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authorDave Airlie2021-08-12 09:43:38 +1000
committerDave Airlie2021-08-12 09:56:04 +1000
commit25fed6b324ac556859d6dd0b7827cc8fb653ca99 (patch)
tree3f634521c723d6434c921fc1adbefa0e7d7e4be7 /Documentation/gpu
parent59b9d6baa1bea254d31042c42bcb8f946c263bae (diff)
parent927dfdd09d8c03ba100ed0c8c3915f8e1d1f5556 (diff)
Merge tag 'drm-intel-gt-next-2021-08-06-1' of ssh://git.freedesktop.org/git/drm/drm-intel into drm-next
UAPI Changes: - Add I915_MMAP_OFFSET_FIXED On devices with local memory `I915_MMAP_OFFSET_FIXED` is the only valid type. On devices without local memory, this caching mode is invalid. As caching mode when specifying `I915_MMAP_OFFSET_FIXED`, WC or WB will be used, depending on the object placement on creation. WB will be used when the object can only exist in system memory, WC otherwise. Userspace: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11888 - Reinstate the mmap ioctl for (already released) integrated Gen12 platforms Rationale: Otherwise media driver breaks eg. for ADL-P. Long term goal is still to sunset the IOCTL even for integrated and require using mmap_offset. - Reject caching/set_domain IOCTLs on discrete Expected to become immutable property of the BO - Disallow changing context parameters after first use on Gen12 and earlier - Require setting context parameters at creation on platforms after Gen12 Rationale (for both): Allow less dynamic changes to the context to simplify the implementation and avoid user shooting theirselves in the foot. - Drop I915_CONTEXT_PARAM_RINGSIZE Userspace PR for compute-driver has not been merged - Drop I915_CONTEXT_PARAM_NO_ZEROMAP Userspace PR for libdrm / Beignet was never landed - Drop CONTEXT_CLONE API Userspace PR for Mesa was never landed - Drop getparam support for I915_CONTEXT_PARAM_ENGINES Only existed for symmetry wrt. setparam, never used. - Disallow bonding of virtual engines Drop the prep work, no hardware has been released needing it. - (Implicit) Disable gpu relocations Media userspace was the last userspace to still use them. They have converted so performance can be regained with an update. Core Changes: - Merge topic branch 'topic/i915-ttm-2021-06-11' (from Maarten) - Merge topic branch 'topic/revid_steppings' (from Matt R) - Merge topic branch 'topic/xehp-dg2-definitions-2021-07-21' (from Matt R) - Backmerges drm-next (Rodrigo) Driver Changes: - Initial workarounds for ADL-P (Clint) - Preliminary code for XeHP/DG2 (Stuart, Umesh, Matt R, Prathap, Ram, Venkata, Akeem, Tvrtko, John, Lucas) - Fix ADL-S DMA mask size to 39 bits (Tejas) - Remove code for CNL (Lucas) - Add ADL-P GuC/HuC firmwares (John) - Update HuC to 7.9.3 for TGL/ADL-S/RKL (John) - Fix -EDEADLK handling regression (Ville) - Implement Wa_1508744258 for DG1 and Gen12 iGFX (Jose) - Extend Wa_1406941453 to ADL-S (Jose) - Drop unnecessary workarounds per stepping for SKL/BXT/ICL (Matt R) - Use fuse info to enable SFC on Gen12 (Venkata) - Unconditionally flush the pages on acquire on EHL/JSL (Matt A) - Probe existence of backing struct pages upon userptr creation (Chris, Matt A) - Add an intermediate GEM proto-context to delay real context creation (Jason) - Implement SINGLE_TIMELINE with a syncobj (Jason) - Set the watchdog timeout directly in intel_context_set_gem (Jason) - Disallow userspace from creating contexts with too many engines (Jason) - Revert "drm/i915/gem: Asynchronous cmdparser" (Jason) - Revert "drm/i915: Propagate errors on awaiting already signaled fences" (Jason) - Revert "drm/i915: Skip over MI_NOOP when parsing" (Jason) - Revert "drm/i915: Shrink the GEM kmem_caches upon idling" (Daniel) - Always let TTM handle object migration (Jason) - Correct the locking and pin pattern for dma-buf (Thomas H, Michael R, Jason) - Migrate to system at dma-buf attach time (Thomas, Michael R) - MAJOR refactoring of the GuC backend code to allow for enabling on Gen11+ (Matt B, John, Michal Wa., Fernando, Daniele, Vinay) - Update GuC firmware interface to v62.0.0 (John, Michal Wa., Matt B) - Add GuCRC feature to hand over the control of HW RC6 to the GuC on Gen12+ when GuC submission is enabled (Vinay, Sujaritha, Daniele, John, Tvrtko) - Use the correct IRQ during resume and eliminate DRM IRQ midlayer (Thomas Z) - Add pipelined page migration and clearing (Chris, Thomas H) - Use TTM for system memory on discrete (Thomas H) - Implement object migration for display vs. dma-buf (Thomas H) - Perform execbuffer object locking as a separate step (Thomas H) - Add support for explicit L3BANK steering (Matt, Daniele) - Remove duplicated call to ops->pread (Daniel) - Fix pagefault disabling in the first execbuf slowpath (Daniel) - Simplify userptr locking (Thomas H) - Improvements to the GuC CTB code (Matt B, John) - Make GT workaround upper bounds exclusive (Matt R) - Check for nomodeset in i915_init() first (Daniel) - Delete now unused gpu reloc code (Daniel) - Document RFC plans for GuC submission, DRM scheduler and new parallel submit uAPI (Matt B) - Reintroduce buddy allocator this time with TTM (Matt A) - Support forcing page size with LMEM (Matt A) - Add i915_sched_engine to abstract a submission queue between backends (Matt B) - Use accelerated move in TTM (Ram) - Fix memory leaks from TTM backend (Thomas H) - Introduce WW transaction helper (Thomas H) - Improve debug Kconfig texts a bit (Daniel) - Unify user object creation code (Jason) - Use a table for i915_init/exit (Jason) - Move slabs to module init/exit (Daniel) - Remove now unused i915_globals (Daniel) - Extract i915_module.c (Daniel) - Consistently use adl-p/adl-s in WA comments (Jose) - Finish INTEL_GEN and friends conversion (Lucas) - Correct variable/function namings (Lucas) - Code checker fixes (Wan, Matt A) - Tracepoint improvements (Matt B) - Kerneldoc improvements (Tvrtko, Jason, Matt A, Maarten) - Selftest improvements (Chris, Matt A, Tejas, Thomas H, John, Matt B, Rahul, Vinay) Signed-off-by: Dave Airlie <airlied@redhat.com> From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/YQ0JmYiXhGskNcrI@jlahtine-mobl.ger.corp.intel.com
Diffstat (limited to 'Documentation/gpu')
-rw-r--r--Documentation/gpu/i915.rst15
-rw-r--r--Documentation/gpu/rfc/i915_parallel_execbuf.h122
-rw-r--r--Documentation/gpu/rfc/i915_scheduler.rst148
-rw-r--r--Documentation/gpu/rfc/index.rst4
4 files changed, 289 insertions, 0 deletions
diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst
index 42ce0196930a..204ebdaadb45 100644
--- a/Documentation/gpu/i915.rst
+++ b/Documentation/gpu/i915.rst
@@ -422,9 +422,16 @@ Batchbuffer Parsing
User Batchbuffer Execution
--------------------------
+.. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_context_types.h
+
.. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
:doc: User command execution
+Scheduling
+----------
+.. kernel-doc:: drivers/gpu/drm/i915/i915_scheduler_types.h
+ :functions: i915_sched_engine
+
Logical Rings, Logical Ring Contexts and Execlists
--------------------------------------------------
@@ -518,6 +525,14 @@ GuC-based command submission
.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
:doc: GuC-based command submission
+GuC ABI
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/abi/guc_messages_abi.h
+.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/abi/guc_communication_mmio_abi.h
+.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/abi/guc_communication_ctb_abi.h
+.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
+
HuC
---
.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_huc.c
diff --git a/Documentation/gpu/rfc/i915_parallel_execbuf.h b/Documentation/gpu/rfc/i915_parallel_execbuf.h
new file mode 100644
index 000000000000..8cbe2c4e0172
--- /dev/null
+++ b/Documentation/gpu/rfc/i915_parallel_execbuf.h
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+
+#define I915_CONTEXT_ENGINES_EXT_PARALLEL_SUBMIT 2 /* see i915_context_engines_parallel_submit */
+
+/**
+ * struct drm_i915_context_engines_parallel_submit - Configure engine for
+ * parallel submission.
+ *
+ * Setup a slot in the context engine map to allow multiple BBs to be submitted
+ * in a single execbuf IOCTL. Those BBs will then be scheduled to run on the GPU
+ * in parallel. Multiple hardware contexts are created internally in the i915
+ * run these BBs. Once a slot is configured for N BBs only N BBs can be
+ * submitted in each execbuf IOCTL and this is implicit behavior e.g. The user
+ * doesn't tell the execbuf IOCTL there are N BBs, the execbuf IOCTL knows how
+ * many BBs there are based on the slot's configuration. The N BBs are the last
+ * N buffer objects or first N if I915_EXEC_BATCH_FIRST is set.
+ *
+ * The default placement behavior is to create implicit bonds between each
+ * context if each context maps to more than 1 physical engine (e.g. context is
+ * a virtual engine). Also we only allow contexts of same engine class and these
+ * contexts must be in logically contiguous order. Examples of the placement
+ * behavior described below. Lastly, the default is to not allow BBs to
+ * preempted mid BB rather insert coordinated preemption on all hardware
+ * contexts between each set of BBs. Flags may be added in the future to change
+ * both of these default behaviors.
+ *
+ * Returns -EINVAL if hardware context placement configuration is invalid or if
+ * the placement configuration isn't supported on the platform / submission
+ * interface.
+ * Returns -ENODEV if extension isn't supported on the platform / submission
+ * interface.
+ *
+ * .. code-block:: none
+ *
+ * Example 1 pseudo code:
+ * CS[X] = generic engine of same class, logical instance X
+ * INVALID = I915_ENGINE_CLASS_INVALID, I915_ENGINE_CLASS_INVALID_NONE
+ * set_engines(INVALID)
+ * set_parallel(engine_index=0, width=2, num_siblings=1,
+ * engines=CS[0],CS[1])
+ *
+ * Results in the following valid placement:
+ * CS[0], CS[1]
+ *
+ * Example 2 pseudo code:
+ * CS[X] = generic engine of same class, logical instance X
+ * INVALID = I915_ENGINE_CLASS_INVALID, I915_ENGINE_CLASS_INVALID_NONE
+ * set_engines(INVALID)
+ * set_parallel(engine_index=0, width=2, num_siblings=2,
+ * engines=CS[0],CS[2],CS[1],CS[3])
+ *
+ * Results in the following valid placements:
+ * CS[0], CS[1]
+ * CS[2], CS[3]
+ *
+ * This can also be thought of as 2 virtual engines described by 2-D array
+ * in the engines the field with bonds placed between each index of the
+ * virtual engines. e.g. CS[0] is bonded to CS[1], CS[2] is bonded to
+ * CS[3].
+ * VE[0] = CS[0], CS[2]
+ * VE[1] = CS[1], CS[3]
+ *
+ * Example 3 pseudo code:
+ * CS[X] = generic engine of same class, logical instance X
+ * INVALID = I915_ENGINE_CLASS_INVALID, I915_ENGINE_CLASS_INVALID_NONE
+ * set_engines(INVALID)
+ * set_parallel(engine_index=0, width=2, num_siblings=2,
+ * engines=CS[0],CS[1],CS[1],CS[3])
+ *
+ * Results in the following valid and invalid placements:
+ * CS[0], CS[1]
+ * CS[1], CS[3] - Not logical contiguous, return -EINVAL
+ */
+struct drm_i915_context_engines_parallel_submit {
+ /**
+ * @base: base user extension.
+ */
+ struct i915_user_extension base;
+
+ /**
+ * @engine_index: slot for parallel engine
+ */
+ __u16 engine_index;
+
+ /**
+ * @width: number of contexts per parallel engine
+ */
+ __u16 width;
+
+ /**
+ * @num_siblings: number of siblings per context
+ */
+ __u16 num_siblings;
+
+ /**
+ * @mbz16: reserved for future use; must be zero
+ */
+ __u16 mbz16;
+
+ /**
+ * @flags: all undefined flags must be zero, currently not defined flags
+ */
+ __u64 flags;
+
+ /**
+ * @mbz64: reserved for future use; must be zero
+ */
+ __u64 mbz64[3];
+
+ /**
+ * @engines: 2-d array of engine instances to configure parallel engine
+ *
+ * length = width (i) * num_siblings (j)
+ * index = j + i * num_siblings
+ */
+ struct i915_engine_class_instance engines[0];
+
+} __packed;
+
diff --git a/Documentation/gpu/rfc/i915_scheduler.rst b/Documentation/gpu/rfc/i915_scheduler.rst
new file mode 100644
index 000000000000..cbda75065dad
--- /dev/null
+++ b/Documentation/gpu/rfc/i915_scheduler.rst
@@ -0,0 +1,148 @@
+=========================================
+I915 GuC Submission/DRM Scheduler Section
+=========================================
+
+Upstream plan
+=============
+For upstream the overall plan for landing GuC submission and integrating the
+i915 with the DRM scheduler is:
+
+* Merge basic GuC submission
+ * Basic submission support for all gen11+ platforms
+ * Not enabled by default on any current platforms but can be enabled via
+ modparam enable_guc
+ * Lots of rework will need to be done to integrate with DRM scheduler so
+ no need to nit pick everything in the code, it just should be
+ functional, no major coding style / layering errors, and not regress
+ execlists
+ * Update IGTs / selftests as needed to work with GuC submission
+ * Enable CI on supported platforms for a baseline
+ * Rework / get CI heathly for GuC submission in place as needed
+* Merge new parallel submission uAPI
+ * Bonding uAPI completely incompatible with GuC submission, plus it has
+ severe design issues in general, which is why we want to retire it no
+ matter what
+ * New uAPI adds I915_CONTEXT_ENGINES_EXT_PARALLEL context setup step
+ which configures a slot with N contexts
+ * After I915_CONTEXT_ENGINES_EXT_PARALLEL a user can submit N batches to
+ a slot in a single execbuf IOCTL and the batches run on the GPU in
+ paralllel
+ * Initially only for GuC submission but execlists can be supported if
+ needed
+* Convert the i915 to use the DRM scheduler
+ * GuC submission backend fully integrated with DRM scheduler
+ * All request queues removed from backend (e.g. all backpressure
+ handled in DRM scheduler)
+ * Resets / cancels hook in DRM scheduler
+ * Watchdog hooks into DRM scheduler
+ * Lots of complexity of the GuC backend can be pulled out once
+ integrated with DRM scheduler (e.g. state machine gets
+ simplier, locking gets simplier, etc...)
+ * Execlists backend will minimum required to hook in the DRM scheduler
+ * Legacy interface
+ * Features like timeslicing / preemption / virtual engines would
+ be difficult to integrate with the DRM scheduler and these
+ features are not required for GuC submission as the GuC does
+ these things for us
+ * ROI low on fully integrating into DRM scheduler
+ * Fully integrating would add lots of complexity to DRM
+ scheduler
+ * Port i915 priority inheritance / boosting feature in DRM scheduler
+ * Used for i915 page flip, may be useful to other DRM drivers as
+ well
+ * Will be an optional feature in the DRM scheduler
+ * Remove in-order completion assumptions from DRM scheduler
+ * Even when using the DRM scheduler the backends will handle
+ preemption, timeslicing, etc... so it is possible for jobs to
+ finish out of order
+ * Pull out i915 priority levels and use DRM priority levels
+ * Optimize DRM scheduler as needed
+
+TODOs for GuC submission upstream
+=================================
+
+* Need an update to GuC firmware / i915 to enable error state capture
+* Open source tool to decode GuC logs
+* Public GuC spec
+
+New uAPI for basic GuC submission
+=================================
+No major changes are required to the uAPI for basic GuC submission. The only
+change is a new scheduler attribute: I915_SCHEDULER_CAP_STATIC_PRIORITY_MAP.
+This attribute indicates the 2k i915 user priority levels are statically mapped
+into 3 levels as follows:
+
+* -1k to -1 Low priority
+* 0 Medium priority
+* 1 to 1k High priority
+
+This is needed because the GuC only has 4 priority bands. The highest priority
+band is reserved with the kernel. This aligns with the DRM scheduler priority
+levels too.
+
+Spec references:
+----------------
+* https://www.khronos.org/registry/EGL/extensions/IMG/EGL_IMG_context_priority.txt
+* https://www.khronos.org/registry/vulkan/specs/1.2-extensions/html/chap5.html#devsandqueues-priority
+* https://spec.oneapi.com/level-zero/latest/core/api.html#ze-command-queue-priority-t
+
+New parallel submission uAPI
+============================
+The existing bonding uAPI is completely broken with GuC submission because
+whether a submission is a single context submit or parallel submit isn't known
+until execbuf time activated via the I915_SUBMIT_FENCE. To submit multiple
+contexts in parallel with the GuC the context must be explicitly registered with
+N contexts and all N contexts must be submitted in a single command to the GuC.
+The GuC interfaces do not support dynamically changing between N contexts as the
+bonding uAPI does. Hence the need for a new parallel submission interface. Also
+the legacy bonding uAPI is quite confusing and not intuitive at all. Furthermore
+I915_SUBMIT_FENCE is by design a future fence, so not really something we should
+continue to support.
+
+The new parallel submission uAPI consists of 3 parts:
+
+* Export engines logical mapping
+* A 'set_parallel' extension to configure contexts for parallel
+ submission
+* Extend execbuf2 IOCTL to support submitting N BBs in a single IOCTL
+
+Export engines logical mapping
+------------------------------
+Certain use cases require BBs to be placed on engine instances in logical order
+(e.g. split-frame on gen11+). The logical mapping of engine instances can change
+based on fusing. Rather than making UMDs be aware of fusing, simply expose the
+logical mapping with the existing query engine info IOCTL. Also the GuC
+submission interface currently only supports submitting multiple contexts to
+engines in logical order which is a new requirement compared to execlists.
+Lastly, all current platforms have at most 2 engine instances and the logical
+order is the same as uAPI order. This will change on platforms with more than 2
+engine instances.
+
+A single bit will be added to drm_i915_engine_info.flags indicating that the
+logical instance has been returned and a new field,
+drm_i915_engine_info.logical_instance, returns the logical instance.
+
+A 'set_parallel' extension to configure contexts for parallel submission
+------------------------------------------------------------------------
+The 'set_parallel' extension configures a slot for parallel submission of N BBs.
+It is a setup step that must be called before using any of the contexts. See
+I915_CONTEXT_ENGINES_EXT_LOAD_BALANCE or I915_CONTEXT_ENGINES_EXT_BOND for
+similar existing examples. Once a slot is configured for parallel submission the
+execbuf2 IOCTL can be called submitting N BBs in a single IOCTL. Initially only
+supports GuC submission. Execlists supports can be added later if needed.
+
+Add I915_CONTEXT_ENGINES_EXT_PARALLEL_SUBMIT and
+drm_i915_context_engines_parallel_submit to the uAPI to implement this
+extension.
+
+.. kernel-doc:: Documentation/gpu/rfc/i915_parallel_execbuf.h
+ :functions: drm_i915_context_engines_parallel_submit
+
+Extend execbuf2 IOCTL to support submitting N BBs in a single IOCTL
+-------------------------------------------------------------------
+Contexts that have been configured with the 'set_parallel' extension can only
+submit N BBs in a single execbuf2 IOCTL. The BBs are either the last N objects
+in the drm_i915_gem_exec_object2 list or the first N if I915_EXEC_BATCH_FIRST is
+set. The number of BBs is implicit based on the slot submitted and how it has
+been configured by 'set_parallel' or other extensions. No uAPI changes are
+required to the execbuf2 IOCTL.
diff --git a/Documentation/gpu/rfc/index.rst b/Documentation/gpu/rfc/index.rst
index 05670442ca1b..91e93a705230 100644
--- a/Documentation/gpu/rfc/index.rst
+++ b/Documentation/gpu/rfc/index.rst
@@ -19,3 +19,7 @@ host such documentation:
.. toctree::
i915_gem_lmem.rst
+
+.. toctree::
+
+ i915_scheduler.rst