From 74bc7ceebfa1c84ddd3a843ebfb56df013bf7ef5 Mon Sep 17 00:00:00 2001 From: Arthur Kepner Date: Tue, 29 Apr 2008 01:00:30 -0700 Subject: [PATCH] dma: add dma_*map*_attrs() interfaces 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 Cc: Tony Luck Cc: Jesse Barnes Cc: Jes Sorensen Cc: Randy Dunlap Cc: Roland Dreier Cc: James Bottomley Cc: David Miller Cc: Benjamin Herrenschmidt Cc: Grant Grundler Cc: Michael Ellerman Signed-off-by: Mark Nelson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/Kconfig | 3 ++ arch/ia64/Kconfig | 1 + include/linux/dma-attrs.h | 74 +++++++++++++++++++++++++++++++++++++ include/linux/dma-mapping.h | 17 +++++++++ 4 files changed, 95 insertions(+) create mode 100644 include/linux/dma-attrs.h diff --git a/arch/Kconfig b/arch/Kconfig index 694c9af520..3ea332b009 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 07f5d353b5..0df5f6f75e 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 select HAVE_KVM default y help diff --git a/include/linux/dma-attrs.h b/include/linux/dma-attrs.h new file mode 100644 index 0000000000..1677e2bfa0 --- /dev/null +++ b/include/linux/dma-attrs.h @@ -0,0 +1,74 @@ +#ifndef _DMA_ATTR_H +#define _DMA_ATTR_H + +#include +#include +#include + +/** + * 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 */ diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 3320307096..952e0f857a 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 -- 2.39.5