#ifndef ASMARM_DMA_MAPPING_H
#define ASMARM_DMA_MAPPING_H
#ifdef __KERNEL__
#include <linux/mm_types.h>
#include <linux/scatterlist.h>
#include <asm-generic/dma-coherent.h>
#include <asm/memory.h>
/*
* page_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_page_to_dma
#if !defined(CONFIG_HIGHMEM)
static inline dma_addr_t page_to_dma(struct device *dev, struct page *page)
{
return (dma_addr_t)__virt_to_bus((unsigned long)page_address(page));
}
#elif defined(__pfn_to_bus)
static inline dma_addr_t page_to_dma(struct device *dev, struct page *page)
{
return (dma_addr_t)__pfn_to_bus(page_to_pfn(page));
}
#else
#error "this machine class needs to define __arch_page_to_dma to use HIGHMEM"
#endif
static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
{
return (void *)__bus_to_virt(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 page_to_dma(struct device *dev, struct page *page)
{
return __arch_page_to_dma(dev, page);
}
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-consistent mapping functions. These allocate/free a region of
* uncached, unwrite-buffered mapped memory space for use with DMA
* devices. This is the "generic" version. The PCI specific version
* is in pci.h
*
* Note: Drivers should NOT use this function directly, as it will break
* platforms with CONFIG_DMABOUNCE.
* Use the driver DMA support - see dma-mapping.h (dma_sync_*)
*/
extern void dma_cache_maint(const void *kaddr, size_t size, int rw);
extern void dma_cache_maint_page(struct page *page, unsigned long offset,
size_t size, int rw);
/*
* Return whether the given device DMA address mask can be supported
* properly. For example, if your device can only drive the low 24-bits
* during bus mastering, then you would pass 0x00ffffff as the mask
* to this function.
*
* FIXME: This should really be a platform specific issue - we should
* return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
*/
static inline int dma_supported(struct device *dev, u64 mask)
{
if (mask < ISA_DMA_THRESHOLD)
return 0;
return 1;
}
static inline int dma_set_mask(struct device *dev, u64 dma_mask)
{
if (!dev->dma_mask || !dma_supported(dev, dma_mask))
return -EIO;
*dev->dma_mask = dma_mask;
return 0;
}
static inline int dma_get_cache_alignment(void)
{
return 32;
}
static inline int dma_is_consistent(struct device *dev, dma_addr_t handle)
{
return !!arch_is_coherent();
}
/*
* 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 == ~0;
}
/*
* 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)
{
}
/**
* dma_alloc_coherent - allocate consistent memory for DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: required memory size
* @handle: bus-specific DMA address
*
* Allocate some uncached, unbuffered memory for a device for
* performing DMA. This function allocates pages, and will
* return the CPU-viewed address, and sets @handle to be the
* device-viewed address.
*/
extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
/**
* dma_free_coherent - free memory allocated by dma_alloc_coherent
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: size of memory originally requested in dma_alloc_coherent
* @cpu_addr: CPU-view address returned from dma_alloc_coherent
* @handle: device-view address returned from dma_alloc_coherent
*
* Free (and unmap) a DMA buffer previously allocated by
* dma_alloc_coherent().
*
* References to memory and mappings associated with cpu_addr/handle
* during and after this call executing are illegal.
*/
extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
/**
* dma_mmap_coherent - map a coherent DMA allocation into user space
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @vma: vm_area_struct describing requested user mapping
* @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
* @handle: device-view address returned from dma_alloc_coherent
* @size: size of memory originally requested in dma_alloc_coherent
*
* Map a coherent DMA buffer previously allocated by dma_alloc_coherent
* into user space. The coherent DMA buffer must not be freed by the
* driver until the user space mapping has been released.
*/
int dma_mmap_coherent(struct device *, struct vm_area_struct *,
void *, dma_addr_t, size_t);
/**
* dma_alloc_writecombine - allocate writecombining memory for DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: required memory size
* @handle: bus-specific DMA address
*
* Allocate some uncached, buffered memory for a device for
* performing DMA. This function allocates pages, and will
* return the CPU-viewed address, and sets @handle to be the
* device-viewed address.
*/
extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
gfp_t);
#define dma_free_writecombine(dev,size,cpu_addr,handle) \
dma_free_coherent(dev,size,cpu_addr,handle)
int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
void *, dma_addr_t, size_t);
#ifdef CONFIG_DMABOUNCE
/*
* 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
*
*/
/**
* dmabounce_register_dev
*
* @dev: valid struct device pointer
* @small_buf_size: size of buffers to use with small buffer pool
* @large_buf_size: size of buffers to use with large buffer pool (can be 0)
*
* This function should be called by low-level platform code to register
* a device as requireing DMA buffer bouncing. The function will allocate
* appropriate DMA pools for the device.
*
*/
extern int dmabounce_register_dev(struct device *, unsigned long,
unsigned long);
/**
* dmabounce_unregister_dev
*
* @dev: valid struct device pointer
*
* This function should be called by low-level platform code when device
* that was previously registered with dmabounce_register_dev is removed
* from the system.
*
*/
extern void dmabounce_unregister_dev(struct device *);
/**
* dma_needs_bounce
*
* @dev: valid struct device pointer
* @dma_handle: dma_handle of unbounced buffer
* @size: size of region being mapped
*
* Platforms that utilize the dmabounce mechanism must implement
* this function.
*
* The dmabounce routines call this function whenever a dma-mapping
* is requested to determine whether a given buffer needs to be bounced
* or not. The function must return 0 if the buffer is OK for
* DMA access and 1 if the buffer needs to be bounced.
*
*/
extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
/*
* The DMA API, implemented by dmabounce.c. See below for descriptions.
*/
extern dma_addr_t dma_map_single(struct device *, void *, size_t,
enum dma_data_direction);
extern dma_addr_t dma_map_page(struct device *, struct page *,
unsigned long, size_t, enum dma_data_direction);
extern void dma_unmap_single(struct device *, dma_addr_t, size_t,
enum dma_data_direction);
/*
* Private functions
*/
int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
size_t, enum dma_data_direction);
int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
size_t, enum dma_data_direction);
#else
static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
unsigned long offset, size_t size, enum dma_data_direction dir)
{
return 1;
}
static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
unsigned long offset, size_t size, enum dma_data_direction dir)
{
return 1;
}
/**
* dma_map_single - map a single buffer for streaming DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @cpu_addr: CPU direct mapped address of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* Ensure that any data held in the cache is appropriately discarded
* or written back.
*
* The device owns this memory once this call has completed. The CPU
* can regain ownership by calling dma_unmap_single() or
* dma_sync_single_for_cpu().
*/
static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
size_t size, enum dma_data_direction dir)
{
BUG_ON(!valid_dma_direction(dir));
if (!arch_is_coherent())
dma_cache_maint(cpu_addr, size, dir);
return virt_to_dma(dev, cpu_addr);
}
/**
* dma_map_page - map a portion of a page for streaming DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @page: page that buffer resides in
* @offset: offset into page for start of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* Ensure that any data held in the cache is appropriately discarded
* or written back.
*
* The device owns this memory once this call has completed. The CPU
* can regain ownership by calling dma_unmap_page().
*/
static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir)
{
BUG_ON(!valid_dma_direction(dir));
if (!arch_is_coherent())
dma_cache_maint_page(page, offset, size, dir);
return page_to_dma(dev, page) + offset;
}
/**
* dma_unmap_single - unmap a single buffer previously mapped
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @handle: DMA address of buffer
* @size: size of buffer (same as passed to dma_map_single)
* @dir: DMA transfer direction (same as passed to dma_map_single)
*
* Unmap a single streaming mode DMA translation. The handle and size
* must match what was provided in the previous dma_map_single() call.
* All other usages are undefined.
*
* After this call, reads by the CPU to the buffer are guaranteed to see
* whatever the device wrote there.
*/
static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
size_t size, enum dma_data_direction dir)
{
/* nothing to do */
}
#endif /* CONFIG_DMABOUNCE */
/**
* dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @handle: DMA address of buffer
* @size: size of buffer (same as passed to dma_map_page)
* @dir: DMA transfer direction (same as passed to dma_map_page)
*
* Unmap a page streaming mode DMA translation. The handle and size
* must match what was provided in the previous dma_map_page() call.
* All other usages are undefined.
*
* After this call, reads by the CPU to the buffer are guaranteed to see
* whatever the device wrote there.
*/
static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
size_t size, enum dma_data_direction dir)
{
dma_unmap_single(dev, handle, size, dir);
}
/**
* dma_sync_single_range_for_cpu
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @handle: DMA address of buffer
* @offset: offset of region to start sync
* @size: size of region to sync
* @dir: DMA transfer direction (same as passed to dma_map_single)
*
* Make physical memory consistent for a single streaming mode DMA
* translation after a transfer.
*
* If you perform a dma_map_single() but wish to interrogate the
* buffer using the cpu, yet do not wish to teardown the PCI dma
* mapping, you must call this function before doing so. At the
* next point you give the PCI dma address back to the card, you
* must first the perform a dma_sync_for_device, and then the
* device again owns the buffer.
*/
static inline void dma_sync_single_range_for_cpu(struct device *dev,
dma_addr_t handle, unsigned long offset, size_t size,
enum dma_data_direction dir)
{
BUG_ON(!valid_dma_direction(dir));
dmabounce_sync_for_cpu(dev, handle, offset, size, dir);
}
static inline void dma_sync_single_range_for_device(struct device *dev,
dma_addr_t handle, unsigned long offset, size_t size,
enum dma_data_direction dir)
{
BUG_ON(!valid_dma_direction(dir));
if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
return;
if (!arch_is_coherent())
dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir);
}
static inline void dma_sync_single_for_cpu(struct device *dev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
}
static inline void dma_sync_single_for_device(struct device *dev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
dma_sync_single_range_for_device(dev, handle, 0, size, dir);
}
/*
* The scatter list versions of the above methods.
*/
extern int dma_map_sg(struct device *, struct scatterlist *, int,
enum dma_data_direction);
extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
enum dma_data_direction);
extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
enum dma_data_direction);
extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
enum dma_data_direction);
#endif /* __KERNEL__ */
#endif
