Hi,
Another version of the series reducing the kmalloc() minimum alignment
on arm64 to 8 (from 128). Other architectures can easily opt in by
defining ARCH_KMALLOC_MINALIGN as 8 and selecting
DMA_BOUNCE_UNALIGNED_KMALLOC.
The first 10 patches decouple ARCH_KMALLOC_MINALIGN from
ARCH_DMA_MINALIGN and, for arm64, limit the kmalloc() caches to those
aligned to the run-time probed cache_line_size(). On arm64 we gain the
kmalloc-{64,192} caches.
The subsequent patches (11 to 15) further reduce the kmalloc() caches to
kmalloc-{8,16,32,96} if the default swiotlb is present by bouncing small
buffers in the DMA API.
Changes since v4:
- Following Robin's suggestions, reworked the iommu handling so that the
buffer size checks are done in the dev_use_swiotlb() and
dev_use_sg_swiotlb() functions (together with dev_is_untrusted()). The
sync operations can now check for the SG_DMA_USE_SWIOTLB flag. Since
this flag is no longer specific to kmalloc() bouncing (covers
dev_is_untrusted() as well), the sg_is_dma_use_swiotlb() and
sg_dma_mark_use_swiotlb() functions are always defined if
CONFIG_SWIOTLB.
- Dropped ARCH_WANT_KMALLOC_DMA_BOUNCE, only left the
DMA_BOUNCE_UNALIGNED_KMALLOC option, selectable by the arch code. The
NEED_SG_DMA_FLAGS is now selected by IOMMU_DMA if SWIOTLB.
- Rather than adding another config option, allow
dma_get_cache_alignment() to be overridden by the arch code
(Christoph's suggestion).
- Added a comment to the dma_kmalloc_needs_bounce() function on the
heuristics behind the bouncing.
- Added acked-by/reviewed-by tags (not adding Ard's tested-by yet as
there were some changes).
The updated patches are also available on this branch:
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux devel/kmalloc-minalign
Thanks.
Catalin Marinas (14):
mm/slab: Decouple ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN
dma: Allow dma_get_cache_alignment() to be overridden by the arch code
mm/slab: Simplify create_kmalloc_cache() args and make it static
mm/slab: Limit kmalloc() minimum alignment to
dma_get_cache_alignment()
drivers/base: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN
drivers/gpu: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN
drivers/usb: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN
drivers/spi: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN
drivers/md: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN
arm64: Allow kmalloc() caches aligned to the smaller cache_line_size()
dma-mapping: Force bouncing if the kmalloc() size is not
cache-line-aligned
iommu/dma: Force bouncing if the size is not cacheline-aligned
mm: slab: Reduce the kmalloc() minimum alignment if DMA bouncing
possible
arm64: Enable ARCH_WANT_KMALLOC_DMA_BOUNCE for arm64
Robin Murphy (1):
scatterlist: Add dedicated config for DMA flags
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/cache.h | 3 ++
arch/arm64/mm/init.c | 7 +++-
drivers/base/devres.c | 6 ++--
drivers/gpu/drm/drm_managed.c | 6 ++--
drivers/iommu/Kconfig | 1 +
drivers/iommu/dma-iommu.c | 50 +++++++++++++++++++++++-----
drivers/md/dm-crypt.c | 2 +-
drivers/pci/Kconfig | 1 +
drivers/spi/spidev.c | 2 +-
drivers/usb/core/buffer.c | 8 ++---
include/linux/dma-map-ops.h | 61 ++++++++++++++++++++++++++++++++++
include/linux/dma-mapping.h | 4 ++-
include/linux/scatterlist.h | 29 +++++++++++++---
include/linux/slab.h | 14 ++++++--
kernel/dma/Kconfig | 7 ++++
kernel/dma/direct.h | 3 +-
mm/slab.c | 6 +---
mm/slab.h | 5 ++-
mm/slab_common.c | 46 +++++++++++++++++++------
20 files changed, 213 insertions(+), 49 deletions(-)
