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From: Finn Callies <fcallies@linux.ibm.com>
To: hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com
Cc: linux-s390@vger.kernel.org, fcallies@linux.ibm.com, freude@linux.ibm.com
Subject: [PATCH v1 1/1] s390/ap: Fix queue depth field length
Date: Thu, 23 Jul 2026 17:00:38 +0200	[thread overview]
Message-ID: <20260723150038.93617-2-fcallies@linux.ibm.com> (raw)
In-Reply-To: <20260723150038.93617-1-fcallies@linux.ibm.com>

The queue depth field is defined as a 5 bit field in the Z architecture
instead of a 4 bit field.

The queue depth (qd) can be in range 0-31 and is reported in bits 59-63
of the TAPQ response. Currently this has no effect as all CEX generations
report a queue depth of 7, which fits into 4 bits. However, future CEX
generations reporting a value >15 would not be properly reflected by the
ap bus and therefore all user space applications relying on it.

Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Finn Callies <fcallies@linux.ibm.com>
---
 arch/s390/include/asm/ap.h   | 4 ++--
 drivers/s390/crypto/ap_bus.h | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/s390/include/asm/ap.h b/arch/s390/include/asm/ap.h
index 3b95c6531a67..c91b6ace199d 100644
--- a/arch/s390/include/asm/ap.h
+++ b/arch/s390/include/asm/ap.h
@@ -125,8 +125,8 @@ struct ap_tapq_hwinfo {
 			unsigned int nd	   :  8; /* nr of domains */
 			unsigned int	   :  4;
 			unsigned int ml	   :  4; /* apxl ml */
-			unsigned int	   :  4;
-			unsigned int qd	   :  4; /* queue depth */
+			unsigned int	   :  3;
+			unsigned int qd	   :  5; /* queue depth */
 		};
 	};
 };
diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index b2e57e5d6c3f..fb4d678336e4 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -181,7 +181,7 @@ struct ap_card {
 	bool chkstop;			/* checkstop state */
 };
 
-#define TAPQ_CARD_HWINFO_MASK 0xFFFF0000FFFF0F0FUL
+#define TAPQ_CARD_HWINFO_MASK 0xFFFF0000FFFF0F1FUL
 #define ASSOC_IDX_INVALID 0x10000
 
 #define to_ap_card(x) container_of((x), struct ap_card, ap_dev.device)
-- 
Finn Callies <fcallies@linux.ibm.com>
Linux on Z - crypto


  reply	other threads:[~2026-07-23 15:00 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-23 15:00 [PATCH v1 0/1] Fix the length of the qd field of the TAPQ response Finn Callies
2026-07-23 15:00 ` Finn Callies [this message]
2026-07-23 15:13   ` [PATCH v1 1/1] s390/ap: Fix queue depth field length sashiko-bot
2026-07-29 11:25 ` [PATCH v1 0/1] Fix the length of the qd field of the TAPQ response Vasily Gorbik

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