From: Boris Brezillon <boris.brezillon@collabora.com>
To: Ketil Johnsen <ketil.johnsen@arm.com>
Cc: Steven Price <steven.price@arm.com>,
Liviu Dudau <liviu.dudau@arm.com>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
David Airlie <airlied@gmail.com>, Simona Vetter <simona@ffwll.ch>,
Daniel Almeida <daniel.almeida@collabora.com>,
Alice Ryhl <aliceryhl@google.com>,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 11/12] drm/panthor: Protm support for groups
Date: Wed, 21 Oct 2026 10:59:04 +0200 [thread overview]
Message-ID: <20261021105904.70fad4b3@fedora-21.home> (raw)
In-Reply-To: <20261012125940.3291951-12-ketil.johnsen@arm.com>
On Mon, 12 Oct 2026 14:59:39 +0200
Ketil Johnsen <ketil.johnsen@arm.com> wrote:
> From: Boris Brezillon <boris.brezillon@collabora.com>
>
> Extends struct drm_panthor_group_create to allow user provided protm
> suspend buffer. This is needed for protm execution with this group.
>
> Make use of the user supplied suspend buffer (import).
>
> Allow PROT_REGION instruction for groups which provided protm
> suspend buffer.
>
> Store the suspend buffer sizes (normal and protected) provided by FW
> after FW start. Unsafe to read directly from FW as these will return
> zero between FW load and FW start.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
> Co-developed-by: Ketil Johnsen <ketil.johnsen@arm.com>
> Signed-off-by: Ketil Johnsen <ketil.johnsen@arm.com>
>
> ---
>
> v4:
> - First version of this change as a separate commit
> ---
> drivers/gpu/drm/panthor/panthor_fw.c | 24 ++++++++++
> drivers/gpu/drm/panthor/panthor_fw.h | 2 +
> drivers/gpu/drm/panthor/panthor_sched.c | 59 ++++++++++++++++++++-----
> include/uapi/drm/panthor_drm.h | 10 ++++-
> 4 files changed, 83 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
> index 0af6addfd55a5..11c370ef86aad 100644
> --- a/drivers/gpu/drm/panthor/panthor_fw.c
> +++ b/drivers/gpu/drm/panthor/panthor_fw.c
> @@ -269,6 +269,12 @@ struct panthor_fw {
> /** @protm_init_lock: Used to serialize protm initialization. */
> struct mutex protm_init_lock;
>
> + /** @suspend_size: Size of regular suspend buffer */
> + u32 suspend_size;
> +
> + /** @protm_suspend_size: Size of protected suspend buffer size */
> + u32 protm_suspend_size;
> +
> /**
> * @req_waitqueue: FW request waitqueue.
> *
> @@ -1006,6 +1012,14 @@ static int panthor_init_csg_iface(struct panthor_device *ptdev,
> }
>
> if (!csg_idx) {
> + /* We make a copy of these sizes, as csg_iface can read these
> + * as zero during full GPU reset, between FW sections being
> + * reloaded and FW fully booted.
> + */
> + ptdev->fw->suspend_size = csg_iface->control->suspend_size;
> + ptdev->fw->protm_suspend_size =
> + csg_iface->control->protm_suspend_size;
> +
> ptdev->protm.info.group_protected_suspend_buf_size =
> csg_iface->control->protm_suspend_size;
> }
> @@ -1523,6 +1537,16 @@ static void panthor_fw_ping_work(struct work_struct *work)
> }
> }
>
> +u32 panthor_fw_suspend_size(struct panthor_device *ptdev)
> +{
> + return ptdev->fw->suspend_size;
> +}
> +
> +u32 panthor_fw_protm_suspend_size(struct panthor_device *ptdev)
> +{
> + return ptdev->fw->protm_suspend_size;
> +}
> +
> static bool wait_protm_enter(struct panthor_device *ptdev,
> s64 protm_session_seqno)
> {
> diff --git a/drivers/gpu/drm/panthor/panthor_fw.h b/drivers/gpu/drm/panthor/panthor_fw.h
> index 34bc9dc82314c..98576114cc803 100644
> --- a/drivers/gpu/drm/panthor/panthor_fw.h
> +++ b/drivers/gpu/drm/panthor/panthor_fw.h
> @@ -531,6 +531,8 @@ void panthor_fw_unplug(struct panthor_device *ptdev);
>
> int panthor_fw_protm_init(struct drm_file *file,
> struct drm_panthor_protm_init *args);
> +u32 panthor_fw_suspend_size(struct panthor_device *ptdev);
> +u32 panthor_fw_protm_suspend_size(struct panthor_device *ptdev);
> int panthor_fw_protm_enter(struct panthor_device *ptdev);
> int panthor_fw_protm_exit(struct panthor_device *ptdev, u32 timeout_ms);
> int panthor_fw_protm_exit_wait(struct panthor_device *ptdev, u32 timeout_ms);
> diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
> index fff805fd794a5..d1178be178a48 100644
> --- a/drivers/gpu/drm/panthor/panthor_sched.c
> +++ b/drivers/gpu/drm/panthor/panthor_sched.c
> @@ -1462,10 +1462,15 @@ cs_slot_process_protm_pending_event_locked(struct panthor_device *ptdev,
> if (!group)
> return;
>
> - /* Do not allow user space work to switch into protected mode, as we
> - * do not fully support this quite yet.
> + /* Do not allow user space work to switch into protected mode if we
> + * do not support protected mode on this device.
> + * User space should query (and init) this support before attempting
> + * to use such GPU instructions.
> */
> - atomic_or(BIT(cs_id), &group->fatal_queues);
> + if (group->protm_suspend_buf)
> + atomic_or(BIT(cs_id), &group->protm_pending_queues);
> + else
> + atomic_or(BIT(cs_id), &group->fatal_queues);
>
> sched_queue_delayed_work(sched, tick, 0);
> }
> @@ -4074,6 +4079,7 @@ static void add_group_kbo_sizes(struct panthor_device *ptdev,
> }
>
> #define MAX_GROUPS_PER_POOL 128
> +#define GROUP_CREATE_FLAGS DRM_PANTHOR_GROUP_CREATE_PROTECTED
>
> int panthor_group_create(struct drm_file *file,
> const struct drm_panthor_group_create *group_args,
> @@ -4083,14 +4089,10 @@ int panthor_group_create(struct drm_file *file,
> struct panthor_device *ptdev = pfile->ptdev;
> struct panthor_group_pool *gpool = pfile->groups;
> struct panthor_scheduler *sched = ptdev->scheduler;
> - struct panthor_fw_csg_iface *csg_iface = panthor_fw_get_csg_iface(ptdev, 0);
> struct panthor_group *group = NULL;
> - u32 gid, i, suspend_size;
> + u32 gid, i;
> int ret;
>
> - if (group_args->pad)
> - return -EINVAL;
> -
> if (group_args->priority >= PANTHOR_CSG_PRIORITY_COUNT)
> return -EINVAL;
>
> @@ -4136,14 +4138,51 @@ int panthor_group_create(struct drm_file *file,
> goto err_put_group;
> }
>
> - suspend_size = csg_iface->control->suspend_size;
> - group->suspend_buf = panthor_fw_alloc_suspend_buf_mem(ptdev, suspend_size);
> + group->suspend_buf = panthor_fw_alloc_suspend_buf_mem(
> + ptdev, panthor_fw_suspend_size(ptdev));
> if (IS_ERR(group->suspend_buf)) {
> ret = PTR_ERR(group->suspend_buf);
> group->suspend_buf = NULL;
> goto err_put_group;
> }
>
> + if (group_args->protected_suspend_bo_handle) {
> + struct drm_gem_object *obj;
> +
> + /* Read a correct snapshot of the state */
> + if (!(smp_load_acquire(&ptdev->protm.info.state) &
> + DRM_PANTHOR_PROTM_INITIALIZED)) {
Same comment I made in previous patch: let's use a regular lock to
access this state.
> + ret = -EINVAL;
> + goto err_put_group;
> + }
> +
> + obj = drm_gem_object_lookup(
> + file, group_args->protected_suspend_bo_handle);
obj = drm_gem_object_lookup(file,
group_args->protected_suspend_bo_handle);
> + if (!obj) {
> + ret = -ENOENT;
> + goto err_put_group;
> + }
> +
> + if (obj->size <
> + ptdev->protm.info.group_protected_suspend_buf_size) {
if (obj->size < ptdev->protm.info.group_protected_suspend_buf_size) {
> + drm_gem_object_put(obj);
> + ret = -EINVAL;
> + goto err_put_group;
> + }
> +
> + group->protm_suspend_buf = panthor_kernel_bo_create_from_gem(
> + ptdev, panthor_fw_vm(ptdev), to_panthor_bo(obj),
> + DRM_PANTHOR_VM_BIND_OP_MAP_NOEXEC,
> + PANTHOR_VM_KERNEL_AUTO_VA,
> + panthor_fw_protm_suspend_size(ptdev));
group->protm_suspend_buf =
panthor_kernel_bo_create_from_gem(ptdev, panthor_fw_vm(ptdev),
to_panthor_bo(obj),
DRM_PANTHOR_VM_BIND_OP_MAP_NOEXEC,
PANTHOR_VM_KERNEL_AUTO_VA,
panthor_fw_protm_suspend_size(ptdev));
> + drm_gem_object_put(obj);
> + if (IS_ERR(group->protm_suspend_buf)) {
> + ret = PTR_ERR(group->protm_suspend_buf);
> + group->protm_suspend_buf = NULL;
> + goto err_put_group;
> + }
> + }
> +
> group->syncobjs = panthor_kernel_bo_create(ptdev, group->vm,
> group_args->queues.count *
> sizeof(struct panthor_syncobj_64b),
> diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h
> index d2d21e3e6bb39..a0ed16041e178 100644
> --- a/include/uapi/drm/panthor_drm.h
> +++ b/include/uapi/drm/panthor_drm.h
> @@ -956,8 +956,14 @@ struct drm_panthor_group_create {
> /** @priority: Group priority (see enum drm_panthor_group_priority). */
> __u8 priority;
>
> - /** @pad: Padding field, MBZ. */
> - __u32 pad;
> + /**
> + * @protected_suspend_bo_handle: BO to use as a protected suspend buffer.
> + *
> + * This BO must have been allocated from a protected DMA-BUF heap and
> + * imported in panthor. It's size must be at least
> + * drm_panthor_protm_info::group_protected_suspend_buf_size.
> + */
> + __u32 protected_suspend_bo_handle;
>
> /**
> * @compute_core_mask: Mask encoding cores that can be used for compute jobs.
next prev parent reply other threads:[~2026-10-21 8:59 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-12 12:59 [PATCH v4 00/12] drm/panthor: Protected mode support for Mali CSF GPUs Ketil Johnsen
2026-10-12 12:59 ` [PATCH v4 01/12] drm/panthor: De-duplicate FW memory section sync Ketil Johnsen
2026-10-12 12:59 ` [PATCH v4 02/12] drm/panthor: Minor scheduler refactoring Ketil Johnsen
2026-10-12 12:59 ` [PATCH v4 03/12] drm/panthor: Pass drm_file instead of panthor_file Ketil Johnsen
2026-10-14 20:19 ` kernel test robot
2026-10-21 8:28 ` Boris Brezillon
2026-10-12 12:59 ` [PATCH v4 04/12] drm/panthor: Don't allocate protm_suspend_buf Ketil Johnsen
2026-10-12 12:59 ` [PATCH v4 05/12] drm/panthor: Add support for entering and exiting protected mode Ketil Johnsen
2026-10-14 23:08 ` kernel test robot
2026-10-19 15:41 ` Boris Brezillon
2026-10-20 16:11 ` Boris Brezillon
2026-10-12 12:59 ` [PATCH v4 06/12] drm/panthor: New function for FW section map flags Ketil Johnsen
2026-10-12 12:59 ` [PATCH v4 07/12] drm/panthor: Keep size and VA in FW section obj Ketil Johnsen
2026-10-12 12:59 ` [PATCH v4 08/12] drm/panthor: Refactor GEM usage flags assignment Ketil Johnsen
2026-10-21 8:35 ` Boris Brezillon
2026-10-12 12:59 ` [PATCH v4 09/12] drm/panthor: Create kernel BO from existing GEM Ketil Johnsen
2026-10-21 8:44 ` Boris Brezillon
2026-10-12 12:59 ` [PATCH v4 10/12] drm/panthor: Support FW init of protm Ketil Johnsen
2026-10-21 8:53 ` Boris Brezillon
2026-10-12 12:59 ` [PATCH v4 11/12] drm/panthor: Protm support for groups Ketil Johnsen
2026-10-21 8:59 ` Boris Brezillon [this message]
2026-10-12 12:59 ` [PATCH v4 12/12] drm/panthor: Bump version to expose protm feature Ketil Johnsen
2026-10-21 9:00 ` Boris Brezillon
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