Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

2 files changed, 92 insertions, 0 deletions

diff --git a/Documentation/gpu/amdgpu/gc/index.rst b/Documentation/gpu/amdgpu/gc/index.rst
new file mode 100644
index 000000000..b6b583c9d
--- /dev/null
+++ b/Documentation/gpu/amdgpu/gc/index.rst
@@ -0,0 +1,54 @@
+.. _amdgpu-gc:
+
+========================================
+ drm/amdgpu - Graphics and Compute (GC)
+========================================
+
+The relationship between the CPU and GPU can be described as the
+producer-consumer problem, where the CPU fills out a buffer with operations
+(producer) to be executed by the GPU (consumer). The requested operations in
+the buffer are called **Command Packets**, which can be summarized as a
+compressed way of transmitting command information to the graphics controller.
+
+The component that acts as the front end between the CPU and the GPU is called
+**Command Processor (CP)**. This component is responsible for providing greater
+flexibility to the **Graphics and Compute (GC)** since CP makes it possible to
+program various aspects of the GPU pipeline. CP also coordinates the
+communication between the CPU and GPU via a mechanism named **Ring Buffers**,
+where the CPU appends information to the buffer while the GPU removes
+operations. CP is also responsible for handling **Indirect Buffers (IB)**.
+
+For reference, internally the CP consists of several sub-blocks (CPC - CP
+compute, CPG - CP graphics, and CPF - CP fetcher). Some of these acronyms
+appear in register names, but this is more of an implementation detail and not
+something that directly impacts driver programming or debugging.
+
+Graphics (GFX) and Compute Microcontrollers
+-------------------------------------------
+
+GC is a large block, and as a result, it has multiple firmware associated with
+it. Some of them are:
+
+CP (Command Processor)
+    The name for the hardware block that encompasses the front end of the
+    GFX/Compute pipeline. Consists mainly of a bunch of microcontrollers
+    (PFP, ME, CE, MEC). The firmware that runs on these microcontrollers
+    provides the driver interface to interact with the GFX/Compute engine.
+
+    MEC (MicroEngine Compute)
+        This is the microcontroller that controls the compute queues on the
+        GFX/compute engine.
+
+    MES (MicroEngine Scheduler)
+        This is the engine for managing queues. For more details check
+        :ref:`MicroEngine Scheduler (MES) <amdgpu-mes>`.
+
+RLC (RunList Controller)
+    This is another microcontroller in the GFX/Compute engine. It handles
+    power management related functionality within the GFX/Compute engine.
+    The name is a vestige of old hardware where it was originally added
+    and doesn't really have much relation to what the engine does now.
+
+.. toctree::
+
+   mes.rst
diff --git a/Documentation/gpu/amdgpu/gc/mes.rst b/Documentation/gpu/amdgpu/gc/mes.rst
new file mode 100644
index 000000000..b99eb211b
--- /dev/null
+++ b/Documentation/gpu/amdgpu/gc/mes.rst
@@ -0,0 +1,38 @@
+.. _amdgpu-mes:
+
+=============================
+ MicroEngine Scheduler (MES)
+=============================
+
+.. note::
+   Queue and ring buffer are used as a synonymous.
+
+.. note::
+   This section assumes that you are familiar with the concept of Pipes, Queues, and GC.
+   If not, check :ref:`GFX, Compute, and SDMA Overall Behavior<pipes-and-queues-description>`
+   and :ref:`drm/amdgpu - Graphics and Compute (GC) <amdgpu-gc>`.
+
+Every GFX has a pipe component with one or more hardware queues. Pipes can
+switch between queues depending on certain conditions, and one of the
+components that can request a queue switch to a pipe is the MicroEngine
+Scheduler (MES). Whenever the driver is initialized, it creates one MQD per
+hardware queue, and then the MQDs are handed to the MES firmware for mapping
+to:
+
+1. Kernel Queues (legacy): This queue is statically mapped to HQDs and never
+   preempted. Even though this is a legacy feature, it is the current default, and
+   most existing hardware supports it. When an application submits work to the
+   kernel driver, it submits all of the application command buffers to the kernel
+   queues. The CS IOCTL takes the command buffer from the applications and
+   schedules them on the kernel queue.
+
+2. User Queues: These queues are dynamically mapped to the HQDs. Regarding the
+   utilization of User Queues, the userspace application will create its user
+   queues and submit work directly to its user queues with no need to IOCTL for
+   each submission and no need to share a single kernel queue.
+
+In terms of User Queues, MES can dynamically map them to the HQD. If there are
+more MQDs than HQDs, the MES firmware will preempt other user queues to make
+sure each queues get a time slice; in other words, MES is a microcontroller
+that handles the mapping and unmapping of MQDs into HQDs, as well as the
+priorities and oversubscription of MQDs.