Commit Graph

75 Commits

Author SHA1 Message Date
Jia He
a409d96009 dma-mapping: fix dma_addressing_limited() if dma_range_map can't cover all system RAM
There is an unusual case that the range map covers right up to the top
of system RAM, but leaves a hole somewhere lower down. Then it prevents
the nvme device dma mapping in the checking path of phys_to_dma() and
causes the hangs at boot.

E.g. On an Armv8 Ampere server, the dsdt ACPI table is:
 Method (_DMA, 0, Serialized)  // _DMA: Direct Memory Access
            {
                Name (RBUF, ResourceTemplate ()
                {
                    QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
                        0x0000000000000000, // Granularity
                        0x0000000000000000, // Range Minimum
                        0x00000000FFFFFFFF, // Range Maximum
                        0x0000000000000000, // Translation Offset
                        0x0000000100000000, // Length
                        ,, , AddressRangeMemory, TypeStatic)
                    QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
                        0x0000000000000000, // Granularity
                        0x0000006010200000, // Range Minimum
                        0x000000602FFFFFFF, // Range Maximum
                        0x0000000000000000, // Translation Offset
                        0x000000001FE00000, // Length
                        ,, , AddressRangeMemory, TypeStatic)
                    QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
                        0x0000000000000000, // Granularity
                        0x00000060F0000000, // Range Minimum
                        0x00000060FFFFFFFF, // Range Maximum
                        0x0000000000000000, // Translation Offset
                        0x0000000010000000, // Length
                        ,, , AddressRangeMemory, TypeStatic)
                    QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
                        0x0000000000000000, // Granularity
                        0x0000007000000000, // Range Minimum
                        0x000003FFFFFFFFFF, // Range Maximum
                        0x0000000000000000, // Translation Offset
                        0x0000039000000000, // Length
                        ,, , AddressRangeMemory, TypeStatic)
                })

But the System RAM ranges are:
cat /proc/iomem |grep -i ram
90000000-91ffffff : System RAM
92900000-fffbffff : System RAM
880000000-fffffffff : System RAM
8800000000-bff5990fff : System RAM
bff59d0000-bff5a4ffff : System RAM
bff8000000-bfffffffff : System RAM
So some RAM ranges are out of dma_range_map.

Fix it by checking whether each of the system RAM resources can be
properly encompassed within the dma_range_map.

Signed-off-by: Jia He <justin.he@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-11-06 08:38:16 +01:00
Jia He
8ae0e97031 dma-mapping: move dma_addressing_limited() out of line
This patch moves dma_addressing_limited() out of line, serving as a
preliminary step to prevent the introduction of a new publicly accessible
low-level helper when validating whether all system RAM is mapped within
the DMA mapping range.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jia He <justin.he@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-11-06 08:35:09 +01:00
Arnd Bergmann
3d6f126b15 dma-mapping: move arch_dma_set_mask() declaration to header
This function has a __weak definition and an override that is only used on
freescale powerpc chips. The powerpc definition however does not see the
declaration that is in a .c file:

arch/powerpc/kernel/dma-mask.c:7:6: error: no previous prototype for 'arch_dma_set_mask' [-Werror=missing-prototypes]

Move it into the linux/dma-map-ops.h header where the other arch_dma_* functions
are declared.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-07-31 17:54:28 +02:00
Jiaxun Yang
1d3f56b295 dma-mapping: provide CONFIG_ARCH_DMA_DEFAULT_COHERENT
Provide a kconfig option to allow arches to manipulate default
value of dma_default_coherent in Kconfig.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-04-07 07:38:25 +02:00
Jiaxun Yang
fe4e5efa40 dma-mapping: provide a fallback dma_default_coherent
dma_default_coherent was decleared unconditionally at kernel/dma/mapping.c
but only decleared when any of non-coherent options is enabled in
dma-map-ops.h.

Guard the declaration in mapping.c with non-coherent options and provide
a fallback definition.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-04-07 07:38:20 +02:00
Christoph Hellwig
3622b86f49 dma-mapping: reject GFP_COMP for noncoherent allocations
While not quite as bogus as for the dma-coherent allocations that were
fixed earlier, GFP_COMP for these allocations has no benefits for
the dma-direct case, and can't be supported at all by dma dma-iommu
backend which splits up allocations into smaller orders.  Due to an
oversight in ffcb754584 that flag stopped being cleared for all
dma allocations, but only got rejected for coherent ones, so fix up
these callers to not allow __GFP_COMP as well after the sound code
has been fixed to not ask for it.

Fixes: ffcb754584 ("dma-mapping: reject __GFP_COMP in dma_alloc_attrs")
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Reported-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Tested-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
2022-12-21 08:45:38 +01:00
Christoph Hellwig
ffcb754584 dma-mapping: reject __GFP_COMP in dma_alloc_attrs
DMA allocations can never be turned back into a page pointer, so
requesting compound pages doesn't make sense and it can't even be
supported at all by various backends.

Reject __GFP_COMP with a warning in dma_alloc_attrs, and stop clearing
the flag in the arm dma ops and dma-iommu.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
2022-11-21 09:37:20 +01:00
Linus Torvalds
27bc50fc90 Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP & KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
2022-10-10 17:53:04 -07:00
Alexander Potapenko
7ade4f1077 dma: kmsan: unpoison DMA mappings
KMSAN doesn't know about DMA memory writes performed by devices.  We
unpoison such memory when it's mapped to avoid false positive reports.

Link: https://lkml.kernel.org/r/20220915150417.722975-22-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:21 -07:00
Christoph Hellwig
9fc18f6d56 dma-mapping: mark dma_supported static
Now that the remaining users in drivers are gone, this function can be
marked static.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-09-07 10:38:28 +02:00
Logan Gunthorpe
8419702489 dma-mapping: reformat comment to suppress htmldoc warning
make html doc reports a cryptic warning with the commit named below:

  kernel/dma/mapping.c:258: WARNING: Option list ends without a blank
                                     line; unexpected unindent.

Seems the parser is a bit fussy about the tabbing and having a single
space tab causes the warning. To suppress the warning add another
tab to the list and reindent everything.

Fixes: 7c2645a2a3 ("dma-mapping: allow EREMOTEIO return code for P2PDMA transfers")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-07-28 07:21:33 -07:00
Logan Gunthorpe
159bf19270 dma-mapping: add flags to dma_map_ops to indicate PCI P2PDMA support
Add a flags member to the dma_map_ops structure with one flag to
indicate support for PCI P2PDMA.

Also, add a helper to check if a device supports PCI P2PDMA.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-07-26 07:27:48 -04:00
Logan Gunthorpe
7c2645a2a3 dma-mapping: allow EREMOTEIO return code for P2PDMA transfers
Add EREMOTEIO error return to dma_map_sgtable() which will be used
by .map_sg() implementations that detect P2PDMA pages that the
underlying DMA device cannot access.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-07-26 07:27:47 -04:00
John Garry
a229cc14f3 dma-mapping: add dma_opt_mapping_size()
Streaming DMA mapping involving an IOMMU may be much slower for larger
total mapping size. This is because every IOMMU DMA mapping requires an
IOVA to be allocated and freed. IOVA sizes above a certain limit are not
cached, which can have a big impact on DMA mapping performance.

Provide an API for device drivers to know this "optimal" limit, such that
they may try to produce mapping which don't exceed it.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-07-19 06:05:41 +02:00
Christoph Hellwig
4fe87e818e dma-mapping: move pgprot_decrypted out of dma_pgprot
pgprot_decrypted is used by AMD SME systems to allow access to memory
that was set to not encrypted using set_memory_decrypted.  That only
happens for dma-direct memory as the IOMMU solves the addressing
challenges for the encryption bit using its own remapping.

Move the pgprot_decrypted call out of dma_pgprot which is also used
by the IOMMU mappings and into dma-direct so that it is only used with
memory that was set decrypted.

Fixes: f5ff79fddf ("dma-mapping: remove CONFIG_DMA_REMAP")
Reported-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
2022-04-01 06:46:51 +02:00
Linus Walleij
00ba9357d1 ARM: ixp4xx: Drop custom DMA coherency and bouncing
The new PCI driver does not need any of this stuff, so just
drop it.

Cc: iommu@lists.linux-foundation.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220211223238.648934-12-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2022-02-12 18:20:04 +01:00
Linus Torvalds
46f8763228 Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
 "There's the usual summary below, but the highlights are support for
  the Armv8.6 timer extensions, KASAN support for asymmetric MTE, the
  ability to kexec() with the MMU enabled and a second attempt at
  switching to the generic pfn_valid() implementation.

  Summary:

   - Support for the Arm8.6 timer extensions, including a
     self-synchronising view of the system registers to elide some
     expensive ISB instructions.

   - Exception table cleanup and rework so that the fixup handlers
     appear correctly in backtraces.

   - A handful of miscellaneous changes, the main one being selection of
     CONFIG_HAVE_POSIX_CPU_TIMERS_TASK_WORK.

   - More mm and pgtable cleanups.

   - KASAN support for "asymmetric" MTE, where tag faults are reported
     synchronously for loads (via an exception) and asynchronously for
     stores (via a register).

   - Support for leaving the MMU enabled during kexec relocation, which
     significantly speeds up the operation.

   - Minor improvements to our perf PMU drivers.

   - Improvements to the compat vDSO build system, particularly when
     building with LLVM=1.

   - Preparatory work for handling some Coresight TRBE tracing errata.

   - Cleanup and refactoring of the SVE code to pave the way for SME
     support in future.

   - Ensure SCS pages are unpoisoned immediately prior to freeing them
     when KASAN is enabled for the vmalloc area.

   - Try moving to the generic pfn_valid() implementation again now that
     the DMA mapping issue from last time has been resolved.

   - Numerous improvements and additions to our FPSIMD and SVE
     selftests"

[ armv8.6 timer updates were in a shared branch and already came in
  through -tip in the timer pull  - Linus ]

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (85 commits)
  arm64: Select POSIX_CPU_TIMERS_TASK_WORK
  arm64: Document boot requirements for FEAT_SME_FA64
  arm64/sve: Fix warnings when SVE is disabled
  arm64/sve: Add stub for sve_max_virtualisable_vl()
  arm64: errata: Add detection for TRBE write to out-of-range
  arm64: errata: Add workaround for TSB flush failures
  arm64: errata: Add detection for TRBE overwrite in FILL mode
  arm64: Add Neoverse-N2, Cortex-A710 CPU part definition
  selftests: arm64: Factor out utility functions for assembly FP tests
  arm64: vmlinux.lds.S: remove `.fixup` section
  arm64: extable: add load_unaligned_zeropad() handler
  arm64: extable: add a dedicated uaccess handler
  arm64: extable: add `type` and `data` fields
  arm64: extable: use `ex` for `exception_table_entry`
  arm64: extable: make fixup_exception() return bool
  arm64: extable: consolidate definitions
  arm64: gpr-num: support W registers
  arm64: factor out GPR numbering helpers
  arm64: kvm: use kvm_exception_table_entry
  arm64: lib: __arch_copy_to_user(): fold fixups into body
  ...
2021-11-01 16:33:53 -07:00
Hamza Mahfooz
c2bbf9d1e9 dma-debug: teach add_dma_entry() about DMA_ATTR_SKIP_CPU_SYNC
Mapping something twice should be possible as long as,
DMA_ATTR_SKIP_CPU_SYNC is passed to the strictly speaking second relevant
mapping operation (that attempts to map the same thing). So, don't issue a
warning if the specified condition is met in add_dma_entry().

Signed-off-by: Hamza Mahfooz <someguy@effective-light.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-10-18 12:46:45 +02:00
Logan Gunthorpe
011a9ce807 dma-mapping: fix the kerneldoc for dma_map_sgtable()
htmldocs began producing the following warnings:

  kernel/dma/mapping.c:256: WARNING: Definition list ends without a
             blank line; unexpected unindent.
  kernel/dma/mapping.c:257: WARNING: Bullet list ends without a blank
             line; unexpected unindent.

Reformatting the list without hyphens fixes the warnings and produces
both a readable text and HTML output.

Fixes: fffe3cc8c2 ("dma-mapping: allow map_sg() ops to return negative error code")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-10-11 13:43:04 +02:00
Mike Rapoport
a9c38c5d26 dma-mapping: remove bogus test for pfn_valid from dma_map_resource
dma_map_resource() uses pfn_valid() to ensure the range is not RAM.
However, pfn_valid() only checks for availability of the memory map for a
PFN but it does not ensure that the PFN is actually backed by RAM.

As dma_map_resource() is the only method in DMA mapping APIs that has this
check, simply drop the pfn_valid() test from dma_map_resource().

Link: https://lore.kernel.org/all/20210824173741.GC623@arm.com/
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20210930013039.11260-2-rppt@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-10-01 14:54:45 +01:00
Christoph Hellwig
a61cb6017d dma-mapping: fix the kerneldoc for dma_map_sg_attrs
Add the missing description for the nents parameter, and fix a trivial
misalignment.

Fixes: fffe3cc8c2 ("dma-mapping: allow map_sg() ops to return negative error codes")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-09-06 14:40:47 +02:00
Christoph Hellwig
2a047e0662 dma-mapping: return an unsigned int from dma_map_sg{,_attrs}
These can only return 0 for failure or the number of entries, so turn
the return value into an unsigned int.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
2021-08-14 09:18:36 +02:00
Logan Gunthorpe
d03c544192 dma-mapping: disallow .map_sg operations from returning zero on error
Now that all the .map_sg operations have been converted to returning
proper error codes, drop the code to handle a zero return value,
add a warning if a zero is returned.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-09 17:15:02 +02:00
Logan Gunthorpe
fffe3cc8c2 dma-mapping: allow map_sg() ops to return negative error codes
Allow dma_map_sgtable() to pass errors from the map_sg() ops. This
will be required for returning appropriate error codes when mapping
P2PDMA memory.

Introduce __dma_map_sg_attrs() which will return the raw error code
from the map_sg operation (whether it be negative or zero). Then add a
dma_map_sg_attrs() wrapper to convert any negative errors to zero to
satisfy the existing calling convention.

dma_map_sgtable() defines three error codes that .map_sg implementations
are allowed to return: -EINVAL, -ENOMEM and -EIO. The latter of which
is a generic return for cases that are passing DMA_MAPPING_ERROR
through.

dma_map_sgtable() will convert a zero error return for old map_sg() ops
into a -EIO return and return any negative errors as reported.

This allows map_sg implementations to start returning multiple
negative error codes. Legacy map_sg implementations can continue
to return zero until they are all converted.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-09 17:13:02 +02:00
Christoph Hellwig
7d5b5738d1 dma-mapping: add a dma_alloc_noncontiguous API
Add a new API that returns a potentiall virtually non-contigous sg_table
and a DMA address.  This API is only properly implemented for dma-iommu
and will simply return a contigious chunk as a fallback.

The intent is that drivers can use this API if either:

 - no kernel mapping or only temporary kernel mappings are required.
   That is as a better replacement for DMA_ATTR_NO_KERNEL_MAPPING
 - a kernel mapping is required for cached and DMA mapped pages, but
   the driver also needs the pages to e.g. map them to userspace.
   In that sense it is a replacement for some aspects of the recently
   removed and never fully implemented DMA_ATTR_NON_CONSISTENT

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Tested-by: Ricardo Ribalda <ribalda@chromium.org>
2021-03-15 10:02:31 +01:00