[PATCH v15 10/26] x86/CPU: Call detect_nopl() only on the BSP

From: Pavel Tatashin
Date: Thu Jul 19 2018 - 16:57:32 EST


From: Borislav Petkov <bp@xxxxxxxxx>

Make it use the setup_* variants and have it be called only on the BSP
and drop the call in generic_identify() - X86_FEATURE_NOPL will be
replicated to the APs through the forced caps. Helps keep the mess at a
manageable level.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
---
arch/x86/kernel/cpu/common.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 71281ac43b15..46408a8cdf62 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1024,12 +1024,12 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
* unless we can find a reliable way to detect all the broken cases.
* Enable it explicitly on 64-bit for non-constant inputs of cpu_has().
*/
-static void detect_nopl(struct cpuinfo_x86 *c)
+static void detect_nopl(void)
{
#ifdef CONFIG_X86_32
- clear_cpu_cap(c, X86_FEATURE_NOPL);
+ setup_clear_cpu_cap(X86_FEATURE_NOPL);
#else
- set_cpu_cap(c, X86_FEATURE_NOPL);
+ setup_force_cpu_cap(X86_FEATURE_NOPL);
#endif
}

@@ -1108,7 +1108,7 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
if (!pgtable_l5_enabled())
setup_clear_cpu_cap(X86_FEATURE_LA57);

- detect_nopl(c);
+ detect_nopl();
}

void __init early_cpu_init(void)
@@ -1206,8 +1206,6 @@ static void generic_identify(struct cpuinfo_x86 *c)

get_model_name(c); /* Default name */

- detect_nopl(c);
-
detect_null_seg_behavior(c);

/*
--
2.18.0