From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/include/linux/sched_clock.h | 33 +++++++++++++++++++++++++++++----
1 files changed, 29 insertions(+), 4 deletions(-)
diff --git a/kernel/include/linux/sched_clock.h b/kernel/include/linux/sched_clock.h
index abe28d5..528718e 100644
--- a/kernel/include/linux/sched_clock.h
+++ b/kernel/include/linux/sched_clock.h
@@ -1,14 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
/*
* sched_clock.h: support for extending counters to full 64-bit ns counter
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
*/
#ifndef LINUX_SCHED_CLOCK
#define LINUX_SCHED_CLOCK
#ifdef CONFIG_GENERIC_SCHED_CLOCK
+/**
+ * struct clock_read_data - data required to read from sched_clock()
+ *
+ * @epoch_ns: sched_clock() value at last update
+ * @epoch_cyc: Clock cycle value at last update.
+ * @sched_clock_mask: Bitmask for two's complement subtraction of non 64bit
+ * clocks.
+ * @read_sched_clock: Current clock source (or dummy source when suspended).
+ * @mult: Multipler for scaled math conversion.
+ * @shift: Shift value for scaled math conversion.
+ *
+ * Care must be taken when updating this structure; it is read by
+ * some very hot code paths. It occupies <=40 bytes and, when combined
+ * with the seqcount used to synchronize access, comfortably fits into
+ * a 64 byte cache line.
+ */
+struct clock_read_data {
+ u64 epoch_ns;
+ u64 epoch_cyc;
+ u64 sched_clock_mask;
+ u64 (*read_sched_clock)(void);
+ u32 mult;
+ u32 shift;
+};
+
+extern struct clock_read_data *sched_clock_read_begin(unsigned int *seq);
+extern int sched_clock_read_retry(unsigned int seq);
+
extern void generic_sched_clock_init(void);
extern void sched_clock_register(u64 (*read)(void), int bits,
--
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