On 04/12/2023 17:32, Boris Brezillon wrote:
> 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.
>
> 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.
>
> Signed-off-by: Boris Brezillon
> Signed-off-by: Steven Price
NIT: I believe the signed-off lines should be like:
Co-developed-by: Steven
Signed-off-by: Steven
Signed-off-by: Boris
So yours at the end not mine (because you're the one posting it) and a
"Co-developed-by" to explain why there's a sign-off from me. I'm
guessing this is actually my fault since I sent the branch to you with
my changes with the sign offs like this.
Otherwise everything looks good:
Reviewed-by: Steven Price
Thanks,
Steve
> ---
> Documentation/gpu/driver-uapi.rst | 5 +
> include/uapi/drm/panthor_drm.h| 892 ++
> 2 files changed, 897 insertions(+)
> create mode 100644 include/uapi/drm/panthor_drm.h
>
> diff --git a/Documentation/gpu/driver-uapi.rst
> b/Documentation/gpu/driver-uapi.rst
> index c08bcbb95fb3..7a667901830f 100644
> --- a/Documentation/gpu/driver-uapi.rst
> +++ b/Documentation/gpu/driver-uapi.rst
> @@ -17,3 +17,8 @@ VM_BIND / EXEC uAPI
> :doc: Overview
>
> .. kernel-doc:: include/uapi/drm/nouveau_drm.h
> +
> +drm/panthor uAPI
> +
> +
> +.. kernel-doc:: include/uapi/drm/panthor_drm.h
> diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h
> new file mode 100644
> index ..6d815df5e829
> --- /dev/null
> +++ b/include/uapi/drm/panthor_drm.h
> @@ -0,0 +1,892 @@
> +/* SPDX-License-Identifier: MIT */
> +/* Copyright (C) 2023 Collabora ltd. */
> +#ifndef _PANTHOR_DRM_H_
> +#define _PANTHOR_DRM_H_
> +
> +#include "drm.h"
> +
> +#if defined(__cplusplus)
> +extern "C" {
> +#endif
> +
> +/**
> + * DOC: Introduction
> + *
> + * This documentation describes the Panthor IOCTLs.
> + *
> + * Just a few generic rules about the data passed to the Panthor IOCTLs:
> + *
> + * - Structures must be aligned on 64-bit/8-byte. If the object is not
> + * naturally aligned, a padding field must be added.
> + * - Fields must be explicitly aligned to their natural type alignment with
> + * pad[0..N] fields.
> + * - All padding fields will be checked by the driver to make sure they are
> + * zeroed.
> + * - Flags can be added, but not removed/replaced.
> + * - New fields can be added to the main structures (the structures
> + * directly passed to the ioctl). Those fields can be added at the end of
> + * the structure, or replace existing padding fields. Any new field being
> + * added must preserve the behavior that existed before those fields were
> + * added when a value of zero is passed.
> + * - New fields can be added to indirect objects (objects pointed by the
> + * main structure), iff those objects are passed a size to reflect the
> + * size known by the userspace driver (see drm_panthor_obj_array::stride
> + * or drm_panthor_dev_query::size).
> + * - If the kernel driver is too old to know some fields, those will be
> + * ignored if zero, and otherwise rejected (and so will be zero on output).
> + * - If userspace is too old to know some fields, those will be zeroed
> + * (input) before the structure is parsed by the kernel driver.
> + * - Each new flag/field addition must come with a driver version update so
> + * the userspace driver doesn't have to trial and error to know which
> + * flags are supported.
> + * - Structures should not contain unions, as this would defeat the
> + * extensibility of such structures.
> + * - IOCTLs can't be removed or replaced. New IOCTL IDs should be
