linux-kernel - [PATCH 3/3] x86/CPU: Get rid of show

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Date:   Mon, 24 Oct 2016 19:38:44 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     X86 ML <x86@...nel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH 3/3] x86/CPU: Get rid of show_msr

From: Borislav Petkov <bp@...e.de>

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>
---
 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 459b301137c2..73de01eb92b6 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3818,12 +3818,6 @@ 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 1a1d668263b9..f3e7ab29c162 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)
-- 
2.10.0