[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. */