mirror of
https://github.com/adulau/aha.git
synced 2024-12-28 19:56:18 +00:00
74bc7ceebf
Introduce new interfaces, dma_*map*_attrs(), for passing architecture-specific
attributes when memory is mapped and unmapped for DMA. Give the interfaces
default implementations which ignore attributes. Also introduce the
dma_{set|get}_attr() interfaces for setting and retrieving individual
attributes. Define one attribute, DMA_ATTR_WRITE_BARRIER, in anticipation of
its use by ia64/sn. Select whether architectures implement arch-specific
versions of the dma_*map*_attrs() interfaces via HAVE_DMA_ATTRS in Kconfig.
[markn@au1.ibm.com: dma_{set,get}_attr() have to be static inline]
Signed-off-by: Arthur Kepner <akepner@sgi.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
74 lines
1.7 KiB
C
74 lines
1.7 KiB
C
#ifndef _DMA_ATTR_H
|
|
#define _DMA_ATTR_H
|
|
|
|
#include <linux/bitmap.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/bug.h>
|
|
|
|
/**
|
|
* an enum dma_attr represents an attribute associated with a DMA
|
|
* mapping. The semantics of each attribute should be defined in
|
|
* Documentation/DMA-attributes.txt.
|
|
*/
|
|
enum dma_attr {
|
|
DMA_ATTR_WRITE_BARRIER,
|
|
DMA_ATTR_MAX,
|
|
};
|
|
|
|
#define __DMA_ATTRS_LONGS BITS_TO_LONGS(DMA_ATTR_MAX)
|
|
|
|
/**
|
|
* struct dma_attrs - an opaque container for DMA attributes
|
|
* @flags - bitmask representing a collection of enum dma_attr
|
|
*/
|
|
struct dma_attrs {
|
|
unsigned long flags[__DMA_ATTRS_LONGS];
|
|
};
|
|
|
|
#define DEFINE_DMA_ATTRS(x) \
|
|
struct dma_attrs x = { \
|
|
.flags = { [0 ... __DMA_ATTRS_LONGS-1] = 0 }, \
|
|
}
|
|
|
|
static inline void init_dma_attrs(struct dma_attrs *attrs)
|
|
{
|
|
bitmap_zero(attrs->flags, __DMA_ATTRS_LONGS);
|
|
}
|
|
|
|
#ifdef CONFIG_HAVE_DMA_ATTRS
|
|
/**
|
|
* dma_set_attr - set a specific attribute
|
|
* @attr: attribute to set
|
|
* @attrs: struct dma_attrs (may be NULL)
|
|
*/
|
|
static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs)
|
|
{
|
|
if (attrs == NULL)
|
|
return;
|
|
BUG_ON(attr >= DMA_ATTR_MAX);
|
|
__set_bit(attr, attrs->flags);
|
|
}
|
|
|
|
/**
|
|
* dma_get_attr - check for a specific attribute
|
|
* @attr: attribute to set
|
|
* @attrs: struct dma_attrs (may be NULL)
|
|
*/
|
|
static inline int dma_get_attr(enum dma_attr attr, struct dma_attrs *attrs)
|
|
{
|
|
if (attrs == NULL)
|
|
return 0;
|
|
BUG_ON(attr >= DMA_ATTR_MAX);
|
|
return test_bit(attr, attrs->flags);
|
|
}
|
|
#else /* !CONFIG_HAVE_DMA_ATTRS */
|
|
static inline void dma_set_attr(enum dma_attr attr, struct dma_attrs *attrs)
|
|
{
|
|
}
|
|
|
|
static inline int dma_get_attr(enum dma_attr attr, struct dma_attrs *attrs)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_HAVE_DMA_ATTRS */
|
|
#endif /* _DMA_ATTR_H */
|