text: /*
   * 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 <linux/gfp.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)
  {
  	gfp_t dma_flag;
  
  	/* ignore region specifiers */
  	gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
  
  #ifdef CONFIG_ISA
  	if (dev == NULL)
  		dma_flag = __GFP_DMA;
  	else
  #endif
  #if defined(CONFIG_ZONE_DMA32) && defined(CONFIG_ZONE_DMA)
  	     if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
  			dma_flag = __GFP_DMA;
  	else if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
  			dma_flag = __GFP_DMA32;
  	else
  #endif
  #if defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_ZONE_DMA)
  	     if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
  		dma_flag = __GFP_DMA32;
  	else
  #endif
  #if defined(CONFIG_ZONE_DMA) && !defined(CONFIG_ZONE_DMA32)
  	     if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
  		dma_flag = __GFP_DMA;
  	else
  #endif
  		dma_flag = 0;
  
  	/* Don't invoke OOM killer */
  	gfp |= __GFP_NORETRY;
  
  	return gfp | dma_flag;
  }
  
  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)
  {
  	extern int hw_coherentio;
  	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);
  			if (!hw_coherentio)
  				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)
  {
  	extern int hw_coherentio;
  	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))
  		if (!hw_coherentio)
  			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);
  
  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);
  