[PATCH v1 0/1] Fix the length of the qd field of the TAPQ response

[PATCH v1 0/1] Fix the length of the qd field of the TAPQ response

[Finn Callies]

====== CHANGELOG ======

v1:
    - initial version
    - review from Harald

Finn Callies (1):
  s390/ap: Fix queue depth field length

 arch/s390/include/asm/ap.h   | 4 ++--
 drivers/s390/crypto/ap_bus.h | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

-- 
Finn Callies <fcallies@linux.ibm.com>
Linux on Z - crypto

[PATCH v1 1/1] s390/ap: Fix queue depth field length

[Finn Callies]

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

Re: [PATCH v1 1/1] s390/ap: Fix queue depth field length

[sashiko-bot]

> 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>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260723150038.93617-2-fcallies@linux.ibm.com?part=1

Re: [PATCH v1 0/1] Fix the length of the qd field of the TAPQ response

[Vasily Gorbik]

On Thu, Jul 23, 2026 at 05:00:37PM +0200, Finn Callies wrote:
> ====== CHANGELOG ======
> 
> v1:
>     - initial version
>     - review from Harald
> 
> Finn Callies (1):
>   s390/ap: Fix queue depth field length
> 
>  arch/s390/include/asm/ap.h   | 4 ++--
>  drivers/s390/crypto/ap_bus.h | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)

Applied, thank you!