From patchwork Tue Oct 25 06:59:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Niranjana Vishwanathapura X-Patchwork-Id: 13018586 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 31ED5C04A95 for ; Tue, 25 Oct 2022 06:59:54 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 49C3510E199; Tue, 25 Oct 2022 06:59:36 +0000 (UTC) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7E61410E196; Tue, 25 Oct 2022 06:59:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1666681156; x=1698217156; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dbFuVC/9aenMlPpG3qScfEyA5fGoYEi+ak/JVAwyXbg=; b=UqyT1/RoCh3n0myrEko/WGqLADUSKEFJ1PSzxb5YPuAlwxd+147xJOR0 1oBAfeIZyxDkGneS9KNevTmZ1BXWU3QEx3LpinDWk8ydealaLwYTB3YGR t7rJjTD474ya5TBAJBZIgWXX5YfHVQmW3fTmJpWCnceMPlTdDvTPdMXE2 kB2uI3/GJZ4HrYPh+RSwvsty5mSgOZZiNzIJc97yebuvzR12nb9Y83vJL iq/u55mTSgrQW9Q030d7Q4WZbgzHmWM4sn3n5M3xATxbwVcCthALVJ9J+ GJ6EaaSmMsuZ3vMA3zUvmwZySJJwdUQtEnCoEX1LM0iv2TPIpf9aIaXsQ A==; X-IronPort-AV: E=McAfee;i="6500,9779,10510"; a="308697613" X-IronPort-AV: E=Sophos;i="5.95,211,1661842800"; d="scan'208";a="308697613" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Oct 2022 23:59:16 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10510"; a="806564449" X-IronPort-AV: E=Sophos;i="5.95,211,1661842800"; d="scan'208";a="806564449" Received: from nvishwa1-desk.sc.intel.com ([172.25.29.76]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Oct 2022 23:59:15 -0700 From: Niranjana Vishwanathapura To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH v5 19/19] drm/i915/vm_bind: Render VM_BIND documentation Date: Mon, 24 Oct 2022 23:59:05 -0700 Message-Id: <20221025065905.13325-20-niranjana.vishwanathapura@intel.com> X-Mailer: git-send-email 2.21.0.rc0.32.g243a4c7e27 In-Reply-To: <20221025065905.13325-1-niranjana.vishwanathapura@intel.com> References: <20221025065905.13325-1-niranjana.vishwanathapura@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: matthew.brost@intel.com, paulo.r.zanoni@intel.com, tvrtko.ursulin@intel.com, jani.nikula@intel.com, lionel.g.landwerlin@intel.com, thomas.hellstrom@intel.com, matthew.auld@intel.com, jason@jlekstrand.net, andi.shyti@linux.intel.com, daniel.vetter@intel.com, christian.koenig@amd.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Update i915 documentation to include VM_BIND changes and render all VM_BIND related documentation. Signed-off-by: Niranjana Vishwanathapura Reviewed-by: Matthew Auld --- Documentation/gpu/i915.rst | 78 ++++++++++++++++++++++++++++---------- 1 file changed, 59 insertions(+), 19 deletions(-) diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst index 4e59db1cfb00..5c55cbc980b1 100644 --- a/Documentation/gpu/i915.rst +++ b/Documentation/gpu/i915.rst @@ -283,15 +283,18 @@ An Intel GPU has multiple engines. There are several engine types. The Intel GPU family is a family of integrated GPU's using Unified Memory Access. For having the GPU "do work", user space will feed the -GPU batch buffers via one of the ioctls `DRM_IOCTL_I915_GEM_EXECBUFFER2` -or `DRM_IOCTL_I915_GEM_EXECBUFFER2_WR`. Most such batchbuffers will -instruct the GPU to perform work (for example rendering) and that work -needs memory from which to read and memory to which to write. All memory -is encapsulated within GEM buffer objects (usually created with the ioctl -`DRM_IOCTL_I915_GEM_CREATE`). An ioctl providing a batchbuffer for the GPU -to create will also list all GEM buffer objects that the batchbuffer reads -and/or writes. For implementation details of memory management see -`GEM BO Management Implementation Details`_. +GPU batch buffers via one of the ioctls `DRM_IOCTL_I915_GEM_EXECBUFFER2`, +`DRM_IOCTL_I915_GEM_EXECBUFFER2_WR` or `DRM_IOCTL_I915_GEM_EXECBUFFER3`. +Most such batchbuffers will instruct the GPU to perform work (for example +rendering) and that work needs memory from which to read and memory to +which to write. All memory is encapsulated within GEM buffer objects +(usually created with the ioctl `DRM_IOCTL_I915_GEM_CREATE`). In vm_bind mode +(see `VM_BIND mode`_), the batch buffer and all the GEM buffer objects that +it reads and/or writes should be bound with vm_bind ioctl before submitting +the batch buffer to GPU. In legacy (non-VM_BIND) mode, an ioctl providing a +batchbuffer for the GPU to create will also list all GEM buffer objects that +the batchbuffer reads and/or writes. For implementation details of memory +management see `GEM BO Management Implementation Details`_. The i915 driver allows user space to create a context via the ioctl `DRM_IOCTL_I915_GEM_CONTEXT_CREATE` which is identified by a 32-bit @@ -309,8 +312,9 @@ In addition to the ordering guarantees, the kernel will restore GPU state via HW context when commands are issued to a context, this saves user space the need to restore (most of atleast) the GPU state at the start of each batchbuffer. The non-deprecated ioctls to submit batchbuffer -work can pass that ID (in the lower bits of drm_i915_gem_execbuffer2::rsvd1) -to identify what context to use with the command. +work can pass that ID (drm_i915_gem_execbuffer3::ctx_id, or in the lower +bits of drm_i915_gem_execbuffer2::rsvd1) to identify what context to use +with the command. The GPU has its own memory management and address space. The kernel driver maintains the memory translation table for the GPU. For older @@ -318,14 +322,14 @@ GPUs (i.e. those before Gen8), there is a single global such translation table, a global Graphics Translation Table (GTT). For newer generation GPUs each context has its own translation table, called Per-Process Graphics Translation Table (PPGTT). Of important note, is that although -PPGTT is named per-process it is actually per context. When user space -submits a batchbuffer, the kernel walks the list of GEM buffer objects -used by the batchbuffer and guarantees that not only is the memory of -each such GEM buffer object resident but it is also present in the -(PP)GTT. If the GEM buffer object is not yet placed in the (PP)GTT, -then it is given an address. Two consequences of this are: the kernel -needs to edit the batchbuffer submitted to write the correct value of -the GPU address when a GEM BO is assigned a GPU address and the kernel +PPGTT is named per-process it is actually per context. In legacy +(non-vm_bind) mode, when user space submits a batchbuffer, the kernel walks +the list of GEM buffer objects used by the batchbuffer and guarantees that +not only is the memory of each such GEM buffer object resident but it is +also present in the (PP)GTT. If the GEM buffer object is not yet placed in +the (PP)GTT, then it is given an address. Two consequences of this are: the +kernel needs to edit the batchbuffer submitted to write the correct value +of the GPU address when a GEM BO is assigned a GPU address and the kernel might evict a different GEM BO from the (PP)GTT to make address room for another GEM BO. Consequently, the ioctls submitting a batchbuffer for execution also include a list of all locations within buffers that @@ -407,6 +411,15 @@ objects, which has the goal to make space in gpu virtual address spaces. .. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_shrinker.c :internal: +VM_BIND mode +------------ + +.. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c + :doc: VM_BIND/UNBIND ioctls + +.. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c + :internal: + Batchbuffer Parsing ------------------- @@ -419,11 +432,38 @@ Batchbuffer Parsing User Batchbuffer Execution -------------------------- +Client state +~~~~~~~~~~~~ + .. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_context_types.h +User command execution +~~~~~~~~~~~~~~~~~~~~~~ + .. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c :doc: User command execution +User command execution in vm_bind mode +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c + :doc: User command execution in vm_bind mode + +Common execbuff utilities +~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_execbuffer_common.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_execbuffer_common.c + :internal: + +Execbuf3 ioctl path +~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c + :internal: + Scheduling ---------- .. kernel-doc:: drivers/gpu/drm/i915/i915_scheduler_types.h