linux/arch/powerpc/include/asm/dma-mapping.h

/*
 * Copyright (C) 2004 IBM
 *
 * Implements the generic device dma API for powerpc.
 * the pci and vio busses
 */
#ifndef _ASM_DMA_MAPPING_H
#define _ASM_DMA_MAPPING_H
#ifdef __KERNEL__

#include <linux/types.h>
#include <linux/cache.h>
/* need struct page definitions */
#include <linux/mm.h>
#include <linux/scatterlist.h>
#include <linux/dma-attrs.h>
#include <linux/dma-debug.h>
#include <asm/io.h>
#include <asm/swiotlb.h>

#define DMA_ERROR_CODE		(~(dma_addr_t)0x0)

/* Some dma direct funcs must be visible for use in other dma_ops */
extern void *dma_direct_alloc_coherent(struct device *dev, size_t size,
				       dma_addr_t *dma_handle, gfp_t flag);
extern void dma_direct_free_coherent(struct device *dev, size_t size,
				     void *vaddr, dma_addr_t dma_handle);

extern unsigned long get_dma_direct_offset(struct device *dev);

#ifdef CONFIG_NOT_COHERENT_CACHE
/*
 * DMA-consistent mapping functions for PowerPCs that don't support
 * cache snooping.  These allocate/free a region of uncached mapped
 * memory space for use with DMA devices.  Alternatively, you could
 * allocate the space "normally" and use the cache management functions
 * to ensure it is consistent.
 */
struct device;
extern void *__dma_alloc_coherent(struct device *dev, size_t size,
				  dma_addr_t *handle, gfp_t gfp);
extern void __dma_free_coherent(size_t size, void *vaddr);
extern void __dma_sync(void *vaddr, size_t size, int direction);
extern void __dma_sync_page(struct page *page, unsigned long offset,
				 size_t size, int direction);

#else /* ! CONFIG_NOT_COHERENT_CACHE */
/*
 * Cache coherent cores.
 */

#define __dma_alloc_coherent(dev, gfp, size, handle)	NULL
#define __dma_free_coherent(size, addr)		((void)0)
#define __dma_sync(addr, size, rw)		((void)0)
#define __dma_sync_page(pg, off, sz, rw)	((void)0)

#endif /* ! CONFIG_NOT_COHERENT_CACHE */

static inline unsigned long device_to_mask(struct device *dev)
{
	if (dev->dma_mask && *dev->dma_mask)
		return *dev->dma_mask;
	/* Assume devices without mask can take 32 bit addresses */
	return 0xfffffffful;
}

/*
 * Available generic sets of operations
 */
#ifdef CONFIG_PPC64
extern struct dma_map_ops dma_iommu_ops;
#endif
extern struct dma_map_ops dma_direct_ops;

static inline struct dma_map_ops *get_dma_ops(struct device *dev)
{
	/* We don't handle the NULL dev case for ISA for now. We could
	 * do it via an out of line call but it is not needed for now. The
	 * only ISA DMA device we support is the floppy and we have a hack
	 * in the floppy driver directly to get a device for us.
	 */
	if (unlikely(dev == NULL))
		return NULL;

	return dev->archdata.dma_ops;
}

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

/* this will be removed soon */
#define flush_write_buffers()

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

static inline int dma_supported(struct device *dev, u64 mask)
{
	struct dma_map_ops *dma_ops = get_dma_ops(dev);

	if (unlikely(dma_ops == NULL))
		return 0;
	if (dma_ops->dma_supported == NULL)
		return 1;
	return dma_ops->dma_supported(dev, mask);
}

/* We have our own implementation of pci_set_dma_mask() */
#define HAVE_ARCH_PCI_SET_DMA_MASK

static inline int dma_set_mask(struct device *dev, u64 dma_mask)
{
	struct dma_map_ops *dma_ops = get_dma_ops(dev);

	if (unlikely(dma_ops == NULL))
		return -EIO;
	if (dma_ops->set_dma_mask != NULL)
		return dma_ops->set_dma_mask(dev, dma_mask);
	if (!dev->dma_mask || !dma_supported(dev, dma_mask))
		return -EIO;
	*dev->dma_mask = dma_mask;
	return 0;
}

static inline void *dma_alloc_coherent(struct device *dev, size_t size,
				       dma_addr_t *dma_handle, gfp_t flag)
{
	struct dma_map_ops *dma_ops = get_dma_ops(dev);
	void *cpu_addr;

	BUG_ON(!dma_ops);

	cpu_addr = dma_ops->alloc_coherent(dev, size, dma_handle, flag);

	debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr);

	return cpu_addr;
}

static inline void dma_free_coherent(struct device *dev, size_t size,
				     void *cpu_addr, dma_addr_t dma_handle)
{
	struct dma_map_ops *dma_ops = get_dma_ops(dev);

	BUG_ON(!dma_ops);

	debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);

	dma_ops->free_coherent(dev, size, cpu_addr, dma_handle);
}

static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
	struct dma_map_ops *dma_ops = get_dma_ops(dev);

	if (dma_ops->mapping_error)
		return dma_ops->mapping_error(dev, dma_addr);

#ifdef CONFIG_PPC64
	return (dma_addr == DMA_ERROR_CODE);
#else
	return 0;
#endif
}

static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
{
#ifdef CONFIG_SWIOTLB
	struct dev_archdata *sd = &dev->archdata;

	if (sd->max_direct_dma_addr && addr + size > sd->max_direct_dma_addr)
		return 0;
#endif

	if (!dev->dma_mask)
		return 0;

	return addr + size <= *dev->dma_mask;
}

static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
{
	return paddr + get_dma_direct_offset(dev);
}

static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
{
	return daddr - get_dma_direct_offset(dev);
}

#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)
#ifdef CONFIG_NOT_COHERENT_CACHE
#define dma_is_consistent(d, h)	(0)
#else
#define dma_is_consistent(d, h)	(1)
#endif

static inline int dma_get_cache_alignment(void)
{
#ifdef CONFIG_PPC64
	/* no easy way to get cache size on all processors, so return
	 * the maximum possible, to be safe */
	return (1 << INTERNODE_CACHE_SHIFT);
#else
	/*
	 * Each processor family will define its own L1_CACHE_SHIFT,
	 * L1_CACHE_BYTES wraps to this, so this is always safe.
	 */
	return L1_CACHE_BYTES;
#endif
}

static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
		enum dma_data_direction direction)
{
	BUG_ON(direction == DMA_NONE);
	__dma_sync(vaddr, size, (int)direction);
}

#endif /* __KERNEL__ */
#endif	/* _ASM_DMA_MAPPING_H */