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authorHarald Freudenberger <freude@linux.ibm.com>2018-11-26 15:50:04 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2018-12-13 10:42:26 +0100
commit42a87d4103ae365e18c3be1333592ab583b8ad9d (patch)
tree0ee25e594ab56b2345bc811393e65f9e18f7a0db /drivers/s390
parent98dfd32620e970eb576ebce5ea39d905cb005e72 (diff)
s390/zcrypt: make sysfs reset attribute trigger queue reset
Until now there is no way to reset a AP queue or card. Driving a card or queue offline and online again does only toggle the 'software' online state. The only way to trigger a (hardware) reset is by running hot-unplug/hot-plug for example on the HMC. This patch makes the queue reset attribute in sysfs writable. Writing into this attribute triggers a reset on the AP queue's state machine. So the AP queue is flushed and state machine runs through the initial states which cause a reset (PQAP(RAPQ)) and a re-registration to interrupts (PQAP(AQIC)) if available. The reset sysfs attribute is writable by root only. So only an administrator is allowed to initiate a reset of AP queues. Please note that the queue's counter values are left untouched by the reset. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/crypto/ap_queue.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index 0aa4b3ccc948..576ac08777c5 100644
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -14,6 +14,9 @@
#include <asm/facility.h>
#include "ap_bus.h"
+#include "ap_debug.h"
+
+static void __ap_flush_queue(struct ap_queue *aq);
/**
* ap_queue_enable_interruption(): Enable interruption on an AP queue.
@@ -541,7 +544,25 @@ static ssize_t reset_show(struct device *dev,
return rc;
}
-static DEVICE_ATTR_RO(reset);
+static ssize_t reset_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);
+ __ap_flush_queue(aq);
+ aq->state = AP_STATE_RESET_START;
+ ap_wait(ap_sm_event(aq, AP_EVENT_POLL));
+ spin_unlock_bh(&aq->lock);
+
+ AP_DBF(DBF_INFO, "reset queue=%02x.%04x triggered by user\n",
+ AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(reset);
static ssize_t interrupt_show(struct device *dev,
struct device_attribute *attr, char *buf)