Thread (34 messages) 34 messages, 6 authors, 2026-01-20
STALE171d REVIEWED: 1 (0M)
Revisions (5)
  1. v8 current
  2. v9 [diff vs current]
  3. v10 [diff vs current]
  4. v11 [diff vs current]
  5. v12 [diff vs current]

[PATCH v8 03/12] arm64/delay: move some constants out to a separate header

From: Ankur Arora <hidden>
Date: 2025-12-15 04:55:02
Also in: bpf, linux-arch, linux-pm, lkml
Subsystem: arm/qualcomm mailing list, arm/qualcomm support, arm64 port (aarch64 architecture), the rest · Maintainers: Bjorn Andersson, Konrad Dybcio, Catalin Marinas, Will Deacon, Linus Torvalds

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

No functional change.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Konrad Dybcio <konradybcio@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Ankur Arora <redacted>
Reviewed-by: Christoph Lameter <redacted>
---
 arch/arm64/include/asm/delay-const.h | 25 +++++++++++++++++++++++++
 arch/arm64/lib/delay.c               | 13 +++----------
 drivers/soc/qcom/rpmh-rsc.c          |  9 +--------
 3 files changed, 29 insertions(+), 18 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);
diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index c6f7d5c9c493..95962fc37295 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -26,6 +26,7 @@
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/wait.h>
+#include <asm/delay-const.h>
 
 #include <clocksource/arm_arch_timer.h>
 #include <soc/qcom/cmd-db.h>
@@ -146,14 +147,6 @@ enum {
  *  +---------------------------------------------------+
  */
 
-#define USECS_TO_CYCLES(time_usecs)			\
-	xloops_to_cycles((time_usecs) * 0x10C7UL)
-
-static inline unsigned long xloops_to_cycles(u64 xloops)
-{
-	return (xloops * loops_per_jiffy * HZ) >> 32;
-}
-
 static u32 rpmh_rsc_reg_offset_ver_2_7[] = {
 	[RSC_DRV_TCS_OFFSET]		= 672,
 	[RSC_DRV_CMD_OFFSET]		= 20,
-- 
2.31.1

Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help