4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Len Brown <len.brown@xxxxxxxxx>
commit d9e6dbcf28f383bf08e6a3180972f5722e514a54 upstream.
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@xxxxxxxxx>
Cc: <stable@xxxxxxxxxx> # v4.14+
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Fixes: 616dd5872e ("x86/apic: Update TSC_DEADLINE quirk with additional SKX stepping")
Link: http://lkml.kernel.org/r/d0c7129e509660be9ec6b233284b8d42d90659e8.1532207856.git.len.brown@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/apic/apic.c | 3 +++
1 file changed, 3 insertions(+)
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -580,6 +580,9 @@ static u32 skx_deadline_rev(void)
case 0x04: return 0x02000014;
}
+ if (boot_cpu_data.x86_stepping > 4)
+ return 0;
+
return ~0U;
}
