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 struct dma_coherent_mem { 20 void *virt_base; 21 u32 device_base; 22 int size; 23 int flags; 24 unsigned long *bitmap; 25 }; 26 27 void *dma_alloc_coherent(struct device *dev, size_t size, 28 dma_addr_t *dma_handle, gfp_t gfp) 29 { 30 void *ret, *ret_nocache; 31 int order = get_order(size); 32 33 if (dma_alloc_from_coherent(dev, size, dma_handle, &ret)) 34 return ret; 35 36 ret = (void *)__get_free_pages(gfp, order); 37 if (!ret) 38 return NULL; 39 40 memset(ret, 0, size); 41 /* 42 * Pages from the page allocator may have data present in 43 * cache. So flush the cache before using uncached memory. 44 */ 45 dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL); 46 47 ret_nocache = ioremap_nocache(virt_to_phys(ret), size); 48 if (!ret_nocache) { 49 free_pages((unsigned long)ret, order); 50 return NULL; 51 } 52 53 *dma_handle = virt_to_phys(ret); 54 return ret_nocache; 55 } 56 EXPORT_SYMBOL(dma_alloc_coherent); 57 58 void dma_free_coherent(struct device *dev, size_t size, 59 void *vaddr, dma_addr_t dma_handle) 60 { 61 struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; 62 int order = get_order(size); 63 64 if (!dma_release_from_coherent(dev, order, vaddr)) { 65 WARN_ON(irqs_disabled()); /* for portability */ 66 BUG_ON(mem && mem->flags & DMA_MEMORY_EXCLUSIVE); 67 free_pages((unsigned long)phys_to_virt(dma_handle), order); 68 iounmap(vaddr); 69 } 70 } 71 EXPORT_SYMBOL(dma_free_coherent); 72 73 void dma_cache_sync(struct device *dev, void *vaddr, size_t size, 74 enum dma_data_direction direction) 75 { 76 #ifdef CONFIG_CPU_SH5 77 void *p1addr = vaddr; 78 #else 79 void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr); 80 #endif 81 82 switch (direction) { 83 case DMA_FROM_DEVICE: /* invalidate only */ 84 __flush_invalidate_region(p1addr, size); 85 break; 86 case DMA_TO_DEVICE: /* writeback only */ 87 __flush_wback_region(p1addr, size); 88 break; 89 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 90 __flush_purge_region(p1addr, size); 91 break; 92 default: 93 BUG(); 94 } 95 } 96 EXPORT_SYMBOL(dma_cache_sync); 97 98 static int __init memchunk_setup(char *str) 99 { 100 return 1; /* accept anything that begins with "memchunk." */ 101 } 102 __setup("memchunk.", memchunk_setup); 103 104 static void __init memchunk_cmdline_override(char *name, unsigned long *sizep) 105 { 106 char *p = boot_command_line; 107 int k = strlen(name); 108 109 while ((p = strstr(p, "memchunk."))) { 110 p += 9; /* strlen("memchunk.") */ 111 if (!strncmp(name, p, k) && p[k] == '=') { 112 p += k + 1; 113 *sizep = memparse(p, NULL); 114 pr_info("%s: forcing memory chunk size to 0x%08lx\n", 115 name, *sizep); 116 break; 117 } 118 } 119 } 120 121 int __init platform_resource_setup_memory(struct platform_device *pdev, 122 char *name, unsigned long memsize) 123 { 124 struct resource *r; 125 dma_addr_t dma_handle; 126 void *buf; 127 128 r = pdev->resource + pdev->num_resources - 1; 129 if (r->flags) { 130 pr_warning("%s: unable to find empty space for resource\n", 131 name); 132 return -EINVAL; 133 } 134 135 memchunk_cmdline_override(name, &memsize); 136 if (!memsize) 137 return 0; 138 139 buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL); 140 if (!buf) { 141 pr_warning("%s: unable to allocate memory\n", name); 142 return -ENOMEM; 143 } 144 145 memset(buf, 0, memsize); 146 147 r->flags = IORESOURCE_MEM; 148 r->start = dma_handle; 149 r->end = r->start + memsize - 1; 150 r->name = name; 151 return 0; 152 } 153