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 *dma_handle = virt_to_phys(ret); 46 return ret_nocache; 47 } 48 EXPORT_SYMBOL(dma_alloc_coherent); 49 50 void dma_free_coherent(struct device *dev, size_t size, 51 void *vaddr, dma_addr_t dma_handle) 52 { 53 int order = get_order(size); 54 55 if (!dma_release_from_coherent(dev, order, vaddr)) { 56 WARN_ON(irqs_disabled()); /* for portability */ 57 free_pages((unsigned long)phys_to_virt(dma_handle), order); 58 iounmap(vaddr); 59 } 60 } 61 EXPORT_SYMBOL(dma_free_coherent); 62 63 void dma_cache_sync(struct device *dev, void *vaddr, size_t size, 64 enum dma_data_direction direction) 65 { 66 #ifdef CONFIG_CPU_SH5 67 void *p1addr = vaddr; 68 #else 69 void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr); 70 #endif 71 72 switch (direction) { 73 case DMA_FROM_DEVICE: /* invalidate only */ 74 __flush_invalidate_region(p1addr, size); 75 break; 76 case DMA_TO_DEVICE: /* writeback only */ 77 __flush_wback_region(p1addr, size); 78 break; 79 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 80 __flush_purge_region(p1addr, size); 81 break; 82 default: 83 BUG(); 84 } 85 } 86 EXPORT_SYMBOL(dma_cache_sync); 87 88 static int __init memchunk_setup(char *str) 89 { 90 return 1; /* accept anything that begins with "memchunk." */ 91 } 92 __setup("memchunk.", memchunk_setup); 93 94 static void __init memchunk_cmdline_override(char *name, unsigned long *sizep) 95 { 96 char *p = boot_command_line; 97 int k = strlen(name); 98 99 while ((p = strstr(p, "memchunk."))) { 100 p += 9; /* strlen("memchunk.") */ 101 if (!strncmp(name, p, k) && p[k] == '=') { 102 p += k + 1; 103 *sizep = memparse(p, NULL); 104 pr_info("%s: forcing memory chunk size to 0x%08lx\n", 105 name, *sizep); 106 break; 107 } 108 } 109 } 110 111 int __init platform_resource_setup_memory(struct platform_device *pdev, 112 char *name, unsigned long memsize) 113 { 114 struct resource *r; 115 dma_addr_t dma_handle; 116 void *buf; 117 118 r = pdev->resource + pdev->num_resources - 1; 119 if (r->flags) { 120 pr_warning("%s: unable to find empty space for resource\n", 121 name); 122 return -EINVAL; 123 } 124 125 memchunk_cmdline_override(name, &memsize); 126 if (!memsize) 127 return 0; 128 129 buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL); 130 if (!buf) { 131 pr_warning("%s: unable to allocate memory\n", name); 132 return -ENOMEM; 133 } 134 135 memset(buf, 0, memsize); 136 137 r->flags = IORESOURCE_MEM; 138 r->start = dma_handle; 139 r->end = r->start + memsize - 1; 140 r->name = name; 141 return 0; 142 } 143