linux/Documentation/core-api
John Garry f3e7d9471c dma-mapping: add dma_opt_mapping_size()
[ Upstream commit a229cc14f3 ]

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>
Stable-dep-of: afc5aa46ed ("iommu/dma: Force swiotlb_max_mapping_size on an untrusted device")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10 16:18:47 +02:00
..
irq Documentation: Fix irq-domain.rst build warning 2021-09-03 09:54:15 +01:00
assoc_array.rst Documentation: Use "while" instead of "whilst" 2018-11-20 09:30:43 -07:00
boot-time-mm.rst docs/boot-time-mm: remove bootmem documentation 2018-10-31 08:54:16 -07:00
bus-virt-phys-mapping.rst docs: core-api: avoid using ReST :doc:foo markup 2021-06-17 13:24:37 -06:00
cachetlb.rst mm: remove flush_kernel_dcache_page 2021-09-03 09:58:13 -07:00
circular-buffers.rst doc: Remove ".vnet" from paulmck email addresses 2019-05-28 09:02:57 -07:00
cpu_hotplug.rst Documentation: core-api/cpuhotplug: Rewrite the API section 2021-09-11 00:41:21 +02:00
debug-objects.rst
debugging-via-ohci1394.rst docs: debugging-via-ohci1394.txt: add it to the core-api book 2020-05-15 11:59:17 -06:00
dma-api-howto.rst docs: move DMA kAPI to Documentation/core-api 2020-05-15 11:51:54 -06:00
dma-api.rst dma-mapping: add dma_opt_mapping_size() 2024-04-10 16:18:47 +02:00
dma-attributes.rst Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE"" 2022-04-08 14:24:13 +02:00
dma-isa-lpc.rst docs: core-api: avoid using ReST :doc:foo markup 2021-06-17 13:24:37 -06:00
errseq.rst errseq: Add to documentation tree 2018-01-01 12:40:27 -07:00
genalloc.rst lib/genalloc.c: rename addr_in_gen_pool to gen_pool_has_addr 2019-12-04 19:44:13 -08:00
generic-radix-tree.rst generic radix trees 2019-03-12 10:04:02 -07:00
genericirq.rst docs: genericirq.rst: don't document chip.c functions twice 2020-10-15 07:49:41 +02:00
gfp_mask-from-fs-io.rst docs: core-api/gfp_mask-from-fs-io: add a label for cross-referencing 2018-09-20 11:02:32 -06:00
idr.rst Core-api: Documentation: Replace deprecated :c:func: Usage 2020-08-11 10:26:08 -06:00
index.rst docs: core-api: avoid using ReST :doc:foo markup 2021-06-17 13:24:37 -06:00
kernel-api.rst block: move fs/block_dev.c to block/bdev.c 2021-09-07 08:39:40 -06:00
kobject.rst kobject: documentation: Replace HTTP links with HTTPS ones 2020-07-13 09:30:41 -06:00
kref.rst docs: move the kref doc into the core-api book 2020-05-15 12:02:19 -06:00
librs.rst docs-rst: convert librs book to ReST 2017-05-16 08:44:16 -03:00
local_ops.rst timer: Remove init_timer() interface 2017-11-21 15:57:09 -08:00
memory-allocation.rst mm: slab: provide krealloc_array() 2020-12-15 12:13:37 -08:00
memory-hotplug.rst docs/core-api: memory-hotplug: add some details about locking internals 2018-10-12 11:14:19 -06:00
mm-api.rst mm/mmzone.h: fix existing kernel-doc comments and link them to core-api 2021-04-30 11:20:43 -07:00
packing.rst docs: packing: move it to core-api book and adjust markups 2019-07-31 13:30:01 -06:00
padata.rst padata: fold padata_alloc_possible() into padata_alloc() 2020-07-23 17:34:18 +10:00
pin_user_pages.rst selftests/vm: only some gup_test items are really benchmarks 2020-12-15 12:13:38 -08:00
printk-basics.rst printk: Move the printk() kerneldoc comment to its new home 2021-07-26 12:36:44 +02:00
printk-formats.rst docs: printk-formats: fix build warning 2021-07-25 14:34:32 -06:00
protection-keys.rst x86/Kconfig: Update config and kernel doc for MPK feature on AMD 2020-05-28 18:27:40 +02:00
rbtree.rst docs: rbtree.rst: Fix a typo 2021-03-25 11:38:51 -06:00
refcount-vs-atomic.rst docs: remove :c:func: from refcount-vs-atomic.rst 2019-10-07 09:08:56 -06:00
symbol-namespaces.rst docs/core-api: Consistent code style 2021-05-03 16:52:50 -06:00
this_cpu_ops.rst docs: move other kAPI documents to core-api 2020-06-26 11:33:42 -06:00
timekeeping.rst docs: timekeeping: Use correct prototype for deprecated functions 2020-04-15 14:48:26 -06:00
tracepoint.rst
unaligned-memory-access.rst docs: move other kAPI documents to core-api 2020-06-26 11:33:42 -06:00
workqueue.rst docs: basics.rst: move kernel-doc workqueue markups to workqueue.rst 2020-10-15 07:49:41 +02:00
xarray.rst XArray: add xas_split 2020-10-16 11:11:15 -07:00