4 files changed, 189 insertions, 16 deletions
diff --git a/Documentation/gpu/amdgpu.rst b/Documentation/gpu/amdgpu.rst
index 17112352f605..57047dcb8d19 100644
--- a/Documentation/gpu/amdgpu.rst
+++ b/Documentation/gpu/amdgpu.rst
@@ -70,6 +70,15 @@ Interrupt Handling
 .. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
    :internal:
 
+IP Blocks
+------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/include/amd_shared.h
+   :doc: IP Blocks
+
+.. kernel-doc:: drivers/gpu/drm/amd/include/amd_shared.h
+   :identifiers: amd_ip_block_type amd_ip_funcs
+
 AMDGPU XGMI Support
 ===================
 
@@ -153,7 +162,7 @@ This section covers hwmon and power/thermal controls.
 HWMON Interfaces
 ----------------
 
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
    :doc: hwmon
 
 GPU sysfs Power State Interfaces
@@ -164,48 +173,54 @@ GPU power controls are exposed via sysfs files.
 power_dpm_state
 ~~~~~~~~~~~~~~~
 
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
    :doc: power_dpm_state
 
 power_dpm_force_performance_level
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
    :doc: power_dpm_force_performance_level
 
 pp_table
 ~~~~~~~~
 
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
    :doc: pp_table
 
 pp_od_clk_voltage
 ~~~~~~~~~~~~~~~~~
 
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
    :doc: pp_od_clk_voltage
 
 pp_dpm_*
 ~~~~~~~~
 
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
    :doc: pp_dpm_sclk pp_dpm_mclk pp_dpm_socclk pp_dpm_fclk pp_dpm_dcefclk pp_dpm_pcie
 
 pp_power_profile_mode
 ~~~~~~~~~~~~~~~~~~~~~
 
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
    :doc: pp_power_profile_mode
 
 *_busy_percent
 ~~~~~~~~~~~~~~
 
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
    :doc: gpu_busy_percent
 
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
    :doc: mem_busy_percent
 
+gpu_metrics
+~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+   :doc: gpu_metrics
+
 GPU Product Information
 =======================
 
@@ -233,7 +248,7 @@ serial_number
 unique_id
 ---------
 
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
    :doc: unique_id
 
 GPU Memory Usage Information
@@ -283,7 +298,7 @@ PCIe Accounting Information
 pcie_bw
 -------
 
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
    :doc: pcie_bw
 
 pcie_replay_count
diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst
index 496d8fcd4da0..7dce175f6d75 100644
--- a/Documentation/gpu/drm-uapi.rst
+++ b/Documentation/gpu/drm-uapi.rst
@@ -1,3 +1,5 @@
+.. Copyright 2020 DisplayLink (UK) Ltd.
+
 ===================
 Userland interfaces
 ===================
@@ -162,6 +164,116 @@ other hand, a driver requires shared state between clients which is
 visible to user-space and accessible beyond open-file boundaries, they
 cannot support render nodes.
 
+Device Hot-Unplug
+=================
+
+.. note::
+   The following is the plan. Implementation is not there yet
+   (2020 May).
+
+Graphics devices (display and/or render) may be connected via USB (e.g.
+display adapters or docking stations) or Thunderbolt (e.g. eGPU). An end
+user is able to hot-unplug this kind of devices while they are being
+used, and expects that the very least the machine does not crash. Any
+damage from hot-unplugging a DRM device needs to be limited as much as
+possible and userspace must be given the chance to handle it if it wants
+to. Ideally, unplugging a DRM device still lets a desktop continue to
+run, but that is going to need explicit support throughout the whole
+graphics stack: from kernel and userspace drivers, through display
+servers, via window system protocols, and in applications and libraries.
+
+Other scenarios that should lead to the same are: unrecoverable GPU
+crash, PCI device disappearing off the bus, or forced unbind of a driver
+from the physical device.
+
+In other words, from userspace perspective everything needs to keep on
+working more or less, until userspace stops using the disappeared DRM
+device and closes it completely. Userspace will learn of the device
+disappearance from the device removed uevent, ioctls returning ENODEV
+(or driver-specific ioctls returning driver-specific things), or open()
+returning ENXIO.
+
+Only after userspace has closed all relevant DRM device and dmabuf file
+descriptors and removed all mmaps, the DRM driver can tear down its
+instance for the device that no longer exists. If the same physical
+device somehow comes back in the mean time, it shall be a new DRM
+device.
+
+Similar to PIDs, chardev minor numbers are not recycled immediately. A
+new DRM device always picks the next free minor number compared to the
+previous one allocated, and wraps around when minor numbers are
+exhausted.
+
+The goal raises at least the following requirements for the kernel and
+drivers.
+
+Requirements for KMS UAPI
+-------------------------
+
+- KMS connectors must change their status to disconnected.
+
+- Legacy modesets and pageflips, and atomic commits, both real and
+  TEST_ONLY, and any other ioctls either fail with ENODEV or fake
+  success.
+
+- Pending non-blocking KMS operations deliver the DRM events userspace
+  is expecting. This applies also to ioctls that faked success.
+
+- open() on a device node whose underlying device has disappeared will
+  fail with ENXIO.
+
+- Attempting to create a DRM lease on a disappeared DRM device will
+  fail with ENODEV. Existing DRM leases remain and work as listed
+  above.
+
+Requirements for Render and Cross-Device UAPI
+---------------------------------------------
+
+- All GPU jobs that can no longer run must have their fences
+  force-signalled to avoid inflicting hangs on userspace.
+  The associated error code is ENODEV.
+
+- Some userspace APIs already define what should happen when the device
+  disappears (OpenGL, GL ES: `GL_KHR_robustness`_; `Vulkan`_:
+  VK_ERROR_DEVICE_LOST; etc.). DRM drivers are free to implement this
+  behaviour the way they see best, e.g. returning failures in
+  driver-specific ioctls and handling those in userspace drivers, or
+  rely on uevents, and so on.
+
+- dmabuf which point to memory that has disappeared will either fail to
+  import with ENODEV or continue to be successfully imported if it would
+  have succeeded before the disappearance. See also about memory maps
+  below for already imported dmabufs.
+
+- Attempting to import a dmabuf to a disappeared device will either fail
+  with ENODEV or succeed if it would have succeeded without the
+  disappearance.
+
+- open() on a device node whose underlying device has disappeared will
+  fail with ENXIO.
+
+.. _GL_KHR_robustness: https://www.khronos.org/registry/OpenGL/extensions/KHR/KHR_robustness.txt
+.. _Vulkan: https://www.khronos.org/vulkan/
+
+Requirements for Memory Maps
+----------------------------
+
+Memory maps have further requirements that apply to both existing maps
+and maps created after the device has disappeared. If the underlying
+memory disappears, the map is created or modified such that reads and
+writes will still complete successfully but the result is undefined.
+This applies to both userspace mmap()'d memory and memory pointed to by
+dmabuf which might be mapped to other devices (cross-device dmabuf
+imports).
+
+Raising SIGBUS is not an option, because userspace cannot realistically
+handle it. Signal handlers are global, which makes them extremely
+difficult to use correctly from libraries like those that Mesa produces.
+Signal handlers are not composable, you can't have different handlers
+for GPU1 and GPU2 from different vendors, and a third handler for
+mmapped regular files. Threads cause additional pain with signal
+handling as well.
+
 .. _drm_driver_ioctl:
 
 IOCTL Support on Device Nodes
@@ -199,7 +311,7 @@ EPERM/EACCES:
         difference between EACCES and EPERM.
 
 ENODEV:
-        The device is not (yet) present or fully initialized.
+        The device is not present anymore or is not yet fully initialized.
 
 EOPNOTSUPP:
         Feature (like PRIME, modesetting, GEM) is not supported by the driver.
diff --git a/Documentation/gpu/pl111.rst b/Documentation/gpu/pl111.rst
index 9b03736d33dd..6d9a1b59a545 100644
--- a/Documentation/gpu/pl111.rst
+++ b/Documentation/gpu/pl111.rst
@@ -1,6 +1,6 @@
-==========================================
- drm/pl111 ARM PrimeCell PL111 CLCD Driver
-==========================================
+====================================================
+ drm/pl111 ARM PrimeCell PL110 and PL111 CLCD Driver
+====================================================
 
 .. kernel-doc:: drivers/gpu/drm/pl111/pl111_drv.c
-   :doc: ARM PrimeCell PL111 CLCD Driver
+   :doc: ARM PrimeCell PL110 and PL111 CLCD Driver
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 7969f106877d..b0ea17da8ff6 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -403,6 +403,52 @@ Contact: Emil Velikov, respective driver maintainers
 
 Level: Intermediate
 
+Plumb drm_atomic_state all over
+-------------------------------
+
+Currently various atomic functions take just a single or a handful of
+object states (eg. plane state). While that single object state can
+suffice for some simple cases, we often have to dig out additional
+object states for dealing with various dependencies between the individual
+objects or the hardware they represent. The process of digging out the
+additional states is rather non-intuitive and error prone.
+
+To fix that most functions should rather take the overall
+drm_atomic_state as one of their parameters. The other parameters
+would generally be the object(s) we mainly want to interact with.
+
+For example, instead of
+
+.. code-block:: c
+
+   int (*atomic_check)(struct drm_plane *plane, struct drm_plane_state *state);
+
+we would have something like
+
+.. code-block:: c
+
+   int (*atomic_check)(struct drm_plane *plane, struct drm_atomic_state *state);
+
+The implementation can then trivially gain access to any required object
+state(s) via drm_atomic_get_plane_state(), drm_atomic_get_new_plane_state(),
+drm_atomic_get_old_plane_state(), and their equivalents for
+other object types.
+
+Additionally many drivers currently access the object->state pointer
+directly in their commit functions. That is not going to work if we
+eg. want to allow deeper commit pipelines as those pointers could
+then point to the states corresponding to a future commit instead of
+the current commit we're trying to process. Also non-blocking commits
+execute locklessly so there are serious concerns with dereferencing
+the object->state pointers without holding the locks that protect them.
+Use of drm_atomic_get_new_plane_state(), drm_atomic_get_old_plane_state(),
+etc. avoids these problems as well since they relate to a specific
+commit via the passed in drm_atomic_state.
+
+Contact: Ville Syrjälä, Daniel Vetter
+
+Level: Intermediate
+
 
 Core refactorings
 =================