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* [PATCH 1/1] x86/apic: Future-proof TSC_DEADLINE quirk for SKX
@ 2018-07-21 21:19 Len Brown
  2018-07-24 15:02 ` [tip:x86/urgent] x86/apic: Future-proof the " tip-bot for Len Brown
  0 siblings, 1 reply; 2+ messages in thread
From: Len Brown @ 2018-07-21 21:19 UTC (permalink / raw)
  To: x86; +Cc: peterz, linux-kernel, Len Brown

From: Len Brown <len.brown@intel.com>

All SKX with stepping higher than 4 support the TSC_DEADLINE,
no matter the microcode version.

Fixes: 616dd5872e ("x86/apic: Update TSC_DEADLINE quirk with additional SKX stepping")

Signed-off-by: Len Brown <len.brown@intel.com>
---
Without this patch, upcoming SKX steppings will not be able to use
their TSC_DEADLINE timer.

 arch/x86/kernel/apic/apic.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index b203af0855b5..5caf8890fbe4 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -573,6 +573,9 @@ static u32 skx_deadline_rev(void)
 	case 0x04: return 0x02000014;
 	}
 
+	if (boot_cpu_data.x86_stepping > 4)
+		return 0;
+
 	return ~0U;
 }
 
-- 
2.18.0-rc0


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* [tip:x86/urgent] x86/apic: Future-proof the TSC_DEADLINE quirk for SKX
  2018-07-21 21:19 [PATCH 1/1] x86/apic: Future-proof TSC_DEADLINE quirk for SKX Len Brown
@ 2018-07-24 15:02 ` tip-bot for Len Brown
  0 siblings, 0 replies; 2+ messages in thread
From: tip-bot for Len Brown @ 2018-07-24 15:02 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: tglx, mingo, torvalds, hpa, linux-kernel, peterz, len.brown

Commit-ID:  d9e6dbcf28f383bf08e6a3180972f5722e514a54
Gitweb:     https://git.kernel.org/tip/d9e6dbcf28f383bf08e6a3180972f5722e514a54
Author:     Len Brown <len.brown@intel.com>
AuthorDate: Sat, 21 Jul 2018 17:19:19 -0400
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 24 Jul 2018 10:05:13 +0200

x86/apic: Future-proof the TSC_DEADLINE quirk for SKX

All SKX with stepping higher than 4 support the TSC_DEADLINE,
no matter the microcode version.

Without this patch, upcoming SKX steppings will not be able to use
their TSC_DEADLINE timer.

Signed-off-by: Len Brown <len.brown@intel.com>
Cc: <stable@kernel.org> # v4.14+
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 616dd5872e ("x86/apic: Update TSC_DEADLINE quirk with additional SKX stepping")
Link: http://lkml.kernel.org/r/d0c7129e509660be9ec6b233284b8d42d90659e8.1532207856.git.len.brown@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/apic/apic.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 2aabd4cb0e3f..adbda5847b14 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -573,6 +573,9 @@ static u32 skx_deadline_rev(void)
 	case 0x04: return 0x02000014;
 	}
 
+	if (boot_cpu_data.x86_stepping > 4)
+		return 0;
+
 	return ~0U;
 }
 

^ permalink raw reply related	[flat|nested] 2+ messages in thread

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