/*
 * 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(struct device *dev,
        dma_addr_t dma_addr)
{
        unsigned long addr = plat_dma_addr_to_phys(dev, 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;

        if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
                return 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)
{
        plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
        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;
        int order = get_order(size);

        if (dma_release_from_coherent(dev, order, vaddr))
                return;

        plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);

        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(dev, dma_addr), size,
                           direction);

        plat_unmap_dma_mem(dev, dma_addr, size, direction);
}

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_sync(addr, size, direction);
        }

        return plat_map_dma_mem_page(dev, page) + offset;
}

EXPORT_SYMBOL(dma_map_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(dev, sg->dma_address, sg->length, direction);
        }
}

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(dev, 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);

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

                addr = dma_addr_to_virt(dev, 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(dev, 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);

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

                addr = dma_addr_to_virt(dev, 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);
        }
}

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);
        }
}

EXPORT_SYMBOL(dma_sync_sg_for_device);

int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
        return plat_dma_mapping_error(dev, dma_addr);
}

EXPORT_SYMBOL(dma_mapping_error);

int dma_supported(struct device *dev, u64 mask)
{
        return plat_dma_supported(dev, mask);
}

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);

        plat_extra_sync_for_device(dev);
        if (!plat_device_is_coherent(dev))
                __dma_sync((unsigned long)vaddr, size, direction);
}

EXPORT_SYMBOL(dma_cache_sync);