Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted

Pull media updates from Mauro Carvalho Chehab:

 - v4l2-core: added ISP statistics support and per-block validation

 - v4l2-core: Allow unknown HDR10 white point and luminance

 - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor

 - New codec: Milos: VPU v2.0 codec support

 - isp driver: gained support for Dreamchip RPPX1 ISP framework

 - vsp1 driver: gained support for RZ/T2H and RZ/N2H

 - Novalake driver: gained CVS support for new NVL hardware

 - dvb-core: fix feed leak on failed DMX_ADD_PID

 - several driver fixes, cleanups and minor improvements

* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
  media: ipu-bridge: check all DMI entries when overriding sensor rotation
  media: v4l2-async: avoid deleting unlinked ASC entry on link error
  media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
  media: intel/ipu6: fix async notifier cleanup leak on parse error
  media: staging/ipu7: fix async notifier UAF on probe error path
  media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
  media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
  media: rcar-isp: Fix VSPX reference leaks
  media: rcar-isp: Release ISPCORE resources
  media: i2c: imx415: Release runtime PM reference on VBLANK error
  media: i2c: imx415: Return test pattern write errors
  media: renesas: vsp1: Declare index variables in for loop statement
  media: renesas: vsp1: Make reset control optional to support platforms without a reset line
  media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
  media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
  media: nxp: imx8-isi: Add additional 32-bit RGB format support
  media: nxp: imx8-isi: Add 16-bit raw Bayer format support
  media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
  media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
  media: nxp: imx8-isi: Correct color map between V4L2 and ISI
  ...

1 files changed, 74 insertions, 0 deletions

diff --git a/Documentation/userspace-api/dma-buf-heaps.rst b/Documentation/userspace-api/dma-buf-heaps.rst
new file mode 100644
index 000000000..f56b743cd
--- /dev/null
+++ b/Documentation/userspace-api/dma-buf-heaps.rst
@@ -0,0 +1,74 @@
+.. 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 ``system_cc_shared`` heap allocates virtually contiguous, cacheable,
+   buffers using shared (decrypted) memory. It is only present on
+   confidential computing (CoCo) VMs where memory encryption is active
+   (e.g., AMD SEV, Intel TDX). The allocated pages have the encryption
+   bit cleared, making them accessible for device DMA without TDISP
+   support. On non-CoCo VM configurations, this heap is not registered.
+
+ - The ``default_cma_region`` 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. Prior
+   to Linux 6.17, its name wasn't stable and could be called
+   ``reserved``, ``linux,cma``, or ``default-pool``, depending on the
+   platform.
+
+ - A heap will be created for each reusable region in the device tree
+   with the ``shared-dma-pool`` compatible, using the full device tree
+   node name as its name. The buffer semantics are identical to
+   ``default-cma-region``.
+
+Naming Convention
+=================
+
+``dma-buf`` heaps name should meet a number of constraints:
+
+- The name must be stable, and must not change from one version to the other.
+  Userspace identifies heaps by their name, so if the names ever change, we
+  would be likely to introduce regressions.
+
+- The name must describe the memory region the heap will allocate from, and
+  must uniquely identify it in a given platform. Since userspace applications
+  use the heap name as the discriminant, it must be able to tell which heap it
+  wants to use reliably if there's multiple heaps.
+
+- The name must not mention implementation details, such as the allocator. The
+  heap driver will change over time, and implementation details when it was
+  introduced might not be relevant in the future.
+
+- The name should describe properties of the buffers that would be allocated.
+  Doing so will make heap identification easier for userspace. Such properties
+  are:
+
+  - ``contiguous`` for physically contiguous buffers;
+
+  - ``protected`` for encrypted buffers not accessible the OS;
+
+- The name may describe intended usage. Doing so will make heap identification
+  easier for userspace applications and users.
+
+For example, assuming a platform with a reserved memory region located
+at the RAM address 0x42000000, intended to allocate video framebuffers,
+physically contiguous, and backed by the CMA kernel allocator, good
+names would be ``memory@42000000-contiguous`` or ``video@42000000``, but
+``cma-video`` wouldn't.