From: Andy Lutomirski <luto@kernel.org>
To: X86 ML <x86@kernel.org>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
Borislav Petkov <bp@alien8.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Brian Gerst <brgerst@gmail.com>,
Matthew Whitehead <tedheadster@gmail.com>,
Borislav Petkov <bp@suse.de>, Andy Lutomirski <luto@kernel.org>
Subject: [PATCH v2 1/6] x86/cpu: Add X86_FEATURE_CPUID
Date: Wed, 18 Jan 2017 11:15:37 -0800 [thread overview]
Message-ID: <dcb355adae3ab812c79397056a61c212f1a0c7cc.1484705016.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1484705016.git.luto@kernel.org>
In-Reply-To: <cover.1484705016.git.luto@kernel.org>
From: Borislav Petkov <bp@suse.de>
Add a synthetic CPUID flag denoting whether the CPU sports the CPUID
instruction or not. This will come useful later when accomodating
CPUID-less CPUs.
Signed-off-by: Borislav Petkov <bp@suse.de>
[slightly prettified by Andy]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/include/asm/cpufeatures.h | 2 +-
arch/x86/kernel/cpu/common.c | 7 ++++---
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 6ccbf1aaa7ce..5108c46e97c4 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -100,7 +100,7 @@
#define X86_FEATURE_XTOPOLOGY ( 3*32+22) /* cpu topology enum extensions */
#define X86_FEATURE_TSC_RELIABLE ( 3*32+23) /* TSC is known to be reliable */
#define X86_FEATURE_NONSTOP_TSC ( 3*32+24) /* TSC does not stop in C states */
-/* free, was #define X86_FEATURE_CLFLUSH_MONITOR ( 3*32+25) * "" clflush reqd with monitor */
+#define X86_FEATURE_CPUID ( 3*32+25) /* CPU has CPUID instruction itself */
#define X86_FEATURE_EXTD_APICID ( 3*32+26) /* has extended APICID (8 bits) */
#define X86_FEATURE_AMD_DCM ( 3*32+27) /* multi-node processor */
#define X86_FEATURE_APERFMPERF ( 3*32+28) /* APERFMPERF */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 1f6b50a449ab..8f06f7ea4262 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -800,14 +800,12 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
memset(&c->x86_capability, 0, sizeof c->x86_capability);
c->extended_cpuid_level = 0;
- if (!have_cpuid_p())
- identify_cpu_without_cpuid(c);
-
/* cyrix could have cpuid enabled via c_identify()*/
if (have_cpuid_p()) {
cpu_detect(c);
get_cpu_vendor(c);
get_cpu_cap(c);
+ setup_force_cpu_cap(X86_FEATURE_CPUID);
if (this_cpu->c_early_init)
this_cpu->c_early_init(c);
@@ -817,6 +815,9 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
if (this_cpu->c_bsp_init)
this_cpu->c_bsp_init(c);
+ } else {
+ identify_cpu_without_cpuid(c);
+ setup_clear_cpu_cap(X86_FEATURE_CPUID);
}
setup_force_cpu_cap(X86_FEATURE_ALWAYS);
--
2.9.3
next prev parent reply other threads:[~2017-01-18 19:16 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-18 19:15 [PATCH v2 0/6] CPUID and FPU fixes Andy Lutomirski
2017-01-18 19:15 ` Andy Lutomirski [this message]
2017-01-25 11:40 ` [tip:x86/fpu] x86/cpu: Add X86_FEATURE_CPUID tip-bot for Borislav Petkov
2017-01-18 19:15 ` [PATCH v2 2/6] x86/cpu: Factor out application of forced cpu caps Andy Lutomirski
2017-01-25 11:40 ` [tip:x86/fpu] x86/cpu: Factor out application of forced CPU caps tip-bot for Andy Lutomirski
2017-01-18 19:15 ` [PATCH v2 3/6] x86/cpu: Re-apply forced caps every time cpu caps are re-read Andy Lutomirski
2017-01-19 11:23 ` Borislav Petkov
2017-01-25 11:41 ` [tip:x86/fpu] x86/cpu: Re-apply forced caps every time CPU " tip-bot for Andy Lutomirski
2017-01-18 19:15 ` [PATCH v2 4/6] x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message Andy Lutomirski
2017-01-25 11:42 ` [tip:x86/fpu] " tip-bot for Andy Lutomirski
2017-01-18 19:15 ` [PATCH v2 5/6] x86/fpu: Fix CPUID-less FPU detection Andy Lutomirski
2017-01-19 11:23 ` Borislav Petkov
2017-01-25 11:42 ` [tip:x86/fpu] " tip-bot for Andy Lutomirski
2017-01-18 19:15 ` [PATCH v2 6/6] x86/fpu: Fix the "Giving up, no FPU found" test Andy Lutomirski
2017-01-25 11:43 ` [tip:x86/fpu] " tip-bot for Andy Lutomirski
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