[PATCH v2 02/23] drm/xe: Modify xe_force_wake_put to handle _get returned mask

[Himal Prasad Ghimiray]

Instead of calling xe_force_wake_put on all domains that were input to
xe_force_wake_get, call _put only on the domains whose reference counts
were successfully incremented by the _get call. Since the return value
of _get can be a mask that does not match any specific value in the enum
xe_force_wake_domains, change the input parameter of _put to int.

Add kernel-doc for the xe_force_wake_put()

Cc: Badal Nilawar <badal.nilawar at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Cc: Nirmoy Das <nirmoy.das at intel.com>
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
---
 drivers/gpu/drm/xe/xe_force_wake.c | 24 ++++++++++++++++++++++--
 drivers/gpu/drm/xe/xe_force_wake.h |  2 +-
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_force_wake.c b/drivers/gpu/drm/xe/xe_force_wake.c
index fa42d652d23f..e91bbcbddb8b 100644
--- a/drivers/gpu/drm/xe/xe_force_wake.c
+++ b/drivers/gpu/drm/xe/xe_force_wake.c
@@ -198,8 +198,21 @@ int xe_force_wake_get(struct xe_force_wake *fw,
 	return ret;
 }
 
+/**
+ * xe_force_wake_put - Decrement the refcount and put domain to sleep if refcount becomes 0
+ * @fw: Pointer to the force wake structure
+ * @domains_mask: forcewake domain mask to put reference
+ *
+ * This function reduces the reference counts for specified domain mask. If
+ * refcount for any of the specified domain reaches 0, it puts the domain to sleep
+ * and waits for acknowledgment for domain to sleep within specified timeout.
+ * Ensure this function is always called with return of xe_force_wake_get() as
+ * @domains_mask.
+ *
+ * Returns 0 in case of success or non-zero in case of timeout of ack
+ */
 int xe_force_wake_put(struct xe_force_wake *fw,
-		      enum xe_force_wake_domains domains)
+		      int domains_mask)
 {
 	struct xe_gt *gt = fw->gt;
 	struct xe_force_wake_domain *domain;
@@ -207,8 +220,15 @@ int xe_force_wake_put(struct xe_force_wake *fw,
 	unsigned long flags;
 	int ret = 0;
 
+	/*
+	 * Avoid unnecessary lock and unlock when the function is called
+	 * in error path of individual domains.
+	 */
+	if (!domains_mask)
+		return 0;
+
 	spin_lock_irqsave(&fw->lock, flags);
-	for_each_fw_domain_masked(domain, domains, fw, tmp) {
+	for_each_fw_domain_masked(domain, domains_mask, fw, tmp) {
 		if (!--domain->ref) {
 			sleep |= BIT(domain->id);
 			domain_sleep(gt, domain);
diff --git a/drivers/gpu/drm/xe/xe_force_wake.h b/drivers/gpu/drm/xe/xe_force_wake.h
index a2577672f4e3..e2bb6b03e495 100644
--- a/drivers/gpu/drm/xe/xe_force_wake.h
+++ b/drivers/gpu/drm/xe/xe_force_wake.h
@@ -18,7 +18,7 @@ void xe_force_wake_init_engines(struct xe_gt *gt,
 int xe_force_wake_get(struct xe_force_wake *fw,
 		      enum xe_force_wake_domains domains);
 int xe_force_wake_put(struct xe_force_wake *fw,
-		      enum xe_force_wake_domains domains);
+		      int domains_mask);
 
 static inline int
 xe_force_wake_ref(struct xe_force_wake *fw,
-- 
2.34.1