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-rw-r--r--arch/x86/include/asm/timer.h38
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/x86/include/asm/timer.h b/arch/x86/include/asm/timer.h
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+++ b/arch/x86/include/asm/timer.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_TIMER_H
+#define _ASM_X86_TIMER_H
+#include <linux/pm.h>
+#include <linux/percpu.h>
+#include <linux/interrupt.h>
+#include <linux/math64.h>
+
+#define TICK_SIZE (tick_nsec / 1000)
+
+unsigned long long native_sched_clock(void);
+extern void recalibrate_cpu_khz(void);
+
+extern int no_timer_check;
+
+extern bool using_native_sched_clock(void);
+
+/*
+ * We use the full linear equation: f(x) = a + b*x, in order to allow
+ * a continuous function in the face of dynamic freq changes.
+ *
+ * Continuity means that when our frequency changes our slope (b); we want to
+ * ensure that: f(t) == f'(t), which gives: a + b*t == a' + b'*t.
+ *
+ * Without an offset (a) the above would not be possible.
+ *
+ * See the comment near cycles_2_ns() for details on how we compute (b).
+ */
+struct cyc2ns_data {
+ u32 cyc2ns_mul;
+ u32 cyc2ns_shift;
+ u64 cyc2ns_offset;
+}; /* 16 bytes */
+
+extern void cyc2ns_read_begin(struct cyc2ns_data *);
+extern void cyc2ns_read_end(void);
+
+#endif /* _ASM_X86_TIMER_H */