release/src-rt-6.x.4708/linux/linux-2.6.36/arch/powerpc/include/asm/dma-mapping.h

   1 /*
   2  * Copyright (C) 2004 IBM
   3  *
   4  * Implements the generic device dma API for powerpc.
   5  * the pci and vio busses
   6  */
   7 #ifndef _ASM_DMA_MAPPING_H
   8 #define _ASM_DMA_MAPPING_H
   9 #ifdef __KERNEL__
  10
  11 #include <linux/types.h>
  12 #include <linux/cache.h>
  13 /* need struct page definitions */
  14 #include <linux/mm.h>
  15 #include <linux/scatterlist.h>
  16 #include <linux/dma-attrs.h>
  17 #include <linux/dma-debug.h>
  18 #include <asm/io.h>
  19 #include <asm/swiotlb.h>
  20
  21 #define DMA_ERROR_CODE          (~(dma_addr_t)0x0)
  22
  23 /* Some dma direct funcs must be visible for use in other dma_ops */
  24 extern void *dma_direct_alloc_coherent(struct device *dev, size_t size,
  25                                        dma_addr_t *dma_handle, gfp_t flag);
  26 extern void dma_direct_free_coherent(struct device *dev, size_t size,
  27                                      void *vaddr, dma_addr_t dma_handle);
  28
  29
  30 #ifdef CONFIG_NOT_COHERENT_CACHE
  31 /*
  32  * DMA-consistent mapping functions for PowerPCs that don't support
  33  * cache snooping.  These allocate/free a region of uncached mapped
  34  * memory space for use with DMA devices.  Alternatively, you could
  35  * allocate the space "normally" and use the cache management functions
  36  * to ensure it is consistent.
  37  */
  38 struct device;
  39 extern void *__dma_alloc_coherent(struct device *dev, size_t size,
  40                                   dma_addr_t *handle, gfp_t gfp);
  41 extern void __dma_free_coherent(size_t size, void *vaddr);
  42 extern void __dma_sync(void *vaddr, size_t size, int direction);
  43 extern void __dma_sync_page(struct page *page, unsigned long offset,
  44                                  size_t size, int direction);
  45
  46 #else /* ! CONFIG_NOT_COHERENT_CACHE */
  47 /*
  48  * Cache coherent cores.
  49  */
  50
  51 #define __dma_alloc_coherent(dev, gfp, size, handle)    NULL
  52 #define __dma_free_coherent(size, addr)         ((void)0)
  53 #define __dma_sync(addr, size, rw)              ((void)0)
  54 #define __dma_sync_page(pg, off, sz, rw)        ((void)0)
  55
  56 #endif /* ! CONFIG_NOT_COHERENT_CACHE */
  57
  58 static inline unsigned long device_to_mask(struct device *dev)
  59 {
  60         if (dev->dma_mask && *dev->dma_mask)
  61                 return *dev->dma_mask;
  62         /* Assume devices without mask can take 32 bit addresses */
  63         return 0xfffffffful;
  64 }
  65
  66 /*
  67  * Available generic sets of operations
  68  */
  69 #ifdef CONFIG_PPC64
  70 extern struct dma_map_ops dma_iommu_ops;
  71 #endif
  72 extern struct dma_map_ops dma_direct_ops;
  73
  74 static inline struct dma_map_ops *get_dma_ops(struct device *dev)
  75 {
  76         /* We don't handle the NULL dev case for ISA for now. We could
  77          * do it via an out of line call but it is not needed for now. The
  78          * only ISA DMA device we support is the floppy and we have a hack
  79          * in the floppy driver directly to get a device for us.
  80          */
  81         if (unlikely(dev == NULL))
  82                 return NULL;
  83
  84         return dev->archdata.dma_ops;
  85 }
  86
  87 static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
  88 {
  89         dev->archdata.dma_ops = ops;
  90 }
  91
  92 /*
  93  * get_dma_offset()
  94  *
  95  * Get the dma offset on configurations where the dma address can be determined
  96  * from the physical address by looking at a simple offset.  Direct dma and
  97  * swiotlb use this function, but it is typically not used by implementations
  98  * with an iommu.
  99  */
 100 static inline dma_addr_t get_dma_offset(struct device *dev)
 101 {
 102         if (dev)
 103                 return dev->archdata.dma_data.dma_offset;
 104
 105         return PCI_DRAM_OFFSET;
 106 }
 107
 108 static inline void set_dma_offset(struct device *dev, dma_addr_t off)
 109 {
 110         if (dev)
 111                 dev->archdata.dma_data.dma_offset = off;
 112 }
 113
 114 /* this will be removed soon */
 115 #define flush_write_buffers()
 116
 117 #include <asm-generic/dma-mapping-common.h>
 118
 119 static inline int dma_supported(struct device *dev, u64 mask)
 120 {
 121         struct dma_map_ops *dma_ops = get_dma_ops(dev);
 122
 123         if (unlikely(dma_ops == NULL))
 124                 return 0;
 125         if (dma_ops->dma_supported == NULL)
 126                 return 1;
 127         return dma_ops->dma_supported(dev, mask);
 128 }
 129
 130 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
 131 {
 132         struct dma_map_ops *dma_ops = get_dma_ops(dev);
 133
 134         if (unlikely(dma_ops == NULL))
 135                 return -EIO;
 136         if (dma_ops->set_dma_mask != NULL)
 137                 return dma_ops->set_dma_mask(dev, dma_mask);
 138         if (!dev->dma_mask || !dma_supported(dev, dma_mask))
 139                 return -EIO;
 140         *dev->dma_mask = dma_mask;
 141         return 0;
 142 }
 143
 144 static inline void *dma_alloc_coherent(struct device *dev, size_t size,
 145                                        dma_addr_t *dma_handle, gfp_t flag)
 146 {
 147         struct dma_map_ops *dma_ops = get_dma_ops(dev);
 148         void *cpu_addr;
 149
 150         BUG_ON(!dma_ops);
 151
 152         cpu_addr = dma_ops->alloc_coherent(dev, size, dma_handle, flag);
 153
 154         debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr);
 155
 156         return cpu_addr;
 157 }
 158
 159 static inline void dma_free_coherent(struct device *dev, size_t size,
 160                                      void *cpu_addr, dma_addr_t dma_handle)
 161 {
 162         struct dma_map_ops *dma_ops = get_dma_ops(dev);
 163
 164         BUG_ON(!dma_ops);
 165
 166         debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);
 167
 168         dma_ops->free_coherent(dev, size, cpu_addr, dma_handle);
 169 }
 170
 171 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 172 {
 173         struct dma_map_ops *dma_ops = get_dma_ops(dev);
 174
 175         if (dma_ops->mapping_error)
 176                 return dma_ops->mapping_error(dev, dma_addr);
 177
 178 #ifdef CONFIG_PPC64
 179         return (dma_addr == DMA_ERROR_CODE);
 180 #else
 181         return 0;
 182 #endif
 183 }
 184
 185 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
 186 {
 187 #ifdef CONFIG_SWIOTLB
 188         struct dev_archdata *sd = &dev->archdata;
 189
 190         if (sd->max_direct_dma_addr && addr + size > sd->max_direct_dma_addr)
 191                 return 0;
 192 #endif
 193
 194         if (!dev->dma_mask)
 195                 return 0;
 196
 197         return addr + size - 1 <= *dev->dma_mask;
 198 }
 199
 200 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
 201 {
 202         return paddr + get_dma_offset(dev);
 203 }
 204
 205 static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
 206 {
 207         return daddr - get_dma_offset(dev);
 208 }
 209
 210 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
 211 #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
 212
 213 static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 214                 enum dma_data_direction direction)
 215 {
 216         BUG_ON(direction == DMA_NONE);
 217         __dma_sync(vaddr, size, (int)direction);
 218 }
 219
 220 #endif /* __KERNEL__ */
 221 #endif  /* _ASM_DMA_MAPPING_H */