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WSL2-Linux-Kernel/kernel/dma/Kconfig

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treewide: Add SPDX license identifier - Makefile/Kconfig Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-19 15:07:45 +03:00
# SPDX-License-Identifier: GPL-2.0-only
dma-mapping: move all DMA mapping code to kernel/dma Currently the code is split over various files with dma- prefixes in the lib/ and drives/base directories, and the number of files keeps growing. Move them into a single directory to keep the code together and remove the file name prefixes. To match the irq infrastructure this directory is placed under the kernel/ directory. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-06-12 20:01:45 +03:00
dma-mapping: consolidate the NO_DMA definition in kernel/dma/Kconfig Have a single definition that architetures can select. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Rich Felker <dalias@libc.org>
2020-07-14 15:18:54 +03:00
config NO_DMA
bool
dma-mapping: move all DMA mapping code to kernel/dma Currently the code is split over various files with dma- prefixes in the lib/ and drives/base directories, and the number of files keeps growing. Move them into a single directory to keep the code together and remove the file name prefixes. To match the irq infrastructure this directory is placed under the kernel/ directory. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-06-12 20:01:45 +03:00
config HAS_DMA
bool
depends on !NO_DMA
default y
dma-mapping: make support for dma ops optional Avoid the overhead of the dma ops support for tiny builds that only use the direct mapping. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-07-08 10:30:00 +03:00
config DMA_OPS
dma-mapping: fix DMA_OPS dependencies Driver that select DMA_OPS need to depend on HAS_DMA support to work. The vop driver was missing that dependency, so add it, and also add a another depends in DMA_OPS itself. That won't fix the issue due to how the Kconfig dependencies work, but at least produce a warning about unmet dependencies. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2020-08-29 11:40:28 +03:00
depends on HAS_DMA
dma-mapping: make support for dma ops optional Avoid the overhead of the dma ops support for tiny builds that only use the direct mapping. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-07-08 10:30:00 +03:00
bool
dma-mapping: add a dma_ops_bypass flag to struct device Several IOMMU drivers have a bypass mode where they can use a direct mapping if the devices DMA mask is large enough. Add generic support to the core dma-mapping code to do that to switch those drivers to a common solution. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
2020-03-23 20:19:30 +03:00
#
# 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
dma-mapping: Allow mixing bypass and mapped DMA operation At the moment we allow bypassing DMA ops only when we can do this for the entire RAM. However there are configs with mixed type memory where we could still allow bypassing IOMMU in most cases; POWERPC with persistent memory is one example. This adds an arch hook to determine where bypass can still work and we invoke direct DMA API. The following patch checks the bus limit on POWERPC to allow or disallow direct mapping. This adds a ARCH_HAS_DMA_MAP_DIRECT config option to make the arch_xxxx hooks no-op by default. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-10-29 04:52:40 +03:00
# Lets platform IOMMU driver choose between bypass and IOMMU
config ARCH_HAS_DMA_MAP_DIRECT
bool
dma-mapping: move all DMA mapping code to kernel/dma Currently the code is split over various files with dma- prefixes in the lib/ and drives/base directories, and the number of files keeps growing. Move them into a single directory to keep the code together and remove the file name prefixes. To match the irq infrastructure this directory is placed under the kernel/ directory. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-06-12 20:01:45 +03:00
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
dma-mapping, powerpc: simplify the arch dma_set_mask override Instead of letting the architecture supply all of dma_set_mask just give it an additional hook selected by Kconfig. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-13 10:01:22 +03:00
config ARCH_HAS_DMA_SET_MASK
bool
dma-mapping: remove arch_dma_mmap_pgprot arch_dma_mmap_pgprot is used for two things: 1) to override the "normal" uncached page attributes for mapping memory coherent to devices that can't snoop the CPU caches 2) to provide the special DMA_ATTR_WRITE_COMBINE semantics on older arm systems and some mips platforms Replace one with the pgprot_dmacoherent macro that is already provided by arm and much simpler to use, and lift the DMA_ATTR_WRITE_COMBINE handling to common code with an explicit arch opt-in. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Acked-by: Paul Burton <paul.burton@mips.com> # mips
2019-08-26 10:03:44 +03:00
#
# 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
dma-mapping: add (back) arch_dma_mark_clean for ia64 Add back a hook to optimize dcache flushing after reading executable code using DMA. This gets ia64 out of the business of pretending to be dma incoherent just for this optimization. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-08-17 17:41:50 +03:00
#
# Select if the architectures provides the arch_dma_mark_clean hook
#
config ARCH_HAS_DMA_MARK_CLEAN
bool
dma-mapping: improve selection of dma_declare_coherent availability This API is primarily used through DT entries, but two architectures and two drivers call it directly. So instead of selecting the config symbol for random architectures pull it in implicitly for the actual users. Also rename the Kconfig option to describe the feature better. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Paul Burton <paul.burton@mips.com> # MIPS Acked-by: Lee Jones <lee.jones@linaro.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-03 22:12:02 +03:00
config DMA_DECLARE_COHERENT
dma-mapping: move all DMA mapping code to kernel/dma Currently the code is split over various files with dma- prefixes in the lib/ and drives/base directories, and the number of files keeps growing. Move them into a single directory to keep the code together and remove the file name prefixes. To match the irq infrastructure this directory is placed under the kernel/ directory. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-06-12 20:01:45 +03:00
bool
dma-mapping: add a kconfig symbol for arch_setup_dma_ops availability Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Paul Burton <paul.burton@mips.com> # MIPS Acked-by: Catalin Marinas <catalin.marinas@arm.com> # arm64
2019-01-07 21:36:20 +03:00
config ARCH_HAS_SETUP_DMA_OPS
bool
dma-mapping: add a kconfig symbol for arch_teardown_dma_ops availability Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> # arm64
2018-12-22 00:14:44 +03:00
config ARCH_HAS_TEARDOWN_DMA_OPS
dma-mapping: move all DMA mapping code to kernel/dma Currently the code is split over various files with dma- prefixes in the lib/ and drives/base directories, and the number of files keeps growing. Move them into a single directory to keep the code together and remove the file name prefixes. To match the irq infrastructure this directory is placed under the kernel/ directory. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-06-12 20:01:45 +03:00
bool
config ARCH_HAS_SYNC_DMA_FOR_DEVICE
bool
config ARCH_HAS_SYNC_DMA_FOR_CPU
bool
select NEED_DMA_MAP_STATE
dma-mapping: add the missing ARCH_HAS_SYNC_DMA_FOR_CPU_ALL declaration The patch adding the infrastructure failed to actually add the symbol declaration, oops.. Fixes: faef87723a ("dma-noncoherent: add a arch_sync_dma_for_cpu_all hook") Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-09-11 09:54:57 +03:00
config ARCH_HAS_SYNC_DMA_FOR_CPU_ALL
bool
dma-mapping: add a Kconfig symbol to indicate arch_dma_prep_coherent presence Add a Kconfig symbol that indicates an architecture provides a arch_dma_prep_coherent implementation, and provide a stub otherwise. This will allow the generic dma-iommu code to use it while still allowing to be built for cache coherent architectures. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2019-03-25 17:44:06 +03:00
config ARCH_HAS_DMA_PREP_COHERENT
bool
dma-direct: Force unencrypted DMA under SME for certain DMA masks If a device doesn't support DMA to a physical address that includes the encryption bit (currently bit 47, so 48-bit DMA), then the DMA must occur to unencrypted memory. SWIOTLB is used to satisfy that requirement if an IOMMU is not active (enabled or configured in passthrough mode). However, commit fafadcd16595 ("swiotlb: don't dip into swiotlb pool for coherent allocations") modified the coherent allocation support in SWIOTLB to use the DMA direct coherent allocation support. When an IOMMU is not active, this resulted in dma_alloc_coherent() failing for devices that didn't support DMA addresses that included the encryption bit. Addressing this requires changes to the force_dma_unencrypted() function in kernel/dma/direct.c. Since the function is now non-trivial and SME/SEV specific, update the DMA direct support to add an arch override for the force_dma_unencrypted() function. The arch override is selected when CONFIG_AMD_MEM_ENCRYPT is set. The arch override function resides in the arch/x86/mm/mem_encrypt.c file and forces unencrypted DMA when either SEV is active or SME is active and the device does not support DMA to physical addresses that include the encryption bit. Fixes: fafadcd16595 ("swiotlb: don't dip into swiotlb pool for coherent allocations") Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> [hch: moved the force_dma_unencrypted declaration to dma-mapping.h, fold the s390 fix from Halil Pasic] Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-07-10 22:01:19 +03:00
config ARCH_HAS_FORCE_DMA_UNENCRYPTED
bool
dma-mapping: move all DMA mapping code to kernel/dma Currently the code is split over various files with dma- prefixes in the lib/ and drives/base directories, and the number of files keeps growing. Move them into a single directory to keep the code together and remove the file name prefixes. To match the irq infrastructure this directory is placed under the kernel/ directory. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-06-12 20:01:45 +03:00
config SWIOTLB
bool
select NEED_DMA_MAP_STATE
dma-mapping: move the remap helpers to a separate file The dma remap code only makes sense for not cache coherent architectures (or possibly the corner case of highmem CMA allocations) and currently is only used by arm, arm64, csky and xtensa. Split it out into a separate file with a separate Kconfig symbol, which gets the right copyright notice given that this code was written by Laura Abbott working for Code Aurora at that point. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Laura Abbott <labbott@redhat.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2018-08-24 11:31:08 +03:00
swiotlb: Add restricted DMA pool initialization Add the initialization function to create restricted DMA pools from matching reserved-memory nodes. Regardless of swiotlb setting, the restricted DMA pool is preferred if available. The restricted DMA pools provide a basic level of protection against the DMA overwriting buffer contents at unexpected times. However, to protect against general data leakage and system memory corruption, the system needs to provide a way to lock down the memory access, e.g., MPU. Signed-off-by: Claire Chang <tientzu@chromium.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Stefano Stabellini <sstabellini@kernel.org> Tested-by: Will Deacon <will@kernel.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2021-06-19 06:40:41 +03:00
config DMA_RESTRICTED_POOL
bool "DMA Restricted Pool"
swiotlb: use depends on for DMA_RESTRICTED_POOL Use depends on instead of select for DMA_RESTRICTED_POOL; otherwise it will make SWIOTLB user configurable and cause compile errors for some arch (e.g. mips). Fixes: 0b84e4f8b793 ("swiotlb: Add restricted DMA pool initialization") Acked-by: Will Deacon <will@kernel.org> Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Claire Chang <tientzu@chromium.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2021-08-27 06:48:02 +03:00
depends on OF && OF_RESERVED_MEM && SWIOTLB
swiotlb: Add restricted DMA pool initialization Add the initialization function to create restricted DMA pools from matching reserved-memory nodes. Regardless of swiotlb setting, the restricted DMA pool is preferred if available. The restricted DMA pools provide a basic level of protection against the DMA overwriting buffer contents at unexpected times. However, to protect against general data leakage and system memory corruption, the system needs to provide a way to lock down the memory access, e.g., MPU. Signed-off-by: Claire Chang <tientzu@chromium.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Stefano Stabellini <sstabellini@kernel.org> Tested-by: Will Deacon <will@kernel.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2021-06-19 06:40:41 +03:00
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".
dma-direct: provide mmap and get_sgtable method overrides For dma-direct we know that the DMA address is an encoding of the physical address that we can trivially decode. Use that fact to provide implementations that do not need the arch_dma_coherent_to_pfn architecture hook. Note that we still can only support mmap of non-coherent memory only if the architecture provides a way to set an uncached bit in the page tables. This must be true for architectures that use the generic remap helpers, but other architectures can also manually select it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
2019-10-29 13:01:37 +03:00
#
# 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
dma-direct: re-enable mmap for !CONFIG_MMU nommu configfs can trivially map the coherent allocations to user space, as no actual page table setup is required and the kernel and the user space programs share the same address space. Fixes: 62fcee9a3bd7 ("dma-mapping: remove CONFIG_ARCH_NO_COHERENT_DMA_MMAP") Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: dillon min <dillon.minfei@gmail.com> Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com> Tested-by: dillon min <dillon.minfei@gmail.com>
2020-06-10 11:29:49 +03:00
default y if !MMU
dma-direct: provide mmap and get_sgtable method overrides For dma-direct we know that the DMA address is an encoding of the physical address that we can trivially decode. Use that fact to provide implementations that do not need the arch_dma_coherent_to_pfn architecture hook. Note that we still can only support mmap of non-coherent memory only if the architecture provides a way to set an uncached bit in the page tables. This must be true for architectures that use the generic remap helpers, but other architectures can also manually select it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
2019-10-29 13:01:37 +03:00
bool
dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL DMA_REMAP is an unnecessary requirement for AMD SEV, which requires DMA_COHERENT_POOL, so avoid selecting it when it is otherwise unnecessary. The only other requirement for DMA coherent pools is DMA_DIRECT_REMAP, so ensure that properly selects the config option when needed. Fixes: 82fef0ad811f ("x86/mm: unencrypted non-blocking DMA allocations use coherent pools") Reported-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca> Signed-off-by: David Rientjes <rientjes@google.com> Tested-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-11 10:25:57 +03:00
config DMA_COHERENT_POOL
dma-mapping: DMA_COHERENT_POOL should select GENERIC_ALLOCATOR The dma coherent pool code needs genalloc. Move the select over from DMA_REMAP, which doesn't actually need it. Fixes: dbed452a078d ("dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David Rientjes <rientjes@google.com>
2020-06-18 18:23:31 +03:00
select GENERIC_ALLOCATOR
dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL DMA_REMAP is an unnecessary requirement for AMD SEV, which requires DMA_COHERENT_POOL, so avoid selecting it when it is otherwise unnecessary. The only other requirement for DMA coherent pools is DMA_DIRECT_REMAP, so ensure that properly selects the config option when needed. Fixes: 82fef0ad811f ("x86/mm: unencrypted non-blocking DMA allocations use coherent pools") Reported-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca> Signed-off-by: David Rientjes <rientjes@google.com> Tested-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-11 10:25:57 +03:00
bool
dma-direct: add support for dma_coherent_default_memory Add an option to allocate uncached memory for dma_alloc_coherent from the global dma_coherent_default_memory. This will allow to move arm-nommu (and eventually other platforms) to use generic code for allocating uncached memory from a pre-populated pool. Note that this is a different pool from the one that platforms that can remap at runtime use for GFP_ATOMIC allocations for now, although there might be opportunities to eventually end up with a common codebase for the two use cases. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-06-23 15:21:16 +03:00
config DMA_GLOBAL_POOL
select DMA_DECLARE_COHERENT
bool
dma-remap: separate DMA atomic pools from direct remap code DMA atomic pools will be needed beyond only CONFIG_DMA_DIRECT_REMAP so separate them out into their own file. This also adds a new Kconfig option that can be subsequently used for options, such as CONFIG_AMD_MEM_ENCRYPT, that will utilize the coherent pools but do not have a dependency on direct remapping. For this patch alone, there is no functional change introduced. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Rientjes <rientjes@google.com> [hch: fixup copyrights and remove unused includes] Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-04-15 03:04:52 +03:00
config DMA_DIRECT_REMAP
bool
select DMA_COHERENT_POOL
dma-mapping: remove CONFIG_DMA_REMAP CONFIG_DMA_REMAP is used to build a few helpers around the core vmalloc code, and to use them in case there is a highmem page in dma-direct, and to make dma coherent allocations be able to use non-contiguous pages allocations for DMA allocations in the dma-iommu layer. Right now it needs to be explicitly selected by architectures, and is only done so by architectures that require remapping to deal with devices that are not DMA coherent. Make it unconditional for builds with CONFIG_MMU as it is very little extra code, but makes it much more likely that large DMA allocations succeed on x86. This fixes hot plugging a NVMe thunderbolt SSD for me, which tries to allocate a 1MB buffer that is otherwise hard to obtain due to memory fragmentation on a heavily used laptop. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2022-02-26 18:40:21 +03:00
select DMA_NONCOHERENT_MMAP
dma-remap: separate DMA atomic pools from direct remap code DMA atomic pools will be needed beyond only CONFIG_DMA_DIRECT_REMAP so separate them out into their own file. This also adds a new Kconfig option that can be subsequently used for options, such as CONFIG_AMD_MEM_ENCRYPT, that will utilize the coherent pools but do not have a dependency on direct remapping. For this patch alone, there is no functional change introduced. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Rientjes <rientjes@google.com> [hch: fixup copyrights and remove unused includes] Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-04-15 03:04:52 +03:00
dma-mapping: move CONFIG_DMA_CMA to kernel/dma/Kconfig This is where all the related code already lives. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-13 21:19:08 +03:00
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.
dma-mapping: merge <linux/dma-contiguous.h> into <linux/dma-map-ops.h> Merge dma-contiguous.h into dma-map-ops.h, after removing the comment describing the contiguous allocator into kernel/dma/contigous.c. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-09-11 11:56:52 +03:00
For more information see <kernel/dma/contiguous.c>.
dma-mapping: move CONFIG_DMA_CMA to kernel/dma/Kconfig This is where all the related code already lives. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-13 21:19:08 +03:00
If unsure, say "n".
if DMA_CMA
dma-contiguous: provide the ability to reserve per-numa CMA Right now, drivers like ARM SMMU are using dma_alloc_coherent() to get coherent DMA buffers to save their command queues and page tables. As there is only one default CMA in the whole system, SMMUs on nodes other than node0 will get remote memory. This leads to significant latency. This patch provides per-numa CMA so that drivers like SMMU can get local memory. Tests show localizing CMA can decrease dma_unmap latency much. For instance, before this patch, SMMU on node2 has to wait for more than 560ns for the completion of CMD_SYNC in an empty command queue; with this patch, it needs 240ns only. A positive side effect of this patch would be improving performance even further for those users who are worried about performance more than DMA security and use iommu.passthrough=1 to skip IOMMU. With local CMA, all drivers can get local coherent DMA buffers. Also, this patch changes the default CONFIG_CMA_AREAS to 19 in NUMA. As 1+CONFIG_CMA_AREAS should be quite enough for most servers on the market even they enable both hugetlb_cma and pernuma_cma. 2 numa nodes: 2(hugetlb) + 2(pernuma) + 1(default global cma) = 5 4 numa nodes: 4(hugetlb) + 4(pernuma) + 1(default global cma) = 9 8 numa nodes: 8(hugetlb) + 8(pernuma) + 1(default global cma) = 17 Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-08-24 02:03:07 +03:00
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.
dma-mapping: move CONFIG_DMA_CMA to kernel/dma/Kconfig This is where all the related code already lives. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-13 21:19:08 +03:00
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"
cma: decrease CMA_ALIGNMENT lower limit to 2 On an embedded system with a tiny (1 MiB) CMA area for video memory, and a simple enough video pipeline, we can decrease the CMA_ALIGNMENT by a factor of 2 to avoid wasting memory, as all the allocations for video buffers will be of the exact same size (dictated by the size of the screen). Signed-off-by: Paul Cercueil <paul@crapouillou.net> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-09-30 13:28:21 +03:00
range 2 12
dma-mapping: move CONFIG_DMA_CMA to kernel/dma/Kconfig This is where all the related code already lives. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-13 21:19:08 +03:00
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
dma-mapping: move debug configuration options to kernel/dma This is a follow up to the commit cf65a0f6f6ff ("dma-mapping: move all DMA mapping code to kernel/dma") which moved source code of DMA API to kernel/dma folder. Since there is no file left in the lib that require DMA API debugging options move the latter to kernel/dma as well. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-02-11 19:12:30 +03:00
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.
dma-mapping: add benchmark support for streaming DMA APIs Nowadays, there are increasing requirements to benchmark the performance of dma_map and dma_unmap particually while the device is attached to an IOMMU. This patch enables the support. Users can run specified number of threads to do dma_map_page and dma_unmap_page on a specific NUMA node with the specified duration. Then dma_map_benchmark will calculate the average latency for map and unmap. A difficulity for this benchmark is that dma_map/unmap APIs must run on a particular device. Each device might have different backend of IOMMU or non-IOMMU. So we use the driver_override to bind dma_map_benchmark to a particual device by: For platform devices: echo dma_map_benchmark > /sys/bus/platform/devices/xxx/driver_override echo xxx > /sys/bus/platform/drivers/xxx/unbind echo xxx > /sys/bus/platform/drivers/dma_map_benchmark/bind For PCI devices: echo dma_map_benchmark > /sys/bus/pci/devices/0000:00:01.0/driver_override echo 0000:00:01.0 > /sys/bus/pci/drivers/xxx/unbind echo 0000:00:01.0 > /sys/bus/pci/drivers/dma_map_benchmark/bind Cc: Will Deacon <will@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> [hch: folded in two fixes from Colin Ian King <colin.king@canonical.com>] Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-11-16 09:08:47 +03:00
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