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linux-next/include/asm-generic/dma-coherent.h
Bjorn Helgaas 88a984ba07 DMA-API: Change dma_declare_coherent_memory() CPU address to phys_addr_t
dma_declare_coherent_memory() takes two addresses for a region of memory: a
"bus_addr" and a "device_addr".  I think the intent is that "bus_addr" is
the physical address a *CPU* would use to access the region, and
"device_addr" is the bus address the *device* would use to address the
region.

Rename "bus_addr" to "phys_addr" and change its type to phys_addr_t.
Most callers already supply a phys_addr_t for this argument.  The others
supply a 32-bit integer (a constant, unsigned int, or __u32) and need no
change.

Use "unsigned long", not phys_addr_t, to hold PFNs.

No functional change (this could theoretically fix a truncation in a config
with 32-bit dma_addr_t and 64-bit phys_addr_t, but I don't think there are
any such cases involving this code).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: James Bottomley <jbottomley@Parallels.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
2014-05-20 16:55:23 -06:00

33 lines
1.0 KiB
C

#ifndef DMA_COHERENT_H
#define DMA_COHERENT_H
#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
/*
* These three functions are only for dma allocator.
* Don't use them in device drivers.
*/
int dma_alloc_from_coherent(struct device *dev, ssize_t size,
dma_addr_t *dma_handle, void **ret);
int dma_release_from_coherent(struct device *dev, int order, void *vaddr);
int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, size_t size, int *ret);
/*
* Standard interface
*/
#define ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
dma_addr_t device_addr, size_t size, int flags);
void dma_release_declared_memory(struct device *dev);
void *dma_mark_declared_memory_occupied(struct device *dev,
dma_addr_t device_addr, size_t size);
#else
#define dma_alloc_from_coherent(dev, size, handle, ret) (0)
#define dma_release_from_coherent(dev, order, vaddr) (0)
#define dma_mmap_from_coherent(dev, vma, vaddr, order, ret) (0)
#endif
#endif