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>

2 files changed, 73 insertions, 4 deletions

diff --git a/arch/x86/kernel/acpi/processor.c b/arch/x86/kernel/acpi/processor.c
index f63e5ff0aca1..a25db514c719 100644
--- 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
index f4b5f7d5dbe6..c26c61fb36c3 100644
--- 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",