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 void *dma_generic_alloc_coherent(struct device *dev, size_t size, 24 dma_addr_t *dma_handle, gfp_t gfp, 25 unsigned long attrs) 26 { 27 void *ret, *ret_nocache; 28 int order = get_order(size); 29 30 gfp |= __GFP_ZERO; 31 32 ret = (void *)__get_free_pages(gfp, order); 33 if (!ret) 34 return NULL; 35 36 /* 37 * Pages from the page allocator may have data present in 38 * cache. So flush the cache before using uncached memory. 39 */ 40 sh_sync_dma_for_device(ret, size, DMA_BIDIRECTIONAL); 41 42 ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size); 43 if (!ret_nocache) { 44 free_pages((unsigned long)ret, order); 45 return NULL; 46 } 47 48 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order); 49 50 *dma_handle = virt_to_phys(ret); 51 if (!WARN_ON(!dev)) 52 *dma_handle -= PFN_PHYS(dev->dma_pfn_offset); 53 54 return ret_nocache; 55 } 56 57 void dma_generic_free_coherent(struct device *dev, size_t size, 58 void *vaddr, dma_addr_t dma_handle, 59 unsigned long attrs) 60 { 61 int order = get_order(size); 62 unsigned long pfn = dma_handle >> PAGE_SHIFT; 63 int k; 64 65 if (!WARN_ON(!dev)) 66 pfn += dev->dma_pfn_offset; 67 68 for (k = 0; k < (1 << order); k++) 69 __free_pages(pfn_to_page(pfn + k), 0); 70 71 iounmap(vaddr); 72 } 73 74 void sh_sync_dma_for_device(void *vaddr, size_t size, 75 enum dma_data_direction direction) 76 { 77 void *addr = sh_cacheop_vaddr(vaddr); 78 79 switch (direction) { 80 case DMA_FROM_DEVICE: /* invalidate only */ 81 __flush_invalidate_region(addr, size); 82 break; 83 case DMA_TO_DEVICE: /* writeback only */ 84 __flush_wback_region(addr, size); 85 break; 86 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 87 __flush_purge_region(addr, size); 88 break; 89 default: 90 BUG(); 91 } 92 } 93 94 static int __init memchunk_setup(char *str) 95 { 96 return 1; /* accept anything that begins with "memchunk." */ 97 } 98 __setup("memchunk.", memchunk_setup); 99 100 static void __init memchunk_cmdline_override(char *name, unsigned long *sizep) 101 { 102 char *p = boot_command_line; 103 int k = strlen(name); 104 105 while ((p = strstr(p, "memchunk."))) { 106 p += 9; /* strlen("memchunk.") */ 107 if (!strncmp(name, p, k) && p[k] == '=') { 108 p += k + 1; 109 *sizep = memparse(p, NULL); 110 pr_info("%s: forcing memory chunk size to 0x%08lx\n", 111 name, *sizep); 112 break; 113 } 114 } 115 } 116 117 int __init platform_resource_setup_memory(struct platform_device *pdev, 118 char *name, unsigned long memsize) 119 { 120 struct resource *r; 121 dma_addr_t dma_handle; 122 void *buf; 123 124 r = pdev->resource + pdev->num_resources - 1; 125 if (r->flags) { 126 pr_warning("%s: unable to find empty space for resource\n", 127 name); 128 return -EINVAL; 129 } 130 131 memchunk_cmdline_override(name, &memsize); 132 if (!memsize) 133 return 0; 134 135 buf = dma_alloc_coherent(&pdev->dev, memsize, &dma_handle, GFP_KERNEL); 136 if (!buf) { 137 pr_warning("%s: unable to allocate memory\n", name); 138 return -ENOMEM; 139 } 140 141 memset(buf, 0, memsize); 142 143 r->flags = IORESOURCE_MEM; 144 r->start = dma_handle; 145 r->end = r->start + memsize - 1; 146 r->name = name; 147 return 0; 148 } 149