Subject: ACPI : Add MSR support for T-States
>From : Zhao Yakui <yakui.zhao@xxxxxxxxx>
Add throttling control via MSR when T-states uses the FixHW Control/
Status registers.
Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx>
Signed-off-by: Li Shaohua <shaohua.li@xxxxxxxxx>
---
arch/x86/kernel/acpi/processor.c | 3 +
drivers/acpi/processor_throttling.c | 72 ++++++++++++++++++++++++++++++++++--
2 files changed, 71 insertions(+), 4 deletions(-)
Index: linux-2.6.24-rc1/drivers/acpi/processor_throttling.c
===================================================================
--- linux-2.6.24-rc1.orig/drivers/acpi/processor_throttling.c
+++ linux-2.6.24-rc1/drivers/acpi/processor_throttling.c
@@ -391,6 +391,71 @@ static int acpi_processor_get_throttling
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)
@@ -415,8 +480,7 @@ static int acpi_read_throttling_status(s
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",
@@ -449,8 +513,7 @@ static int acpi_write_throttling_state(s
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",
@@ -504,6 +567,7 @@ static int acpi_processor_get_throttling
pr->throttling.state = 0;
local_irq_disable();
+ value = 0;
ret = acpi_read_throttling_status(pr, &value);
if (ret >= 0) {
state = acpi_get_throttling_state(pr, value);
Index: linux-2.6.24-rc1/arch/x86/kernel/acpi/processor.c
===================================================================
--- linux-2.6.24-rc1.orig/arch/x86/kernel/acpi/processor.c
+++ linux-2.6.24-rc1/arch/x86/kernel/acpi/processor.c
@@ -49,6 +49,9 @@ static void init_intel_pdc(struct acpi_p
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;
-
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