[RFC 8/9] drm/xe/xe_late_bind_fw: Introduce debug fs node to disable late binding

[Badal Nilawar]

Introduce a debug filesystem node to disable late binding fw reload
during the system or runtime resume. This is intended for situations
where the late binding fw needs to be loaded from user mode.

Signed-off-by: Badal Nilawar <badal.nilawar at intel.com>
---
 drivers/gpu/drm/xe/xe_debugfs.c            | 42 ++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_late_bind_fw.c       |  3 ++
 drivers/gpu/drm/xe/xe_late_bind_fw_types.h |  2 ++
 3 files changed, 47 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_debugfs.c b/drivers/gpu/drm/xe/xe_debugfs.c
index d0503959a8ed..7f238a9e1a49 100644
--- a/drivers/gpu/drm/xe/xe_debugfs.c
+++ b/drivers/gpu/drm/xe/xe_debugfs.c
@@ -185,12 +185,51 @@ static ssize_t wedged_mode_set(struct file *f, const char __user *ubuf,
 	return size;
 }
 
+static ssize_t disable_late_binding_show(struct file *f, char __user *ubuf,
+					 size_t size, loff_t *pos)
+{
+	struct xe_device *xe = file_inode(f)->i_private;
+	struct xe_late_bind *late_bind = &xe->late_bind;
+	char buf[32];
+	int len;
+
+	len = scnprintf(buf, sizeof(buf), "%d\n", late_bind->disable);
+
+	return simple_read_from_buffer(ubuf, size, pos, buf, len);
+}
+
+static ssize_t disable_late_binding_set(struct file *f, const char __user *ubuf,
+					size_t size, loff_t *pos)
+{
+	struct xe_device *xe = file_inode(f)->i_private;
+	struct xe_late_bind *late_bind = &xe->late_bind;
+	u32 uval;
+	ssize_t ret;
+
+	ret = kstrtouint_from_user(ubuf, size, sizeof(uval), &uval);
+	if (ret)
+		return ret;
+
+	if (uval > 1)
+		return -EINVAL;
+
+	late_bind->disable = (uval == 1) ? true : false;
+
+	return size;
+}
+
 static const struct file_operations wedged_mode_fops = {
 	.owner = THIS_MODULE,
 	.read = wedged_mode_show,
 	.write = wedged_mode_set,
 };
 
+static const struct file_operations disable_late_binding_fops = {
+	.owner = THIS_MODULE,
+	.read = disable_late_binding_show,
+	.write = disable_late_binding_set,
+};
+
 void xe_debugfs_register(struct xe_device *xe)
 {
 	struct ttm_device *bdev = &xe->ttm;
@@ -211,6 +250,9 @@ void xe_debugfs_register(struct xe_device *xe)
 	debugfs_create_file("wedged_mode", 0600, root, xe,
 			    &wedged_mode_fops);
 
+	debugfs_create_file("disable_late_binding", 0600, root, xe,
+			    &disable_late_binding_fops);
+
 	for (mem_type = XE_PL_VRAM0; mem_type <= XE_PL_VRAM1; ++mem_type) {
 		man = ttm_manager_type(bdev, mem_type);
 
diff --git a/drivers/gpu/drm/xe/xe_late_bind_fw.c b/drivers/gpu/drm/xe/xe_late_bind_fw.c
index 7d2bc959027d..1626cf793b23 100644
--- a/drivers/gpu/drm/xe/xe_late_bind_fw.c
+++ b/drivers/gpu/drm/xe/xe_late_bind_fw.c
@@ -111,6 +111,9 @@ int xe_late_bind_fw_load(struct xe_late_bind *late_bind)
 	if (!late_bind->component_added)
 		return -EINVAL;
 
+	if (late_bind->disable)
+		return 0;
+
 	for (id = 0; id < MAX_ID; id++) {
 		lbfw = &late_bind->late_bind_fw[id];
 		if (lbfw->valid) {
diff --git a/drivers/gpu/drm/xe/xe_late_bind_fw_types.h b/drivers/gpu/drm/xe/xe_late_bind_fw_types.h
index ea11061ce556..ccd482e67f91 100644
--- a/drivers/gpu/drm/xe/xe_late_bind_fw_types.h
+++ b/drivers/gpu/drm/xe/xe_late_bind_fw_types.h
@@ -90,6 +90,8 @@ struct xe_late_bind {
 	/** @late_bind.late_bind_fw: late binding firmwares */
 	struct xe_late_bind_fw late_bind_fw[MAX_ID];
 
+	/** @late_bind.disable to block late binding reload during pm resume flow*/
+	bool disable;
 };
 
 #endif
-- 
2.34.1