From e01f18c5af543e893bdc70f2273f68ee4a16b18a Mon Sep 17 00:00:00 2001 From: Harald Freudenberger Date: Mon, 19 Jan 2026 10:37:28 +0100 Subject: [PATCH] s390/ap: Fix wrong APQN fill calculation commit 3317785a8803db629efc759d811d0f589d3a0b2d upstream. The upper limit of the firmware queue fill state for each APQN is reported by the hwinfo.qd field. This field shows the numbers 0-7 for 1-8 queue spaces available. But the exploiting code assumed the real boundary is stored there and thus stoppes queuing in messages one tick too early. Correct the limit calculation and thus offer a boost of 12.5% performance for high traffic on one APQN. Fixes: d4c53ae8e4948 ("s390/ap: store TAPQ hwinfo in struct ap_card") Cc: stable@vger.kernel.org Reported-by: Ingo Franzki Reviewed-by: Ingo Franzki Signed-off-by: Harald Freudenberger Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman --- drivers/s390/crypto/ap_card.c | 2 +- drivers/s390/crypto/ap_queue.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/s390/crypto/ap_card.c b/drivers/s390/crypto/ap_card.c index ce953cbbd564..64a7f645eaf4 100644 --- a/drivers/s390/crypto/ap_card.c +++ b/drivers/s390/crypto/ap_card.c @@ -44,7 +44,7 @@ static ssize_t depth_show(struct device *dev, struct device_attribute *attr, { struct ap_card *ac = to_ap_card(dev); - return sysfs_emit(buf, "%d\n", ac->hwinfo.qd); + return sysfs_emit(buf, "%d\n", ac->hwinfo.qd + 1); } static DEVICE_ATTR_RO(depth); diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c index 9a0e6e4d8a5e..eed40770f679 100644 --- a/drivers/s390/crypto/ap_queue.c +++ b/drivers/s390/crypto/ap_queue.c @@ -268,7 +268,7 @@ static enum ap_sm_wait ap_sm_write(struct ap_queue *aq) list_move_tail(&ap_msg->list, &aq->pendingq); aq->requestq_count--; aq->pendingq_count++; - if (aq->queue_count < aq->card->hwinfo.qd) { + if (aq->queue_count < aq->card->hwinfo.qd + 1) { aq->sm_state = AP_SM_STATE_WORKING; return AP_SM_WAIT_AGAIN; }