linux-kernel - [PATCH V3] s390: Simplify the calculation of variables

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Date:   Thu, 7 Apr 2022 10:16:47 +0800
From:   Haowen Bai <baihaowen@...zu.com>
To:     Heiko Carstens <hca@...ux.ibm.com>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Alexander Gordeev <agordeev@...ux.ibm.com>,
        Christian Borntraeger <borntraeger@...ux.ibm.com>,
        Sven Schnelle <svens@...ux.ibm.com>
CC:     Haowen Bai <baihaowen@...zu.com>, <linux-s390@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: [PATCH V3] s390: Simplify the calculation of variables

Fix the following coccicheck warnings:
./arch/s390/include/asm/scsw.h:695:47-49: WARNING
 !A || A && B is equivalent to !A || B

I apply a readable version just to get rid of a warning.

Signed-off-by: Haowen Bai <baihaowen@...zu.com>
---
V1->V2: apply a readable and simple version as suggestion.
V2->V3: scsw->tm instead of scsw->cmd; fix logic flow as suggestion.

 arch/s390/include/asm/scsw.h | 79 +++++++++++++++++++++++++++++++++++---------
 1 file changed, 64 insertions(+), 15 deletions(-)

diff --git a/arch/s390/include/asm/scsw.h b/arch/s390/include/asm/scsw.h
index a7c3ccf681da..5cb893706d66 100644
--- a/arch/s390/include/asm/scsw.h
+++ b/arch/s390/include/asm/scsw.h
@@ -508,9 +508,21 @@ static inline int scsw_cmd_is_valid_zcc(union scsw *scsw)
  */
 static inline int scsw_cmd_is_valid_ectl(union scsw *scsw)
 {
-	return (scsw->cmd.stctl & SCSW_STCTL_STATUS_PEND) &&
-	       !(scsw->cmd.stctl & SCSW_STCTL_INTER_STATUS) &&
-	       (scsw->cmd.stctl & SCSW_STCTL_ALERT_STATUS);
+	/* Must be status pending. */
+	if (!(scsw->cmd.stctl & SCSW_STCTL_STATUS_PEND))
+		return 0;
+
+	/* Must have alert status. */
+	if (!(scsw->cmd.stctl & SCSW_STCTL_ALERT_STATUS))
+		return 0;
+
+	/* Must be alone or together with primary, secondary or both,
+	 * => no intermediate status.
+	 */
+	if (scsw->cmd.stctl & SCSW_STCTL_INTER_STATUS)
+		return 0;
+
+	return 1;
 }
 
 /**
@@ -522,10 +533,25 @@ static inline int scsw_cmd_is_valid_ectl(union scsw *scsw)
  */
 static inline int scsw_cmd_is_valid_pno(union scsw *scsw)
 {
-	return (scsw->cmd.fctl != 0) &&
-	       (scsw->cmd.stctl & SCSW_STCTL_STATUS_PEND) &&
-	       (!(scsw->cmd.stctl & SCSW_STCTL_INTER_STATUS) ||
-		  (scsw->cmd.actl & SCSW_ACTL_SUSPENDED));
+	/* Must indicate at least one I/O function. */
+	if (!scsw->cmd.fctl)
+		return 0;
+
+	/* Must be status pending. */
+	if (!(scsw->cmd.stctl & SCSW_STCTL_STATUS_PEND))
+		return 0;
+
+	/* Can be status pending alone, or with any combination of primary,
+	 * secondary and alert => no intermediate status.
+	 */
+	if (!(scsw->cmd.stctl & SCSW_STCTL_INTER_STATUS))
+		return 1;
+
+	/* If intermediate, must be suspended. */
+	if (scsw->cmd.actl & SCSW_ACTL_SUSPENDED)
+		return 1;
+
+	return 0;
 }
 
 /**
@@ -675,9 +700,21 @@ static inline int scsw_tm_is_valid_q(union scsw *scsw)
  */
 static inline int scsw_tm_is_valid_ectl(union scsw *scsw)
 {
-	return (scsw->tm.stctl & SCSW_STCTL_STATUS_PEND) &&
-	       !(scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) &&
-	       (scsw->tm.stctl & SCSW_STCTL_ALERT_STATUS);
+	/* Must be status pending. */
+	if (!(scsw->tm.stctl & SCSW_STCTL_STATUS_PEND))
+		return 0;
+
+	/* Must have alert status. */
+	if (!(scsw->tm.stctl & SCSW_STCTL_ALERT_STATUS))
+		return 0;
+
+	/* Must be alone or together with primary, secondary or both,
+	 * => no intermediate status.
+	 */
+	if (scsw->tm.stctl & SCSW_STCTL_INTER_STATUS)
+		return 0;
+
+	return 1;
 }
 
 /**
@@ -689,11 +725,25 @@ static inline int scsw_tm_is_valid_ectl(union scsw *scsw)
  */
 static inline int scsw_tm_is_valid_pno(union scsw *scsw)
 {
-	return (scsw->tm.fctl != 0) &&
-	       (scsw->tm.stctl & SCSW_STCTL_STATUS_PEND) &&
-	       (!(scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) ||
-		 ((scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) &&
-		  (scsw->tm.actl & SCSW_ACTL_SUSPENDED)));
+	/* Must indicate at least one I/O function. */
+	if (!scsw->tm.fctl)
+		return 0;
+
+	/* Must be status pending. */
+	if (!(scsw->tm.stctl & SCSW_STCTL_STATUS_PEND))
+		return 0;
+
+	/* Can be status pending alone, or with any combination of primary,
+	 * secondary and alert => no intermediate status.
+	 */
+	if (!(scsw->tm.stctl & SCSW_STCTL_INTER_STATUS))
+		return 1;
+
+	/* If intermediate, must be suspended. */
+	if (scsw->tm.actl & SCSW_ACTL_SUSPENDED)
+		return 1;
+
+	return 0;
 }
 
 /**
-- 
2.7.4