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dma-default.c

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2000  Ani Joshi <ajoshi@unixbox.com>
 * Copyright (C) 2000, 2001, 06  Ralf Baechle <ralf@linux-mips.org>
 * swiped from i386, and cloned for MIPS by Geert, polished by Ralf.
 */

#include <linux/types.h>
#include <linux/dma-mapping.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/string.h>

#include <asm/cache.h>
#include <asm/io.h>

#include <dma-coherence.h>

static inline unsigned long dma_addr_to_virt(dma_addr_t dma_addr)
{
      unsigned long addr = plat_dma_addr_to_phys(dma_addr);

      return (unsigned long)phys_to_virt(addr);
}

/*
 * Warning on the terminology - Linux calls an uncached area coherent;
 * MIPS terminology calls memory areas with hardware maintained coherency
 * coherent.
 */

static inline int cpu_is_noncoherent_r10000(struct device *dev)
{
      return !plat_device_is_coherent(dev) &&
             (current_cpu_type() == CPU_R10000 ||
             current_cpu_type() == CPU_R12000);
}

static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
{
      /* ignore region specifiers */
      gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);

#ifdef CONFIG_ZONE_DMA
      if (dev == NULL)
            gfp |= __GFP_DMA;
      else if (dev->coherent_dma_mask < DMA_BIT_MASK(24))
            gfp |= __GFP_DMA;
      else
#endif
#ifdef CONFIG_ZONE_DMA32
           if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
            gfp |= __GFP_DMA32;
      else
#endif
            ;

      /* Don't invoke OOM killer */
      gfp |= __GFP_NORETRY;

      return gfp;
}

void *dma_alloc_noncoherent(struct device *dev, size_t size,
      dma_addr_t * dma_handle, gfp_t gfp)
{
      void *ret;

      gfp = massage_gfp_flags(dev, gfp);

      ret = (void *) __get_free_pages(gfp, get_order(size));

      if (ret != NULL) {
            memset(ret, 0, size);
            *dma_handle = plat_map_dma_mem(dev, ret, size);
      }

      return ret;
}

EXPORT_SYMBOL(dma_alloc_noncoherent);

void *dma_alloc_coherent(struct device *dev, size_t size,
      dma_addr_t * dma_handle, gfp_t gfp)
{
      void *ret;

      gfp = massage_gfp_flags(dev, gfp);

      ret = (void *) __get_free_pages(gfp, get_order(size));

      if (ret) {
            memset(ret, 0, size);
            *dma_handle = plat_map_dma_mem(dev, ret, size);

            if (!plat_device_is_coherent(dev)) {
                  dma_cache_wback_inv((unsigned long) ret, size);
                  ret = UNCAC_ADDR(ret);
            }
      }

      return ret;
}

EXPORT_SYMBOL(dma_alloc_coherent);

void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
      dma_addr_t dma_handle)
{
      free_pages((unsigned long) vaddr, get_order(size));
}

EXPORT_SYMBOL(dma_free_noncoherent);

void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
      dma_addr_t dma_handle)
{
      unsigned long addr = (unsigned long) vaddr;

      if (!plat_device_is_coherent(dev))
            addr = CAC_ADDR(addr);

      free_pages(addr, get_order(size));
}

EXPORT_SYMBOL(dma_free_coherent);

static inline void __dma_sync(unsigned long addr, size_t size,
      enum dma_data_direction direction)
{
      switch (direction) {
      case DMA_TO_DEVICE:
            dma_cache_wback(addr, size);
            break;

      case DMA_FROM_DEVICE:
            dma_cache_inv(addr, size);
            break;

      case DMA_BIDIRECTIONAL:
            dma_cache_wback_inv(addr, size);
            break;

      default:
            BUG();
      }
}

dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
      enum dma_data_direction direction)
{
      unsigned long addr = (unsigned long) ptr;

      if (!plat_device_is_coherent(dev))
            __dma_sync(addr, size, direction);

      return plat_map_dma_mem(dev, ptr, size);
}

EXPORT_SYMBOL(dma_map_single);

void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
      enum dma_data_direction direction)
{
      if (cpu_is_noncoherent_r10000(dev))
            __dma_sync(dma_addr_to_virt(dma_addr), size,
                       direction);

      plat_unmap_dma_mem(dma_addr);
}

EXPORT_SYMBOL(dma_unmap_single);

int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
      enum dma_data_direction direction)
{
      int i;

      BUG_ON(direction == DMA_NONE);

      for (i = 0; i < nents; i++, sg++) {
            unsigned long addr;

            addr = (unsigned long) sg_virt(sg);
            if (!plat_device_is_coherent(dev) && addr)
                  __dma_sync(addr, sg->length, direction);
            sg->dma_address = plat_map_dma_mem(dev,
                                           (void *)addr, sg->length);
      }

      return nents;
}

EXPORT_SYMBOL(dma_map_sg);

dma_addr_t dma_map_page(struct device *dev, struct page *page,
      unsigned long offset, size_t size, enum dma_data_direction direction)
{
      BUG_ON(direction == DMA_NONE);

      if (!plat_device_is_coherent(dev)) {
            unsigned long addr;

            addr = (unsigned long) page_address(page) + offset;
            dma_cache_wback_inv(addr, size);
      }

      return plat_map_dma_mem_page(dev, page) + offset;
}

EXPORT_SYMBOL(dma_map_page);

void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
      enum dma_data_direction direction)
{
      BUG_ON(direction == DMA_NONE);

      if (!plat_device_is_coherent(dev) && direction != DMA_TO_DEVICE) {
            unsigned long addr;

            addr = plat_dma_addr_to_phys(dma_address);
            dma_cache_wback_inv(addr, size);
      }

      plat_unmap_dma_mem(dma_address);
}

EXPORT_SYMBOL(dma_unmap_page);

void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
      enum dma_data_direction direction)
{
      unsigned long addr;
      int i;

      BUG_ON(direction == DMA_NONE);

      for (i = 0; i < nhwentries; i++, sg++) {
            if (!plat_device_is_coherent(dev) &&
                direction != DMA_TO_DEVICE) {
                  addr = (unsigned long) sg_virt(sg);
                  if (addr)
                        __dma_sync(addr, sg->length, direction);
            }
            plat_unmap_dma_mem(sg->dma_address);
      }
}

EXPORT_SYMBOL(dma_unmap_sg);

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);

      if (cpu_is_noncoherent_r10000(dev)) {
            unsigned long addr;

            addr = dma_addr_to_virt(dma_handle);
            __dma_sync(addr, size, direction);
      }
}

EXPORT_SYMBOL(dma_sync_single_for_cpu);

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);

      if (!plat_device_is_coherent(dev)) {
            unsigned long addr;

            addr = dma_addr_to_virt(dma_handle);
            __dma_sync(addr, size, direction);
      }
}

EXPORT_SYMBOL(dma_sync_single_for_device);

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)
{
      BUG_ON(direction == DMA_NONE);

      if (cpu_is_noncoherent_r10000(dev)) {
            unsigned long addr;

            addr = dma_addr_to_virt(dma_handle);
            __dma_sync(addr + offset, size, direction);
      }
}

EXPORT_SYMBOL(dma_sync_single_range_for_cpu);

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)
{
      BUG_ON(direction == DMA_NONE);

      if (!plat_device_is_coherent(dev)) {
            unsigned long addr;

            addr = dma_addr_to_virt(dma_handle);
            __dma_sync(addr + offset, size, direction);
      }
}

EXPORT_SYMBOL(dma_sync_single_range_for_device);

void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
      enum dma_data_direction direction)
{
      int i;

      BUG_ON(direction == DMA_NONE);

      /* Make sure that gcc doesn't leave the empty loop body.  */
      for (i = 0; i < nelems; i++, sg++) {
            if (cpu_is_noncoherent_r10000(dev))
                  __dma_sync((unsigned long)page_address(sg_page(sg)),
                             sg->length, direction);
            plat_unmap_dma_mem(sg->dma_address);
      }
}

EXPORT_SYMBOL(dma_sync_sg_for_cpu);

void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems,
      enum dma_data_direction direction)
{
      int i;

      BUG_ON(direction == DMA_NONE);

      /* Make sure that gcc doesn't leave the empty loop body.  */
      for (i = 0; i < nelems; i++, sg++) {
            if (!plat_device_is_coherent(dev))
                  __dma_sync((unsigned long)page_address(sg_page(sg)),
                             sg->length, direction);
            plat_unmap_dma_mem(sg->dma_address);
      }
}

EXPORT_SYMBOL(dma_sync_sg_for_device);

int dma_mapping_error(dma_addr_t dma_addr)
{
      return 0;
}

EXPORT_SYMBOL(dma_mapping_error);

int dma_supported(struct device *dev, u64 mask)
{
      /*
       * we fall back to GFP_DMA when the mask isn't all 1s,
       * so we can't guarantee allocations that must be
       * within a tighter range than GFP_DMA..
       */
      if (mask < DMA_BIT_MASK(24))
            return 0;

      return 1;
}

EXPORT_SYMBOL(dma_supported);

int dma_is_consistent(struct device *dev, dma_addr_t dma_addr)
{
      return plat_device_is_coherent(dev);
}

EXPORT_SYMBOL(dma_is_consistent);

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

      if (!plat_device_is_coherent(dev))
            dma_cache_wback_inv((unsigned long)vaddr, size);
}

EXPORT_SYMBOL(dma_cache_sync);

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