[PATCH v2 2/6] drm/xe: Move exponential sleep logic to helper

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

We want to reuse the same increased sleep logic in other places.
To avoid code duplication, move it to the helper.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
---
 drivers/gpu/drm/xe/xe_guc_submit.c |  5 +----
 drivers/gpu/drm/xe/xe_sleep.h      | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
index 4ea14f2794f4..66dffa13553e 100644
--- a/drivers/gpu/drm/xe/xe_guc_submit.c
+++ b/drivers/gpu/drm/xe/xe_guc_submit.c
@@ -1045,10 +1045,7 @@ static int wq_wait_for_space(struct xe_exec_queue *q, u32 wqi_size)
 				return -ENODEV;
 			}
 
-			msleep(sleep_period_ms);
-			sleep_total_ms += sleep_period_ms;
-			if (sleep_period_ms < 64)
-				sleep_period_ms <<= 1;
+			sleep_total_ms += xe_sleep_exponential_ms(&sleep_period_ms, 64);
 			goto try_again;
 		}
 	}
diff --git a/drivers/gpu/drm/xe/xe_sleep.h b/drivers/gpu/drm/xe/xe_sleep.h
index a772f1a37395..2bc3f4c0ee0b 100644
--- a/drivers/gpu/drm/xe/xe_sleep.h
+++ b/drivers/gpu/drm/xe/xe_sleep.h
@@ -33,4 +33,25 @@ static inline void xe_sleep_relaxed_ms(unsigned int delay_ms)
 	usleep_range(min_us, max_us);
 }
 
+/**
+ * xe_sleep_exponential_ms() - Sleep for a exponentially increased time.
+ * @sleep_period_ms: current time in msec to sleep
+ * @max_sleep_ms: maximum time in msec to sleep
+ *
+ * Sleep for the @sleep_period_ms and exponentially increase this time for the
+ * next loop, unless reaching the @max_sleep_ms limit.
+ *
+ * Return: approximate time in msec the task was delayed.
+ */
+static inline unsigned int xe_sleep_exponential_ms(unsigned int *sleep_period_ms,
+						   unsigned int max_sleep_ms)
+{
+	unsigned int delay_ms = *sleep_period_ms;
+	unsigned int next_delay_ms = 2 * delay_ms;
+
+	xe_sleep_relaxed_ms(delay_ms);
+	*sleep_period_ms = min(next_delay_ms, max_sleep_ms);
+	return delay_ms;
+}
+
 #endif
-- 
2.47.1