Messages in this thread Patch in this message | | | From | akepner@sgi ... | Date | Mon, 31 Mar 2008 18:34:57 -0700 | Subject | [PATCH 0/3 v6] dma: add dma_*map*_attrs() interfaces |
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v5-v6 changes:
- if CONFIG_HAVE_DMA_ATTRS isn't defined , use macros to define dma_*map*_attrs() - this gets around a build problem on alpha, and maybe other arches, too.
- fix ib_umem_get() call in drivers/infiniband/hw/nes/nes_verbs.c
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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.
Signed-off-by: Arthur Kepner <akepner@sgi.com>
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arch/Kconfig | 3 + arch/ia64/Kconfig | 1 include/linux/dma-attrs.h | 74 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/dma-mapping.h | 17 ++++++++++ 4 files changed, 95 insertions(+)
diff --git a/arch/Kconfig b/arch/Kconfig index 694c9af..3ea332b 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -36,3 +36,6 @@ config HAVE_KPROBES config HAVE_KRETPROBES def_bool n + +config HAVE_DMA_ATTRS + def_bool n diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 8fa3faf..985b267 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -19,6 +19,7 @@ config IA64 select HAVE_OPROFILE select HAVE_KPROBES select HAVE_KRETPROBES + select HAVE_DMA_ATTRS default y help The Itanium Processor Family is Intel's 64-bit successor to diff --git a/include/linux/dma-attrs.h b/include/linux/dma-attrs.h index e69de29..5f151fb 100644 --- a/include/linux/dma-attrs.h +++ b/include/linux/dma-attrs.h @@ -0,0 +1,74 @@ +#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) + */ +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) + */ +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 */ diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 3320307..952e0f8 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -146,4 +146,21 @@ static inline void dmam_release_declared_memory(struct device *dev) } #endif /* ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY */ +#ifndef CONFIG_HAVE_DMA_ATTRS +struct dma_attrs; + +#define dma_map_single_attrs(dev, cpu_addr, size, dir, attrs) \ + dma_map_single(dev, cpu_addr, size, dir) + +#define dma_unmap_single_attrs(dev, dma_addr, size, dir, attrs) \ + dma_unmap_single(dev, dma_addr, size, dir) + +#define dma_map_sg_attrs(dev, sgl, nents, dir, attrs) \ + dma_map_sg(dev, sgl, nents, dir) + +#define dma_unmap_sg_attrs(dev, sgl, nents, dir, attrs) \ + dma_unmap_sg(dev, sgl, nents, dir) + +#endif /* CONFIG_HAVE_DMA_ATTRS */ + #endif
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