Panthor follows the lead of other recently submitted drivers with
ioctls allowing us to support modern Vulkan features, like sparse memory
binding:
- Pretty standard GEM management ioctls (BO_CREATE and BO_MMAP_OFFSET),
with the 'exclusive-VM' bit to speed-up BO reservation on job submission
- VM management ioctls (VM_CREATE, VM_DESTROY and VM_BIND). The VM_BIND
ioctl is loosely based on the Xe model, and can handle both
asynchronous and synchronous requests
- GPU execution context creation/destruction, tiler heap context creation
and job submission. Those ioctls reflect how the hardware/scheduler
works and are thus driver specific.
We also have a way to expose IO regions, such that the usermode driver
can directly access specific/well-isolate registers, like the
LATEST_FLUSH register used to implement cache-flush reduction.
This uAPI intentionally keeps usermode queues out of the scope, which
explains why doorbell registers and command stream ring-buffers are not
directly exposed to userspace.
v6:
- Add Maxime's and Heiko's acks
v5:
- Fix typo
- Add Liviu's R-b
v4:
- Add a VM_GET_STATE ioctl
- Fix doc
- Expose the CORE_FEATURES register so we can deal with variants in the
UMD
- Add Steve's R-b
v3:
- Add the concept of sync-only VM operation
- Fix support for 32-bit userspace
- Rework drm_panthor_vm_create to pass the user VA size instead of
the kernel VA size (suggested by Robin Murphy)
- Typo fixes
- Explicitly cast enums with top bit set to avoid compiler warnings in
-pedantic mode.
- Drop property core_group_count as it can be easily calculated by the
number of bits set in l2_present.
Co-developed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240229162230.2634044-2-boris.brezillon@collabora.com
Make sure the uapi gets picked up by the normal docs build.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Francois Dugast <francois.dugast@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Francois Dugast <francois.dugast@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
This commit provides the implementation for the new uapi motivated by the
Vulkan API. It allows user mode drivers (UMDs) to:
1) Initialize a GPU virtual address (VA) space via the new
DRM_IOCTL_NOUVEAU_VM_INIT ioctl for UMDs to specify the portion of VA
space managed by the kernel and userspace, respectively.
2) Allocate and free a VA space region as well as bind and unbind memory
to the GPUs VA space via the new DRM_IOCTL_NOUVEAU_VM_BIND ioctl.
UMDs can request the named operations to be processed either
synchronously or asynchronously. It supports DRM syncobjs
(incl. timelines) as synchronization mechanism. The management of the
GPU VA mappings is implemented with the DRM GPU VA manager.
3) Execute push buffers with the new DRM_IOCTL_NOUVEAU_EXEC ioctl. The
execution happens asynchronously. It supports DRM syncobj (incl.
timelines) as synchronization mechanism. DRM GEM object locking is
handled with drm_exec.
Both, DRM_IOCTL_NOUVEAU_VM_BIND and DRM_IOCTL_NOUVEAU_EXEC, use the DRM
GPU scheduler for the asynchronous paths.
Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230804182406.5222-12-dakr@redhat.com
This commit provides the interfaces for the new UAPI motivated by the
Vulkan API. It allows user mode drivers (UMDs) to:
1) Initialize a GPU virtual address (VA) space via the new
DRM_IOCTL_NOUVEAU_VM_INIT ioctl. UMDs can provide a kernel reserved
VA area.
2) Bind and unbind GPU VA space mappings via the new
DRM_IOCTL_NOUVEAU_VM_BIND ioctl.
3) Execute push buffers with the new DRM_IOCTL_NOUVEAU_EXEC ioctl.
Both, DRM_IOCTL_NOUVEAU_VM_BIND and DRM_IOCTL_NOUVEAU_EXEC support
asynchronous processing with DRM syncobjs as synchronization mechanism.
The default DRM_IOCTL_NOUVEAU_VM_BIND is synchronous processing,
DRM_IOCTL_NOUVEAU_EXEC supports asynchronous processing only.
Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Co-developed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230804182406.5222-4-dakr@redhat.com
