dma-mapping.h

Go to the documentation of this file.

/* DMA mapping routines for the MN10300 arch
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */
#ifndef _ASM_DMA_MAPPING_H
#define _ASM_DMA_MAPPING_H

#include <linux/mm.h>
#include <linux/scatterlist.h>

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

/*
 * See Documentation/DMA-API.txt for the description of how the
 * following DMA API should work.
 */

extern void *dma_alloc_coherent(struct device *dev, size_t size,
                dma_addr_t *dma_handle, int flag);

extern void dma_free_coherent(struct device *dev, size_t size,
                  void *vaddr, dma_addr_t dma_handle);

#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))

static inline
dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
              enum dma_data_direction direction)
{
    BUG_ON(direction == DMA_NONE);
    mn10300_dcache_flush_inv();
    return virt_to_bus(ptr);
}

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

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

    BUG_ON(!valid_dma_direction(direction));
    WARN_ON(nents == 0 || sglist[0].length == 0);

    for_each_sg(sglist, sg, nents, i) {
        BUG_ON(!sg_page(sg));

        sg->dma_address = sg_phys(sg);
    }

    mn10300_dcache_flush_inv();
    return nents;
}

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

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)
{
    BUG_ON(direction == DMA_NONE);
    return page_to_bus(page) + offset;
}

static inline
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);
}

static inline
void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
                 size_t size, enum dma_data_direction 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)
{
    mn10300_dcache_flush_inv();
}

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)
{
}

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)
{
    mn10300_dcache_flush_inv();
}


static inline
void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
             int nelems, enum dma_data_direction direction)
{
}

static inline
void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
                int nelems, enum dma_data_direction direction)
{
    mn10300_dcache_flush_inv();
}

static inline
int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
    return 0;
}

static inline
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 < 0x00ffffff)
        return 0;
    return 1;
}

static inline
int dma_set_mask(struct device *dev, u64 mask)
{
    if (!dev->dma_mask || !dma_supported(dev, mask))
        return -EIO;

    *dev->dma_mask = mask;
    return 0;
}

static inline
void dma_cache_sync(void *vaddr, size_t size,
            enum dma_data_direction direction)
{
    mn10300_dcache_flush_inv();
}

#endif