1 files changed, 32 insertions, 15 deletions

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 50163fa9034f..98a13db5f4be 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -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;
@@ -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
@@ -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,
 };