[RFC PATCH 12/29] drm/xe: Add exec queue post init extension processing

[Matthew Brost <matthew.brost@xxxxxxxxx>]

Add exec queue post init extension processing which is needed for more
complex extensions in which data is returned to the user.

Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
---
 drivers/gpu/drm/xe/xe_exec_queue.c | 48 ++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
index aab9e561153d..f402988b4fc0 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue.c
+++ b/drivers/gpu/drm/xe/xe_exec_queue.c
@@ -33,6 +33,8 @@ enum xe_exec_queue_sched_prop {
 
 static int exec_queue_user_extensions(struct xe_device *xe, struct xe_exec_queue *q,
 				      u64 extensions, int ext_number);
+static int exec_queue_user_extensions_post_init(struct xe_device *xe, struct xe_exec_queue *q,
+						u64 extensions, int ext_number);
 
 static void __xe_exec_queue_free(struct xe_exec_queue *q)
 {
@@ -446,6 +448,10 @@ static const xe_exec_queue_user_extension_fn exec_queue_user_extension_funcs[] =
 	[DRM_XE_EXEC_QUEUE_EXTENSION_SET_PROPERTY] = exec_queue_user_ext_set_property,
 };
 
+static const xe_exec_queue_user_extension_fn exec_queue_user_extension_post_init_funcs[] = {
+	[DRM_XE_EXEC_QUEUE_EXTENSION_SET_PROPERTY] = NULL,
+};
+
 #define MAX_USER_EXTENSIONS	16
 static int exec_queue_user_extensions(struct xe_device *xe, struct xe_exec_queue *q,
 				      u64 extensions, int ext_number)
@@ -480,6 +486,42 @@ static int exec_queue_user_extensions(struct xe_device *xe, struct xe_exec_queue
 	return 0;
 }
 
+static int exec_queue_user_extensions_post_init(struct xe_device *xe, struct xe_exec_queue *q,
+						u64 extensions, int ext_number)
+{
+	u64 __user *address = u64_to_user_ptr(extensions);
+	struct drm_xe_user_extension ext;
+	int err;
+	u32 idx;
+
+	if (XE_IOCTL_DBG(xe, ext_number >= MAX_USER_EXTENSIONS))
+		return -E2BIG;
+
+	err = __copy_from_user(&ext, address, sizeof(ext));
+	if (XE_IOCTL_DBG(xe, err))
+		return -EFAULT;
+
+	if (XE_IOCTL_DBG(xe, ext.pad) ||
+	    XE_IOCTL_DBG(xe, ext.name >=
+			 ARRAY_SIZE(exec_queue_user_extension_post_init_funcs)))
+		return -EINVAL;
+
+	idx = array_index_nospec(ext.name,
+				 ARRAY_SIZE(exec_queue_user_extension_post_init_funcs));
+	if (exec_queue_user_extension_post_init_funcs[idx]) {
+		err = exec_queue_user_extension_post_init_funcs[idx](xe, q, extensions);
+		if (XE_IOCTL_DBG(xe, err))
+			return err;
+	}
+
+	if (ext.next_extension)
+		return exec_queue_user_extensions_post_init(xe, q,
+							    ext.next_extension,
+							    ++ext_number);
+
+	return 0;
+}
+
 static u32 calc_validate_logical_mask(struct xe_device *xe, struct xe_gt *gt,
 				      struct drm_xe_engine_class_instance *eci,
 				      u16 width, u16 num_placements)
@@ -647,6 +689,12 @@ int xe_exec_queue_create_ioctl(struct drm_device *dev, void *data,
 
 	q->xef = xe_file_get(xef);
 
+	if (args->extensions) {
+		err = exec_queue_user_extensions_post_init(xe, q, args->extensions, 0);
+		if (err)
+			goto kill_exec_queue;
+	}
+
 	/* user id alloc must always be last in ioctl to prevent UAF */
 	err = xa_alloc(&xef->exec_queue.xa, &id, q, xa_limit_32b, GFP_KERNEL);
 	if (err)
-- 
2.34.1