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dma-mapping.h

/*
 * Copyright (C) 2004 IBM
 *
 * Implements the generic device dma API for powerpc.
 * the pci and vio busses
 */
#ifndef _ASM_DMA_MAPPING_H
#define _ASM_DMA_MAPPING_H
#ifdef __KERNEL__

#include <linux/types.h>
#include <linux/cache.h>
/* need struct page definitions */
#include <linux/mm.h>
#include <linux/scatterlist.h>
#include <linux/dma-attrs.h>
#include <asm/io.h>

#define DMA_ERROR_CODE        (~(dma_addr_t)0x0)

#ifdef CONFIG_NOT_COHERENT_CACHE
/*
 * DMA-consistent mapping functions for PowerPCs that don't support
 * cache snooping.  These allocate/free a region of uncached mapped
 * memory space for use with DMA devices.  Alternatively, you could
 * allocate the space "normally" and use the cache management functions
 * to ensure it is consistent.
 */
extern void *__dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp);
extern void __dma_free_coherent(size_t size, void *vaddr);
extern void __dma_sync(void *vaddr, size_t size, int direction);
extern void __dma_sync_page(struct page *page, unsigned long offset,
                         size_t size, int direction);

#else /* ! CONFIG_NOT_COHERENT_CACHE */
/*
 * Cache coherent cores.
 */

#define __dma_alloc_coherent(gfp, size, handle) NULL
#define __dma_free_coherent(size, addr)         ((void)0)
#define __dma_sync(addr, size, rw)        ((void)0)
#define __dma_sync_page(pg, off, sz, rw)  ((void)0)

#endif /* ! CONFIG_NOT_COHERENT_CACHE */

static inline unsigned long device_to_mask(struct device *dev)
{
      if (dev->dma_mask && *dev->dma_mask)
            return *dev->dma_mask;
      /* Assume devices without mask can take 32 bit addresses */
      return 0xfffffffful;
}

/*
 * DMA operations are abstracted for G5 vs. i/pSeries, PCI vs. VIO
 */
struct dma_mapping_ops {
      void *            (*alloc_coherent)(struct device *dev, size_t size,
                        dma_addr_t *dma_handle, gfp_t flag);
      void        (*free_coherent)(struct device *dev, size_t size,
                        void *vaddr, dma_addr_t dma_handle);
      dma_addr_t  (*map_single)(struct device *dev, void *ptr,
                        size_t size, enum dma_data_direction direction,
                        struct dma_attrs *attrs);
      void        (*unmap_single)(struct device *dev, dma_addr_t dma_addr,
                        size_t size, enum dma_data_direction direction,
                        struct dma_attrs *attrs);
      int         (*map_sg)(struct device *dev, struct scatterlist *sg,
                        int nents, enum dma_data_direction direction,
                        struct dma_attrs *attrs);
      void        (*unmap_sg)(struct device *dev, struct scatterlist *sg,
                        int nents, enum dma_data_direction direction,
                        struct dma_attrs *attrs);
      int         (*dma_supported)(struct device *dev, u64 mask);
      int         (*set_dma_mask)(struct device *dev, u64 dma_mask);
      dma_addr_t  (*map_page)(struct device *dev, struct page *page,
                        unsigned long offset, size_t size,
                        enum dma_data_direction direction,
                        struct dma_attrs *attrs);
      void        (*unmap_page)(struct device *dev,
                        dma_addr_t dma_address, size_t size,
                        enum dma_data_direction direction,
                        struct dma_attrs *attrs);
};

/*
 * Available generic sets of operations
 */
#ifdef CONFIG_PPC64
extern struct dma_mapping_ops dma_iommu_ops;
#endif
extern struct dma_mapping_ops dma_direct_ops;

static inline struct dma_mapping_ops *get_dma_ops(struct device *dev)
{
      /* We don't handle the NULL dev case for ISA for now. We could
       * do it via an out of line call but it is not needed for now. The
       * only ISA DMA device we support is the floppy and we have a hack
       * in the floppy driver directly to get a device for us.
       */

      if (unlikely(dev == NULL) || dev->archdata.dma_ops == NULL) {
#ifdef CONFIG_PPC64
            return NULL;
#else
            /* Use default on 32-bit if dma_ops is not set up */
            /* TODO: Long term, we should fix drivers so that dev and
             * archdata dma_ops are set up for all buses.
             */
            return &dma_direct_ops;
#endif
      }

      return dev->archdata.dma_ops;
}

static inline void set_dma_ops(struct device *dev, struct dma_mapping_ops *ops)
{
      dev->archdata.dma_ops = ops;
}

static inline int dma_supported(struct device *dev, u64 mask)
{
      struct dma_mapping_ops *dma_ops = get_dma_ops(dev);

      if (unlikely(dma_ops == NULL))
            return 0;
      if (dma_ops->dma_supported == NULL)
            return 1;
      return dma_ops->dma_supported(dev, mask);
}

/* We have our own implementation of pci_set_dma_mask() */
#define HAVE_ARCH_PCI_SET_DMA_MASK

static inline int dma_set_mask(struct device *dev, u64 dma_mask)
{
      struct dma_mapping_ops *dma_ops = get_dma_ops(dev);

      if (unlikely(dma_ops == NULL))
            return -EIO;
      if (dma_ops->set_dma_mask != NULL)
            return dma_ops->set_dma_mask(dev, dma_mask);
      if (!dev->dma_mask || !dma_supported(dev, dma_mask))
            return -EIO;
      *dev->dma_mask = dma_mask;
      return 0;
}

/*
 * TODO: map_/unmap_single will ideally go away, to be completely
 * replaced by map/unmap_page.   Until then, we allow dma_ops to have
 * one or the other, or both by checking to see if the specific
 * function requested exists; and if not, falling back on the other set.
 */
static inline dma_addr_t dma_map_single_attrs(struct device *dev,
                                    void *cpu_addr,
                                    size_t size,
                                    enum dma_data_direction direction,
                                    struct dma_attrs *attrs)
{
      struct dma_mapping_ops *dma_ops = get_dma_ops(dev);

      BUG_ON(!dma_ops);

      if (dma_ops->map_single)
            return dma_ops->map_single(dev, cpu_addr, size, direction,
                                 attrs);

      return dma_ops->map_page(dev, virt_to_page(cpu_addr),
                         (unsigned long)cpu_addr % PAGE_SIZE, size,
                         direction, attrs);
}

static inline void dma_unmap_single_attrs(struct device *dev,
                                dma_addr_t dma_addr,
                                size_t size,
                                enum dma_data_direction direction,
                                struct dma_attrs *attrs)
{
      struct dma_mapping_ops *dma_ops = get_dma_ops(dev);

      BUG_ON(!dma_ops);

      if (dma_ops->unmap_single) {
            dma_ops->unmap_single(dev, dma_addr, size, direction, attrs);
            return;
      }

      dma_ops->unmap_page(dev, dma_addr, size, direction, attrs);
}

static inline dma_addr_t dma_map_page_attrs(struct device *dev,
                                  struct page *page,
                                  unsigned long offset, size_t size,
                                  enum dma_data_direction direction,
                                  struct dma_attrs *attrs)
{
      struct dma_mapping_ops *dma_ops = get_dma_ops(dev);

      BUG_ON(!dma_ops);

      if (dma_ops->map_page)
            return dma_ops->map_page(dev, page, offset, size, direction,
                               attrs);

      return dma_ops->map_single(dev, page_address(page) + offset, size,
                           direction, attrs);
}

static inline void dma_unmap_page_attrs(struct device *dev,
                              dma_addr_t dma_address,
                              size_t size,
                              enum dma_data_direction direction,
                              struct dma_attrs *attrs)
{
      struct dma_mapping_ops *dma_ops = get_dma_ops(dev);

      BUG_ON(!dma_ops);

      if (dma_ops->unmap_page) {
            dma_ops->unmap_page(dev, dma_address, size, direction, attrs);
            return;
      }

      dma_ops->unmap_single(dev, dma_address, size, direction, attrs);
}

static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
                           int nents, enum dma_data_direction direction,
                           struct dma_attrs *attrs)
{
      struct dma_mapping_ops *dma_ops = get_dma_ops(dev);

      BUG_ON(!dma_ops);
      return dma_ops->map_sg(dev, sg, nents, direction, attrs);
}

static inline void dma_unmap_sg_attrs(struct device *dev,
                              struct scatterlist *sg,
                              int nhwentries,
                              enum dma_data_direction direction,
                              struct dma_attrs *attrs)
{
      struct dma_mapping_ops *dma_ops = get_dma_ops(dev);

      BUG_ON(!dma_ops);
      dma_ops->unmap_sg(dev, sg, nhwentries, direction, attrs);
}

static inline void *dma_alloc_coherent(struct device *dev, size_t size,
                               dma_addr_t *dma_handle, gfp_t flag)
{
      struct dma_mapping_ops *dma_ops = get_dma_ops(dev);

      BUG_ON(!dma_ops);
      return dma_ops->alloc_coherent(dev, size, dma_handle, flag);
}

static inline void dma_free_coherent(struct device *dev, size_t size,
                             void *cpu_addr, dma_addr_t dma_handle)
{
      struct dma_mapping_ops *dma_ops = get_dma_ops(dev);

      BUG_ON(!dma_ops);
      dma_ops->free_coherent(dev, size, cpu_addr, dma_handle);
}

static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
                              size_t size,
                              enum dma_data_direction direction)
{
      return dma_map_single_attrs(dev, cpu_addr, size, direction, NULL);
}

static inline void dma_unmap_single(struct device *dev, dma_addr_t dma_addr,
                            size_t size,
                            enum dma_data_direction direction)
{
      dma_unmap_single_attrs(dev, dma_addr, size, direction, NULL);
}

static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
                              unsigned long offset, size_t size,
                              enum dma_data_direction direction)
{
      return dma_map_page_attrs(dev, page, offset, size, direction, NULL);
}

static inline void dma_unmap_page(struct device *dev, dma_addr_t dma_address,
                          size_t size,
                          enum dma_data_direction direction)
{
      dma_unmap_page_attrs(dev, dma_address, size, direction, NULL);
}

static inline int dma_map_sg(struct device *dev, struct scatterlist *sg,
                       int nents, enum dma_data_direction direction)
{
      return dma_map_sg_attrs(dev, sg, nents, direction, NULL);
}

static inline void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
                        int nhwentries,
                        enum dma_data_direction direction)
{
      dma_unmap_sg_attrs(dev, sg, nhwentries, direction, NULL);
}

static inline void dma_sync_single_for_cpu(struct device *dev,
            dma_addr_t dma_handle, size_t size,
            enum dma_data_direction direction)
{
      BUG_ON(direction == DMA_NONE);
      __dma_sync(bus_to_virt(dma_handle), size, direction);
}

static inline void dma_sync_single_for_device(struct device *dev,
            dma_addr_t dma_handle, size_t size,
            enum dma_data_direction direction)
{
      BUG_ON(direction == DMA_NONE);
      __dma_sync(bus_to_virt(dma_handle), size, direction);
}

static inline void dma_sync_sg_for_cpu(struct device *dev,
            struct scatterlist *sgl, int nents,
            enum dma_data_direction direction)
{
      struct scatterlist *sg;
      int i;

      BUG_ON(direction == DMA_NONE);

      for_each_sg(sgl, sg, nents, i)
            __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}

static inline void dma_sync_sg_for_device(struct device *dev,
            struct scatterlist *sgl, int nents,
            enum dma_data_direction direction)
{
      struct scatterlist *sg;
      int i;

      BUG_ON(direction == DMA_NONE);

      for_each_sg(sgl, sg, nents, i)
            __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}

static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
#ifdef CONFIG_PPC64
      return (dma_addr == DMA_ERROR_CODE);
#else
      return 0;
#endif
}

#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
#ifdef CONFIG_NOT_COHERENT_CACHE
#define dma_is_consistent(d, h)     (0)
#else
#define dma_is_consistent(d, h)     (1)
#endif

static inline int dma_get_cache_alignment(void)
{
#ifdef CONFIG_PPC64
      /* no easy way to get cache size on all processors, so return
       * the maximum possible, to be safe */
      return (1 << INTERNODE_CACHE_SHIFT);
#else
      /*
       * Each processor family will define its own L1_CACHE_SHIFT,
       * L1_CACHE_BYTES wraps to this, so this is always safe.
       */
      return L1_CACHE_BYTES;
#endif
}

static inline void dma_sync_single_range_for_cpu(struct device *dev,
            dma_addr_t dma_handle, unsigned long offset, size_t size,
            enum dma_data_direction direction)
{
      /* just sync everything for now */
      dma_sync_single_for_cpu(dev, dma_handle, offset + size, direction);
}

static inline void dma_sync_single_range_for_device(struct device *dev,
            dma_addr_t dma_handle, unsigned long offset, size_t size,
            enum dma_data_direction direction)
{
      /* just sync everything for now */
      dma_sync_single_for_device(dev, dma_handle, offset + size, direction);
}

static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
            enum dma_data_direction direction)
{
      BUG_ON(direction == DMA_NONE);
      __dma_sync(vaddr, size, (int)direction);
}

#endif /* __KERNEL__ */
#endif      /* _ASM_DMA_MAPPING_H */

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