linux-kernel - [PATCH 5.15 642/779] s390/smp: cleanup control register update routines

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Date:   Mon, 15 Aug 2022 20:04:46 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Heiko Carstens <hca@...ux.ibm.com>,
        Alexander Gordeev <agordeev@...ux.ibm.com>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.15 642/779] s390/smp: cleanup control register update routines

From: Alexander Gordeev <agordeev@...ux.ibm.com>

[ Upstream commit 9097fc793f74ef9c677f8c4aed0c24f6f07f0133 ]

Get rid of duplicate code and redundant data.

Reviewed-by: Heiko Carstens <hca@...ux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@...ux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@...ux.ibm.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/s390/include/asm/ctl_reg.h | 16 ++++++++++-----
 arch/s390/kernel/smp.c          | 36 +++++++++++----------------------
 2 files changed, 23 insertions(+), 29 deletions(-)

diff --git a/arch/s390/include/asm/ctl_reg.h b/arch/s390/include/asm/ctl_reg.h
index 04dc65f8901d..80b93c06a2bb 100644
--- a/arch/s390/include/asm/ctl_reg.h
+++ b/arch/s390/include/asm/ctl_reg.h
@@ -72,8 +72,17 @@ static __always_inline void __ctl_clear_bit(unsigned int cr, unsigned int bit)
 	__ctl_load(reg, cr, cr);
 }
 
-void smp_ctl_set_bit(int cr, int bit);
-void smp_ctl_clear_bit(int cr, int bit);
+void smp_ctl_set_clear_bit(int cr, int bit, bool set);
+
+static inline void ctl_set_bit(int cr, int bit)
+{
+	smp_ctl_set_clear_bit(cr, bit, true);
+}
+
+static inline void ctl_clear_bit(int cr, int bit)
+{
+	smp_ctl_set_clear_bit(cr, bit, false);
+}
 
 union ctlreg0 {
 	unsigned long val;
@@ -128,8 +137,5 @@ union ctlreg15 {
 	};
 };
 
-#define ctl_set_bit(cr, bit) smp_ctl_set_bit(cr, bit)
-#define ctl_clear_bit(cr, bit) smp_ctl_clear_bit(cr, bit)
-
 #endif /* __ASSEMBLY__ */
 #endif /* __ASM_CTL_REG_H */
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 982b72ca677c..7bbcb5b8d3f6 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -579,39 +579,27 @@ static void smp_ctl_bit_callback(void *info)
 }
 
 static DEFINE_SPINLOCK(ctl_lock);
-static unsigned long ctlreg;
 
-/*
- * Set a bit in a control register of all cpus
- */
-void smp_ctl_set_bit(int cr, int bit)
+void smp_ctl_set_clear_bit(int cr, int bit, bool set)
 {
-	struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
-
-	spin_lock(&ctl_lock);
-	memcpy_absolute(&ctlreg, &S390_lowcore.cregs_save_area[cr], sizeof(ctlreg));
-	__set_bit(bit, &ctlreg);
-	memcpy_absolute(&S390_lowcore.cregs_save_area[cr], &ctlreg, sizeof(ctlreg));
-	spin_unlock(&ctl_lock);
-	on_each_cpu(smp_ctl_bit_callback, &parms, 1);
-}
-EXPORT_SYMBOL(smp_ctl_set_bit);
-
-/*
- * Clear a bit in a control register of all cpus
- */
-void smp_ctl_clear_bit(int cr, int bit)
-{
-	struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
+	struct ec_creg_mask_parms parms = { .cr = cr, };
+	u64 ctlreg;
 
+	if (set) {
+		parms.orval = 1UL << bit;
+		parms.andval = -1UL;
+	} else {
+		parms.orval = 0;
+		parms.andval = ~(1UL << bit);
+	}
 	spin_lock(&ctl_lock);
 	memcpy_absolute(&ctlreg, &S390_lowcore.cregs_save_area[cr], sizeof(ctlreg));
-	__clear_bit(bit, &ctlreg);
+	ctlreg = (ctlreg & parms.andval) | parms.orval;
 	memcpy_absolute(&S390_lowcore.cregs_save_area[cr], &ctlreg, sizeof(ctlreg));
 	spin_unlock(&ctl_lock);
 	on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 }
-EXPORT_SYMBOL(smp_ctl_clear_bit);
+EXPORT_SYMBOL(smp_ctl_set_clear_bit);
 
 #ifdef CONFIG_CRASH_DUMP
 
-- 
2.35.1