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 const struct dma_map_ops *dma_ops; 24 EXPORT_SYMBOL(dma_ops); 25 26 void *dma_generic_alloc_coherent(struct device *dev, size_t size, 27 dma_addr_t *dma_handle, gfp_t gfp, 28 unsigned long attrs) 29 { 30 void *ret, *ret_nocache; 31 int order = get_order(size); 32 33 gfp |= __GFP_ZERO; 34 35 ret = (void *)__get_free_pages(gfp, order); 36 if (!ret) 37 return NULL; 38 39 /* 40 * Pages from the page allocator may have data present in 41 * cache. So flush the cache before using uncached memory. 42 */ 43 sh_sync_dma_for_device(ret, size, DMA_BIDIRECTIONAL); 44 45 ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size); 46 if (!ret_nocache) { 47 free_pages((unsigned long)ret, order); 48 return NULL; 49 } 50 51 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order); 52 53 *dma_handle = virt_to_phys(ret); 54 if (!WARN_ON(!dev)) 55 *dma_handle -= PFN_PHYS(dev->dma_pfn_offset); 56 57 return ret_nocache; 58 } 59 60 void dma_generic_free_coherent(struct device *dev, size_t size, 61 void *vaddr, dma_addr_t dma_handle, 62 unsigned long attrs) 63 { 64 int order = get_order(size); 65 unsigned long pfn = dma_handle >> PAGE_SHIFT; 66 int k; 67 68 if (!WARN_ON(!dev)) 69 pfn += dev->dma_pfn_offset; 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 sh_sync_dma_for_device(void *vaddr, size_t size, 78 enum dma_data_direction direction) 79 { 80 void *addr; 81 82 addr = __in_29bit_mode() ? 83 (void *)CAC_ADDR((unsigned long)vaddr) : vaddr; 84 85 switch (direction) { 86 case DMA_FROM_DEVICE: /* invalidate only */ 87 __flush_invalidate_region(addr, size); 88 break; 89 case DMA_TO_DEVICE: /* writeback only */ 90 __flush_wback_region(addr, size); 91 break; 92 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 93 __flush_purge_region(addr, size); 94 break; 95 default: 96 BUG(); 97 } 98 } 99 EXPORT_SYMBOL(sh_sync_dma_for_device); 100 101 static int __init memchunk_setup(char *str) 102 { 103 return 1; /* accept anything that begins with "memchunk." */ 104 } 105 __setup("memchunk.", memchunk_setup); 106 107 static void __init memchunk_cmdline_override(char *name, unsigned long *sizep) 108 { 109 char *p = boot_command_line; 110 int k = strlen(name); 111 112 while ((p = strstr(p, "memchunk."))) { 113 p += 9; /* strlen("memchunk.") */ 114 if (!strncmp(name, p, k) && p[k] == '=') { 115 p += k + 1; 116 *sizep = memparse(p, NULL); 117 pr_info("%s: forcing memory chunk size to 0x%08lx\n", 118 name, *sizep); 119 break; 120 } 121 } 122 } 123 124 int __init platform_resource_setup_memory(struct platform_device *pdev, 125 char *name, unsigned long memsize) 126 { 127 struct resource *r; 128 dma_addr_t dma_handle; 129 void *buf; 130 131 r = pdev->resource + pdev->num_resources - 1; 132 if (r->flags) { 133 pr_warning("%s: unable to find empty space for resource\n", 134 name); 135 return -EINVAL; 136 } 137 138 memchunk_cmdline_override(name, &memsize); 139 if (!memsize) 140 return 0; 141 142 buf = dma_alloc_coherent(&pdev->dev, memsize, &dma_handle, GFP_KERNEL); 143 if (!buf) { 144 pr_warning("%s: unable to allocate memory\n", name); 145 return -ENOMEM; 146 } 147 148 memset(buf, 0, memsize); 149 150 r->flags = IORESOURCE_MEM; 151 r->start = dma_handle; 152 r->end = r->start + memsize - 1; 153 r->name = name; 154 return 0; 155 } 156