[PATCH 3.16 03/76] x86/cpu: Factor out application of forced CPU caps

From: Ben Hutchings <ben@decadent.org.uk>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: akpm@linux-foundation.org,
	"Linus Torvalds" <torvalds@linux-foundation.org>,
	"Borislav Petkov" <bp@suse.de>, "H. Peter Anvin" <hpa@zytor.com>,
	"Fenghua Yu" <fenghua.yu@intel.com>,
	"Matthew Whitehead" <tedheadster@gmail.com>,
	"Yu-cheng Yu" <yu-cheng.yu@intel.com>,
	"Andy Lutomirski" <luto@kernel.org>,
	"Oleg Nesterov" <oleg@redhat.com>,
	"Peter Zijlstra" <peterz@infradead.org>,
	"One Thousand Gnomes" <gnomes@lxorguk.ukuu.org.uk>,
	"Dave Hansen" <dave.hansen@linux.intel.com>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Borislav Petkov" <bp@alien8.de>,
	"Ingo Molnar" <mingo@kernel.org>,
	"Rik van Riel" <riel@redhat.com>,
	"Brian Gerst" <brgerst@gmail.com>
Subject: [PATCH 3.16 03/76] x86/cpu: Factor out application of forced CPU caps
Date: Mon, 12 Mar 2018 03:06:12 +0000	[thread overview]
Message-ID: <lsq.1520823972.130287871@decadent.org.uk> (raw)
In-Reply-To: <lsq.1520823971.5976735@decadent.org.uk>

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

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

From: Andy Lutomirski <luto@kernel.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@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Whitehead <tedheadster@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/623ff7555488122143e4417de09b18be2085ad06.1484705016.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.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
@@ -670,6 +670,16 @@ 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 tfms, xlvl;
@@ -915,10 +925,7 @@ static void identify_cpu(struct cpuinfo_
 		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);
@@ -978,10 +985,7 @@ static void identify_cpu(struct cpuinfo_
 	 * 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
