linux-stable.git/kernel/dma, branch v6.3.2 Linux kernel stable tree swiotlb: fix debugfs reporting of reserved memory pools 2023-05-11T14:17:33+00:00 Michael Kelley mikelley@microsoft.com 2023-04-13T15:37:30+00:00 a68ed2e0a8544c43873dd19f0f2d14a1b6971bed [ Upstream commit 5499d01c029069044a3b3e50501c77b474c96178 ] For io_tlb_nslabs, the debugfs code reports the correct value for a specific reserved memory pool. But for io_tlb_used, the value reported is always for the default pool, not the specific reserved pool. Fix this. Fixes: 5c850d31880e ("swiotlb: fix passing local variable to debugfs_create_ulong()") Signed-off-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 5499d01c029069044a3b3e50501c77b474c96178 ]

For io_tlb_nslabs, the debugfs code reports the correct value for a
specific reserved memory pool.  But for io_tlb_used, the value reported
is always for the default pool, not the specific reserved pool. Fix this.

Fixes: 5c850d31880e ("swiotlb: fix passing local variable to debugfs_create_ulong()")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
swiotlb: relocate PageHighMem test away from rmem_swiotlb_setup 2023-05-11T14:17:33+00:00 Doug Berger opendmb@gmail.com 2023-04-14T21:29:25+00:00 4116bd222b1b67f9be6caf6f8b6bf0adbed9eae3 [ Upstream commit a90922fa25370902322e9de6640e58737d459a50 ] The reservedmem_of_init_fn's are invoked very early at boot before the memory zones have even been defined. This makes it inappropriate to test whether the page corresponding to a PFN is in ZONE_HIGHMEM from within one. Removing the check allows an ARM 32-bit kernel with SPARSEMEM enabled to boot properly since otherwise we would be de-referencing an uninitialized sparsemem map to perform pfn_to_page() check. The arm64 architecture happens to work (and also has no high memory) but other 32-bit architectures could also be having similar issues. While it would be nice to provide early feedback about a reserved DMA pool residing in highmem, it is not possible to do that until the first time we try to use it, which is where the check is moved to. Fixes: 0b84e4f8b793 ("swiotlb: Add restricted DMA pool initialization") Signed-off-by: Doug Berger <opendmb@gmail.com> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a90922fa25370902322e9de6640e58737d459a50 ]

The reservedmem_of_init_fn's are invoked very early at boot before the
memory zones have even been defined. This makes it inappropriate to test
whether the page corresponding to a PFN is in ZONE_HIGHMEM from within
one.

Removing the check allows an ARM 32-bit kernel with SPARSEMEM enabled to
boot properly since otherwise we would be de-referencing an
uninitialized sparsemem map to perform pfn_to_page() check.

The arm64 architecture happens to work (and also has no high memory) but
other 32-bit architectures could also be having similar issues.

While it would be nice to provide early feedback about a reserved DMA
pool residing in highmem, it is not possible to do that until the first
time we try to use it, which is where the check is moved to.

Fixes: 0b84e4f8b793 ("swiotlb: Add restricted DMA pool initialization")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
swiotlb: fix a braino in the alignment check fix 2023-04-06T14:45:12+00:00 Petr Tesarik petr.tesarik.ext@huawei.com 2023-04-06T14:35:39+00:00 bbb73a103fbbed6f63cb738d3783261c4241b4b2 The alignment mask in swiotlb_do_find_slots() masks off the high bits which are not relevant for the alignment, so multiple requirements are combined with a bitwise OR rather than AND. In plain English, the stricter the alignment, the more bits must be set in iotlb_align_mask. Confusion may arise from the fact that the same variable is also used to mask off the offset within a swiotlb slot, which is achieved with a bitwise AND. Fixes: 0eee5ae10256 ("swiotlb: fix slot alignment checks") Reported-by: Dexuan Cui <decui@microsoft.com> Link: https://lore.kernel.org/all/CAA42JLa1y9jJ7BgQvXeUYQh-K2mDNHd2BYZ4iZUz33r5zY7oAQ@mail.gmail.com/ Reported-by: Kelsey Steele <kelseysteele@linux.microsoft.com> Link: https://lore.kernel.org/all/20230405003549.GA21326@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net/ Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Tested-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
The alignment mask in swiotlb_do_find_slots() masks off the high
bits which are not relevant for the alignment, so multiple
requirements are combined with a bitwise OR rather than AND.
In plain English, the stricter the alignment, the more bits must
be set in iotlb_align_mask.

Confusion may arise from the fact that the same variable is also
used to mask off the offset within a swiotlb slot, which is
achieved with a bitwise AND.

Fixes: 0eee5ae10256 ("swiotlb: fix slot alignment checks")
Reported-by: Dexuan Cui <decui@microsoft.com>
Link: https://lore.kernel.org/all/CAA42JLa1y9jJ7BgQvXeUYQh-K2mDNHd2BYZ4iZUz33r5zY7oAQ@mail.gmail.com/
Reported-by: Kelsey Steele <kelseysteele@linux.microsoft.com>
Link: https://lore.kernel.org/all/20230405003549.GA21326@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net/
Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com>
Tested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
swiotlb: fix slot alignment checks 2023-03-22T08:03:17+00:00 Petr Tesarik petr.tesarik.ext@huawei.com 2023-03-21T08:31:27+00:00 0eee5ae1025699ea93d44fdb6ef2365505082103 Explicit alignment and page alignment are used only to calculate the stride, not when checking actual slot physical address. Originally, only page alignment was implemented, and that worked, because the whole SWIOTLB is allocated on a page boundary, so aligning the start index was sufficient to ensure a page-aligned slot. When commit 1f221a0d0dbf ("swiotlb: respect min_align_mask") added support for min_align_mask, the index could be incremented in the search loop, potentially finding an unaligned slot if minimum device alignment is between IO_TLB_SIZE and PAGE_SIZE. The bug could go unnoticed, because the slot size is 2 KiB, and the most common page size is 4 KiB, so there is no alignment value in between. IIUC the intention has been to find a slot that conforms to all alignment constraints: device minimum alignment, an explicit alignment (given as function parameter) and optionally page alignment (if allocation size is >= PAGE_SIZE). The most restrictive mask can be trivially computed with logical AND. The rest can stay. Fixes: 1f221a0d0dbf ("swiotlb: respect min_align_mask") Fixes: e81e99bacc9f ("swiotlb: Support aligned swiotlb buffers") Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
Explicit alignment and page alignment are used only to calculate
the stride, not when checking actual slot physical address.

Originally, only page alignment was implemented, and that worked,
because the whole SWIOTLB is allocated on a page boundary, so
aligning the start index was sufficient to ensure a page-aligned
slot.

When commit 1f221a0d0dbf ("swiotlb: respect min_align_mask") added
support for min_align_mask, the index could be incremented in the
search loop, potentially finding an unaligned slot if minimum device
alignment is between IO_TLB_SIZE and PAGE_SIZE.  The bug could go
unnoticed, because the slot size is 2 KiB, and the most common page
size is 4 KiB, so there is no alignment value in between.

IIUC the intention has been to find a slot that conforms to all
alignment constraints: device minimum alignment, an explicit
alignment (given as function parameter) and optionally page
alignment (if allocation size is >= PAGE_SIZE). The most
restrictive mask can be trivially computed with logical AND. The
rest can stay.

Fixes: 1f221a0d0dbf ("swiotlb: respect min_align_mask")
Fixes: e81e99bacc9f ("swiotlb: Support aligned swiotlb buffers")
Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
swiotlb: use wrap_area_index() instead of open-coding it 2023-03-22T08:02:35+00:00 Petr Tesarik petr.tesarik.ext@huawei.com 2023-03-21T08:31:26+00:00 39e7d2ab6ea9fd6b389091ec223d566934fe7be5 No functional change, just use an existing helper. Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
No functional change, just use an existing helper.

Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
swiotlb: fix the deadlock in swiotlb_do_find_slots 2023-03-15T14:47:40+00:00 GuoRui.Yu GuoRui.Yu@linux.alibaba.com 2023-02-22T16:53:15+00:00 7c3940bf81e5664cdb50c3fedfec8f0a756a34fb In general, if swiotlb is sufficient, the logic of index = wrap_area_index(mem, index + 1) is fine, it will quickly take a slot and release the area->lock; But if swiotlb is insufficient and the device has min_align_mask requirements, such as NVME, we may not be able to satisfy index == wrap and exit the loop properly. In this case, other kernel threads will not be able to acquire the area->lock and release the slot, resulting in a deadlock. The current implementation of wrap_area_index does not involve a modulo operation, so adjusting the wrap to ensure the loop ends is not trivial. Introduce a new variable to record the number of loops and exit the loop after completing the traversal. Backtraces: Other CPUs are waiting this core to exit the swiotlb_do_find_slots loop. [10199.924391] RIP: 0010:swiotlb_do_find_slots+0x1fe/0x3e0 [10199.924403] Call Trace: [10199.924404] <TASK> [10199.924405] swiotlb_tbl_map_single+0xec/0x1f0 [10199.924407] swiotlb_map+0x5c/0x260 [10199.924409] ? nvme_pci_setup_prps+0x1ed/0x340 [10199.924411] dma_direct_map_page+0x12e/0x1c0 [10199.924413] nvme_map_data+0x304/0x370 [10199.924415] nvme_prep_rq.part.0+0x31/0x120 [10199.924417] nvme_queue_rq+0x77/0x1f0 ... [ 9639.596311] NMI backtrace for cpu 48 [ 9639.596336] Call Trace: [ 9639.596337] [ 9639.596338] _raw_spin_lock_irqsave+0x37/0x40 [ 9639.596341] swiotlb_do_find_slots+0xef/0x3e0 [ 9639.596344] swiotlb_tbl_map_single+0xec/0x1f0 [ 9639.596347] swiotlb_map+0x5c/0x260 [ 9639.596349] dma_direct_map_sg+0x7a/0x280 [ 9639.596352] __dma_map_sg_attrs+0x30/0x70 [ 9639.596355] dma_map_sgtable+0x1d/0x30 [ 9639.596356] nvme_map_data+0xce/0x370 ... [ 9639.595665] NMI backtrace for cpu 50 [ 9639.595682] Call Trace: [ 9639.595682] [ 9639.595683] _raw_spin_lock_irqsave+0x37/0x40 [ 9639.595686] swiotlb_release_slots.isra.0+0x86/0x180 [ 9639.595688] dma_direct_unmap_sg+0xcf/0x1a0 [ 9639.595690] nvme_unmap_data.part.0+0x43/0xc0 Fixes: 1f221a0d0dbf ("swiotlb: respect min_align_mask") Signed-off-by: GuoRui.Yu <GuoRui.Yu@linux.alibaba.com> Signed-off-by: Xiaokang Hu <xiaokang.hxk@alibaba-inc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
In general, if swiotlb is sufficient, the logic of index =
wrap_area_index(mem, index + 1) is fine, it will quickly take a slot and
release the area->lock; But if swiotlb is insufficient and the device
has min_align_mask requirements, such as NVME, we may not be able to
satisfy index == wrap and exit the loop properly. In this case, other
kernel threads will not be able to acquire the area->lock and release
the slot, resulting in a deadlock.

The current implementation of wrap_area_index does not involve a modulo
operation, so adjusting the wrap to ensure the loop ends is not trivial.
Introduce a new variable to record the number of loops and exit the loop
after completing the traversal.

Backtraces:
Other CPUs are waiting this core to exit the swiotlb_do_find_slots
loop.
[10199.924391] RIP: 0010:swiotlb_do_find_slots+0x1fe/0x3e0
[10199.924403] Call Trace:
[10199.924404]  <TASK>
[10199.924405]  swiotlb_tbl_map_single+0xec/0x1f0
[10199.924407]  swiotlb_map+0x5c/0x260
[10199.924409]  ? nvme_pci_setup_prps+0x1ed/0x340
[10199.924411]  dma_direct_map_page+0x12e/0x1c0
[10199.924413]  nvme_map_data+0x304/0x370
[10199.924415]  nvme_prep_rq.part.0+0x31/0x120
[10199.924417]  nvme_queue_rq+0x77/0x1f0

...
[ 9639.596311] NMI backtrace for cpu 48
[ 9639.596336] Call Trace:
[ 9639.596337]
[ 9639.596338] _raw_spin_lock_irqsave+0x37/0x40
[ 9639.596341] swiotlb_do_find_slots+0xef/0x3e0
[ 9639.596344] swiotlb_tbl_map_single+0xec/0x1f0
[ 9639.596347] swiotlb_map+0x5c/0x260
[ 9639.596349] dma_direct_map_sg+0x7a/0x280
[ 9639.596352] __dma_map_sg_attrs+0x30/0x70
[ 9639.596355] dma_map_sgtable+0x1d/0x30
[ 9639.596356] nvme_map_data+0xce/0x370

...
[ 9639.595665] NMI backtrace for cpu 50
[ 9639.595682] Call Trace:
[ 9639.595682]
[ 9639.595683] _raw_spin_lock_irqsave+0x37/0x40
[ 9639.595686] swiotlb_release_slots.isra.0+0x86/0x180
[ 9639.595688] dma_direct_unmap_sg+0xcf/0x1a0
[ 9639.595690] nvme_unmap_data.part.0+0x43/0xc0

Fixes: 1f221a0d0dbf ("swiotlb: respect min_align_mask")
Signed-off-by: GuoRui.Yu <GuoRui.Yu@linux.alibaba.com>
Signed-off-by: Xiaokang Hu <xiaokang.hxk@alibaba-inc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
swiotlb: mark swiotlb_memblock_alloc() as __init 2023-02-22T14:44:48+00:00 Randy Dunlap rdunlap@infradead.org 2023-02-22T07:04:11+00:00 9b07d27d0fbb7f7441aa986859a0f53ec93a0335 swiotlb_memblock_alloc() calls memblock_alloc(), which calls (__init) memblock_alloc_try_nid(). However, swiotlb_membloc_alloc() can be marked as __init since it is only called by swiotlb_init_remap(), which is already marked as __init. This prevents a modpost build warning/error: WARNING: modpost: vmlinux.o: section mismatch in reference: swiotlb_memblock_alloc (section: .text) -> memblock_alloc_try_nid (section: .init.text) WARNING: modpost: vmlinux.o: section mismatch in reference: swiotlb_memblock_alloc (section: .text) -> memblock_alloc_try_nid (section: .init.text) This fixes the build warning/error seen on ARM64, PPC64, S390, i386, and x86_64. Fixes: 8d58aa484920 ("swiotlb: reduce the swiotlb buffer size on allocation failure") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Alexey Kardashevskiy <aik@amd.com> Cc: Christoph Hellwig <hch@lst.de> Cc: iommu@lists.linux.dev Cc: Mike Rapoport <rppt@kernel.org> Cc: linux-mm@kvack.org Signed-off-by: Christoph Hellwig <hch@lst.de> 
swiotlb_memblock_alloc() calls memblock_alloc(), which calls
(__init) memblock_alloc_try_nid(). However, swiotlb_membloc_alloc()
can be marked as __init since it is only called by swiotlb_init_remap(),
which is already marked as __init. This prevents a modpost build
warning/error:

WARNING: modpost: vmlinux.o: section mismatch in reference: swiotlb_memblock_alloc (section: .text) -> memblock_alloc_try_nid (section: .init.text)
WARNING: modpost: vmlinux.o: section mismatch in reference: swiotlb_memblock_alloc (section: .text) -> memblock_alloc_try_nid (section: .init.text)

This fixes the build warning/error seen on ARM64, PPC64, S390, i386,
and x86_64.

Fixes: 8d58aa484920 ("swiotlb: reduce the swiotlb buffer size on allocation failure")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexey Kardashevskiy <aik@amd.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux.dev
Cc: Mike Rapoport <rppt@kernel.org>
Cc: linux-mm@kvack.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
swiotlb: remove swiotlb_max_segment 2023-02-16T17:10:18+00:00 Christoph Hellwig hch@lst.de 2023-02-16T06:24:19+00:00 5e7b9a6ae8c352819a2d998a065910b536de0e8c swiotlb_max_segment has always been a bogus API, so remove it now that the remaining callers are gone. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> 
swiotlb_max_segment has always been a bogus API, so remove it now that
the remaining callers are gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
dma-mapping: reject GFP_COMP for noncoherent allocations 2022-12-21T07:45:38+00:00 Christoph Hellwig hch@lst.de 2022-12-20T08:08:12+00:00 3622b86f49f84e52fb41fee9eb55f9290613dfc3 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 ffcb75458460 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: ffcb75458460 ("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> 
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 ffcb75458460 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: ffcb75458460 ("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>
dma-mapping: reject __GFP_COMP in dma_alloc_attrs 2022-11-21T08:37:20+00:00 Christoph Hellwig hch@lst.de 2022-11-09T07:37:17+00:00 ffcb754584603adf7039d7972564fbf6febdc542 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> 
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>