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/platform_device.h> 14 #include <linux/dma-mapping.h> 15 #include <asm/cacheflush.h> 16 #include <asm/addrspace.h> 17 #include <asm/io.h> 18 19 void *dma_alloc_coherent(struct device *dev, size_t size, 20 dma_addr_t *dma_handle, gfp_t gfp) 21 { 22 void *ret, *ret_nocache; 23 int order = get_order(size); 24 25 if (dma_alloc_from_coherent(dev, size, dma_handle, &ret)) 26 return ret; 27 28 ret = (void *)__get_free_pages(gfp, order); 29 if (!ret) 30 return NULL; 31 32 memset(ret, 0, size); 33 /* 34 * Pages from the page allocator may have data present in 35 * cache. So flush the cache before using uncached memory. 36 */ 37 dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL); 38 39 ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size); 40 if (!ret_nocache) { 41 free_pages((unsigned long)ret, order); 42 return NULL; 43 } 44 45 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order); 46 47 *dma_handle = virt_to_phys(ret); 48 return ret_nocache; 49 } 50 EXPORT_SYMBOL(dma_alloc_coherent); 51 52 void dma_free_coherent(struct device *dev, size_t size, 53 void *vaddr, dma_addr_t dma_handle) 54 { 55 int order = get_order(size); 56 unsigned long pfn = dma_handle >> PAGE_SHIFT; 57 int k; 58 59 if (!dma_release_from_coherent(dev, order, vaddr)) { 60 WARN_ON(irqs_disabled()); /* for portability */ 61 for (k = 0; k < (1 << order); k++) 62 __free_pages(pfn_to_page(pfn + k), 0); 63 iounmap(vaddr); 64 } 65 } 66 EXPORT_SYMBOL(dma_free_coherent); 67 68 void dma_cache_sync(struct device *dev, void *vaddr, size_t size, 69 enum dma_data_direction direction) 70 { 71 #ifdef CONFIG_CPU_SH5 72 void *p1addr = vaddr; 73 #else 74 void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr); 75 #endif 76 77 switch (direction) { 78 case DMA_FROM_DEVICE: /* invalidate only */ 79 __flush_invalidate_region(p1addr, size); 80 break; 81 case DMA_TO_DEVICE: /* writeback only */ 82 __flush_wback_region(p1addr, size); 83 break; 84 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 85 __flush_purge_region(p1addr, size); 86 break; 87 default: 88 BUG(); 89 } 90 } 91 EXPORT_SYMBOL(dma_cache_sync); 92 93 static int __init memchunk_setup(char *str) 94 { 95 return 1; /* accept anything that begins with "memchunk." */ 96 } 97 __setup("memchunk.", memchunk_setup); 98 99 static void __init memchunk_cmdline_override(char *name, unsigned long *sizep) 100 { 101 char *p = boot_command_line; 102 int k = strlen(name); 103 104 while ((p = strstr(p, "memchunk."))) { 105 p += 9; /* strlen("memchunk.") */ 106 if (!strncmp(name, p, k) && p[k] == '=') { 107 p += k + 1; 108 *sizep = memparse(p, NULL); 109 pr_info("%s: forcing memory chunk size to 0x%08lx\n", 110 name, *sizep); 111 break; 112 } 113 } 114 } 115 116 int __init platform_resource_setup_memory(struct platform_device *pdev, 117 char *name, unsigned long memsize) 118 { 119 struct resource *r; 120 dma_addr_t dma_handle; 121 void *buf; 122 123 r = pdev->resource + pdev->num_resources - 1; 124 if (r->flags) { 125 pr_warning("%s: unable to find empty space for resource\n", 126 name); 127 return -EINVAL; 128 } 129 130 memchunk_cmdline_override(name, &memsize); 131 if (!memsize) 132 return 0; 133 134 buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL); 135 if (!buf) { 136 pr_warning("%s: unable to allocate memory\n", name); 137 return -ENOMEM; 138 } 139 140 memset(buf, 0, memsize); 141 142 r->flags = IORESOURCE_MEM; 143 r->start = dma_handle; 144 r->end = r->start + memsize - 1; 145 r->name = name; 146 return 0; 147 } 148