linux.git/kernel/dma, branch v6.5

Merge tag 'dma-mapping-6.5-2023-07-09' of git://git.infradead.org/users/hch/dma-mapping

2023-07-09T17:24:22+00:00

Pull dma-mapping fixes from Christoph Hellwig:

 - swiotlb area sizing fixes (Petr Tesarik)

* tag 'dma-mapping-6.5-2023-07-09' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: reduce the number of areas to match actual memory pool size
  swiotlb: always set the number of areas before allocating the pool

Merge tag 'dma-mapping-6.5-2023-06-28' of git://git.infradead.org/users/hch/dma-mapping

2023-06-30T04:12:20+00:00

Pull dma-mapping updates from Christoph Hellwig:

 - swiotlb cleanups (Petr Tesarik)

 - use kvmalloc_array (gaoxu)

 - a small step towards removing is_swiotlb_active (Christoph Hellwig)

 - fix a Kconfig typo Sui Jingfeng)

* tag 'dma-mapping-6.5-2023-06-28' of git://git.infradead.org/users/hch/dma-mapping:
  drm/nouveau: stop using is_swiotlb_active
  swiotlb: use the atomic counter of total used slabs if available
  swiotlb: remove unused field "used" from struct io_tlb_mem
  dma-remap: use kvmalloc_array/kvfree for larger dma memory remap
  dma-mapping: fix a Kconfig typo

swiotlb: reduce the number of areas to match actual memory pool size

2023-06-29T05:10:28+00:00

Although the desired size of the SWIOTLB memory pool is increased in
swiotlb_adjust_nareas() to match the number of areas, the actual allocation
may be smaller, which may require reducing the number of areas.

For example, Xen uses swiotlb_init_late(), which in turn uses the page
allocator. On x86, page size is 4 KiB and MAX_ORDER is 10 (1024 pages),
resulting in a maximum memory pool size of 4 MiB. This corresponds to 2048
slots of 2 KiB each. The minimum area size is 128 (IO_TLB_SEGSIZE),
allowing at most 2048 / 128 = 16 areas.

If num_possible_cpus() is greater than the maximum number of areas, areas
are smaller than IO_TLB_SEGSIZE and contiguous groups of free slots will
span multiple areas. When allocating and freeing slots, only one area will
be properly locked, causing race conditions on the unlocked slots and
ultimately data corruption, kernel hangs and crashes.

Fixes: 20347fca71a3 ("swiotlb: split up the global swiotlb lock")
Signed-off-by: Petr Tesarik 
Reviewed-by: Roberto Sassu 
Signed-off-by: Christoph Hellwig

swiotlb: always set the number of areas before allocating the pool

2023-06-29T05:10:00+00:00

The number of areas defaults to the number of possible CPUs. However, the
total number of slots may have to be increased after adjusting the number
of areas. Consequently, the number of areas must be determined before
allocating the memory pool. This is even explained with a comment in
swiotlb_init_remap(), but swiotlb_init_late() adjusts the number of areas
after slots are already allocated. The areas may end up being smaller than
IO_TLB_SEGSIZE, which breaks per-area locking.

While fixing swiotlb_init_late(), move all relevant comments before the
definition of swiotlb_adjust_nareas() and convert them to kernel-doc.

Fixes: 20347fca71a3 ("swiotlb: split up the global swiotlb lock")
Signed-off-by: Petr Tesarik 
Reviewed-by: Roberto Sassu 
Signed-off-by: Christoph Hellwig

dma-mapping: force bouncing if the kmalloc() size is not cache-line-aligned

2023-06-19T23:19:23+00:00

For direct DMA, if the size is small enough to have originated from a
kmalloc() cache below ARCH_DMA_MINALIGN, check its alignment against
dma_get_cache_alignment() and bounce if necessary.  For larger sizes, it
is the responsibility of the DMA API caller to ensure proper alignment.

At this point, the kmalloc() caches are properly aligned but this will
change in a subsequent patch.

Architectures can opt in by selecting DMA_BOUNCE_UNALIGNED_KMALLOC.

Link: https://lkml.kernel.org/r/20230612153201.554742-15-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Robin Murphy 
Tested-by: Isaac J. Manjarres 
Cc: Alasdair Kergon 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: Daniel Vetter 
Cc: Greg Kroah-Hartman 
Cc: Herbert Xu 
Cc: Jerry Snitselaar 
Cc: Joerg Roedel 
Cc: Jonathan Cameron 
Cc: Jonathan Cameron 
Cc: Lars-Peter Clausen 
Cc: Logan Gunthorpe 
Cc: Marc Zyngier 
Cc: Mark Brown 
Cc: Mike Snitzer 
Cc: "Rafael J. Wysocki" 
Cc: Saravana Kannan 
Cc: Vlastimil Babka 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

dma-mapping: name SG DMA flag helpers consistently

2023-06-19T23:19:22+00:00

sg_is_dma_bus_address() is inconsistent with the naming pattern of its
corresponding setters and its own kerneldoc, so take the majority vote and
rename it sg_dma_is_bus_address() (and fix up the missing underscores in
the kerneldoc too).  This gives us a nice clear pattern where SG DMA flags
are SG_DMA_, and the helpers for acting on them are
sg_dma__().

Link: https://lkml.kernel.org/r/20230612153201.554742-14-catalin.marinas@arm.com
Signed-off-by: Robin Murphy 
Signed-off-by: Catalin Marinas 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Jerry Snitselaar 
Reviewed-by: Logan Gunthorpe 
  Link: https://lore.kernel.org/r/fa2eca2862c7ffc41b50337abffb2dfd2864d3ea.1685036694.git.robin.murphy@arm.com
Tested-by: Isaac J. Manjarres 
Cc: Alasdair Kergon 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: Daniel Vetter 
Cc: Greg Kroah-Hartman 
Cc: Herbert Xu 
Cc: Joerg Roedel 
Cc: Jonathan Cameron 
Cc: Jonathan Cameron 
Cc: Lars-Peter Clausen 
Cc: Marc Zyngier 
Cc: Mark Brown 
Cc: Mike Snitzer 
Cc: "Rafael J. Wysocki" 
Cc: Saravana Kannan 
Cc: Vlastimil Babka 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

scatterlist: add dedicated config for DMA flags

2023-06-19T23:19:22+00:00

The DMA flags field will be useful for users beyond PCI P2P, so upgrade to
its own dedicated config option.

[catalin.marinas@arm.com: use #ifdef CONFIG_NEED_SG_DMA_FLAGS in scatterlist.h]
[catalin.marinas@arm.com: update PCI_P2PDMA dma_flags comment in scatterlist.h]
Link: https://lkml.kernel.org/r/20230612153201.554742-13-catalin.marinas@arm.com
Signed-off-by: Robin Murphy 
Signed-off-by: Catalin Marinas 
Reviewed-by: Christoph Hellwig 
Tested-by: Isaac J. Manjarres 
Cc: Alasdair Kergon 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: Daniel Vetter 
Cc: Greg Kroah-Hartman 
Cc: Herbert Xu 
Cc: Jerry Snitselaar 
Cc: Joerg Roedel 
Cc: Jonathan Cameron 
Cc: Jonathan Cameron 
Cc: Lars-Peter Clausen 
Cc: Logan Gunthorpe 
Cc: Marc Zyngier 
Cc: Mark Brown 
Cc: Mike Snitzer 
Cc: "Rafael J. Wysocki" 
Cc: Saravana Kannan 
Cc: Vlastimil Babka 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

swiotlb: use the atomic counter of total used slabs if available

2023-06-07T13:06:40+00:00

If DEBUG_FS is enabled, the cost of keeping an exact number of total
used slabs is already paid. In this case, there is no reason to use an
inexact number for statistics and kernel messages.

Signed-off-by: Petr Tesarik 
Signed-off-by: Christoph Hellwig

dma-remap: use kvmalloc_array/kvfree for larger dma memory remap

2023-06-07T13:06:28+00:00

If dma_direct_alloc() alloc memory in size of 64MB, the inner function
dma_common_contiguous_remap() will allocate 128KB memory by invoking
the function kmalloc_array(). and the kmalloc_array seems to fail to try to
allocate 128KB mem.

Call trace:
[14977.928623] qcrosvm: page allocation failure: order:5, mode:0x40cc0
[14977.928638] dump_backtrace.cfi_jt+0x0/0x8
[14977.928647] dump_stack_lvl+0x80/0xb8
[14977.928652] warn_alloc+0x164/0x200
[14977.928657] __alloc_pages_slowpath+0x9f0/0xb4c
[14977.928660] __alloc_pages+0x21c/0x39c
[14977.928662] kmalloc_order+0x48/0x108
[14977.928666] kmalloc_order_trace+0x34/0x154
[14977.928668] __kmalloc+0x548/0x7e4
[14977.928673] dma_direct_alloc+0x11c/0x4f8
[14977.928678] dma_alloc_attrs+0xf4/0x138
[14977.928680] gh_vm_ioctl_set_fw_name+0x3c4/0x610 [gunyah]
[14977.928698] gh_vm_ioctl+0x90/0x14c [gunyah]
[14977.928705] __arm64_sys_ioctl+0x184/0x210

work around by doing kvmalloc_array instead.

Signed-off-by: Gao Xu 
Reviewed-by: Suren Baghdasaryan 
Signed-off-by: Christoph Hellwig

dma-mapping: fix a Kconfig typo

2023-06-07T13:06:09+00:00

'thing' -> 'think'

Signed-off-by: Sui Jingfeng 
Signed-off-by: Christoph Hellwig