[tip:x86/cpu] x86, Intel: Convert to the new bit access MSR accessors

From: tip-bot for Borislav Petkov
Date: Thu Mar 13 2014 - 19:19:17 EST


Commit-ID: c0a639ad0bc6b178b46996bd1f821a04643e2bde
Gitweb: http://git.kernel.org/tip/c0a639ad0bc6b178b46996bd1f821a04643e2bde
Author: Borislav Petkov <bp@xxxxxxx>
AuthorDate: Sun, 9 Mar 2014 18:05:25 +0100
Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Thu, 13 Mar 2014 15:35:09 -0700

x86, Intel: Convert to the new bit access MSR accessors

... and save some lines of code.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: http://lkml.kernel.org/r/1394384725-10796-4-git-send-email-bp@xxxxxxxxx
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
arch/x86/include/uapi/asm/msr-index.h | 9 ++++++---
arch/x86/kernel/cpu/intel.c | 30 +++++++-----------------------
2 files changed, 13 insertions(+), 26 deletions(-)

diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h
index c19fc60..045e6db 100644
--- a/arch/x86/include/uapi/asm/msr-index.h
+++ b/arch/x86/include/uapi/asm/msr-index.h
@@ -368,14 +368,16 @@
#define THERM_LOG_THRESHOLD1 (1 << 9)

/* MISC_ENABLE bits: architectural */
-#define MSR_IA32_MISC_ENABLE_FAST_STRING (1ULL << 0)
+#define MSR_BIT_FAST_STRING 0
+#define MSR_IA32_MISC_ENABLE_FAST_STRING (1ULL << MSR_BIT_FAST_STRING)
#define MSR_IA32_MISC_ENABLE_TCC (1ULL << 1)
#define MSR_IA32_MISC_ENABLE_EMON (1ULL << 7)
#define MSR_IA32_MISC_ENABLE_BTS_UNAVAIL (1ULL << 11)
#define MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL (1ULL << 12)
#define MSR_IA32_MISC_ENABLE_ENHANCED_SPEEDSTEP (1ULL << 16)
#define MSR_IA32_MISC_ENABLE_MWAIT (1ULL << 18)
-#define MSR_IA32_MISC_ENABLE_LIMIT_CPUID (1ULL << 22)
+#define MSR_BIT_LIMIT_CPUID 22
+#define MSR_IA32_MISC_ENABLE_LIMIT_CPUID (1ULL << MSR_BIT_LIMIT_CPUID);
#define MSR_IA32_MISC_ENABLE_XTPR_DISABLE (1ULL << 23)
#define MSR_IA32_MISC_ENABLE_XD_DISABLE (1ULL << 34)

@@ -385,7 +387,8 @@
#define MSR_IA32_MISC_ENABLE_SPLIT_LOCK_DISABLE (1ULL << 4)
#define MSR_IA32_MISC_ENABLE_L3CACHE_DISABLE (1ULL << 6)
#define MSR_IA32_MISC_ENABLE_SUPPRESS_LOCK (1ULL << 8)
-#define MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE (1ULL << 9)
+#define MSR_BIT_PRF_DIS 9
+#define MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE (1ULL << MSR_BIT_PRF_DIS)
#define MSR_IA32_MISC_ENABLE_FERR (1ULL << 10)
#define MSR_IA32_MISC_ENABLE_FERR_MULTIPLEX (1ULL << 10)
#define MSR_IA32_MISC_ENABLE_TM2 (1ULL << 13)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 5cd9bfa..44ca631 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -31,11 +31,7 @@ static void early_init_intel(struct cpuinfo_x86 *c)

/* Unmask CPUID levels if masked: */
if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
- rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
-
- if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
- misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
- wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
+ if (msr_clear_bit(MSR_IA32_MISC_ENABLE, MSR_BIT_LIMIT_CPUID) > 0) {
c->cpuid_level = cpuid_eax(0);
get_cpu_cap(c);
}
@@ -129,16 +125,9 @@ static void early_init_intel(struct cpuinfo_x86 *c)
* Ingo Molnar reported a Pentium D (model 6) and a Xeon
* (model 2) with the same problem.
*/
- if (c->x86 == 15) {
- rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
-
- if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) {
- printk(KERN_INFO "kmemcheck: Disabling fast string operations\n");
-
- misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING;
- wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
- }
- }
+ if (c->x86 == 15)
+ if (msr_clear_bit(MSR_IA32_MISC_ENABLE, MSR_BIT_FAST_STRING) > 0)
+ pr_info("kmemcheck: Disabling fast string operations\n");
#endif

/*
@@ -197,8 +186,6 @@ static void intel_smp_check(struct cpuinfo_x86 *c)

static void intel_workarounds(struct cpuinfo_x86 *c)
{
- unsigned long lo, hi;
-
#ifdef CONFIG_X86_F00F_BUG
/*
* All current models of Pentium and Pentium with MMX technology CPUs
@@ -229,12 +216,9 @@ static void intel_workarounds(struct cpuinfo_x86 *c)
* Hardware prefetcher may cause stale data to be loaded into the cache.
*/
if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
- rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
- if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) {
- printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
- printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
- lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
- wrmsr(MSR_IA32_MISC_ENABLE, lo, hi);
+ if (msr_set_bit(MSR_IA32_MISC_ENABLE, MSR_BIT_PRF_DIS) > 0) {
+ pr_info("CPU: C0 stepping P4 Xeon detected.\n");
+ pr_info("CPU: Disabling hardware prefetching (Errata 037)\n");
}
}

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