From: Bin Gao <bin.gao@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, H Peter Anvin <hpa@zytor.com>,
x86@kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, Bin Gao <bin.gao@intel.com>
Subject: [PATCH 2/2] x86: use KNOWN_FREQ and RELIABLE TSC flags on certain processors/SoCs
Date: Tue, 1 Nov 2016 10:14:42 -0700 [thread overview]
Message-ID: <1478020482-231459-3-git-send-email-bin.gao@intel.com> (raw)
In-Reply-To: <1478020482-231459-1-git-send-email-bin.gao@intel.com>
With X86_FEATURE_TSC_RELIABLE is split into X86_FEATURE_TSC_KNOWN_FREQ
and X86_FEATURE_TSC_KNOWN_FREQ, some platforms with reliable and
frequency-known TSC have to be marked with these new flags. These platforms
are Intel processors/SoCs supporting getting TSC frequency by MSR or CPUID.
Signed-off-by: Bin Gao <bin.gao@intel.com>
---
arch/x86/kernel/tsc.c | 9 +++++++++
arch/x86/kernel/tsc_msr.c | 4 ++++
arch/x86/platform/intel-mid/mfld.c | 5 +++--
arch/x86/platform/intel-mid/mrfld.c | 4 ++--
4 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index b4c82f8..4197768 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -702,6 +702,15 @@ unsigned long native_calibrate_tsc(void)
}
}
+ setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
+
+ /*
+ * For Atom SoCs TSC is the only reliable clocksource.
+ * Mark TSC reliable so no watchdog on it.
+ */
+ if (boot_cpu_data.x86_model == INTEL_FAM6_ATOM_GOLDMONT)
+ setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
+
return crystal_khz * ebx_numerator / eax_denominator;
}
diff --git a/arch/x86/kernel/tsc_msr.c b/arch/x86/kernel/tsc_msr.c
index 0fe720d..d6aa75a 100644
--- a/arch/x86/kernel/tsc_msr.c
+++ b/arch/x86/kernel/tsc_msr.c
@@ -100,5 +100,9 @@ unsigned long cpu_khz_from_msr(void)
#ifdef CONFIG_X86_LOCAL_APIC
lapic_timer_frequency = (freq * 1000) / HZ;
#endif
+
+ setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
+ setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
+
return res;
}
diff --git a/arch/x86/platform/intel-mid/mfld.c b/arch/x86/platform/intel-mid/mfld.c
index 1eb47b6..3fa41b4 100644
--- a/arch/x86/platform/intel-mid/mfld.c
+++ b/arch/x86/platform/intel-mid/mfld.c
@@ -49,8 +49,9 @@ static unsigned long __init mfld_calibrate_tsc(void)
fast_calibrate = ratio * fsb;
pr_debug("read penwell tsc %lu khz\n", fast_calibrate);
lapic_timer_frequency = fsb * 1000 / HZ;
- /* mark tsc clocksource as reliable */
- set_cpu_cap(&boot_cpu_data, X86_FEATURE_TSC_RELIABLE);
+
+ setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
+ setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
return fast_calibrate;
}
diff --git a/arch/x86/platform/intel-mid/mrfld.c b/arch/x86/platform/intel-mid/mrfld.c
index 59253db..9477b7e 100644
--- a/arch/x86/platform/intel-mid/mrfld.c
+++ b/arch/x86/platform/intel-mid/mrfld.c
@@ -78,8 +78,8 @@ static unsigned long __init tangier_calibrate_tsc(void)
pr_debug("Setting lapic_timer_frequency = %d\n",
lapic_timer_frequency);
- /* mark tsc clocksource as reliable */
- set_cpu_cap(&boot_cpu_data, X86_FEATURE_TSC_RELIABLE);
+ setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
+ setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
return fast_calibrate;
}
--
1.9.1
next prev parent reply other threads:[~2016-11-01 17:08 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-01 17:14 [PATCH 0/2] x86/tsc: split X86_FEATURE_TSC_RELIABLE into two Bin Gao
2016-11-01 17:14 ` [PATCH 1/2] x86/tsc: add X86_FEATURE_TSC_KNOWN_FREQ flag Bin Gao
2016-11-09 21:09 ` Thomas Gleixner
[not found] ` <4460FA1017EA3844B646E90DA4E984057E2ECB7C@ORSMSX112.amr.corp.intel.com>
2016-11-10 22:51 ` Bin Gao
2016-11-01 17:14 ` Bin Gao [this message]
2016-11-09 21:25 ` [PATCH 2/2] x86: use KNOWN_FREQ and RELIABLE TSC flags on certain processors/SoCs Thomas Gleixner
[not found] ` <4460FA1017EA3844B646E90DA4E984057E2ECB85@ORSMSX112.amr.corp.intel.com>
2016-11-10 23:20 ` Bin Gao
2016-11-10 23:26 ` Thomas Gleixner
2016-11-11 0:06 ` Bin Gao
2016-11-11 0:01 ` Thomas Gleixner
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