On 29/12/17 08:18, Christoph Hellwig wrote: > The trivial direct mapping implementation already does a virtual to > physical translation which isn't strictly a noop, and will soon learn > to do non-direct but linear physical to dma translations through the > device offset and a few small tricks. Rename it to a better fitting > name. > > Signed-off-by: Christoph Hellwig <h...@lst.de> > --- > MAINTAINERS | 2 +- > arch/arm/Kconfig | 2 +- > arch/arm/include/asm/dma-mapping.h | 2 +- > arch/arm/mm/dma-mapping-nommu.c | 8 ++++---- > arch/m32r/Kconfig | 2 +- > arch/riscv/Kconfig | 2 +- > arch/s390/Kconfig | 2 +- > include/asm-generic/dma-mapping.h | 2 +- > include/linux/dma-mapping.h | 2 +- > lib/Kconfig | 2 +- > lib/Makefile | 2 +- > lib/{dma-noop.c => dma-direct.c} | 35 +++++++++++++++-------------------- > 12 files changed, 29 insertions(+), 34 deletions(-) > rename lib/{dma-noop.c => dma-direct.c} (53%) > > diff --git a/MAINTAINERS b/MAINTAINERS > index a8b35d9f41b2..b4005fe06e4c 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -4336,7 +4336,7 @@ T: git > git://git.infradead.org/users/hch/dma-mapping.git > W: http://git.infradead.org/users/hch/dma-mapping.git > S: Supported > F: lib/dma-debug.c > -F: lib/dma-noop.c > +F: lib/dma-direct.c > F: lib/dma-virt.c > F: drivers/base/dma-mapping.c > F: drivers/base/dma-coherent.c > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 00d889a37965..430a0aa710d6 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -25,7 +25,7 @@ config ARM > select CLONE_BACKWARDS > select CPU_PM if (SUSPEND || CPU_IDLE) > select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS > - select DMA_NOOP_OPS if !MMU > + select DMA_DIRECT_OPS if !MMU > select EDAC_SUPPORT > select EDAC_ATOMIC_SCRUB > select GENERIC_ALLOCATOR > diff --git a/arch/arm/include/asm/dma-mapping.h > b/arch/arm/include/asm/dma-mapping.h > index e5d9020c9ee1..8436f6ade57d 100644 > --- a/arch/arm/include/asm/dma-mapping.h > +++ b/arch/arm/include/asm/dma-mapping.h > @@ -18,7 +18,7 @@ extern const struct dma_map_ops arm_coherent_dma_ops; > > static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type > *bus) > { > - return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_noop_ops; > + return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_direct_ops; > } > > #ifdef __arch_page_to_dma > diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c > index 1cced700e45a..49e9831dc0f1 100644 > --- a/arch/arm/mm/dma-mapping-nommu.c > +++ b/arch/arm/mm/dma-mapping-nommu.c > @@ -22,7 +22,7 @@ > #include "dma.h" > > /* > - * dma_noop_ops is used if > + * dma_direct_ops is used if > * - MMU/MPU is off > * - cpu is v7m w/o cache support > * - device is coherent > @@ -39,7 +39,7 @@ static void *arm_nommu_dma_alloc(struct device *dev, size_t > size, > unsigned long attrs) > > { > - const struct dma_map_ops *ops = &dma_noop_ops; > + const struct dma_map_ops *ops = &dma_direct_ops; > void *ret; > > /* > @@ -70,7 +70,7 @@ static void arm_nommu_dma_free(struct device *dev, size_t > size, > void *cpu_addr, dma_addr_t dma_addr, > unsigned long attrs) > { > - const struct dma_map_ops *ops = &dma_noop_ops; > + const struct dma_map_ops *ops = &dma_direct_ops; > > if (attrs & DMA_ATTR_NON_CONSISTENT) { > ops->free(dev, size, cpu_addr, dma_addr, attrs); > @@ -214,7 +214,7 @@ EXPORT_SYMBOL(arm_nommu_dma_ops); > > static const struct dma_map_ops *arm_nommu_get_dma_map_ops(bool coherent) > { > - return coherent ? &dma_noop_ops : &arm_nommu_dma_ops; > + return coherent ? &dma_direct_ops : &arm_nommu_dma_ops; > } > > void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, > diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig > index 498398d915c1..dd84ee194579 100644 > --- a/arch/m32r/Kconfig > +++ b/arch/m32r/Kconfig > @@ -19,7 +19,7 @@ config M32R > select MODULES_USE_ELF_RELA > select HAVE_DEBUG_STACKOVERFLOW > select CPU_NO_EFFICIENT_FFS > - select DMA_NOOP_OPS > + select DMA_DIRECT_OPS > select ARCH_NO_COHERENT_DMA_MMAP if !MMU > > config SBUS > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 2c6adf12713a..865e14f50c14 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -83,7 +83,7 @@ config PGTABLE_LEVELS > config HAVE_KPROBES > def_bool n > > -config DMA_NOOP_OPS > +config DMA_DIRECT_OPS > def_bool y > > menu "Platform type" > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > index 829c67986db7..9376637229c9 100644 > --- a/arch/s390/Kconfig > +++ b/arch/s390/Kconfig > @@ -140,7 +140,7 @@ config S390 > select HAVE_DEBUG_KMEMLEAK > select HAVE_DMA_API_DEBUG > select HAVE_DMA_CONTIGUOUS > - select DMA_NOOP_OPS > + select DMA_DIRECT_OPS > select HAVE_DYNAMIC_FTRACE > select HAVE_DYNAMIC_FTRACE_WITH_REGS > select HAVE_EFFICIENT_UNALIGNED_ACCESS > diff --git a/include/asm-generic/dma-mapping.h > b/include/asm-generic/dma-mapping.h > index 164031531d85..880a292d792f 100644 > --- a/include/asm-generic/dma-mapping.h > +++ b/include/asm-generic/dma-mapping.h > @@ -4,7 +4,7 @@ > > static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type > *bus) > { > - return &dma_noop_ops; > + return &dma_direct_ops; > } > > #endif /* _ASM_GENERIC_DMA_MAPPING_H */ > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index 72568bf4fc12..ff3528de5322 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -143,7 +143,7 @@ struct dma_map_ops { > bool is_phys; > }; > > -extern const struct dma_map_ops dma_noop_ops; > +extern const struct dma_map_ops dma_direct_ops; > extern const struct dma_map_ops dma_virt_ops; > > #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) > diff --git a/lib/Kconfig b/lib/Kconfig > index c5e84fbcb30b..9d3d649c9dc9 100644 > --- a/lib/Kconfig > +++ b/lib/Kconfig > @@ -409,7 +409,7 @@ config HAS_DMA > depends on !NO_DMA > default y > > -config DMA_NOOP_OPS > +config DMA_DIRECT_OPS > bool > depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT) > default n > diff --git a/lib/Makefile b/lib/Makefile > index d11c48ec8ffd..749851abe85a 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -28,7 +28,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ > > lib-$(CONFIG_MMU) += ioremap.o > lib-$(CONFIG_SMP) += cpumask.o > -lib-$(CONFIG_DMA_NOOP_OPS) += dma-noop.o > +lib-$(CONFIG_DMA_DIRECT_OPS) += dma-direct.o > lib-$(CONFIG_DMA_VIRT_OPS) += dma-virt.o > > lib-y += kobject.o klist.o > diff --git a/lib/dma-noop.c b/lib/dma-direct.c > similarity index 53% > rename from lib/dma-noop.c > rename to lib/dma-direct.c > index c3728a0551f5..439db40854b7 100644 > --- a/lib/dma-noop.c > +++ b/lib/dma-direct.c > @@ -10,9 +10,8 @@ > #include <linux/scatterlist.h> > #include <linux/pfn.h> > > -static void *dma_noop_alloc(struct device *dev, size_t size, > - dma_addr_t *dma_handle, gfp_t gfp, > - unsigned long attrs) > +static void *dma_direct_alloc(struct device *dev, size_t size, > + dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) > { > void *ret; > > @@ -23,24 +22,21 @@ static void *dma_noop_alloc(struct device *dev, size_t > size, > return ret; > } > > -static void dma_noop_free(struct device *dev, size_t size, > - void *cpu_addr, dma_addr_t dma_addr, > - unsigned long attrs) > +static void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, > + dma_addr_t dma_addr, unsigned long attrs) > { > free_pages((unsigned long)cpu_addr, get_order(size)); > } > > -static dma_addr_t dma_noop_map_page(struct device *dev, struct page *page, > - unsigned long offset, size_t size, > - enum dma_data_direction dir, > - unsigned long attrs) > +static dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, > + unsigned long offset, size_t size, enum dma_data_direction dir, > + unsigned long attrs) > { > return page_to_phys(page) + offset - PFN_PHYS(dev->dma_pfn_offset); > } > > -static int dma_noop_map_sg(struct device *dev, struct scatterlist *sgl, int > nents, > - enum dma_data_direction dir, > - unsigned long attrs) > +static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, > + int nents, enum dma_data_direction dir, unsigned long attrs) > { > int i; > struct scatterlist *sg; > @@ -58,12 +54,11 @@ static int dma_noop_map_sg(struct device *dev, struct > scatterlist *sgl, int nent > return nents; > } > > -const struct dma_map_ops dma_noop_ops = { > - .alloc = dma_noop_alloc, > - .free = dma_noop_free, > - .map_page = dma_noop_map_page, > - .map_sg = dma_noop_map_sg, > +const struct dma_map_ops dma_direct_ops = { > + .alloc = dma_direct_alloc, > + .free = dma_direct_free, > + .map_page = dma_direct_map_page, > + .map_sg = dma_direct_map_sg, > .is_phys = true, > }; > - > -EXPORT_SYMBOL(dma_noop_ops); > +EXPORT_SYMBOL(dma_direct_ops); >
>From ARM NOMMU perspective Reviewed-by: Vladimir Murzin <vladimir.mur...@arm.com> Thanks Vladimir