dma-mapping.h

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#ifndef ASMARM_DMA_MAPPING_H
#define ASMARM_DMA_MAPPING_H

#ifdef __KERNEL__

#include <linux/mm_types.h>
#include <linux/scatterlist.h>
#include <linux/dma-attrs.h>
#include <linux/dma-debug.h>

#include <asm-generic/dma-coherent.h>
#include <asm/memory.h>

#define DMA_ERROR_CODE  (~0)
extern struct dma_map_ops arm_dma_ops;
extern struct dma_map_ops arm_coherent_dma_ops;

static inline struct dma_map_ops *get_dma_ops(struct device *dev)
{
    if (dev && dev->archdata.dma_ops)
        return dev->archdata.dma_ops;
    return &arm_dma_ops;
}

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

#include <asm-generic/dma-mapping-common.h>

static inline int dma_set_mask(struct device *dev, u64 mask)
{
    return get_dma_ops(dev)->set_dma_mask(dev, mask);
}

#ifdef __arch_page_to_dma
#error Please update to __arch_pfn_to_dma
#endif

/*
 * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
 * functions used internally by the DMA-mapping API to provide DMA
 * addresses. They must not be used by drivers.
 */
#ifndef __arch_pfn_to_dma
static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
{
    return (dma_addr_t)__pfn_to_bus(pfn);
}

static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
{
    return __bus_to_pfn(addr);
}

static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
{
    return (void *)__bus_to_virt((unsigned long)addr);
}

static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
{
    return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
}
#else
static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
{
    return __arch_pfn_to_dma(dev, pfn);
}

static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
{
    return __arch_dma_to_pfn(dev, addr);
}

static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
{
    return __arch_dma_to_virt(dev, addr);
}

static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
{
    return __arch_virt_to_dma(dev, addr);
}
#endif

/*
 * DMA errors are defined by all-bits-set in the DMA address.
 */
static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
    return dma_addr == DMA_ERROR_CODE;
}

/*
 * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
 * function so drivers using this API are highlighted with build warnings.
 */
static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
        dma_addr_t *handle, gfp_t gfp)
{
    return NULL;
}

static inline void dma_free_noncoherent(struct device *dev, size_t size,
        void *cpu_addr, dma_addr_t handle)
{
}

extern int dma_supported(struct device *dev, u64 mask);

extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
               gfp_t gfp, struct dma_attrs *attrs);

#define dma_alloc_coherent(d, s, h, f) dma_alloc_attrs(d, s, h, f, NULL)

static inline void *dma_alloc_attrs(struct device *dev, size_t size,
                       dma_addr_t *dma_handle, gfp_t flag,
                       struct dma_attrs *attrs)
{
    struct dma_map_ops *ops = get_dma_ops(dev);
    void *cpu_addr;
    BUG_ON(!ops);

    cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs);
    debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr);
    return cpu_addr;
}

extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
             dma_addr_t handle, struct dma_attrs *attrs);

#define dma_free_coherent(d, s, c, h) dma_free_attrs(d, s, c, h, NULL)

static inline void dma_free_attrs(struct device *dev, size_t size,
                     void *cpu_addr, dma_addr_t dma_handle,
                     struct dma_attrs *attrs)
{
    struct dma_map_ops *ops = get_dma_ops(dev);
    BUG_ON(!ops);

    debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);
    ops->free(dev, size, cpu_addr, dma_handle, attrs);
}

extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
            void *cpu_addr, dma_addr_t dma_addr, size_t size,
            struct dma_attrs *attrs);

static inline void *dma_alloc_writecombine(struct device *dev, size_t size,
                       dma_addr_t *dma_handle, gfp_t flag)
{
    DEFINE_DMA_ATTRS(attrs);
    dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
    return dma_alloc_attrs(dev, size, dma_handle, flag, &attrs);
}

static inline void dma_free_writecombine(struct device *dev, size_t size,
                     void *cpu_addr, dma_addr_t dma_handle)
{
    DEFINE_DMA_ATTRS(attrs);
    dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
    return dma_free_attrs(dev, size, cpu_addr, dma_handle, &attrs);
}

/*
 * This can be called during early boot to increase the size of the atomic
 * coherent DMA pool above the default value of 256KiB. It must be called
 * before postcore_initcall.
 */
extern void __init init_dma_coherent_pool_size(unsigned long size);

/*
 * This can be called during boot to increase the size of the consistent
 * DMA region above it's default value of 2MB. It must be called before the
 * memory allocator is initialised, i.e. before any core_initcall.
 */
static inline void init_consistent_dma_size(unsigned long size) { }

/*
 * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 * and utilize bounce buffers as needed to work around limited DMA windows.
 *
 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 *
 * The following are helper functions used by the dmabounce subystem
 *
 */

extern int dmabounce_register_dev(struct device *, unsigned long,
        unsigned long, int (*)(struct device *, dma_addr_t, size_t));

extern void dmabounce_unregister_dev(struct device *);



/*
 * The scatter list versions of the above methods.
 */
extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
        enum dma_data_direction, struct dma_attrs *attrs);
extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
        enum dma_data_direction, struct dma_attrs *attrs);
extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
        enum dma_data_direction);
extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
        enum dma_data_direction);
extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
        void *cpu_addr, dma_addr_t dma_addr, size_t size,
        struct dma_attrs *attrs);

#endif /* __KERNEL__ */
#endif