[PATCH 4.9 67/96] x86/cpu: Factor out application of forced CPU caps

From: Greg Kroah-Hartman
Date: Mon Jan 15 2018 - 07:46:59 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Andy Lutomirski <luto@xxxxxxxxxx>

commit 8bf1ebca215c262e48c15a4a15f175991776f57f upstream.

There are multiple call sites that apply forced CPU caps. Factor
them into a helper.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matthew Whitehead <tedheadster@xxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: One Thousand Gnomes <gnomes@xxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
Link: http://lkml.kernel.org/r/623ff7555488122143e4417de09b18be2085ad06.1484705016.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/kernel/cpu/common.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -706,6 +706,16 @@ void cpu_detect(struct cpuinfo_x86 *c)
}
}

+static void apply_forced_caps(struct cpuinfo_x86 *c)
+{
+ int i;
+
+ for (i = 0; i < NCAPINTS; i++) {
+ c->x86_capability[i] &= ~cpu_caps_cleared[i];
+ c->x86_capability[i] |= cpu_caps_set[i];
+ }
+}
+
void get_cpu_cap(struct cpuinfo_x86 *c)
{
u32 eax, ebx, ecx, edx;
@@ -1086,10 +1096,7 @@ static void identify_cpu(struct cpuinfo_
this_cpu->c_identify(c);

/* Clear/Set all flags overridden by options, after probe */
- for (i = 0; i < NCAPINTS; i++) {
- c->x86_capability[i] &= ~cpu_caps_cleared[i];
- c->x86_capability[i] |= cpu_caps_set[i];
- }
+ apply_forced_caps(c);

#ifdef CONFIG_X86_64
c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
@@ -1151,10 +1158,7 @@ static void identify_cpu(struct cpuinfo_
* Clear/Set all flags overridden by options, need do it
* before following smp all cpus cap AND.
*/
- for (i = 0; i < NCAPINTS; i++) {
- c->x86_capability[i] &= ~cpu_caps_cleared[i];
- c->x86_capability[i] |= cpu_caps_set[i];
- }
+ apply_forced_caps(c);

/*
* On SMP, boot_cpu_data holds the common feature set between