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Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linu…
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…x/kernel/git/tip/tip

Pull x86 cpu updates from Ingo Molnar:
 "Two changes: a suspend/resume quirk and a new CPUID bit definition"

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpufeature: Add feature bit for Intel's Silicon Debug CPUID bit
  x86/cpu: Restore MSR_IA32_ENERGY_PERF_BIAS after resume
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Linus Torvalds committed Sep 1, 2015
2 parents 0c0fee0 + b1c599b commit 6b2282a
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Showing 4 changed files with 52 additions and 15 deletions.
1 change: 1 addition & 0 deletions arch/x86/include/asm/cpufeature.h
Original file line number Diff line number Diff line change
Expand Up @@ -119,6 +119,7 @@
#define X86_FEATURE_TM2 ( 4*32+ 8) /* Thermal Monitor 2 */
#define X86_FEATURE_SSSE3 ( 4*32+ 9) /* Supplemental SSE-3 */
#define X86_FEATURE_CID ( 4*32+10) /* Context ID */
#define X86_FEATURE_SDBG ( 4*32+11) /* Silicon Debug */
#define X86_FEATURE_FMA ( 4*32+12) /* Fused multiply-add */
#define X86_FEATURE_CX16 ( 4*32+13) /* CMPXCHG16B */
#define X86_FEATURE_XTPR ( 4*32+14) /* Send Task Priority Messages */
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18 changes: 18 additions & 0 deletions arch/x86/kernel/cpu/common.c
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@
#include <linux/kgdb.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/syscore_ops.h>

#include <asm/stackprotector.h>
#include <asm/perf_event.h>
Expand Down Expand Up @@ -1488,3 +1489,20 @@ inline bool __static_cpu_has_safe(u16 bit)
return boot_cpu_has(bit);
}
EXPORT_SYMBOL_GPL(__static_cpu_has_safe);

static void bsp_resume(void)
{
if (this_cpu->c_bsp_resume)
this_cpu->c_bsp_resume(&boot_cpu_data);
}

static struct syscore_ops cpu_syscore_ops = {
.resume = bsp_resume,
};

static int __init init_cpu_syscore(void)
{
register_syscore_ops(&cpu_syscore_ops);
return 0;
}
core_initcall(init_cpu_syscore);
1 change: 1 addition & 0 deletions arch/x86/kernel/cpu/cpu.h
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@ struct cpu_dev {
void (*c_init)(struct cpuinfo_x86 *);
void (*c_identify)(struct cpuinfo_x86 *);
void (*c_detect_tlb)(struct cpuinfo_x86 *);
void (*c_bsp_resume)(struct cpuinfo_x86 *);
int c_x86_vendor;
#ifdef CONFIG_X86_32
/* Optional vendor specific routine to obtain the cache size. */
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47 changes: 32 additions & 15 deletions arch/x86/kernel/cpu/intel.c
Original file line number Diff line number Diff line change
Expand Up @@ -371,6 +371,36 @@ static void detect_vmx_virtcap(struct cpuinfo_x86 *c)
}
}

static void init_intel_energy_perf(struct cpuinfo_x86 *c)
{
u64 epb;

/*
* Initialize MSR_IA32_ENERGY_PERF_BIAS if not already initialized.
* (x86_energy_perf_policy(8) is available to change it at run-time.)
*/
if (!cpu_has(c, X86_FEATURE_EPB))
return;

rdmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
if ((epb & 0xF) != ENERGY_PERF_BIAS_PERFORMANCE)
return;

pr_warn_once("ENERGY_PERF_BIAS: Set to 'normal', was 'performance'\n");
pr_warn_once("ENERGY_PERF_BIAS: View and update with x86_energy_perf_policy(8)\n");
epb = (epb & ~0xF) | ENERGY_PERF_BIAS_NORMAL;
wrmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
}

static void intel_bsp_resume(struct cpuinfo_x86 *c)
{
/*
* MSR_IA32_ENERGY_PERF_BIAS is lost across suspend/resume,
* so reinitialize it properly like during bootup:
*/
init_intel_energy_perf(c);
}

static void init_intel(struct cpuinfo_x86 *c)
{
unsigned int l2 = 0;
Expand Down Expand Up @@ -478,21 +508,7 @@ static void init_intel(struct cpuinfo_x86 *c)
if (cpu_has(c, X86_FEATURE_VMX))
detect_vmx_virtcap(c);

/*
* Initialize MSR_IA32_ENERGY_PERF_BIAS if BIOS did not.
* x86_energy_perf_policy(8) is available to change it at run-time
*/
if (cpu_has(c, X86_FEATURE_EPB)) {
u64 epb;

rdmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
if ((epb & 0xF) == ENERGY_PERF_BIAS_PERFORMANCE) {
pr_warn_once("ENERGY_PERF_BIAS: Set to 'normal', was 'performance'\n");
pr_warn_once("ENERGY_PERF_BIAS: View and update with x86_energy_perf_policy(8)\n");
epb = (epb & ~0xF) | ENERGY_PERF_BIAS_NORMAL;
wrmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
}
}
init_intel_energy_perf(c);
}

#ifdef CONFIG_X86_32
Expand Down Expand Up @@ -747,6 +763,7 @@ static const struct cpu_dev intel_cpu_dev = {
.c_detect_tlb = intel_detect_tlb,
.c_early_init = early_init_intel,
.c_init = init_intel,
.c_bsp_resume = intel_bsp_resume,
.c_x86_vendor = X86_VENDOR_INTEL,
};

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