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authorLinus Torvalds <torvalds@linux-foundation.org>2025-03-24 18:42:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-03-24 18:42:27 -0700
commitf81c2b81508c4f479f2cf1ac0dbb138927dc6188 (patch)
tree7e9adec195e720111148855fafba741b1ea04d24 /Documentation/userspace-api
parent8541bc1a52e7e8facd67cef1e659f5714abc95ab (diff)
parent323cc36ef68bc2c8ca0bd5f528736432afc1a36a (diff)
Merge tag 'docs-6.15' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet: "It has been a reasonably busy cycle for docs... - Significant changes throughout the tree to bring Python code up to current standards and raise the minimum Python required to 3.9 Much of this is preparatory to replacing the ancient Perl scripts/kernel-doc horror with a slightly less horrifying Python implementation, expected for 6.16 - Update the minimum Sphinx required to 3.4.3, allowing us to remove a bunch of older compatibility code - Rework and improve the generation of the ABI documentation (All of the above done by Mauro) - Lots of translation updates. Alex Shi and Yanteng Si are taking on responsibility for the Chinese translations going forward; that work will still get to you via docs-next - Try to standardize the format for indicating a developer's affiliation in commit tags - Clarify the TAB's role in CoC enforcement actions - Try to spell out the rules for when a commit tag can name another developer without their explicit permission Plus lots of other typo fixes and updates" * tag 'docs-6.15' of git://git.lwn.net/linux: (98 commits) docs/zh_CN: fix spelling mistake docs/Chinese: change the disclaimer words docs/zh_CN: Add snp-tdx-threat-model index Chinese translation docs: driver-api: firmware: clarify userspace requirements docs: clarify rules wrt tagging other people docs: Remove outdated highuid.rst documentation Documentation: dma-buf: heaps: Add heap name definitions docs/.../submit-checklist: Use Documentation/admin-guide/abi.rst for cross-ref of README docs: Correct installation instruction Documentation: kcsan: fix "Plain Accesses and Data Races" URL in kcsan.rst Documentation/CoC: Spell out the TAB role in enforcement decisions Documentation: ocxl.rst: Update consortium site scripts: get_feat.pl: substitute s390x with s390 scripts/kernel-doc: drop dead code for Wcontents_before_sections scripts/kernel-doc: don't add not needed new lines docs: driver-api/infiniband.rst: fix Kerneldoc markup drivers: firewire: firewire-cdev.h: fix identation on a kernel-doc markup drivers: media: intel-ipu3.h: fix identation on a kernel-doc markup include/asm-generic/io.h: fix kerneldoc markup Docs/arch/arm64: Fix spelling in amu.rst ...
Diffstat (limited to 'Documentation/userspace-api')
-rw-r--r--Documentation/userspace-api/accelerators/ocxl.rst7
-rw-r--r--Documentation/userspace-api/dma-buf-heaps.rst25
-rw-r--r--Documentation/userspace-api/index.rst1
-rw-r--r--Documentation/userspace-api/media/rc/rc-sysfs-nodes.rst2
4 files changed, 32 insertions, 3 deletions
diff --git a/Documentation/userspace-api/accelerators/ocxl.rst b/Documentation/userspace-api/accelerators/ocxl.rst
index db7570d5e50d..4e213af70237 100644
--- a/Documentation/userspace-api/accelerators/ocxl.rst
+++ b/Documentation/userspace-api/accelerators/ocxl.rst
@@ -3,8 +3,11 @@ OpenCAPI (Open Coherent Accelerator Processor Interface)
========================================================
OpenCAPI is an interface between processors and accelerators. It aims
-at being low-latency and high-bandwidth. The specification is
-developed by the `OpenCAPI Consortium <http://opencapi.org/>`_.
+at being low-latency and high-bandwidth.
+
+The specification was developed by the OpenCAPI Consortium, and is now
+available from the `Compute Express Link Consortium
+<https://computeexpresslink.org/resource/opencapi-specification-archive/>`_.
It allows an accelerator (which could be an FPGA, ASICs, ...) to access
the host memory coherently, using virtual addresses. An OpenCAPI
diff --git a/Documentation/userspace-api/dma-buf-heaps.rst b/Documentation/userspace-api/dma-buf-heaps.rst
new file mode 100644
index 000000000000..535f49047ce6
--- /dev/null
+++ b/Documentation/userspace-api/dma-buf-heaps.rst
@@ -0,0 +1,25 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============================
+Allocating dma-buf using heaps
+==============================
+
+Dma-buf Heaps are a way for userspace to allocate dma-buf objects. They are
+typically used to allocate buffers from a specific allocation pool, or to share
+buffers across frameworks.
+
+Heaps
+=====
+
+A heap represents a specific allocator. The Linux kernel currently supports the
+following heaps:
+
+ - The ``system`` heap allocates virtually contiguous, cacheable, buffers.
+
+ - The ``cma`` heap allocates physically contiguous, cacheable,
+ buffers. Only present if a CMA region is present. Such a region is
+ usually created either through the kernel commandline through the
+ `cma` parameter, a memory region Device-Tree node with the
+ `linux,cma-default` property set, or through the `CMA_SIZE_MBYTES` or
+ `CMA_SIZE_PERCENTAGE` Kconfig options. Depending on the platform, it
+ might be called ``reserved``, ``linux,cma``, or ``default-pool``.
diff --git a/Documentation/userspace-api/index.rst b/Documentation/userspace-api/index.rst
index b1395d94b3fd..9cbe4390c872 100644
--- a/Documentation/userspace-api/index.rst
+++ b/Documentation/userspace-api/index.rst
@@ -44,6 +44,7 @@ Devices and I/O
:maxdepth: 1
accelerators/ocxl
+ dma-buf-heaps
dma-buf-alloc-exchange
gpio/index
iommufd
diff --git a/Documentation/userspace-api/media/rc/rc-sysfs-nodes.rst b/Documentation/userspace-api/media/rc/rc-sysfs-nodes.rst
index 34d6a0a1f4d3..70b5966aaff8 100644
--- a/Documentation/userspace-api/media/rc/rc-sysfs-nodes.rst
+++ b/Documentation/userspace-api/media/rc/rc-sysfs-nodes.rst
@@ -6,7 +6,7 @@
Remote Controller's sysfs nodes
*******************************
-As defined at ``Documentation/ABI/testing/sysfs-class-rc``, those are
+As defined at Documentation/ABI/testing/sysfs-class-rc, those are
the sysfs nodes that control the Remote Controllers: