s390/zcrypt: Enable request count reset for cards and queues.

This patch introduces the possibility to reset the
request_count attribute for cards and queues to zero.
This can be used to set a clear state on the counters before
running an application and try out if and which hardware is
actually used. If the request_count counter of a card is
reset, for all associated queues the request_count is also
zeroed. If just a queue request_count is reset the card
counter is not updated however.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 17 insertions, 4 deletions

diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index 7be67fa9f224..480c58a63769 100644
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -459,9 +459,9 @@ EXPORT_SYMBOL(ap_queue_resume);
 /*
  * AP queue related attributes.
  */
-static ssize_t ap_request_count_show(struct device *dev,
-				     struct device_attribute *attr,
-				     char *buf)
+static ssize_t ap_req_count_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
 {
 	struct ap_queue *aq = to_ap_queue(dev);
 	unsigned int req_cnt;
@@ -472,7 +472,20 @@ static ssize_t ap_request_count_show(struct device *dev,
 	return snprintf(buf, PAGE_SIZE, "%d\n", req_cnt);
 }
 
-static DEVICE_ATTR(request_count, 0444, ap_request_count_show, NULL);
+static ssize_t ap_req_count_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct ap_queue *aq = to_ap_queue(dev);
+
+	spin_lock_bh(&aq->lock);
+	aq->total_request_count = 0;
+	spin_unlock_bh(&aq->lock);
+
+	return count;
+}
+
+static DEVICE_ATTR(request_count, 0644, ap_req_count_show, ap_req_count_store);
 
 static ssize_t ap_requestq_count_show(struct device *dev,
 				      struct device_attribute *attr, char *buf)