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authorLinus Torvalds <torvalds@linux-foundation.org>2017-11-14 04:07:38 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-14 04:07:38 +0100
commit99306dfc067e6098365d395168b6fd5db3095292 (patch)
treef3da80eba0c633da69bcad47df565f06ff075947 /arch/x86/kernel/tsc.c
parentMerge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kern... (diff)
parentx86/tsc: Mark cyc2ns_init() and detect_art() __init (diff)
downloadlinux-99306dfc067e6098365d395168b6fd5db3095292.tar.xz
linux-99306dfc067e6098365d395168b6fd5db3095292.zip
Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 timer updates from Thomas Gleixner: "These updates are related to TSC handling: - Support platforms which have synchronized TSCs but the boot CPU has a non zero TSC_ADJUST value, which is considered a firmware bug on normal systems. This applies to HPE/SGI UV platforms where the platform firmware uses TSC_ADJUST to ensure TSC synchronization across a huge number of sockets, but due to power on timings the boot CPU cannot be guaranteed to have a zero TSC_ADJUST register value. - Fix the ordering of udelay calibration and kvmclock_init() - Cleanup the udelay and calibration code" * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/tsc: Mark cyc2ns_init() and detect_art() __init x86/platform/UV: Mark tsc_check_sync as an init function x86/tsc: Make CONFIG_X86_TSC=n build work again x86/platform/UV: Add check of TSC state set by UV BIOS x86/tsc: Provide a means to disable TSC ART x86/tsc: Drastically reduce the number of firmware bug warnings x86/tsc: Skip TSC test and error messages if already unstable x86/tsc: Add option that TSC on Socket 0 being non-zero is valid x86/timers: Move simple_udelay_calibration() past kvmclock_init() x86/timers: Make recalibrate_cpu_khz() void x86/timers: Move the simple udelay calibration to tsc.h
Diffstat (limited to 'arch/x86/kernel/tsc.c')
-rw-r--r--arch/x86/kernel/tsc.c39
1 files changed, 29 insertions, 10 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index ad2b925a808e..8ea117f8142e 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -112,7 +112,7 @@ static void cyc2ns_data_init(struct cyc2ns_data *data)
data->cyc2ns_offset = 0;
}
-static void cyc2ns_init(int cpu)
+static void __init cyc2ns_init(int cpu)
{
struct cyc2ns *c2n = &per_cpu(cyc2ns, cpu);
@@ -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
}
@@ -959,17 +955,21 @@ core_initcall(cpufreq_register_tsc_scaling);
/*
* If ART is present detect the numerator:denominator to convert to TSC
*/
-static void detect_art(void)
+static void __init detect_art(void)
{
unsigned int unused[2];
if (boot_cpu_data.cpuid_level < ART_CPUID_LEAF)
return;
- /* Don't enable ART in a VM, non-stop TSC and TSC_ADJUST required */
+ /*
+ * Don't enable ART in a VM, non-stop TSC and TSC_ADJUST required,
+ * and the TSC counter resets must not occur asynchronously.
+ */
if (boot_cpu_has(X86_FEATURE_HYPERVISOR) ||
!boot_cpu_has(X86_FEATURE_NONSTOP_TSC) ||
- !boot_cpu_has(X86_FEATURE_TSC_ADJUST))
+ !boot_cpu_has(X86_FEATURE_TSC_ADJUST) ||
+ tsc_async_resets)
return;
cpuid(ART_CPUID_LEAF, &art_to_tsc_denominator,
@@ -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;