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Linus Torvalds 3de18c865f Merge branch 'stable/for-linus-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb

Pull swiotlb updates from Konrad Rzeszutek Wilk:
 "A new feature called restricted DMA pools. It allows SWIOTLB to
  utilize per-device (or per-platform) allocated memory pools instead of
  using the global one.

  The first big user of this is ARM Confidential Computing where the
  memory for DMA operations can be set per platform"

* 'stable/for-linus-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: (23 commits)
  swiotlb: use depends on for DMA_RESTRICTED_POOL
  of: restricted dma: Don't fail device probe on rmem init failure
  of: Move of_dma_set_restricted_buffer() into device.c
  powerpc/svm: Don't issue ultracalls if !mem_encrypt_active()
  s390/pv: fix the forcing of the swiotlb
  swiotlb: Free tbl memory in swiotlb_exit()
  swiotlb: Emit diagnostic in swiotlb_exit()
  swiotlb: Convert io_default_tlb_mem to static allocation
  of: Return success from of_dma_set_restricted_buffer() when !OF_ADDRESS
  swiotlb: add overflow checks to swiotlb_bounce
  swiotlb: fix implicit debugfs declarations
  of: Add plumbing for restricted DMA pool
  dt-bindings: of: Add restricted DMA pool
  swiotlb: Add restricted DMA pool initialization
  swiotlb: Add restricted DMA alloc/free support
  swiotlb: Refactor swiotlb_tbl_unmap_single
  swiotlb: Move alloc_size to swiotlb_find_slots
  swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing
  swiotlb: Update is_swiotlb_active to add a struct device argument
  swiotlb: Update is_swiotlb_buffer to add a struct device argument
  ...

2021-09-03 10:34:44 -07:00

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SPDX-License-Identifier: GPL-2.0-only

config NO_DMA bool

config HAS_DMA bool depends on !NO_DMA default y

config DMA_OPS depends on HAS_DMA bool

IOMMU drivers that can bypass the IOMMU code and optionally use the direct

mapping fast path should select this option and set the dma_ops_bypass

flag in struct device where applicable

config DMA_OPS_BYPASS bool

Lets platform IOMMU driver choose between bypass and IOMMU

config ARCH_HAS_DMA_MAP_DIRECT bool

config NEED_SG_DMA_LENGTH bool

config NEED_DMA_MAP_STATE bool

config ARCH_DMA_ADDR_T_64BIT def_bool 64BIT || PHYS_ADDR_T_64BIT

config ARCH_HAS_DMA_SET_MASK bool

Select this option if the architecture needs special handling for

DMA_ATTR_WRITE_COMBINE. Normally the "uncached" mapping should be what

people thing of when saying write combine, so very few platforms should

need to enable this.

config ARCH_HAS_DMA_WRITE_COMBINE bool

Select if the architectures provides the arch_dma_mark_clean hook

config ARCH_HAS_DMA_MARK_CLEAN bool

config DMA_DECLARE_COHERENT bool

config ARCH_HAS_SETUP_DMA_OPS bool

config ARCH_HAS_TEARDOWN_DMA_OPS bool

config ARCH_HAS_SYNC_DMA_FOR_DEVICE bool

config ARCH_HAS_SYNC_DMA_FOR_CPU bool select NEED_DMA_MAP_STATE

config ARCH_HAS_SYNC_DMA_FOR_CPU_ALL bool

config ARCH_HAS_DMA_PREP_COHERENT bool

config ARCH_HAS_FORCE_DMA_UNENCRYPTED bool

config SWIOTLB bool select NEED_DMA_MAP_STATE

config DMA_RESTRICTED_POOL bool "DMA Restricted Pool" depends on OF && OF_RESERVED_MEM && SWIOTLB help This enables support for restricted DMA pools which provide a level of DMA memory protection on systems with limited hardware protection capabilities, such as those lacking an IOMMU.

  For more information see
  <Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt>
  and <kernel/dma/swiotlb.c>.
  If unsure, say "n".

Should be selected if we can mmap non-coherent mappings to userspace.

The only thing that is really required is a way to set an uncached bit

in the pagetables

config DMA_NONCOHERENT_MMAP default y if !MMU bool

config DMA_COHERENT_POOL select GENERIC_ALLOCATOR bool

config DMA_GLOBAL_POOL select DMA_DECLARE_COHERENT bool

config DMA_REMAP bool depends on MMU select DMA_NONCOHERENT_MMAP

config DMA_DIRECT_REMAP bool select DMA_REMAP select DMA_COHERENT_POOL

config DMA_CMA bool "DMA Contiguous Memory Allocator" depends on HAVE_DMA_CONTIGUOUS && CMA help This enables the Contiguous Memory Allocator which allows drivers to allocate big physically-contiguous blocks of memory for use with hardware components that do not support I/O map nor scatter-gather.

  You can disable CMA by specifying "cma=0" on the kernel's command
  line.

  For more information see <kernel/dma/contiguous.c>.
  If unsure, say "n".

if DMA_CMA

config DMA_PERNUMA_CMA bool "Enable separate DMA Contiguous Memory Area for each NUMA Node" default NUMA && ARM64 help Enable this option to get pernuma CMA areas so that devices like ARM64 SMMU can get local memory by DMA coherent APIs.

  You can set the size of pernuma CMA by specifying "cma_pernuma=size"
  on the kernel's command line.

comment "Default contiguous memory area size:"

config CMA_SIZE_MBYTES int "Size in Mega Bytes" depends on !CMA_SIZE_SEL_PERCENTAGE default 0 if X86 default 16 help Defines the size (in MiB) of the default memory area for Contiguous Memory Allocator. If the size of 0 is selected, CMA is disabled by default, but it can be enabled by passing cma=size[MG] to the kernel.

config CMA_SIZE_PERCENTAGE int "Percentage of total memory" depends on !CMA_SIZE_SEL_MBYTES default 0 if X86 default 10 help Defines the size of the default memory area for Contiguous Memory Allocator as a percentage of the total memory in the system. If 0 percent is selected, CMA is disabled by default, but it can be enabled by passing cma=size[MG] to the kernel.

choice prompt "Selected region size" default CMA_SIZE_SEL_MBYTES

config CMA_SIZE_SEL_MBYTES bool "Use mega bytes value only"

config CMA_SIZE_SEL_PERCENTAGE bool "Use percentage value only"

config CMA_SIZE_SEL_MIN bool "Use lower value (minimum)"

config CMA_SIZE_SEL_MAX bool "Use higher value (maximum)"

endchoice

config CMA_ALIGNMENT int "Maximum PAGE_SIZE order of alignment for contiguous buffers" range 2 12 default 8 help DMA mapping framework by default aligns all buffers to the smallest PAGE_SIZE order which is greater than or equal to the requested buffer size. This works well for buffers up to a few hundreds kilobytes, but for larger buffers it just a memory waste. With this parameter you can specify the maximum PAGE_SIZE order for contiguous buffers. Larger buffers will be aligned only to this specified order. The order is expressed as a power of two multiplied by the PAGE_SIZE.

  For example, if your system defaults to 4KiB pages, the order value
  of 8 means that the buffers will be aligned up to 1MiB only.

  If unsure, leave the default value "8".

endif

config DMA_API_DEBUG bool "Enable debugging of DMA-API usage" select NEED_DMA_MAP_STATE help Enable this option to debug the use of the DMA API by device drivers. With this option you will be able to detect common bugs in device drivers like double-freeing of DMA mappings or freeing mappings that were never allocated.

  This option causes a performance degradation.  Use only if you want to
  debug device drivers and dma interactions.

  If unsure, say N.

config DMA_API_DEBUG_SG bool "Debug DMA scatter-gather usage" default y depends on DMA_API_DEBUG help Perform extra checking that callers of dma_map_sg() have respected the appropriate segment length/boundary limits for the given device when preparing DMA scatterlists.

  This is particularly likely to have been overlooked in cases where the
  dma_map_sg() API is used for general bulk mapping of pages rather than
  preparing literal scatter-gather descriptors, where there is a risk of
  unexpected behaviour from DMA API implementations if the scatterlist
  is technically out-of-spec.

  If unsure, say N.

config DMA_MAP_BENCHMARK bool "Enable benchmarking of streaming DMA mapping" depends on DEBUG_FS help Provides /sys/kernel/debug/dma_map_benchmark that helps with testing performance of dma_(un)map_page.

  See tools/testing/selftests/dma/dma_map_benchmark.c

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