/*
 * drivers/base/dma-mapping.c - arch-independent dma-mapping routines
 *
 * Copyright (c) 2006  SUSE Linux Products GmbH
 * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
 *
 * This file is released under the GPLv2.
 */

#include <linux/dma-mapping.h>
#include <linux/export.h>
#include <linux/gfp.h>
#include <asm-generic/dma-coherent.h>

/*
 * Managed DMA API
 */
struct dma_devres {
        size_t          size;
        void            *vaddr;
        dma_addr_t      dma_handle;
};

static void dmam_coherent_release(struct device *dev, void *res)
{
        struct dma_devres *this = res;

        dma_free_coherent(dev, this->size, this->vaddr, this->dma_handle);
}

static void dmam_noncoherent_release(struct device *dev, void *res)
{
        struct dma_devres *this = res;

        dma_free_noncoherent(dev, this->size, this->vaddr, this->dma_handle);
}

static int dmam_match(struct device *dev, void *res, void *match_data)
{
        struct dma_devres *this = res, *match = match_data;

        if (this->vaddr == match->vaddr) {
                WARN_ON(this->size != match->size ||
                        this->dma_handle != match->dma_handle);
                return 1;
        }
        return 0;
}

/**
 * dmam_alloc_coherent - Managed dma_alloc_coherent()
 * @dev: Device to allocate coherent memory for
 * @size: Size of allocation
 * @dma_handle: Out argument for allocated DMA handle
 * @gfp: Allocation flags
 *
 * Managed dma_alloc_coherent().  Memory allocated using this function
 * will be automatically released on driver detach.
 *
 * RETURNS:
 * Pointer to allocated memory on success, NULL on failure.
 */
void * dmam_alloc_coherent(struct device *dev, size_t size,
                           dma_addr_t *dma_handle, gfp_t gfp)
{
        struct dma_devres *dr;
        void *vaddr;

        dr = devres_alloc(dmam_coherent_release, sizeof(*dr), gfp);
        if (!dr)
                return NULL;

        vaddr = dma_alloc_coherent(dev, size, dma_handle, gfp);
        if (!vaddr) {
                devres_free(dr);
                return NULL;
        }

        dr->vaddr = vaddr;
        dr->dma_handle = *dma_handle;
        dr->size = size;

        devres_add(dev, dr);

        return vaddr;
}
EXPORT_SYMBOL(dmam_alloc_coherent);

/**
 * dmam_free_coherent - Managed dma_free_coherent()
 * @dev: Device to free coherent memory for
 * @size: Size of allocation
 * @vaddr: Virtual address of the memory to free
 * @dma_handle: DMA handle of the memory to free
 *
 * Managed dma_free_coherent().
 */
void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
                        dma_addr_t dma_handle)
{
        struct dma_devres match_data = { size, vaddr, dma_handle };

        dma_free_coherent(dev, size, vaddr, dma_handle);
        WARN_ON(devres_destroy(dev, dmam_coherent_release, dmam_match,
                               &match_data));
}
EXPORT_SYMBOL(dmam_free_coherent);

/**
 * dmam_alloc_non_coherent - Managed dma_alloc_non_coherent()
 * @dev: Device to allocate non_coherent memory for
 * @size: Size of allocation
 * @dma_handle: Out argument for allocated DMA handle
 * @gfp: Allocation flags
 *
 * Managed dma_alloc_non_coherent().  Memory allocated using this
 * function will be automatically released on driver detach.
 *
 * RETURNS:
 * Pointer to allocated memory on success, NULL on failure.
 */
void *dmam_alloc_noncoherent(struct device *dev, size_t size,
                             dma_addr_t *dma_handle, gfp_t gfp)
{
        struct dma_devres *dr;
        void *vaddr;

        dr = devres_alloc(dmam_noncoherent_release, sizeof(*dr), gfp);
        if (!dr)
                return NULL;

        vaddr = dma_alloc_noncoherent(dev, size, dma_handle, gfp);
        if (!vaddr) {
                devres_free(dr);
                return NULL;
        }

        dr->vaddr = vaddr;
        dr->dma_handle = *dma_handle;
        dr->size = size;

        devres_add(dev, dr);

        return vaddr;
}
EXPORT_SYMBOL(dmam_alloc_noncoherent);

/**
 * dmam_free_coherent - Managed dma_free_noncoherent()
 * @dev: Device to free noncoherent memory for
 * @size: Size of allocation
 * @vaddr: Virtual address of the memory to free
 * @dma_handle: DMA handle of the memory to free
 *
 * Managed dma_free_noncoherent().
 */
void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr,
                           dma_addr_t dma_handle)
{
        struct dma_devres match_data = { size, vaddr, dma_handle };

        dma_free_noncoherent(dev, size, vaddr, dma_handle);
        WARN_ON(!devres_destroy(dev, dmam_noncoherent_release, dmam_match,
                                &match_data));
}
EXPORT_SYMBOL(dmam_free_noncoherent);

#ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY

static void dmam_coherent_decl_release(struct device *dev, void *res)
{
        dma_release_declared_memory(dev);
}

/**
 * dmam_declare_coherent_memory - Managed dma_declare_coherent_memory()
 * @dev: Device to declare coherent memory for
 * @bus_addr: Bus address of coherent memory to be declared
 * @device_addr: Device address of coherent memory to be declared
 * @size: Size of coherent memory to be declared
 * @flags: Flags
 *
 * Managed dma_declare_coherent_memory().
 *
 * RETURNS:
 * 0 on success, -errno on failure.
 */
int dmam_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
                                 dma_addr_t device_addr, size_t size, int flags)
{
        void *res;
        int rc;

        res = devres_alloc(dmam_coherent_decl_release, 0, GFP_KERNEL);
        if (!res)
                return -ENOMEM;

        rc = dma_declare_coherent_memory(dev, bus_addr, device_addr, size,
                                         flags);
        if (rc == 0)
                devres_add(dev, res);
        else
                devres_free(res);

        return rc;
}
EXPORT_SYMBOL(dmam_declare_coherent_memory);

/**
 * dmam_release_declared_memory - Managed dma_release_declared_memory().
 * @dev: Device to release declared coherent memory for
 *
 * Managed dmam_release_declared_memory().
 */
void dmam_release_declared_memory(struct device *dev)
{
        WARN_ON(devres_destroy(dev, dmam_coherent_decl_release, NULL, NULL));
}
EXPORT_SYMBOL(dmam_release_declared_memory);

#endif

/*
 * Create scatter-list for the already allocated DMA buffer.
 */
int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
                 void *cpu_addr, dma_addr_t handle, size_t size)
{
        struct page *page = virt_to_page(cpu_addr);
        int ret;

        ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
        if (unlikely(ret))
                return ret;

        sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
        return 0;
}
EXPORT_SYMBOL(dma_common_get_sgtable);

/*
 * Create userspace mapping for the DMA-coherent memory.
 */
int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
                    void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
        int ret = -ENXIO;
#ifdef CONFIG_MMU
        unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
        unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
        unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
        unsigned long off = vma->vm_pgoff;

        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

        if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
                return ret;

        if (off < count && user_count <= (count - off)) {
                ret = remap_pfn_range(vma, vma->vm_start,
                                      pfn + off,
                                      user_count << PAGE_SHIFT,
                                      vma->vm_page_prot);
        }
#endif  /* CONFIG_MMU */

        return ret;
}
EXPORT_SYMBOL(dma_common_mmap);