kernel.git/arch/x86/kernel/cpu/intel.c, branch master

x86/cpufeature: Replace X86_FEATURE_SYSENTER32 with X86_FEATURE_SYSFAST32

2026-01-14T00:37:58Z

In most cases, the use of "fast 32-bit system call" depends either on X86_FEATURE_SEP or X86_FEATURE_SYSENTER32 || X86_FEATURE_SYSCALL32. However, nearly all the logic for both is identical. Define X86_FEATURE_SYSFAST32 which indicates that *either* SYSENTER32 or SYSCALL32 should be used, for either 32- or 64-bit kernels. This defaults to SYSENTER; use SYSCALL if the SYSCALL32 bit is also set. As this removes ALL existing uses of X86_FEATURE_SYSENTER32, which is a kernel-only synthetic feature bit, simply remove it and replace it with X86_FEATURE_SYSFAST32. This leaves an unused alternative for a true 32-bit kernel, but that should really not matter in any way. The clearing of X86_FEATURE_SYSCALL32 can be removed once the patches for automatically clearing disabled features has been merged. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Dave Hansen Link: https://patch.msgid.link/20251216212606.1325678-10-hpa@zytor.com

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

2025-08-25T15:23:37Z

Pentium 4's which are INTEL_P4_PRESCOTT (model 0x03) and later have a constant TSC. This was correctly captured until commit fadb6f569b10 ("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: fadb6f569b10 ("x86/cpu/intel: Limit the non-architectural constant_tsc model checks") Signed-off-by: Suchit Karunakaran Signed-off-by: Dave Hansen Reviewed-by: Sohil Mehta Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20250816065126.5000-1-suchitkarunakaran%40gmail.com

x86/cpu/intel: Rename CPUID(0x2) descriptors iterator parameter

2025-05-16T08:49:55Z

The CPUID(0x2) descriptors iterator has been renamed from: for_each_leaf_0x2_entry() to: for_each_cpuid_0x2_desc() since it iterates over CPUID(0x2) cache and TLB "descriptors", not "entries". In the macro's x86/cpu call-site, rename the parameter denoting the parsed descriptor at each iteration from 'entry' to 'desc'. Signed-off-by: Ahmed S. Darwish Signed-off-by: Ingo Molnar Cc: H. Peter Anvin Cc: Andrew Cooper Cc: John Ogness Cc: x86-cpuid@lists.linux.dev Link: https://lore.kernel.org/r/20250508150240.172915-8-darwi@linutronix.de

x86/cpuid: Rename cpuid_get_leaf_0x2_regs() to cpuid_leaf_0x2()

2025-05-16T08:49:48Z

Rename the CPUID(0x2) register accessor function: cpuid_get_leaf_0x2_regs(regs) to: cpuid_leaf_0x2(regs) for consistency with other accessors that return full CPUID registers outputs like: cpuid_leaf(regs) cpuid_subleaf(regs) In the same vein, rename the CPUID(0x2) iteration macro: for_each_leaf_0x2_entry() to: for_each_cpuid_0x2_desc() to include "cpuid" in the macro name, and since what is iterated upon is CPUID(0x2) cache and TLB "descriptos", not "entries". Prefix an underscore to that iterator macro parameters, so that the newly renamed 'desc' parameter do not get mixed with "union leaf_0x2_regs :: desc[]" in the macro's implementation. Adjust all the affected call-sites accordingly. While at it, use "CPUID(0x2)" instead of "CPUID leaf 0x2" as this is the recommended style. No change in functionality intended. Signed-off-by: Ahmed S. Darwish Signed-off-by: Ingo Molnar Cc: H. Peter Anvin Cc: Andrew Cooper Cc: John Ogness Cc: x86-cpuid@lists.linux.dev Link: https://lore.kernel.org/r/20250508150240.172915-6-darwi@linutronix.de

x86/cpuid: Set as the main CPUID header

2025-05-15T16:23:55Z

The main CPUID header was originally a storefront for the headers: Now that the latter CPUID(0x2) header has been merged into the former, there is no practical difference between and . Migrate all users to the header, in preparation of the removal of . Don't remove just yet, in case some new code in -next started using it. Suggested-by: Ingo Molnar Signed-off-by: Ahmed S. Darwish Signed-off-by: Ingo Molnar Cc: Andrew Cooper Cc: H. Peter Anvin Cc: John Ogness Cc: x86-cpuid@lists.linux.dev Link: https://lore.kernel.org/r/20250508150240.172915-3-darwi@linutronix.de

Merge branch 'x86/msr' into x86/core, to resolve conflicts

2025-05-13T08:42:06Z

Conflicts: arch/x86/boot/startup/sme.c arch/x86/coco/sev/core.c arch/x86/kernel/fpu/core.c arch/x86/kernel/fpu/xstate.c Semantic conflict: arch/x86/include/asm/sev-internal.h Signed-off-by: Ingo Molnar

Merge tag 'v6.15-rc1' into x86/cpu, to refresh the branch with upstream changes

2025-04-11T09:13:27Z

Signed-off-by: Ingo Molnar

x86/msr: Rename 'rdmsrl_safe()' to 'rdmsrq_safe()'

2025-04-10T09:58:38Z

Suggested-by: "H. Peter Anvin" Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra (Intel) Cc: Juergen Gross Cc: Dave Hansen Cc: Xin Li Cc: Linus Torvalds

x86/msr: Rename 'wrmsrl()' to 'wrmsrq()'

2025-04-10T09:58:33Z

Suggested-by: "H. Peter Anvin" Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra (Intel) Cc: Juergen Gross Cc: Dave Hansen Cc: Xin Li Cc: Linus Torvalds

x86/msr: Rename 'rdmsrl()' to 'rdmsrq()'

2025-04-10T09:58:27Z

Suggested-by: "H. Peter Anvin" Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra (Intel) Cc: Juergen Gross Cc: Dave Hansen Cc: Xin Li Cc: Linus Torvalds