Commit 24963ae1 authored by Suchit Karunakaran's avatar Suchit Karunakaran Committed by Dave Hansen
Browse files

x86/cpu/intel: Fix the constant_tsc model check for Pentium 4 



Pentium 4's which are INTEL_P4_PRESCOTT (model 0x03) and later have
a constant TSC. This was correctly captured until commit fadb6f56
("x86/cpu/intel: Limit the non-architectural constant_tsc model checks").

In that commit, an error was introduced while selecting the last P4
model (0x06) as the upper bound. Model 0x06 was transposed to
INTEL_P4_WILLAMETTE, which is just plain wrong. That was presumably a
simple typo, probably just copying and pasting the wrong P4 model.

Fix the constant TSC logic to cover all later P4 models. End at
INTEL_P4_CEDARMILL which accurately corresponds to the last P4 model.

Fixes: fadb6f56 ("x86/cpu/intel: Limit the non-architectural constant_tsc model checks")
Signed-off-by: default avatarSuchit Karunakaran <suchitkarunakaran@gmail.com>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: default avatarSohil Mehta <sohil.mehta@intel.com>
Cc:stable@vger.kernel.org
Link: https://lore.kernel.org/all/20250816065126.5000-1-suchitkarunakaran%40gmail.com
parent 1b237f19

arch/x86/kernel/cpu/intel.c

+1 −1
Original line number Diff line number Diff line
@@ -262,7 +262,7 @@ static void early_init_intel(struct cpuinfo_x86 *c) 
	if (c->x86_power & (1 << 8)) {

		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);

		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);

	} else if ((c->x86_vfm >= INTEL_P4_PRESCOTT && c->x86_vfm <= INTEL_P4_WILLAMETTE) ||

	} else if ((c->x86_vfm >= INTEL_P4_PRESCOTT && c->x86_vfm <= INTEL_P4_CEDARMILL) ||

		   (c->x86_vfm >= INTEL_CORE_YONAH  && c->x86_vfm <= INTEL_IVYBRIDGE)) {

		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);

	}