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   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         struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
  32         int order = get_order(size);
  33
  34         if (mem) {
  35                 int page = bitmap_find_free_region(mem->bitmap, mem->size,
  36                                                      order);
  37                 if (page >= 0) {
  38                         *dma_handle = mem->device_base + (page << PAGE_SHIFT);
  39                         ret = mem->virt_base + (page << PAGE_SHIFT);
  40                         memset(ret, 0, size);
  41                         return ret;
  42                 }
  43                 if (mem->flags & DMA_MEMORY_EXCLUSIVE)
  44                         return NULL;
  45         }
  46
  47         ret = (void *)__get_free_pages(gfp, order);
  48         if (!ret)
  49                 return NULL;
  50
  51         memset(ret, 0, size);
  52         /*
  53          * Pages from the page allocator may have data present in
  54          * cache. So flush the cache before using uncached memory.
  55          */
  56         dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);
  57
  58         ret_nocache = ioremap_nocache(virt_to_phys(ret), size);
  59         if (!ret_nocache) {
  60                 free_pages((unsigned long)ret, order);
  61                 return NULL;
  62         }
  63
  64         *dma_handle = virt_to_phys(ret);
  65         return ret_nocache;
  66 }
  67 EXPORT_SYMBOL(dma_alloc_coherent);
  68
  69 void dma_free_coherent(struct device *dev, size_t size,
  70                          void *vaddr, dma_addr_t dma_handle)
  71 {
  72         struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
  73         int order = get_order(size);
  74
  75         if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
  76                 int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
  77
  78                 bitmap_release_region(mem->bitmap, page, order);
  79         } else {
  80                 WARN_ON(irqs_disabled());       /* for portability */
  81                 BUG_ON(mem && mem->flags & DMA_MEMORY_EXCLUSIVE);
  82                 free_pages((unsigned long)phys_to_virt(dma_handle), order);
  83                 iounmap(vaddr);
  84         }
  85 }
  86 EXPORT_SYMBOL(dma_free_coherent);
  87
  88 int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
  89                                 dma_addr_t device_addr, size_t size, int flags)
  90 {
  91         void __iomem *mem_base = NULL;
  92         int pages = size >> PAGE_SHIFT;
  93         int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
  94
  95         if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
  96                 goto out;
  97         if (!size)
  98                 goto out;
  99         if (dev->dma_mem)
 100                 goto out;
 101
 102         /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
 103
 104         mem_base = ioremap_nocache(bus_addr, size);
 105         if (!mem_base)
 106                 goto out;
 107
 108         dev->dma_mem = kmalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
 109         if (!dev->dma_mem)
 110                 goto out;
 111         dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
 112         if (!dev->dma_mem->bitmap)
 113                 goto free1_out;
 114
 115         dev->dma_mem->virt_base = mem_base;
 116         dev->dma_mem->device_base = device_addr;
 117         dev->dma_mem->size = pages;
 118         dev->dma_mem->flags = flags;
 119
 120         if (flags & DMA_MEMORY_MAP)
 121                 return DMA_MEMORY_MAP;
 122
 123         return DMA_MEMORY_IO;
 124
 125  free1_out:
 126         kfree(dev->dma_mem);
 127  out:
 128         if (mem_base)
 129                 iounmap(mem_base);
 130         return 0;
 131 }
 132 EXPORT_SYMBOL(dma_declare_coherent_memory);
 133
 134 void dma_release_declared_memory(struct device *dev)
 135 {
 136         struct dma_coherent_mem *mem = dev->dma_mem;
 137
 138         if (!mem)
 139                 return;
 140         dev->dma_mem = NULL;
 141         iounmap(mem->virt_base);
 142         kfree(mem->bitmap);
 143         kfree(mem);
 144 }
 145 EXPORT_SYMBOL(dma_release_declared_memory);
 146
 147 void *dma_mark_declared_memory_occupied(struct device *dev,
 148                                         dma_addr_t device_addr, size_t size)
 149 {
 150         struct dma_coherent_mem *mem = dev->dma_mem;
 151         int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1) >> PAGE_SHIFT;
 152         int pos, err;
 153
 154         if (!mem)
 155                 return ERR_PTR(-EINVAL);
 156
 157         pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
 158         err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
 159         if (err != 0)
 160                 return ERR_PTR(err);
 161         return mem->virt_base + (pos << PAGE_SHIFT);
 162 }
 163 EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
 164
 165 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 166                     enum dma_data_direction direction)
 167 {
 168 #ifdef CONFIG_CPU_SH5
 169         void *p1addr = vaddr;
 170 #else
 171         void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
 172 #endif
 173
 174         switch (direction) {
 175         case DMA_FROM_DEVICE:           /* invalidate only */
 176                 __flush_invalidate_region(p1addr, size);
 177                 break;
 178         case DMA_TO_DEVICE:             /* writeback only */
 179                 __flush_wback_region(p1addr, size);
 180                 break;
 181         case DMA_BIDIRECTIONAL:         /* writeback and invalidate */
 182                 __flush_purge_region(p1addr, size);
 183                 break;
 184         default:
 185                 BUG();
 186         }
 187 }
 188 EXPORT_SYMBOL(dma_cache_sync);
 189
 190 int platform_resource_setup_memory(struct platform_device *pdev,
 191                                    char *name, unsigned long memsize)
 192 {
 193         struct resource *r;
 194         dma_addr_t dma_handle;
 195         void *buf;
 196
 197         r = pdev->resource + pdev->num_resources - 1;
 198         if (r->flags) {
 199                 pr_warning("%s: unable to find empty space for resource\n",
 200                         name);
 201                 return -EINVAL;
 202         }
 203
 204         buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
 205         if (!buf) {
 206                 pr_warning("%s: unable to allocate memory\n", name);
 207                 return -ENOMEM;
 208         }
 209
 210         memset(buf, 0, memsize);
 211
 212         r->flags = IORESOURCE_MEM;
 213         r->start = dma_handle;
 214         r->end = r->start + memsize - 1;
 215         r->name = name;
 216         return 0;
 217 }