[RFC 04/20] drm/xe: Convert xe_pm_runtime_{get, put} to void and protect from recursion

[Rodrigo Vivi]

With mem_access will go away and pm_runtime calls will be called instead.
So, we need to protect these against recursions.

For D3cold, the TTM migration helpers will call for the job execution.
Jobs execution will be protected by direct runtime_pm calls, but they
cannot be called again if we are already at a runtime suspend/resume
transaction when evicting/restoring memory for D3Cold. So, we will check
for the xe_pm_read_callback_task.

The put is asynchronous so there's no need to block it. However, for a
proper balance, we need to ensure that the references are taken and
restored regardless of the flow. So, let's convert them all to void and
use some direct linux/pm_runtime functions.

Cases that need to check for the references or runtime status will
be handled separate from these main get and put functions here.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/xe/xe_pm.c | 19 +++++++++----------
 drivers/gpu/drm/xe/xe_pm.h |  4 ++--
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
index 32db9068ac169..bd5ca41e19c5e 100644
--- a/drivers/gpu/drm/xe/xe_pm.c
+++ b/drivers/gpu/drm/xe/xe_pm.c
@@ -366,26 +366,25 @@ int xe_pm_runtime_resume(struct xe_device *xe)
 /**
  * xe_pm_runtime_get - Get a runtime_pm reference and resume synchronously
  * @xe: xe device instance
- *
- * Returns: Any number grater than or equal to 0 for success, negative error
- * code otherwise.
  */
-int xe_pm_runtime_get(struct xe_device *xe)
+void xe_pm_runtime_get(struct xe_device *xe)
 {
-	return pm_runtime_get_sync(xe->drm.dev);
+	pm_runtime_get_noresume(xe->drm.dev);
+
+	if (xe_pm_read_callback_task(xe) == current)
+                return;
+
+	pm_runtime_resume(xe->drm.dev);
 }
 
 /**
  * xe_pm_runtime_put - Put the runtime_pm reference back and mark as idle
  * @xe: xe device instance
- *
- * Returns: Any number grater than or equal to 0 for success, negative error
- * code otherwise.
  */
-int xe_pm_runtime_put(struct xe_device *xe)
+void xe_pm_runtime_put(struct xe_device *xe)
 {
 	pm_runtime_mark_last_busy(xe->drm.dev);
-	return pm_runtime_put(xe->drm.dev);
+	pm_runtime_put(xe->drm.dev);
 }
 
 /**
diff --git a/drivers/gpu/drm/xe/xe_pm.h b/drivers/gpu/drm/xe/xe_pm.h
index b812281635673..069f41c61505b 100644
--- a/drivers/gpu/drm/xe/xe_pm.h
+++ b/drivers/gpu/drm/xe/xe_pm.h
@@ -24,8 +24,8 @@ void xe_pm_init(struct xe_device *xe);
 void xe_pm_runtime_fini(struct xe_device *xe);
 int xe_pm_runtime_suspend(struct xe_device *xe);
 int xe_pm_runtime_resume(struct xe_device *xe);
-int xe_pm_runtime_get(struct xe_device *xe);
-int xe_pm_runtime_put(struct xe_device *xe);
+void xe_pm_runtime_get(struct xe_device *xe);
+void xe_pm_runtime_put(struct xe_device *xe);
 int xe_pm_runtime_get_if_active(struct xe_device *xe);
 bool xe_pm_runtime_get_if_in_use(struct xe_device *xe);
 bool xe_pm_runtime_resume_and_get(struct xe_device *xe);
-- 
2.43.0