drm/panthor: Add DEV_QUERY_GROUP_PRIORITIES_INFO dev query

Expose allowed group priorities with a new device query.

This new uAPI will be used in Mesa to properly report what priorities a
user can use for EGL_IMG_context_priority.

Since this extends the uAPI and because userland needs a way to
advertise priorities accordingly, this also bumps the driver minor
version.

v2:
- Remove drm_panthor_group_allow_priority_flags definition
- Document that allowed_mask is a bitmask of drm_panthor_group_priority

v3:
- Use BIT macro in panthor_query_group_priorities_info
- Add r-b from Steven Price and Boris Brezillon

Signed-off-by: Mary Guillemard <mary.guillemard@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240909064820.34982-4-mary.guillemard@collabora.com

diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index 7b1db2adcb4c52f10c34fc209ba25e708552e671..0d825d63d712a09696bbc19f01aca29a5b19c5e0 100644 (file)
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -170,6 +170,7 @@ panthor_get_uobj_array(const struct drm_panthor_obj_array *in, u32 min_stride,
                 PANTHOR_UOBJ_DECL(struct drm_panthor_gpu_info, tiler_present), \
                 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_sync_op, timeline_value), \
                 PANTHOR_UOBJ_DECL(struct drm_panthor_queue_submit, syncs), \
                 PANTHOR_UOBJ_DECL(struct drm_panthor_queue_create, ringbuf_size), \
@@ -777,11 +778,41 @@ static int panthor_query_timestamp_info(struct panthor_device *ptdev,
        return 0;
 }
 
+static int group_priority_permit(struct drm_file *file,
+                                u8 priority)
+{
+       /* Ensure that priority is valid */
+       if (priority > PANTHOR_GROUP_PRIORITY_REALTIME)
+               return -EINVAL;
+
+       /* Medium priority and below are always allowed */
+       if (priority <= PANTHOR_GROUP_PRIORITY_MEDIUM)
+               return 0;
+
+       /* Higher priorities require CAP_SYS_NICE or DRM_MASTER */
+       if (capable(CAP_SYS_NICE) || drm_is_current_master(file))
+               return 0;
+
+       return -EACCES;
+}
+
+static void panthor_query_group_priorities_info(struct drm_file *file,
+                                               struct drm_panthor_group_priorities_info *arg)
+{
+       int prio;
+
+       for (prio = PANTHOR_GROUP_PRIORITY_REALTIME; prio >= 0; prio--) {
+               if (!group_priority_permit(file, prio))
+                       arg->allowed_mask |= BIT(prio);
+       }
+}
+
 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;
        int ret;
 
        if (!args->pointer) {
@@ -798,6 +829,10 @@ static int panthor_ioctl_dev_query(struct drm_device *ddev, void *data, struct d
                        args->size = sizeof(timestamp_info);
                        return 0;
 
+               case DRM_PANTHOR_DEV_QUERY_GROUP_PRIORITIES_INFO:
+                       args->size = sizeof(priorities_info);
+                       return 0;
+
                default:
                        return -EINVAL;
                }
@@ -818,6 +853,10 @@ static int panthor_ioctl_dev_query(struct drm_device *ddev, void *data, struct d
 
                return PANTHOR_UOBJ_SET(args->pointer, args->size, timestamp_info);
 
+       case DRM_PANTHOR_DEV_QUERY_GROUP_PRIORITIES_INFO:
+               panthor_query_group_priorities_info(file, &priorities_info);
+               return PANTHOR_UOBJ_SET(args->pointer, args->size, priorities_info);
+
        default:
                return -EINVAL;
        }
@@ -1037,24 +1076,6 @@ static int panthor_ioctl_group_destroy(struct drm_device *ddev, void *data,
        return panthor_group_destroy(pfile, args->group_handle);
 }
 
-static int group_priority_permit(struct drm_file *file,
-                                u8 priority)
-{
-       /* Ensure that priority is valid */
-       if (priority > PANTHOR_GROUP_PRIORITY_REALTIME)
-               return -EINVAL;
-
-       /* Medium priority and below are always allowed */
-       if (priority <= PANTHOR_GROUP_PRIORITY_MEDIUM)
-               return 0;
-
-       /* Higher priorities require CAP_SYS_NICE or DRM_MASTER */
-       if (capable(CAP_SYS_NICE) || drm_is_current_master(file))
-               return 0;
-
-       return -EACCES;
-}
-
 static int panthor_ioctl_group_create(struct drm_device *ddev, void *data,
                                      struct drm_file *file)
 {
@@ -1436,6 +1457,8 @@ static void panthor_debugfs_init(struct drm_minor *minor)
  * PanCSF driver version:
  * - 1.0 - initial interface
  * - 1.1 - adds DEV_QUERY_TIMESTAMP_INFO query
+ * - 1.2 - adds DEV_QUERY_GROUP_PRIORITIES_INFO query
+ *       - adds PANTHOR_GROUP_PRIORITY_REALTIME priority
  */
 static const struct drm_driver panthor_drm_driver = {
        .driver_features = DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ |
@@ -1449,7 +1472,7 @@ static const struct drm_driver panthor_drm_driver = {
        .desc = "Panthor DRM driver",
        .date = "20230801",
        .major = 1,
-       .minor = 1,
+       .minor = 2,
 
        .gem_create_object = panthor_gem_create_object,
        .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table,

diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h
index 011a555e46740ccc5cf60ae52c220e7c6048101b..87c9cb555dd1d19ba7e042203d38de0e74f69e05 100644 (file)
--- a/include/uapi/drm/panthor_drm.h
+++ b/include/uapi/drm/panthor_drm.h
@@ -263,6 +263,11 @@ enum drm_panthor_dev_query_type {
 
        /** @DRM_PANTHOR_DEV_QUERY_TIMESTAMP_INFO: Query timestamp information. */
        DRM_PANTHOR_DEV_QUERY_TIMESTAMP_INFO,
+
+       /**
+        * @DRM_PANTHOR_DEV_QUERY_GROUP_PRIORITIES_INFO: Query allowed group priorities information.
+        */
+       DRM_PANTHOR_DEV_QUERY_GROUP_PRIORITIES_INFO,
 };
 
 /**
@@ -399,6 +404,23 @@ struct drm_panthor_timestamp_info {
        __u64 timestamp_offset;
 };
 
+/**
+ * struct drm_panthor_group_priorities_info - Group priorities information
+ *
+ * Structure grouping all queryable information relating to the allowed group priorities.
+ */
+struct drm_panthor_group_priorities_info {
+       /**
+        * @allowed_mask: Bitmask of the allowed group priorities.
+        *
+        * Each bit represents a variant of the enum drm_panthor_group_priority.
+        */
+       __u8 allowed_mask;
+
+       /** @pad: Padding fields, MBZ. */
+       __u8 pad[3];
+};
+
 /**
  * struct drm_panthor_dev_query - Arguments passed to DRM_PANTHOR_IOCTL_DEV_QUERY
  */