linux-kernel - [tip:x86/cpu] x86/cpu: Get rid of the show

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Date:   Tue, 25 Oct 2016 03:34:08 -0700
From:   tip-bot for Borislav Petkov <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     bp@...e.de, tglx@...utronix.de, brgerst@...il.com,
        linux-kernel@...r.kernel.org, bp@...en8.de,
        torvalds@...ux-foundation.org, hpa@...or.com, jpoimboe@...hat.com,
        mingo@...nel.org, luto@...nel.org, peterz@...radead.org,
        dvlasenk@...hat.com
Subject: [tip:x86/cpu] x86/cpu: Get rid of the show_msr= boot option

Commit-ID:  59c6f278bdeea4147e8be92a3ed50a9907e60088
Gitweb:     http://git.kernel.org/tip/59c6f278bdeea4147e8be92a3ed50a9907e60088
Author:     Borislav Petkov <bp@...e.de>
AuthorDate: Mon, 24 Oct 2016 19:38:44 +0200
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Tue, 25 Oct 2016 11:48:50 +0200

x86/cpu: Get rid of the show_msr= boot option

It is useless as it dumps the MSRs too early BUT(!) we do set MSRs later too.
Also, it dumps only BSP MSRs as it gets called only for CPU 0.

And the MSR range array would need constant updating anyway, and so on
and so on...

Oh, and we have msr.ko and msr-tools which are the much better solution
anyway. So off it goes...

Signed-off-by: Borislav Petkov <bp@...e.de>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Brian Gerst <brgerst@...il.com>
Cc: Denys Vlasenko <dvlasenk@...hat.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Josh Poimboeuf <jpoimboe@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Link: http://lkml.kernel.org/r/20161024173844.23038-4-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 Documentation/kernel-parameters.txt |  6 -----
 arch/x86/kernel/cpu/common.c        | 53 -------------------------------------
 2 files changed, 59 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 37babf9..b676a05a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3824,12 +3824,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 	shapers=	[NET]
 			Maximal number of shapers.
 
-	show_msr=	[x86] show boot-time MSR settings
-			Format: { <integer> }
-			Show boot-time (BIOS-initialized) MSR settings.
-			The parameter means the number of CPUs to show,
-			for example 1 means boot CPU only.
-
 	simeth=		[IA-64]
 	simscsi=
 
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 9bd910a..2e6719f 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1162,51 +1162,6 @@ void identify_secondary_cpu(struct cpuinfo_x86 *c)
 	mtrr_ap_init();
 }
 
-struct msr_range {
-	unsigned	min;
-	unsigned	max;
-};
-
-static const struct msr_range msr_range_array[] = {
-	{ 0x00000000, 0x00000418},
-	{ 0xc0000000, 0xc000040b},
-	{ 0xc0010000, 0xc0010142},
-	{ 0xc0011000, 0xc001103b},
-};
-
-static void __print_cpu_msr(void)
-{
-	unsigned index_min, index_max;
-	unsigned index;
-	u64 val;
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
-		index_min = msr_range_array[i].min;
-		index_max = msr_range_array[i].max;
-
-		for (index = index_min; index < index_max; index++) {
-			if (rdmsrl_safe(index, &val))
-				continue;
-			pr_info(" MSR%08x: %016llx\n", index, val);
-		}
-	}
-}
-
-static int show_msr;
-
-static __init int setup_show_msr(char *arg)
-{
-	int num;
-
-	get_option(&arg, &num);
-
-	if (num > 0)
-		show_msr = num;
-	return 1;
-}
-__setup("show_msr=", setup_show_msr);
-
 static __init int setup_noclflush(char *arg)
 {
 	setup_clear_cpu_cap(X86_FEATURE_CLFLUSH);
@@ -1240,14 +1195,6 @@ void print_cpu_info(struct cpuinfo_x86 *c)
 		pr_cont(", stepping: 0x%x)\n", c->x86_mask);
 	else
 		pr_cont(")\n");
-
-	print_cpu_msr(c);
-}
-
-void print_cpu_msr(struct cpuinfo_x86 *c)
-{
-	if (c->cpu_index < show_msr)
-		__print_cpu_msr();
 }
 
 static __init int setup_disablecpuid(char *arg)