drm/panfrost: Add a PANFROST_SYNC_BO ioctl

This will be used by the UMD to synchronize CPU-cached mappings when
the UMD can't do it directly (no usermode cache maintenance instruction
on Arm32).

v2:
- Add more to the commit message
- Change the flags to better match the drm_gem_shmem_sync semantics

v3:
- Add Steve's R-b

v4:
- No changes

v5:
- Drop Steve's R-b (semantics changes requiring a new review)

v6:
- Bail out early in panfrost_ioctl_sync_bo() if op_count is zero

v7:
- Hand-roll our own bo_sync() helper

v8:
- Collect R-b

Signed-off-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patch.msgid.link/20251208100841.730527-11-boris.brezillon@collabora.com
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/include/uapi/drm/panfrost_drm.h b/include/uapi/drm/panfrost_drm.h
index 0c59714ae42b..e194e087a0c8 100644
--- a/include/uapi/drm/panfrost_drm.h
+++ b/include/uapi/drm/panfrost_drm.h
@@ -24,6 +24,7 @@ extern "C" {
 #define DRM_PANFROST_SET_LABEL_BO		0x09
 #define DRM_PANFROST_JM_CTX_CREATE		0x0a
 #define DRM_PANFROST_JM_CTX_DESTROY		0x0b
+#define DRM_PANFROST_SYNC_BO			0x0c
 
 #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)
@@ -35,6 +36,7 @@ extern "C" {
 #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)
+#define DRM_IOCTL_PANFROST_SYNC_BO		DRM_IOWR(DRM_COMMAND_BASE + DRM_PANFROST_SYNC_BO, struct drm_panfrost_sync_bo)
 
 /*
  * Unstable ioctl(s): only exposed when the unsafe unstable_ioctls module
@@ -308,6 +310,49 @@ struct drm_panfrost_set_label_bo {
 	__u64 label;
 };
 
+/* Valid flags to pass to drm_panfrost_bo_sync_op */
+#define PANFROST_BO_SYNC_CPU_CACHE_FLUSH			0
+#define PANFROST_BO_SYNC_CPU_CACHE_FLUSH_AND_INVALIDATE		1
+
+/**
+ * struct drm_panthor_bo_flush_map_op - BO map sync op
+ */
+struct drm_panfrost_bo_sync_op {
+	/** @handle: Handle of the buffer object to sync. */
+	__u32 handle;
+
+	/** @type: Type of sync operation. */
+	__u32 type;
+
+	/**
+	 * @offset: Offset into the BO at which the sync range starts.
+	 *
+	 * This will be rounded down to the nearest cache line as needed.
+	 */
+	__u32 offset;
+
+	/**
+	 * @size: Size of the range to sync
+	 *
+	 * @size + @offset will be rounded up to the nearest cache line as
+	 * needed.
+	 */
+	__u32 size;
+};
+
+/**
+ * struct drm_panfrost_sync_bo - ioctl argument for syncing BO maps
+ */
+struct drm_panfrost_sync_bo {
+	/** Array of struct drm_panfrost_bo_sync_op */
+	__u64 ops;
+
+	/** Number of BO sync ops */
+	__u32 op_count;
+
+	__u32 pad;
+};
+
 /* Definitions for coredump decoding in user space */
 #define PANFROSTDUMP_MAJOR 1
 #define PANFROSTDUMP_MINOR 0