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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>
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dma_contiguous_set_default contains a trivial assignment, and has a
single caller that is compiled if CONFIG_CMA_DMA is enabled.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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dev_set_cma_area contains a trivial assignment. It has just three
callers that all have a non-NULL device and depend on CONFIG_DMA_CMA,
so remove the wrapper.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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dma_declare_contiguous is a trivial wrapper around
dma_contiguous_reserve_area and just has a single caller.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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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>
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The new dma_alloc_contiguous hides if we allocate CMA or regular
pages, and thus fails to retry a ZONE_NORMAL allocation if the CMA
allocation succeeds but isn't addressable. That means we either fail
outright or dip into a small zone that might not succeed either.
Thanks to Hillf Danton for debugging this issue.
Fixes: b1d2dc009dec ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Reported-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
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Commit fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous()
helpers") adds a pair of new helper functions so as to abstract code in
the dma-direct (and other places in the future), however it breaks QEMU
boot feature using x86_64 defconfig.
That's because x86_64 defconfig has CONFIG_DMA_CMA=n so those two newly
introduced helper functions are empty in their !CONFIG_DMA_CMA version,
while previously the platform independent dma-direct code had fallback
alloc_pages_node() and __free_pages().
So this patch fixes it by adding alloc_pages_node() and __free_pages()
in the !CONFIG_DMA_CMA version of the two helper functions.
Tested with below QEMU command:
qemu-system-x86_64 -m 512m \
-drive file=images/x86_64/rootfs.ext4,format=raw,if=ide \
-append 'console=ttyS0 root=/dev/sda' -nographic \
-kernel arch/x86_64/boot/bzImage
with the rootfs from the below link:
https://github.com/ClangBuiltLinux/continuous-integration/raw/master/images/x86_64/rootfs.ext4
Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Both dma_alloc_from_contiguous() and dma_release_from_contiguous() are
very simply implemented, but requiring callers to pass certain
parameters like count and align, and taking a boolean parameter to check
__GFP_NOWARN in the allocation flags. So every function call duplicates
similar work:
unsigned long order = get_order(size);
size_t count = size >> PAGE_SHIFT;
page = dma_alloc_from_contiguous(dev, count, order,
gfp & __GFP_NOWARN);
[...]
dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
Additionally, as CMA can be used only in the context which permits
sleeping, most of callers do a gfpflags_allow_blocking() check and a
corresponding fallback allocation of normal pages upon any false result:
if (gfpflags_allow_blocking(flag))
page = dma_alloc_from_contiguous();
if (!page)
page = alloc_pages();
[...]
if (!dma_release_from_contiguous(dev, page, count))
__free_pages(page, get_order(size));
So this patch simplifies those function calls by abstracting these
operations into the two new functions: dma_{alloc,free}_contiguous.
As some callers of dma_{alloc,release}_from_contiguous() might be
complicated, this patch just implements these two new functions to
kernel/dma/direct.c only as an initial step.
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your optional any later version of the license
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520075212.713472955@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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dma_alloc_from_contiguous()
The CMA memory allocator doesn't support standard gfp flags for memory
allocation, so there is no point having it as a parameter for
dma_alloc_from_contiguous() function. Replace it by a boolean no_warn
argument, which covers all the underlaying cma_alloc() function
supports.
This will help to avoid giving false feeling that this function supports
standard gfp flags and callers can pass __GFP_ZERO to get zeroed buffer,
what has already been an issue: see commit dd65a941f6ba ("arm64:
dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag").
Link: http://lkml.kernel.org/r/20180709122020eucas1p21a71b092975cb4a3b9954ffc63f699d1~-sqUFoa-h2939329393eucas1p2Y@eucas1p2.samsung.com
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Michał Nazarewicz <mina86@mina86.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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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>
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The callers of the DMA alloc functions already provide the proper
context GFP flags. Make sure to pass them through to the CMA allocator,
to make the CMA compaction context aware.
Link: http://lkml.kernel.org/r/20170127172328.18574-3-l.stach@pengutronix.de
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alexander Graf <agraf@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This was found during userspace fuzzing test when a large size dma cma
allocation is made by driver(like ion) through userspace.
show_stack+0x10/0x1c
dump_stack+0x74/0xc8
kasan_report_error+0x2b0/0x408
kasan_report+0x34/0x40
__asan_storeN+0x15c/0x168
memset+0x20/0x44
__dma_alloc_coherent+0x114/0x18c
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently, there are two users on CMA functionality, one is the DMA
subsystem and the other is the KVM on powerpc. They have their own code
to manage CMA reserved area even if they looks really similar. From my
guess, it is caused by some needs on bitmap management. KVM side wants
to maintain bitmap not for 1 page, but for more size. Eventually it use
bitmap where one bit represents 64 pages.
When I implement CMA related patches, I should change those two places
to apply my change and it seem to be painful to me. I want to change
this situation and reduce future code management overhead through this
patch.
This change could also help developer who want to use CMA in their new
feature development, since they can use CMA easily without copying &
pasting this reserved area management code.
In previous patches, we have prepared some features to generalize CMA
reserved area management and now it's time to do it. This patch moves
core functions to mm/cma.c and change DMA APIs to use these functions.
There is no functional change in DMA APIs.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Gleb Natapov <gleb@kernel.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently, "cma=" kernel parameter is used to specify the size of CMA,
but we can't specify where it is located. We want to locate CMA below
4GB for devices only supporting 32-bit addressing on 64-bit systems
without iommu.
This enables to specify the placement of CMA by extending "cma=" kernel
parameter.
Examples:
1. locate 64MB CMA below 4GB by "cma=64M@0-4G"
2. locate 64MB CMA exact at 512MB by "cma=64M@512M"
Note that the DMA contiguous memory allocator on x86 assumes that
page_address() works for the pages to allocate. So this change requires
to limit end address of contiguous memory area upto max_pfn_mapped to
prevent from locating it on highmem area by the argument of
dma_contiguous_reserve().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This patch cleans the initialization of dma contiguous framework. The
all-in-one dma_declare_contiguous() function is now separated into
dma_contiguous_reserve_area() which only steals the the memory from
memblock allocator and dma_contiguous_add_device() function, which
assigns given device to the specified reserved memory area. This improves
the flexibility in defining contiguous memory areas and assigning device
to them, because now it is possible to assign more than one device to
the given contiguous memory area. Such split in initialization procedure
is also required for upcoming device tree support.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Tomasz Figa <t.figa@samsung.com>
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We want to use CMA for allocating hash page table and real mode area for
PPC64. Hence move DMA contiguous related changes into a seperate config
so that ppc64 can enable CMA without requiring DMA contiguous.
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[removed defconfig changes]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
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This commit changes the CMA early initialization code to use phys_addr_t
for representing physical addresses instead of unsigned long.
Without this change, among other things, dma_declare_contiguous() simply
discards any memory regions whose address is not representable as unsigned
long.
This is a problem on 32-bit PAE machines where unsigned long is 32-bit
but physical address space is larger.
Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
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The Contiguous Memory Allocator is a set of helper functions for DMA
mapping framework that improves allocations of contiguous memory chunks.
CMA grabs memory on system boot, marks it with MIGRATE_CMA migrate type
and gives back to the system. Kernel is allowed to allocate only movable
pages within CMA's managed memory so that it can be used for example for
page cache when DMA mapping do not use it. On
dma_alloc_from_contiguous() request such pages are migrated out of CMA
area to free required contiguous block and fulfill the request. This
allows to allocate large contiguous chunks of memory at any time
assuming that there is enough free memory available in the system.
This code is heavily based on earlier works by Michal Nazarewicz.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
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