arch/powerpc/kernel/dma.c

   1 /*
   2  * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
   3  *
   4  * Provide default implementations of the DMA mapping callbacks for
   5  * directly mapped busses.
   6  */
   7
   8 #include <linux/device.h>
   9 #include <linux/dma-mapping.h>
  10 #include <linux/dma-debug.h>
  11 #include <linux/gfp.h>
  12 #include <linux/memblock.h>
  13 #include <linux/export.h>
  14 #include <linux/pci.h>
  15 #include <asm/vio.h>
  16 #include <asm/bug.h>
  17 #include <asm/machdep.h>
  18 #include <asm/swiotlb.h>
  19
  20 /*
  21  * Generic direct DMA implementation
  22  *
  23  * This implementation supports a per-device offset that can be applied if
  24  * the address at which memory is visible to devices is not 0. Platform code
  25  * can set archdata.dma_data to an unsigned long holding the offset. By
  26  * default the offset is PCI_DRAM_OFFSET.
  27  */
  28
  29 static u64 __maybe_unused get_pfn_limit(struct device *dev)
  30 {
  31         u64 pfn = (dev->coherent_dma_mask >> PAGE_SHIFT) + 1;
  32         struct dev_archdata __maybe_unused *sd = &dev->archdata;
  33
  34 #ifdef CONFIG_SWIOTLB
  35         if (sd->max_direct_dma_addr && sd->dma_ops == &swiotlb_dma_ops)
  36                 pfn = min_t(u64, pfn, sd->max_direct_dma_addr >> PAGE_SHIFT);
  37 #endif
  38
  39         return pfn;
  40 }
  41
  42 void *dma_direct_alloc_coherent(struct device *dev, size_t size,
  43                                 dma_addr_t *dma_handle, gfp_t flag,
  44                                 struct dma_attrs *attrs)
  45 {
  46         void *ret;
  47 #ifdef CONFIG_NOT_COHERENT_CACHE
  48         ret = __dma_alloc_coherent(dev, size, dma_handle, flag);
  49         if (ret == NULL)
  50                 return NULL;
  51         *dma_handle += get_dma_offset(dev);
  52         return ret;
  53 #else
  54         struct page *page;
  55         int node = dev_to_node(dev);
  56 #ifdef CONFIG_FSL_SOC
  57         u64 pfn = get_pfn_limit(dev);
  58         int zone;
  59
  60         /*
  61          * This code should be OK on other platforms, but we have drivers that
  62          * don't set coherent_dma_mask. As a workaround we just ifdef it. This
  63          * whole routine needs some serious cleanup.
  64          */
  65
  66         zone = dma_pfn_limit_to_zone(pfn);
  67         if (zone < 0) {
  68                 dev_err(dev, "%s: No suitable zone for pfn %#llx\n",
  69                         __func__, pfn);
  70                 return NULL;
  71         }
  72
  73         switch (zone) {
  74         case ZONE_DMA:
  75                 flag |= GFP_DMA;
  76                 break;
  77 #ifdef CONFIG_ZONE_DMA32
  78         case ZONE_DMA32:
  79                 flag |= GFP_DMA32;
  80                 break;
  81 #endif
  82         };
  83 #endif /* CONFIG_FSL_SOC */
  84
  85         /* ignore region specifiers */
  86         flag  &= ~(__GFP_HIGHMEM);
  87
  88         page = alloc_pages_node(node, flag, get_order(size));
  89         if (page == NULL)
  90                 return NULL;
  91         ret = page_address(page);
  92         memset(ret, 0, size);
  93         *dma_handle = __pa(ret) + get_dma_offset(dev);
  94
  95         return ret;
  96 #endif
  97 }
  98
  99 void dma_direct_free_coherent(struct device *dev, size_t size,
 100                               void *vaddr, dma_addr_t dma_handle,
 101                               struct dma_attrs *attrs)
 102 {
 103 #ifdef CONFIG_NOT_COHERENT_CACHE
 104         __dma_free_coherent(size, vaddr);
 105 #else
 106         free_pages((unsigned long)vaddr, get_order(size));
 107 #endif
 108 }
 109
 110 int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 111                              void *cpu_addr, dma_addr_t handle, size_t size,
 112                              struct dma_attrs *attrs)
 113 {
 114         unsigned long pfn;
 115
 116 #ifdef CONFIG_NOT_COHERENT_CACHE
 117         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 118         pfn = __dma_get_coherent_pfn((unsigned long)cpu_addr);
 119 #else
 120         pfn = page_to_pfn(virt_to_page(cpu_addr));
 121 #endif
 122         return remap_pfn_range(vma, vma->vm_start,
 123                                pfn + vma->vm_pgoff,
 124                                vma->vm_end - vma->vm_start,
 125                                vma->vm_page_prot);
 126 }
 127
 128 static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
 129                              int nents, enum dma_data_direction direction,
 130                              struct dma_attrs *attrs)
 131 {
 132         struct scatterlist *sg;
 133         int i;
 134
 135         for_each_sg(sgl, sg, nents, i) {
 136                 sg->dma_address = sg_phys(sg) + get_dma_offset(dev);
 137                 sg->dma_length = sg->length;
 138                 __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
 139         }
 140
 141         return nents;
 142 }
 143
 144 static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
 145                                 int nents, enum dma_data_direction direction,
 146                                 struct dma_attrs *attrs)
 147 {
 148 }
 149
 150 static int dma_direct_dma_supported(struct device *dev, u64 mask)
 151 {
 152 #ifdef CONFIG_PPC64
 153         /* Could be improved so platforms can set the limit in case
 154          * they have limited DMA windows
 155          */
 156         return mask >= get_dma_offset(dev) + (memblock_end_of_DRAM() - 1);
 157 #else
 158         return 1;
 159 #endif
 160 }
 161
 162 static u64 dma_direct_get_required_mask(struct device *dev)
 163 {
 164         u64 end, mask;
 165
 166         end = memblock_end_of_DRAM() + get_dma_offset(dev);
 167
 168         mask = 1ULL << (fls64(end) - 1);
 169         mask += mask - 1;
 170
 171         return mask;
 172 }
 173
 174 static inline dma_addr_t dma_direct_map_page(struct device *dev,
 175                                              struct page *page,
 176                                              unsigned long offset,
 177                                              size_t size,
 178                                              enum dma_data_direction dir,
 179                                              struct dma_attrs *attrs)
 180 {
 181         BUG_ON(dir == DMA_NONE);
 182         __dma_sync_page(page, offset, size, dir);
 183         return page_to_phys(page) + offset + get_dma_offset(dev);
 184 }
 185
 186 static inline void dma_direct_unmap_page(struct device *dev,
 187                                          dma_addr_t dma_address,
 188                                          size_t size,
 189                                          enum dma_data_direction direction,
 190                                          struct dma_attrs *attrs)
 191 {
 192 }
 193
 194 #ifdef CONFIG_NOT_COHERENT_CACHE
 195 static inline void dma_direct_sync_sg(struct device *dev,
 196                 struct scatterlist *sgl, int nents,
 197                 enum dma_data_direction direction)
 198 {
 199         struct scatterlist *sg;
 200         int i;
 201
 202         for_each_sg(sgl, sg, nents, i)
 203                 __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
 204 }
 205
 206 static inline void dma_direct_sync_single(struct device *dev,
 207                                           dma_addr_t dma_handle, size_t size,
 208                                           enum dma_data_direction direction)
 209 {
 210         __dma_sync(bus_to_virt(dma_handle), size, direction);
 211 }
 212 #endif
 213
 214 struct dma_map_ops dma_direct_ops = {
 215         .alloc                          = dma_direct_alloc_coherent,
 216         .free                           = dma_direct_free_coherent,
 217         .mmap                           = dma_direct_mmap_coherent,
 218         .map_sg                         = dma_direct_map_sg,
 219         .unmap_sg                       = dma_direct_unmap_sg,
 220         .dma_supported                  = dma_direct_dma_supported,
 221         .map_page                       = dma_direct_map_page,
 222         .unmap_page                     = dma_direct_unmap_page,
 223         .get_required_mask              = dma_direct_get_required_mask,
 224 #ifdef CONFIG_NOT_COHERENT_CACHE
 225         .sync_single_for_cpu            = dma_direct_sync_single,
 226         .sync_single_for_device         = dma_direct_sync_single,
 227         .sync_sg_for_cpu                = dma_direct_sync_sg,
 228         .sync_sg_for_device             = dma_direct_sync_sg,
 229 #endif
 230 };
 231 EXPORT_SYMBOL(dma_direct_ops);
 232
 233 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 234
 235 int __dma_set_mask(struct device *dev, u64 dma_mask)
 236 {
 237         struct dma_map_ops *dma_ops = get_dma_ops(dev);
 238
 239         if ((dma_ops != NULL) && (dma_ops->set_dma_mask != NULL))
 240                 return dma_ops->set_dma_mask(dev, dma_mask);
 241         if (!dev->dma_mask || !dma_supported(dev, dma_mask))
 242                 return -EIO;
 243         *dev->dma_mask = dma_mask;
 244         return 0;
 245 }
 246
 247 int dma_set_mask(struct device *dev, u64 dma_mask)
 248 {
 249         if (ppc_md.dma_set_mask)
 250                 return ppc_md.dma_set_mask(dev, dma_mask);
 251         return __dma_set_mask(dev, dma_mask);
 252 }
 253 EXPORT_SYMBOL(dma_set_mask);
 254
 255 u64 __dma_get_required_mask(struct device *dev)
 256 {
 257         struct dma_map_ops *dma_ops = get_dma_ops(dev);
 258
 259         if (unlikely(dma_ops == NULL))
 260                 return 0;
 261
 262         if (dma_ops->get_required_mask)
 263                 return dma_ops->get_required_mask(dev);
 264
 265         return DMA_BIT_MASK(8 * sizeof(dma_addr_t));
 266 }
 267
 268 u64 dma_get_required_mask(struct device *dev)
 269 {
 270         if (ppc_md.dma_get_required_mask)
 271                 return ppc_md.dma_get_required_mask(dev);
 272
 273         return __dma_get_required_mask(dev);
 274 }
 275 EXPORT_SYMBOL_GPL(dma_get_required_mask);
 276
 277 static int __init dma_init(void)
 278 {
 279         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 280 #ifdef CONFIG_PCI
 281         dma_debug_add_bus(&pci_bus_type);
 282 #endif
 283 #ifdef CONFIG_IBMVIO
 284         dma_debug_add_bus(&vio_bus_type);
 285 #endif
 286
 287        return 0;
 288 }
 289 fs_initcall(dma_init);
 290