s390/ap/zcrypt: notify userspace with online, config and mode info

This patch brings 3 reworked/new uevent changes:
* All AP uevents caused by an ap card or queue device now carry an
  additional uevent env value MODE=<accel|cca|ep11>. Here is an
  example:
    KERNEL[1267.301292] add	 /devices/ap/card0a (ap)
    ACTION=add
    DEVPATH=/devices/ap/card0a
    SUBSYSTEM=ap
    DEVTYPE=ap_card
    DEV_TYPE=000D
    MODALIAS=ap:t0D
    MODE=ep11			 <- this is new
    SEQNUM=1095
  This is true for bind, unbind, add, remove, and change uevents
  related to ap card or ap queue devices.
* On a change of the soft online attribute on a zcrypt queue or card
  device a new CHANGE uevent is sent with an env value ONLINE=<0|1>.
  Example uevent:
    KERNEL[613.067531] change	/devices/ap/card09/09.0011 (ap)
    ACTION=change
    DEVPATH=/devices/ap/card09/09.0011
    SUBSYSTEM=ap
    ONLINE=0			<- this is new
    DEVTYPE=ap_queue
    DRIVER=cex4queue
    MODE=cca
    SEQNUM=1070
- On a change of the config state of an zcrypt card device a new
  CHANGE uevent is sent with an env value CONFIG=<0|1>.
  Example uevent:
    KERNEL[876.258680] change	/devices/ap/card09 (ap)
    ACTION=change
    DEVPATH=/devices/ap/card09
    SUBSYSTEM=ap
    CONFIG=0			<- this is new
    DEVTYPE=ap_card
    DRIVER=cex4card
    DEV_TYPE=000D
    MODALIAS=ap:t0D
    MODE=cca
    SEQNUM=1073
  Setting a card config on/off causes the dependent queue devices to
  follow the config state change and thus uevents informing about the
  config state change for the queue devices are also emitted.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

1 files changed, 28 insertions, 2 deletions

diff --git a/drivers/s390/crypto/zcrypt_card.c b/drivers/s390/crypto/zcrypt_card.c
index 09fe6bb8880b..40fd5d37d26a 100644
--- a/drivers/s390/crypto/zcrypt_card.c
+++ b/drivers/s390/crypto/zcrypt_card.c
@@ -64,7 +64,8 @@ static ssize_t online_store(struct device *dev,
 	struct ap_card *ac = to_ap_card(dev);
 	struct zcrypt_card *zc = ac->private;
 	struct zcrypt_queue *zq;
-	int online, id;
+	int online, id, i = 0, maxzqs = 0;
+	struct zcrypt_queue **zq_uelist = NULL;
 
 	if (sscanf(buf, "%d\n", &online) != 1 || online < 0 || online > 1)
 		return -EINVAL;
@@ -77,10 +78,35 @@ static ssize_t online_store(struct device *dev,
 
 	ZCRYPT_DBF(DBF_INFO, "card=%02x online=%d\n", id, online);
 
+	ap_send_online_uevent(&ac->ap_dev, online);
+
 	spin_lock(&zcrypt_list_lock);
+	/*
+	 * As we are in atomic context here, directly sending uevents
+	 * does not work. So collect the zqueues in a dynamic array
+	 * and process them after zcrypt_list_lock release. As we get/put
+	 * the zqueue objects, we make sure they exist after lock release.
+	 */
+	list_for_each_entry(zq, &zc->zqueues, list)
+		maxzqs++;
+	if (maxzqs > 0)
+		zq_uelist = kcalloc(maxzqs + 1, sizeof(zq), GFP_ATOMIC);
 	list_for_each_entry(zq, &zc->zqueues, list)
-		zcrypt_queue_force_online(zq, online);
+		if (zcrypt_queue_force_online(zq, online))
+			if (zq_uelist) {
+				zcrypt_queue_get(zq);
+				zq_uelist[i++] = zq;
+			}
 	spin_unlock(&zcrypt_list_lock);
+	if (zq_uelist) {
+		for (i = 0; zq_uelist[i]; i++) {
+			zq = zq_uelist[i];
+			ap_send_online_uevent(&zq->queue->ap_dev, online);
+			zcrypt_queue_put(zq);
+		}
+		kfree(zq_uelist);
+	}
+
 	return count;
 }