From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:54250 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727356AbfKVFty (ORCPT ); Fri, 22 Nov 2019 00:49:54 -0500 From: Sasha Levin Subject: [PATCH AUTOSEL 4.19 041/219] s390/zcrypt: make sysfs reset attribute trigger queue reset Date: Fri, 22 Nov 2019 00:46:13 -0500 Message-Id: <20191122054911.1750-34-sashal@kernel.org> In-Reply-To: <20191122054911.1750-1-sashal@kernel.org> References: <20191122054911.1750-1-sashal@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Harald Freudenberger , Martin Schwidefsky , Sasha Levin , linux-s390@vger.kernel.org From: Harald Freudenberger [ Upstream commit 42a87d4103ae365e18c3be1333592ab583b8ad9d ] 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 Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin --- drivers/s390/crypto/ap_queue.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c index 0aa4b3ccc948c..576ac08777c50 100644 --- a/drivers/s390/crypto/ap_queue.c +++ b/drivers/s390/crypto/ap_queue.c @@ -14,6 +14,9 @@ #include #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) -- 2.20.1