ACPI: Enable MSR (FixedHW) support for T-States

Add throttling control via MSR when T-states uses the FixHW Control Status registers. Signed-off-by: Zhao Yakui <yakui.zhao@intel.com> Signed-off-by: Li Shaohua <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
torvalds · Nov 17, 2007 · f79f06a · f79f06a
1 parent 0ac3c57
commit f79f06a
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Showing 2 changed files with 73 additions and 4 deletions.
diff --git a/arch/x86/kernel/acpi/processor.c b/arch/x86/kernel/acpi/processor.c
@@ -49,6 +49,9 @@ static void init_intel_pdc(struct acpi_processor *pr, struct cpuinfo_x86 *c)
 	if (cpu_has(c, X86_FEATURE_EST))
 		buf[2] |= ACPI_PDC_EST_CAPABILITY_SWSMP;
 
+	if (cpu_has(c, X86_FEATURE_ACPI))
+		buf[2] |= ACPI_PDC_T_FFH;
+
 	obj->type = ACPI_TYPE_BUFFER;
 	obj->buffer.length = 12;
 	obj->buffer.pointer = (u8 *) buf;

diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
@@ -393,6 +393,74 @@ static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 	return 0;
 }
 
+#ifdef CONFIG_X86
+static int acpi_throttling_rdmsr(struct acpi_processor *pr,
+					acpi_integer * value)
+{
+	struct cpuinfo_x86 *c;
+	u64 msr_high, msr_low;
+	unsigned int cpu;
+	u64 msr = 0;
+	int ret = -1;
+
+	cpu = pr->id;
+	c = &cpu_data(cpu);
+
+	if ((c->x86_vendor != X86_VENDOR_INTEL) ||
+		!cpu_has(c, X86_FEATURE_ACPI)) {
+		printk(KERN_ERR PREFIX
+			"HARDWARE addr space,NOT supported yet\n");
+	} else {
+		msr_low = 0;
+		msr_high = 0;
+		rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL,
+			(u32 *)&msr_low , (u32 *) &msr_high);
+		msr = (msr_high << 32) | msr_low;
+		*value = (acpi_integer) msr;
+		ret = 0;
+	}
+	return ret;
+}
+
+static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
+{
+	struct cpuinfo_x86 *c;
+	unsigned int cpu;
+	int ret = -1;
+	u64 msr;
+
+	cpu = pr->id;
+	c = &cpu_data(cpu);
+
+	if ((c->x86_vendor != X86_VENDOR_INTEL) ||
+		!cpu_has(c, X86_FEATURE_ACPI)) {
+		printk(KERN_ERR PREFIX
+			"HARDWARE addr space,NOT supported yet\n");
+	} else {
+		msr = value;
+		wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL,
+			msr & 0xffffffff, msr >> 32);
+		ret = 0;
+	}
+	return ret;
+}
+#else
+static int acpi_throttling_rdmsr(struct acpi_processor *pr,
+				acpi_integer * value)
+{
+	printk(KERN_ERR PREFIX
+		"HARDWARE addr space,NOT supported yet\n");
+	return -1;
+}
+
+static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
+{
+	printk(KERN_ERR PREFIX
+		"HARDWARE addr space,NOT supported yet\n");
+	return -1;
+}
+#endif
+
 static int acpi_read_throttling_status(struct acpi_processor *pr,
 					acpi_integer *value)
 {
@@ -417,8 +485,7 @@ static int acpi_read_throttling_status(struct acpi_processor *pr,
 		ret = 0;
 		break;
 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
-		printk(KERN_ERR PREFIX
-		       "HARDWARE addr space,NOT supported yet\n");
+		ret = acpi_throttling_rdmsr(pr, value);
 		break;
 	default:
 		printk(KERN_ERR PREFIX "Unknown addr space %d\n",
@@ -451,8 +518,7 @@ static int acpi_write_throttling_state(struct acpi_processor *pr,
 		ret = 0;
 		break;
 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
-		printk(KERN_ERR PREFIX
-		       "HARDWARE addr space,NOT supported yet\n");
+		ret = acpi_throttling_wrmsr(pr, value);
 		break;
 	default:
 		printk(KERN_ERR PREFIX "Unknown addr space %d\n",