[S390] zcrypt: fix request timeout handling

Under very high load zcrypt requests may timeout while waiting on the
request queue. Modify zcrypt that timeouts are based on crypto adapter
responses. A timeout occurs only if a crypto adapter does not respond
within a given time frame to sumitted requests.

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index 008559ea742b..87c2d6442875 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -33,6 +33,7 @@
 #define AP_DEVICES 64		/* Number of AP devices. */
 #define AP_DOMAINS 16		/* Number of AP domains. */
 #define AP_MAX_RESET 90		/* Maximum number of resets. */
+#define AP_RESET_TIMEOUT (HZ/2)	/* Time in ticks for reset timeouts. */
 #define AP_CONFIG_TIME 30	/* Time in seconds between AP bus rescans. */
 #define AP_POLL_TIME 1		/* Time in ticks between receive polls. */
 
@@ -83,6 +84,13 @@ struct ap_queue_status {
 #define AP_DEVICE_TYPE_CEX2A	6
 #define AP_DEVICE_TYPE_CEX2C	7
 
+/**
+ * AP reset flag states
+ */
+#define AP_RESET_IGNORE	0	/* request timeout will be ignored */
+#define AP_RESET_ARMED	1	/* request timeout timer is active */
+#define AP_RESET_DO	2	/* AP reset required */
+
 struct ap_device;
 struct ap_message;
 
@@ -95,6 +103,7 @@ struct ap_driver {
 	/* receive is called from tasklet context */
 	void (*receive)(struct ap_device *, struct ap_message *,
 			struct ap_message *);
+	int request_timeout;		/* request timeout in jiffies */
 };
 
 #define to_ap_drv(x) container_of((x), struct ap_driver, driver)
@@ -112,6 +121,8 @@ struct ap_device {
 	int queue_depth;		/* AP queue depth.*/
 	int device_type;		/* AP device type. */
 	int unregistered;		/* marks AP device as unregistered */
+	struct timer_list timeout;	/* Timer for request timeouts. */
+	int reset;			/* Reset required after req. timeout. */
 
 	int queue_count;		/* # messages currently on AP queue. */