#ifndef ASMARM_DMA_MAPPING_H
#define ASMARM_DMA_MAPPING_H
#ifdef __KERNEL__
#include <linux/config.h>
#include <linux/mm.h> /* need struct page */
#include <asm/scatterlist.h>
/*
* 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
*/
extern void consistent_sync(void *kaddr, 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)
{
return dev->dma_mask && *dev->dma_mask != 0;
}
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(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(dma_addr_t dma_addr)
{
return dma_addr == ~0;
}
/**
* 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 *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
/**
* 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 *dev, size_t size, void *cpu_addr,
dma_addr_t handle);
/**
* 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 *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t handle, size_t size);
/**
* 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 *dev, size_t size, dma_addr_t *handle, gfp_t gfp);
#define dma_free_writecombine(dev,size,cpu_addr,handle) \
dma_free_coherent(dev,size,cpu_addr,handle)
int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t handle, size_t size);
/**
* 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().
*/
#ifndef CONFIG_DMABOUNCE
static inline dma_addr_t
dma_map_single(struct device *dev, void *cpu_addr, size_t size,
enum dma_data_direction dir)
{
if (!arch_is_coherent())
consistent_sync(cpu_addr, size, dir);
return virt_to_dma(dev, (unsigned long)cpu_addr);
}
#else
extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
#endif
/**
* 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() or
* dma_sync_single_for_cpu().
*/
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)
{
return dma_map_single(dev, page_address(page) + offset, size, (int)dir);
}
/**
* 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 to map
* @dir: DMA transfer direction
*
* 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.
*/
#ifndef CONFIG_DMABOUNCE
static inline void
dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
enum dma_data_direction dir)
{
/* nothing to do */
}
#else
extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
#endif
/**
* 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 to map
* @dir: DMA transfer direction
*
* 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_page(struct device *dev, dma_addr_t handle, size_t size,
enum dma_data_direction dir)
{
dma_unmap_single(dev, handle, size, (int)dir);
}
/**
* dma_map_sg - map a set of SG buffers for streaming mode DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Map a set of buffers described by scatterlist in streaming
* mode for DMA. This is the scatter-gather version of the
* above dma_map_single interface. Here the scatter gather list
* elements are each tagged with the appropriate dma address
* and length. They are obtained via sg_dma_{address,length}(SG).
*
* NOTE: An implementation may be able to use a smaller number of
* DMA address/length pairs than there are SG table elements.
* (for example via virtual mapping capabilities)
* The routine returns the number of addr/length pairs actually
* used, at most nents.
*
* Device ownership issues as mentioned above for dma_map_single are
* the same here.
*/
#ifndef CONFIG_DMABOUNCE
static inline int
dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
int i;
for (i = 0; i < nents; i++, sg++) {
char *virt;
sg->dma_address = page_to_dma(dev, sg->page) + sg->offset;
virt = page_address(sg->page) + sg->offset;
if (!arch_is_coherent())
consistent_sync(virt, sg->length, dir);
}
return nents;
}
#else
extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
#endif
/**
* dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Unmap a set of streaming mode DMA translations.
* Again, CPU read rules concerning calls here are the same as for
* dma_unmap_single() above.
*/
#ifndef CONFIG_DMABOUNCE
static inline void
dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
/* nothing to do */
}
#else
extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
#endif
/**
* dma_sync_single_for_cpu
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @handle: DMA address of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* 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.
*/
#ifndef CONFIG_DMABOUNCE
static inline void
dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
enum dma_data_direction dir)
{
if (!arch_is_coherent())
consistent_sync((void *)dma_to_virt(dev, handle), 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)
{
if (!arch_is_coherent())
consistent_sync((void *)dma_to_virt(dev, handle), size, dir);
}
#else
extern void dma_sync_single_for_cpu(struct device*, dma_addr_t, size_t, enum dma_data_direction);
extern void dma_sync_single_for_device(struct device*, dma_addr_t, size_t, enum dma_data_direction);
#endif
/**
* dma_sync_sg_for_cpu
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Make physical memory consistent for a set of streaming
* mode DMA translations after a transfer.
*
* The same as dma_sync_single_for_* but for a scatter-gather list,
* same rules and usage.
*/
#ifndef CONFIG_DMABOUNCE
static inline void
dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
int i;
for (i = 0; i < nents; i++, sg++) {
char *virt = page_address(sg->page) + sg->offset;
if (!arch_is_coherent())
consistent_sync(virt, sg->length, dir);
}
}
static inline void
dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
int i;
for (i = 0; i < nents; i++, sg++) {
char *virt = page_address(sg->page) + sg->offset;
if (!arch_is_coherent())
consistent_sync(virt, sg->length, dir);
}
}
#else
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
#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 sytems, 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 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);
#endif /* CONFIG_DMABOUNCE */
#endif /* __KERNEL__ */
#endif
