Hi,
This is fourth approach for replacing struct dma_attrs with unsigned long.
The main patch (1/44) doing the change is split into many subpatches for easier review (2-42). They should be squashed together when applying.
*Important:* Patchset is tested on my ARM platforms and *only* build tested on allyesconfigs: ARM, ARM64, i386, x86_64 and powerpc. Please kindly provide reviewes and tests for other platforms.
Rebased on next-20160607.
For easier testing the patchset is available here: repo: https://github.com/krzk/linux branch: for-next/dma-attrs-const-v4
Changes since v3 ================ 1. Collect some acks. 2. Drop wrong patch 1/45 ("powerpc: dma-mapping: Don't hard-code the value of DMA_ATTR_WEAK_ORDERING"). 3. Minor fix pointed out by Michael Ellerman.
Changes since v2 ================ 1. Follow Christoph Hellwig's comments (don't use BIT add documentation, remove dma_get_attr).
Rationale ========= The dma-mapping core and the implementations do not change the DMA attributes passed by pointer. Thus the pointer can point to const data. However the attributes do not have to be a bitfield. Instead unsigned long will do fine:
1. This is just simpler. Both in terms of reading the code and setting attributes. Instead of initializing local attributes on the stack and passing pointer to it to dma_set_attr(), just set the bits.
2. It brings safeness and checking for const correctness because the attributes are passed by value.
Best regards, Krzysztof
Krzysztof Kozlowski (44): dma-mapping: Use unsigned long for dma_attrs alpha: dma-mapping: Use unsigned long for dma_attrs arc: dma-mapping: Use unsigned long for dma_attrs ARM: dma-mapping: Use unsigned long for dma_attrs arm64: dma-mapping: Use unsigned long for dma_attrs avr32: dma-mapping: Use unsigned long for dma_attrs blackfin: dma-mapping: Use unsigned long for dma_attrs c6x: dma-mapping: Use unsigned long for dma_attrs cris: dma-mapping: Use unsigned long for dma_attrs frv: dma-mapping: Use unsigned long for dma_attrs drm/exynos: dma-mapping: Use unsigned long for dma_attrs drm/mediatek: dma-mapping: Use unsigned long for dma_attrs drm/msm: dma-mapping: Use unsigned long for dma_attrs drm/nouveau: dma-mapping: Use unsigned long for dma_attrs drm/rockship: dma-mapping: Use unsigned long for dma_attrs infiniband: dma-mapping: Use unsigned long for dma_attrs iommu: dma-mapping: Use unsigned long for dma_attrs [media] dma-mapping: Use unsigned long for dma_attrs xen: dma-mapping: Use unsigned long for dma_attrs swiotlb: dma-mapping: Use unsigned long for dma_attrs powerpc: dma-mapping: Use unsigned long for dma_attrs video: dma-mapping: Use unsigned long for dma_attrs x86: dma-mapping: Use unsigned long for dma_attrs iommu: intel: dma-mapping: Use unsigned long for dma_attrs h8300: dma-mapping: Use unsigned long for dma_attrs hexagon: dma-mapping: Use unsigned long for dma_attrs ia64: dma-mapping: Use unsigned long for dma_attrs m68k: dma-mapping: Use unsigned long for dma_attrs metag: dma-mapping: Use unsigned long for dma_attrs microblaze: dma-mapping: Use unsigned long for dma_attrs mips: dma-mapping: Use unsigned long for dma_attrs mn10300: dma-mapping: Use unsigned long for dma_attrs nios2: dma-mapping: Use unsigned long for dma_attrs openrisc: dma-mapping: Use unsigned long for dma_attrs parisc: dma-mapping: Use unsigned long for dma_attrs misc: mic: dma-mapping: Use unsigned long for dma_attrs s390: dma-mapping: Use unsigned long for dma_attrs sh: dma-mapping: Use unsigned long for dma_attrs sparc: dma-mapping: Use unsigned long for dma_attrs tile: dma-mapping: Use unsigned long for dma_attrs unicore32: dma-mapping: Use unsigned long for dma_attrs xtensa: dma-mapping: Use unsigned long for dma_attrs dma-mapping: Remove dma_get_attr dma-mapping: Document the DMA attributes next to the declaration
Documentation/DMA-API.txt | 33 +++--- Documentation/DMA-attributes.txt | 2 +- arch/alpha/include/asm/dma-mapping.h | 2 - arch/alpha/kernel/pci-noop.c | 2 +- arch/alpha/kernel/pci_iommu.c | 12 +- arch/arc/mm/dma.c | 12 +- arch/arm/common/dmabounce.c | 4 +- arch/arm/include/asm/dma-mapping.h | 13 +-- arch/arm/include/asm/xen/page-coherent.h | 16 +-- arch/arm/mm/dma-mapping.c | 121 ++++++++++--------- arch/arm/xen/mm.c | 8 +- arch/arm64/mm/dma-mapping.c | 67 +++++------ arch/avr32/mm/dma-coherent.c | 12 +- arch/blackfin/kernel/dma-mapping.c | 8 +- arch/c6x/include/asm/dma-mapping.h | 4 +- arch/c6x/kernel/dma.c | 9 +- arch/c6x/mm/dma-coherent.c | 4 +- arch/cris/arch-v32/drivers/pci/dma.c | 9 +- arch/frv/mb93090-mb00/pci-dma-nommu.c | 8 +- arch/frv/mb93090-mb00/pci-dma.c | 9 +- arch/h8300/kernel/dma.c | 8 +- arch/hexagon/include/asm/dma-mapping.h | 1 - arch/hexagon/kernel/dma.c | 8 +- arch/ia64/hp/common/sba_iommu.c | 22 ++-- arch/ia64/include/asm/machvec.h | 1 - arch/ia64/kernel/pci-swiotlb.c | 4 +- arch/ia64/sn/pci/pci_dma.c | 22 ++-- arch/m68k/kernel/dma.c | 12 +- arch/metag/kernel/dma.c | 16 +-- arch/microblaze/include/asm/dma-mapping.h | 1 - arch/microblaze/kernel/dma.c | 12 +- arch/mips/cavium-octeon/dma-octeon.c | 8 +- arch/mips/loongson64/common/dma-swiotlb.c | 10 +- arch/mips/mm/dma-default.c | 20 ++-- arch/mips/netlogic/common/nlm-dma.c | 4 +- arch/mn10300/mm/dma-alloc.c | 8 +- arch/nios2/mm/dma-mapping.c | 12 +- arch/openrisc/kernel/dma.c | 21 ++-- arch/parisc/kernel/pci-dma.c | 18 +-- arch/powerpc/include/asm/dma-mapping.h | 7 +- arch/powerpc/include/asm/iommu.h | 10 +- arch/powerpc/kernel/dma-iommu.c | 12 +- arch/powerpc/kernel/dma.c | 18 +-- arch/powerpc/kernel/ibmebus.c | 12 +- arch/powerpc/kernel/iommu.c | 12 +- arch/powerpc/kernel/vio.c | 12 +- arch/powerpc/platforms/cell/iommu.c | 28 ++--- arch/powerpc/platforms/pasemi/iommu.c | 2 +- arch/powerpc/platforms/powernv/npu-dma.c | 8 +- arch/powerpc/platforms/powernv/pci-ioda.c | 4 +- arch/powerpc/platforms/powernv/pci.c | 2 +- arch/powerpc/platforms/powernv/pci.h | 2 +- arch/powerpc/platforms/ps3/system-bus.c | 18 +-- arch/powerpc/platforms/pseries/iommu.c | 6 +- arch/powerpc/sysdev/dart_iommu.c | 2 +- arch/s390/include/asm/dma-mapping.h | 1 - arch/s390/pci/pci_dma.c | 23 ++-- arch/sh/include/asm/dma-mapping.h | 4 +- arch/sh/kernel/dma-nommu.c | 4 +- arch/sh/mm/consistent.c | 4 +- arch/sparc/kernel/iommu.c | 12 +- arch/sparc/kernel/ioport.c | 24 ++-- arch/sparc/kernel/pci_sun4v.c | 12 +- arch/tile/kernel/pci-dma.c | 28 ++--- arch/unicore32/mm/dma-swiotlb.c | 4 +- arch/x86/include/asm/dma-mapping.h | 5 +- arch/x86/include/asm/swiotlb.h | 4 +- arch/x86/include/asm/xen/page-coherent.h | 9 +- arch/x86/kernel/amd_gart_64.c | 20 ++-- arch/x86/kernel/pci-calgary_64.c | 14 +-- arch/x86/kernel/pci-dma.c | 4 +- arch/x86/kernel/pci-nommu.c | 4 +- arch/x86/kernel/pci-swiotlb.c | 4 +- arch/x86/pci/sta2x11-fixup.c | 2 +- arch/x86/pci/vmd.c | 16 +-- arch/xtensa/kernel/pci-dma.c | 12 +- drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 2 +- drivers/gpu/drm/exynos/exynos_drm_g2d.c | 12 +- drivers/gpu/drm/exynos/exynos_drm_gem.c | 20 ++-- drivers/gpu/drm/exynos/exynos_drm_gem.h | 2 +- drivers/gpu/drm/mediatek/mtk_drm_gem.c | 13 +-- drivers/gpu/drm/mediatek/mtk_drm_gem.h | 2 +- drivers/gpu/drm/msm/msm_drv.c | 13 +-- .../gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c | 13 +-- drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 17 ++- drivers/gpu/drm/rockchip/rockchip_drm_gem.h | 2 +- drivers/infiniband/core/umem.c | 7 +- drivers/iommu/amd_iommu.c | 12 +- drivers/iommu/dma-iommu.c | 8 +- drivers/iommu/intel-iommu.c | 12 +- drivers/media/platform/sti/bdisp/bdisp-hw.c | 26 ++--- drivers/media/v4l2-core/videobuf2-dma-contig.c | 30 ++--- drivers/media/v4l2-core/videobuf2-dma-sg.c | 19 +-- drivers/misc/mic/host/mic_boot.c | 20 ++-- drivers/parisc/ccio-dma.c | 16 +-- drivers/parisc/sba_iommu.c | 16 +-- drivers/video/fbdev/omap2/omapfb/omapfb-main.c | 12 +- drivers/video/fbdev/omap2/omapfb/omapfb.h | 3 +- drivers/xen/swiotlb-xen.c | 14 +-- include/linux/dma-attrs.h | 72 ------------ include/linux/dma-iommu.h | 6 +- include/linux/dma-mapping.h | 128 ++++++++++++++------- include/linux/swiotlb.h | 10 +- include/media/videobuf2-dma-contig.h | 7 +- include/rdma/ib_verbs.h | 8 +- include/xen/swiotlb-xen.h | 12 +- lib/dma-noop.c | 9 +- lib/swiotlb.c | 13 ++- 108 files changed, 691 insertions(+), 793 deletions(-) delete mode 100644 include/linux/dma-attrs.h