - 1; 141 if (r->flags) { 142 pr_warning("%s: unable to find empty space for resource\n", 143 name); 144 return -EINVAL; 145 } 146 147 memchunk_cmdline_override(name, &memsize); 148 if (!memsize) 149 return 0; 150 151 buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL); 152 if (!buf) { 153 pr_warning("%s: unable to allocate memory\n", name); 154 return -ENOMEM; 155 } 156 157 memset(buf, 0, memsize); 158 159 r->flags = IORESOURCE_MEM; 160 r->start = dma_handle; 161 r->end = r->start + memsize - 1; 162 r->name = name; 163 return 0; 164 } 165