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Diffstat (limited to 'Documentation/gpu/rfc/xe.rst')
| -rw-r--r-- | Documentation/gpu/rfc/xe.rst | 132 |
1 files changed, 67 insertions, 65 deletions
diff --git a/Documentation/gpu/rfc/xe.rst b/Documentation/gpu/rfc/xe.rst index c29113a0ac30..97cf87578f97 100644 --- a/Documentation/gpu/rfc/xe.rst +++ b/Documentation/gpu/rfc/xe.rst @@ -70,35 +70,42 @@ When the time comes for Xe, the protection will be lifted on Xe and kept in i915 Xe – Pre-Merge Goals - Work-in-Progress ======================================= -Drm_scheduler -------------- -Xe primarily uses Firmware based scheduling (GuC FW). However, it will use -drm_scheduler as the scheduler ‘frontend’ for userspace submission in order to -resolve syncobj and dma-buf implicit sync dependencies. However, drm_scheduler is -not yet prepared to handle the 1-to-1 relationship between drm_gpu_scheduler and -drm_sched_entity. +Display integration with i915 +----------------------------- +In order to share the display code with the i915 driver so that there is maximum +reuse, the i915/display/ code is built twice, once for i915.ko and then for +xe.ko. Currently, the i915/display code in Xe tree is polluted with many 'ifdefs' +depending on the build target. The goal is to refactor both Xe and i915/display +code simultaneously in order to get a clean result before they land upstream, so +that display can already be part of the initial pull request towards drm-next. -Deeper changes to drm_scheduler should *not* be required to get Xe accepted, but -some consensus needs to be reached between Xe and other community drivers that -could also benefit from this work, for coupling FW based/assisted submission such -as the ARM’s new Mali GPU driver, and others. +However, display code should not gate the acceptance of Xe in upstream. Xe +patches will be refactored in a way that display code can be removed, if needed, +from the first pull request of Xe towards drm-next. The expectation is that when +both drivers are part of the drm-tip, the introduction of cleaner patches will be +easier and speed up. -As a key measurable result, the patch series introducing Xe itself shall not -depend on any other patch touching drm_scheduler itself that was not yet merged -through drm-misc. This, by itself, already includes the reach of an agreement for -uniform 1 to 1 relationship implementation / usage across drivers. +Xe – uAPI high level overview +============================= -ASYNC VM_BIND -------------- -Although having a common DRM level IOCTL for VM_BIND is not a requirement to get -Xe merged, it is mandatory to have a consensus with other drivers and Mesa. -It needs to be clear how to handle async VM_BIND and interactions with userspace -memory fences. Ideally with helper support so people don't get it wrong in all -possible ways. +...Warning: To be done in follow up patches after/when/where the main consensus in various items are individually reached. -As a key measurable result, the benefits of ASYNC VM_BIND and a discussion of -various flavors, error handling and sample API suggestions are documented in -:doc:`The ASYNC VM_BIND document </gpu/drm-vm-bind-async>`. +Xe – Pre-Merge Goals - Completed +================================ + +Drm_exec +-------- +Helper to make dma_resv locking for a big number of buffers is getting removed in +the drm_exec series proposed in https://patchwork.freedesktop.org/patch/524376/ +If that happens, Xe needs to change and incorporate the changes in the driver. +The goal is to engage with the Community to understand if the best approach is to +move that to the drivers that are using it or if we should keep the helpers in +place waiting for Xe to get merged. + +This item ties into the GPUVA, VM_BIND, and even long-running compute support. + +As a key measurable result, we need to have a community consensus documented in +this document and the Xe driver prepared for the changes, if necessary. Userptr integration and vm_bind ------------------------------- @@ -123,10 +130,45 @@ Documentation should include: * O(1) complexity under VM_BIND. +The document is now included in the drm documentation :doc:`here </gpu/drm-vm-bind-async>`. + Some parts of userptr like mmu_notifiers should become GPUVA or DRM helpers when the second driver supporting VM_BIND+userptr appears. Details to be defined when the time comes. +The DRM GPUVM helpers do not yet include the userptr parts, but discussions +about implementing them are ongoing. + +ASYNC VM_BIND +------------- +Although having a common DRM level IOCTL for VM_BIND is not a requirement to get +Xe merged, it is mandatory to have a consensus with other drivers and Mesa. +It needs to be clear how to handle async VM_BIND and interactions with userspace +memory fences. Ideally with helper support so people don't get it wrong in all +possible ways. + +As a key measurable result, the benefits of ASYNC VM_BIND and a discussion of +various flavors, error handling and sample API suggestions are documented in +:doc:`The ASYNC VM_BIND document </gpu/drm-vm-bind-async>`. + +Drm_scheduler +------------- +Xe primarily uses Firmware based scheduling (GuC FW). However, it will use +drm_scheduler as the scheduler ‘frontend’ for userspace submission in order to +resolve syncobj and dma-buf implicit sync dependencies. However, drm_scheduler is +not yet prepared to handle the 1-to-1 relationship between drm_gpu_scheduler and +drm_sched_entity. + +Deeper changes to drm_scheduler should *not* be required to get Xe accepted, but +some consensus needs to be reached between Xe and other community drivers that +could also benefit from this work, for coupling FW based/assisted submission such +as the ARM’s new Mali GPU driver, and others. + +As a key measurable result, the patch series introducing Xe itself shall not +depend on any other patch touching drm_scheduler itself that was not yet merged +through drm-misc. This, by itself, already includes the reach of an agreement for +uniform 1 to 1 relationship implementation / usage across drivers. + Long running compute: minimal data structure/scaffolding -------------------------------------------------------- The generic scheduler code needs to include the handling of endless compute @@ -139,46 +181,6 @@ this minimal drm/scheduler work, if needed, merged to drm-misc in a way that any drm driver, including Xe, could re-use and add their own individual needs on top in a next stage. However, this should not block the initial merge. -This is a non-blocker item since the driver without the support for the long -running compute enabled is not a showstopper. - -Display integration with i915 ------------------------------ -In order to share the display code with the i915 driver so that there is maximum -reuse, the i915/display/ code is built twice, once for i915.ko and then for -xe.ko. Currently, the i915/display code in Xe tree is polluted with many 'ifdefs' -depending on the build target. The goal is to refactor both Xe and i915/display -code simultaneously in order to get a clean result before they land upstream, so -that display can already be part of the initial pull request towards drm-next. - -However, display code should not gate the acceptance of Xe in upstream. Xe -patches will be refactored in a way that display code can be removed, if needed, -from the first pull request of Xe towards drm-next. The expectation is that when -both drivers are part of the drm-tip, the introduction of cleaner patches will be -easier and speed up. - -Drm_exec --------- -Helper to make dma_resv locking for a big number of buffers is getting removed in -the drm_exec series proposed in https://patchwork.freedesktop.org/patch/524376/ -If that happens, Xe needs to change and incorporate the changes in the driver. -The goal is to engage with the Community to understand if the best approach is to -move that to the drivers that are using it or if we should keep the helpers in -place waiting for Xe to get merged. - -This item ties into the GPUVA, VM_BIND, and even long-running compute support. - -As a key measurable result, we need to have a community consensus documented in -this document and the Xe driver prepared for the changes, if necessary. - -Xe – uAPI high level overview -============================= - -...Warning: To be done in follow up patches after/when/where the main consensus in various items are individually reached. - -Xe – Pre-Merge Goals - Completed -================================ - Dev_coredump ------------ |