[PATCH v2 1/4] drm/panfrost: Introduce uAPI for JM context creation

From: Adrián Larumbe
Date: Wed Sep 03 2025 - 20:12:02 EST


From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>

The new uAPI lets user space query the KM driver for the available
priorities a job can be given at submit time. These are managed through
the notion of a context, for which we also provide new creation and
destruction ioctls.

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
---
include/uapi/drm/panfrost_drm.h | 50 +++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)

diff --git a/include/uapi/drm/panfrost_drm.h b/include/uapi/drm/panfrost_drm.h
index ed67510395bd..e8b47c9f6976 100644
--- a/include/uapi/drm/panfrost_drm.h
+++ b/include/uapi/drm/panfrost_drm.h
@@ -22,6 +22,8 @@ extern "C" {
#define DRM_PANFROST_PERFCNT_DUMP 0x07
#define DRM_PANFROST_MADVISE 0x08
#define DRM_PANFROST_SET_LABEL_BO 0x09
+#define DRM_PANFROST_JM_CTX_CREATE 0x0a
+#define DRM_PANFROST_JM_CTX_DESTROY 0x0b

#define DRM_IOCTL_PANFROST_SUBMIT DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_SUBMIT, struct drm_panfrost_submit)
#define DRM_IOCTL_PANFROST_WAIT_BO DRM_IOW(DRM_COMMAND_BASE + DRM_PANFROST_WAIT_BO, struct drm_panfrost_wait_bo)
@@ -31,6 +33,8 @@ extern "C" {
#define DRM_IOCTL_PANFROST_GET_BO_OFFSET DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_GET_BO_OFFSET, struct drm_panfrost_get_bo_offset)
#define DRM_IOCTL_PANFROST_MADVISE DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_MADVISE, struct drm_panfrost_madvise)
#define DRM_IOCTL_PANFROST_SET_LABEL_BO DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_SET_LABEL_BO, struct drm_panfrost_set_label_bo)
+#define DRM_IOCTL_PANFROST_JM_CTX_CREATE DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_JM_CTX_CREATE, struct drm_panfrost_jm_ctx_create)
+#define DRM_IOCTL_PANFROST_JM_CTX_DESTROY DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_JM_CTX_DESTROY, struct drm_panfrost_jm_ctx_destroy)

/*
* Unstable ioctl(s): only exposed when the unsafe unstable_ioctls module
@@ -71,6 +75,12 @@ struct drm_panfrost_submit {

/** A combination of PANFROST_JD_REQ_* */
__u32 requirements;
+
+ /** JM context handle. Zero if you want to use the default context. */
+ __u32 jm_ctx_handle;
+
+ /** Padding field. MBZ. */
+ __u32 pad;
};

/**
@@ -177,6 +187,7 @@ enum drm_panfrost_param {
DRM_PANFROST_PARAM_AFBC_FEATURES,
DRM_PANFROST_PARAM_SYSTEM_TIMESTAMP,
DRM_PANFROST_PARAM_SYSTEM_TIMESTAMP_FREQUENCY,
+ DRM_PANFROST_PARAM_ALLOWED_JM_CTX_PRIORITIES,
};

struct drm_panfrost_get_param {
@@ -299,6 +310,45 @@ struct panfrost_dump_registers {
__u32 value;
};

+enum drm_panfrost_jm_ctx_priority {
+ /**
+ * @PANFROST_JM_CTX_PRIORITY_LOW: Low priority context.
+ */
+ PANFROST_JM_CTX_PRIORITY_LOW = 0,
+
+ /**
+ * @PANFROST_JM_CTX_PRIORITY_MEDIUM: Medium priority context.
+ */
+ PANFROST_JM_CTX_PRIORITY_MEDIUM,
+
+ /**
+ * @PANFROST_JM_CTX_PRIORITY_HIGH: High priority context.
+ *
+ * Requires CAP_SYS_NICE or DRM_MASTER.
+ */
+ PANFROST_JM_CTX_PRIORITY_HIGH,
+};
+
+struct drm_panfrost_jm_ctx_create {
+ /** @handle: Handle of the created JM context */
+ __u32 handle;
+
+ /** @priority: Context priority (see enum drm_panfrost_jm_ctx_priority). */
+ __u32 priority;
+};
+
+struct drm_panfrost_jm_ctx_destroy {
+ /**
+ * @handle: Handle of the JM context to destroy.
+ *
+ * Must be a valid context handle returned by DRM_IOCTL_PANTHOR_JM_CTX_CREATE.
+ */
+ __u32 handle;
+
+ /** @pad: Padding field, MBZ. */
+ __u32 pad;
+};
+
#if defined(__cplusplus)
}
#endif
--
2.50.0