linux-kernel - [PATCH 3.2 039/104] x86/cpu: Factor out application of forced CPU caps

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Date:   Mon, 12 Mar 2018 03:03:34 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, "Rik van Riel" <riel@...hat.com>,
        "Matthew Whitehead" <tedheadster@...il.com>,
        "Ingo Molnar" <mingo@...nel.org>,
        "One Thousand Gnomes" <gnomes@...rguk.ukuu.org.uk>,
        "Peter Zijlstra" <peterz@...radead.org>,
        "Brian Gerst" <brgerst@...il.com>,
        "Andy Lutomirski" <luto@...nel.org>,
        "Linus Torvalds" <torvalds@...ux-foundation.org>,
        "Fenghua Yu" <fenghua.yu@...el.com>,
        "Dave Hansen" <dave.hansen@...ux.intel.com>,
        "Borislav Petkov" <bp@...en8.de>, "H. Peter Anvin" <hpa@...or.com>,
        "Borislav Petkov" <bp@...e.de>, "Oleg Nesterov" <oleg@...hat.com>,
        "Yu-cheng Yu" <yu-cheng.yu@...el.com>,
        "Thomas Gleixner" <tglx@...utronix.de>
Subject: [PATCH 3.2 039/104] x86/cpu: Factor out application of forced CPU
 caps

3.2.101-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Andy Lutomirski <luto@...nel.org>

commit 8bf1ebca215c262e48c15a4a15f175991776f57f upstream.

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

Signed-off-by: Andy Lutomirski <luto@...nel.org>
Reviewed-by: Borislav Petkov <bp@...e.de>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Brian Gerst <brgerst@...il.com>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Fenghua Yu <fenghua.yu@...el.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Matthew Whitehead <tedheadster@...il.com>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: One Thousand Gnomes <gnomes@...rguk.ukuu.org.uk>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Rik van Riel <riel@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@...el.com>
Link: http://lkml.kernel.org/r/623ff7555488122143e4417de09b18be2085ad06.1484705016.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 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
@@ -632,6 +632,16 @@ void __cpuinit cpu_detect(struct cpuinfo
 	}
 }
 
+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 __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
 {
 	u32 tfms, xlvl;
@@ -880,10 +890,7 @@ static void __cpuinit identify_cpu(struc
 		this_cpu->c_identify(c);
 
 	/* Clear/Set all flags overriden 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);
@@ -939,10 +946,7 @@ static void __cpuinit identify_cpu(struc
 	 * Clear/Set all flags overriden 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