2017-07-14 03:34:39

by Dou Liyang

Subject: [PATCH 1/2] x86/timers: Move the simple udelay calibration to tsc.h

Commit dd759d93f4dd ("x86/timers: Add simple udelay calibration") adds
an static function in x86 boot-time initializations.

But, this function is actually related to TSC, should be maintained
in tsc.c, not in setup.c.

Move simple_udelay_calibration() from setup.c to tsc.c and repalce
its name with tsc_early_delay_calibrate for more readability.

Signed-off-by: Dou Liyang <[email protected]>
---
arch/x86/include/asm/tsc.h | 1 +
arch/x86/kernel/setup.c | 22 +---------------------
arch/x86/kernel/tsc.c | 19 +++++++++++++++++++
3 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
index f5e6f1c..d0509c7 100644
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h
@@ -31,6 +31,7 @@ static inline cycles_t get_cycles(void)

extern struct system_counterval_t convert_art_to_tsc(u64 art);

+extern void tsc_early_delay_calibrate(void);
extern void tsc_init(void);
extern void mark_tsc_unstable(char *reason);
extern int unsynchronized_tsc(void);
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 3486d04..9512d5b 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -812,26 +812,6 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
return 0;
}

-static void __init simple_udelay_calibration(void)
-{
- unsigned int tsc_khz, cpu_khz;
- unsigned long lpj;
-
- if (!boot_cpu_has(X86_FEATURE_TSC))
- return;
-
- cpu_khz = x86_platform.calibrate_cpu();
- tsc_khz = x86_platform.calibrate_tsc();
-
- tsc_khz = tsc_khz ? : cpu_khz;
- if (!tsc_khz)
- return;
-
- lpj = tsc_khz * 1000;
- do_div(lpj, HZ);
- loops_per_jiffy = lpj;
-}
-
/*
* Determine if we were loaded by an EFI loader. If so, then we have also been
* passed the efi memmap, systab, etc., so we should use these data structures
@@ -1039,7 +1019,7 @@ void __init setup_arch(char **cmdline_p)
*/
init_hypervisor_platform();

- simple_udelay_calibration();
+ tsc_early_delay_calibrate();

x86_init.resources.probe_roms();

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 796d96b..c173dce 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -1263,6 +1263,25 @@ static int __init init_tsc_clocksource(void)
*/
device_initcall(init_tsc_clocksource);

+void __init tsc_early_delay_calibrate(void)
+{
+ unsigned long lpj;
+
+ if (!boot_cpu_has(X86_FEATURE_TSC))
+ return;
+
+ cpu_khz = x86_platform.calibrate_cpu();
+ tsc_khz = x86_platform.calibrate_tsc();
+
+ tsc_khz = tsc_khz ? : cpu_khz;
+ if (!tsc_khz)
+ return;
+
+ lpj = tsc_khz * 1000;
+ do_div(lpj, HZ);
+ loops_per_jiffy = lpj;
+}
+
void __init tsc_init(void)
{
u64 lpj, cyc;
--
2.5.5

2017-07-14 03:34:37

by Dou Liyang

Subject: [PATCH 2/2] x86/timers: Make recalibrate_cpu_khz() void

recalibrate_cpu_khz() is called from powernow K7 and Pentium 4/Xeon
CPU freq driver. It recalibrates cpu frequency in case of SMP = n
and doesn't need to return anything.

Mark it void, also remove the #else branch.

Signed-off-by: Dou Liyang <[email protected]>
---
arch/x86/include/asm/timer.h | 2 +-
arch/x86/kernel/tsc.c | 8 ++------
2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/timer.h b/arch/x86/include/asm/timer.h
index 2016962..e90edbe 100644
--- a/arch/x86/include/asm/timer.h
+++ b/arch/x86/include/asm/timer.h
@@ -8,7 +8,7 @@
#define TICK_SIZE (tick_nsec / 1000)

unsigned long long native_sched_clock(void);
-extern int recalibrate_cpu_khz(void);
+extern void recalibrate_cpu_khz(void);

extern int no_timer_check;

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index c173dce..896dbe3 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -812,13 +812,13 @@ unsigned long native_calibrate_cpu(void)
return tsc_pit_min;
}

-int recalibrate_cpu_khz(void)
+void recalibrate_cpu_khz(void)
{
#ifndef CONFIG_SMP
unsigned long cpu_khz_old = cpu_khz;

if (!boot_cpu_has(X86_FEATURE_TSC))
- return -ENODEV;
+ return;

cpu_khz = x86_platform.calibrate_cpu();
tsc_khz = x86_platform.calibrate_tsc();
@@ -828,10 +828,6 @@ int recalibrate_cpu_khz(void)
cpu_khz = tsc_khz;
cpu_data(0).loops_per_jiffy = cpufreq_scale(cpu_data(0).loops_per_jiffy,
cpu_khz_old, cpu_khz);
-
- return 0;
-#else
- return -ENODEV;
#endif
}

--
2.5.5