[PATCH 8/8] drm/panthor: Expose protected rendering features

Ketil Johnsen
2026-05-05T14:06:07Z

Add query for protected rendering capability.
Add flag to group creation to specify need for protected rendering.
Bump panthor version number.

Signed-off-by: Ketil Johnsen <ketil.johnsen@arm.com>
---
drivers/gpu/drm/panthor/panthor_drv.c | 21 +++++++++++-
drivers/gpu/drm/panthor/panthor_sched.c | 21 +++++++-----
include/uapi/drm/panthor_drm.h | 45 +++++++++++++++++++++++--
3 files changed, 76 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index 73fc983dc9b44..817df17f31f15 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -177,6 +177,7 @@ panthor_get_uobj_array(const struct drm_panthor_obj_array *in, u32 min_stride,
PANTHOR_UOBJ_DECL(struct drm_panthor_csif_info, pad), \
PANTHOR_UOBJ_DECL(struct drm_panthor_timestamp_info, current_timestamp), \
PANTHOR_UOBJ_DECL(struct drm_panthor_group_priorities_info, pad), \
+ PANTHOR_UOBJ_DECL(struct drm_panthor_protected_info, features), \
PANTHOR_UOBJ_DECL(struct drm_panthor_sync_op, timeline_value), \
PANTHOR_UOBJ_DECL(struct drm_panthor_queue_submit, syncs), \
PANTHOR_UOBJ_DECL(struct drm_panthor_queue_create, ringbuf_size), \
@@ -928,12 +929,20 @@ static void panthor_query_group_priorities_info(struct drm_file *file,
}
}

+static void panthor_query_protected_info(struct panthor_device *ptdev,
+ struct drm_panthor_protected_info *arg)
+{
+ arg->features =
+ ptdev->protm.heap ? DRM_PANTHOR_PROTECTED_FEATURE_BASIC : 0;
+}
+
static int panthor_ioctl_dev_query(struct drm_device *ddev, void *data, struct drm_file *file)
{
struct panthor_device *ptdev = container_of(ddev, struct panthor_device, base);
struct drm_panthor_dev_query *args = data;
struct drm_panthor_timestamp_info timestamp_info;
struct drm_panthor_group_priorities_info priorities_info;
+ struct drm_panthor_protected_info protected_info;
int ret;

if (!args->pointer) {
@@ -954,6 +963,10 @@ static int panthor_ioctl_dev_query(struct drm_device *ddev, void *data, struct d
args->size = sizeof(priorities_info);
return 0;

+ case DRM_PANTHOR_DEV_QUERY_PROTECTED_INFO:
+ args->size = sizeof(protected_info);
+ return 0;
+
default:
return -EINVAL;
}
@@ -984,6 +997,11 @@ static int panthor_ioctl_dev_query(struct drm_device *ddev, void *data, struct d
panthor_query_group_priorities_info(file, &priorities_info);
return PANTHOR_UOBJ_SET(args->pointer, args->size, priorities_info);

+ case DRM_PANTHOR_DEV_QUERY_PROTECTED_INFO:
+ panthor_query_protected_info(ptdev, &protected_info);
+ return PANTHOR_UOBJ_SET(args->pointer, args->size,
+ protected_info);
+
default:
return -EINVAL;
}
@@ -1779,6 +1797,7 @@ static void panthor_debugfs_init(struct drm_minor *minor)
* - adds DRM_IOCTL_PANTHOR_BO_QUERY_INFO ioctl
* - adds drm_panthor_gpu_info::selected_coherency
* - 1.8 - extends DEV_QUERY_TIMESTAMP_INFO with flags
+ * - 1.9 - adds DEV_QUERY_PROTECTED_INFO query
*/
static const struct drm_driver panthor_drm_driver = {
.driver_features = DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ |
@@ -1792,7 +1811,7 @@ static const struct drm_driver panthor_drm_driver = {
.name = "panthor",
.desc = "Panthor DRM driver",
.major = 1,
- .minor = 8,
+ .minor = 9,

.gem_prime_import_sg_table = panthor_gem_prime_import_sg_table,
.gem_prime_import = panthor_gem_prime_import,
diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index acb04250c7def..0e8a1059de589 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -3868,6 +3868,7 @@ 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 panthor_file *pfile,
const struct drm_panthor_group_create *group_args,
@@ -3882,10 +3883,10 @@ int panthor_group_create(struct panthor_file *pfile,
u32 gid, i, suspend_size;
int ret;

- if (group_args->pad)
+ if (group_args->priority >= PANTHOR_CSG_PRIORITY_COUNT)
return -EINVAL;

- if (group_args->priority >= PANTHOR_CSG_PRIORITY_COUNT)
+ if (group_args->flags & ~GROUP_CREATE_FLAGS)
return -EINVAL;

if ((group_args->compute_core_mask & ~ptdev->gpu_info.shader_present) ||
@@ -3937,12 +3938,16 @@ int panthor_group_create(struct panthor_file *pfile,
goto err_put_group;
}

- suspend_size = csg_iface->control->protm_suspend_size;
- group->protm_suspend_buf = panthor_fw_alloc_protm_suspend_buf_mem(ptdev, suspend_size);
- if (IS_ERR(group->protm_suspend_buf)) {
- ret = PTR_ERR(group->protm_suspend_buf);
- group->protm_suspend_buf = NULL;
- goto err_put_group;
+ if (group_args->flags & DRM_PANTHOR_GROUP_CREATE_PROTECTED) {
+ suspend_size = csg_iface->control->protm_suspend_size;
+ group->protm_suspend_buf =
+ panthor_fw_alloc_protm_suspend_buf_mem(ptdev,
+ suspend_size);
+ 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,
diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h
index 0e455d91e77d4..914110003bcd1 100644
--- a/include/uapi/drm/panthor_drm.h
+++ b/include/uapi/drm/panthor_drm.h
@@ -253,6 +253,11 @@ enum drm_panthor_dev_query_type {
* @DRM_PANTHOR_DEV_QUERY_GROUP_PRIORITIES_INFO: Query allowed group priorities information.
*/
DRM_PANTHOR_DEV_QUERY_GROUP_PRIORITIES_INFO,
+
+ /**
+ * @DRM_PANTHOR_DEV_QUERY_PROTECTED_INFO: Query supported protected rendering information.
+ */
+ DRM_PANTHOR_DEV_QUERY_PROTECTED_INFO,
};

/**
@@ -504,6 +509,28 @@ struct drm_panthor_group_priorities_info {
__u8 pad[3];
};

+/**
+ * enum drm_panthor_protected_feature_flags - Supported protected rendering features
+ *
+ * Place new types at the end, don't re-order, don't remove or replace.
+ */
+enum drm_panthor_protected_feature_flags {
+ /** @DRM_PANTHOR_PROTECTED_FEATURE_BASIC: Protected rendering available */
+ DRM_PANTHOR_PROTECTED_FEATURE_BASIC = 1 << 0,
+};
+
+/**
+ * struct drm_panthor_protected_info - protected support information
+ *
+ * Structure grouping all queryable information relating to the allowed group priorities.
+ */
+struct drm_panthor_protected_info {
+ /**
+ * @features: Combination of enum drm_panthor_protected_feature_flags flags.
+ */
+ __u32 features;
+};
+
/**
* struct drm_panthor_dev_query - Arguments passed to DRM_PANTHOR_IOCTL_DEV_QUERY
*/
@@ -843,6 +870,18 @@ enum drm_panthor_group_priority {
PANTHOR_GROUP_PRIORITY_REALTIME,
};

+/**
+ * enum drm_panthor_group_create_flags - Group create flags
+ */
+enum drm_panthor_group_create_flags {
+ /**
+ * @DRM_PANTHOR_GROUP_CREATE_PROTECTED: Support protected mode
+ *
+ * Enable protected rendering work to be executed on this group.
+ */
+ DRM_PANTHOR_GROUP_CREATE_PROTECTED = 1 << 0,
+};
+
/**
* struct drm_panthor_group_create - Arguments passed to DRM_IOCTL_PANTHOR_GROUP_CREATE
*/
@@ -877,8 +916,10 @@ struct drm_panthor_group_create {
/** @priority: Group priority (see enum drm_panthor_group_priority). */
__u8 priority;

- /** @pad: Padding field, MBZ. */
- __u32 pad;
+ /**
+ * @flags: Flags. Must be a combination of drm_panthor_group_create_flags flags.
+ */
+ __u32 flags;

/**
* @compute_core_mask: Mask encoding cores that can be used for compute jobs.
--
2.43.0