linux-kernel - [RFC PATCH v9 14/15] arm64/delay: move some constants out to a separate header

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Message-Id: <20241107190818.522639-15-ankur.a.arora@oracle.com>
Date: Thu,  7 Nov 2024 11:08:17 -0800
From: Ankur Arora <ankur.a.arora@...cle.com>
To: linux-pm@...r.kernel.org, kvm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-arch@...r.kernel.org
Cc: catalin.marinas@....com, will@...nel.org, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com,
        x86@...nel.org, hpa@...or.com, pbonzini@...hat.com,
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        boris.ostrovsky@...cle.com, konrad.wilk@...cle.com
Subject: [RFC PATCH v9 14/15] arm64/delay: move some constants out to a separate header

Moves some constants and functions related to xloops, cycles computation
out to a new header.

No functional change.

Signed-off-by: Ankur Arora <ankur.a.arora@...cle.com>
---
 arch/arm64/include/asm/delay-const.h | 25 +++++++++++++++++++++++++
 arch/arm64/lib/delay.c               | 13 +++----------
 2 files changed, 28 insertions(+), 10 deletions(-)
 create mode 100644 arch/arm64/include/asm/delay-const.h

diff --git a/arch/arm64/include/asm/delay-const.h b/arch/arm64/include/asm/delay-const.h
new file mode 100644
index 000000000000..63fb5fc24a90
--- /dev/null
+++ b/arch/arm64/include/asm/delay-const.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASM_DELAY_CONST_H
+#define _ASM_DELAY_CONST_H
+
+#include <asm/param.h>	/* For HZ */
+
+/* 2**32 / 1000000 (rounded up) */
+#define __usecs_to_xloops_mult	0x10C7UL
+
+/* 2**32 / 1000000000 (rounded up) */
+#define __nsecs_to_xloops_mult	0x5UL
+
+extern unsigned long loops_per_jiffy;
+static inline unsigned long xloops_to_cycles(unsigned long xloops)
+{
+	return (xloops * loops_per_jiffy * HZ) >> 32;
+}
+
+#define USECS_TO_CYCLES(time_usecs) \
+	xloops_to_cycles((time_usecs) * __usecs_to_xloops_mult)
+
+#define NSECS_TO_CYCLES(time_nsecs) \
+	xloops_to_cycles((time_nsecs) * __nsecs_to_xloops_mult)
+
+#endif	/* _ASM_DELAY_CONST_H */
diff --git a/arch/arm64/lib/delay.c b/arch/arm64/lib/delay.c
index cb2062e7e234..511b5597e2a5 100644
--- a/arch/arm64/lib/delay.c
+++ b/arch/arm64/lib/delay.c
@@ -12,17 +12,10 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/timex.h>
+#include <asm/delay-const.h>
 
 #include <clocksource/arm_arch_timer.h>
 
-#define USECS_TO_CYCLES(time_usecs)			\
-	xloops_to_cycles((time_usecs) * 0x10C7UL)
-
-static inline unsigned long xloops_to_cycles(unsigned long xloops)
-{
-	return (xloops * loops_per_jiffy * HZ) >> 32;
-}
-
 void __delay(unsigned long cycles)
 {
 	cycles_t start = get_cycles();
@@ -58,12 +51,12 @@ EXPORT_SYMBOL(__const_udelay);
 
 void __udelay(unsigned long usecs)
 {
-	__const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
+	__const_udelay(usecs * __usecs_to_xloops_mult);
 }
 EXPORT_SYMBOL(__udelay);
 
 void __ndelay(unsigned long nsecs)
 {
-	__const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
+	__const_udelay(nsecs * __nsecs_to_xloops_mult);
 }
 EXPORT_SYMBOL(__ndelay);
-- 
2.43.5