ACPI: enable MWAIT for C1 idle

Add MWAIT idle for C1 state instead of halt, on platforms that support
C1 state with MWAIT.

Renames cx->space_id to something more appropriate.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 106a229..4ba3a9a 100644 (file)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -265,7 +265,7 @@ static atomic_t c3_cpu_count;
 /* Common C-state entry for C2, C3, .. */
 static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
 {
-       if (cstate->space_id == ACPI_CSTATE_FFH) {
+       if (cstate->entry_method == ACPI_CSTATE_FFH) {
                /* Call into architectural FFH based C-state */
                acpi_processor_ffh_cstate_enter(cstate);
        } else {
@@ -929,20 +929,20 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
                cx.address = reg->address;
                cx.index = current_count + 1;
 
-               cx.space_id = ACPI_CSTATE_SYSTEMIO;
+               cx.entry_method = ACPI_CSTATE_SYSTEMIO;
                if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
                        if (acpi_processor_ffh_cstate_probe
                                        (pr->id, &cx, reg) == 0) {
-                               cx.space_id = ACPI_CSTATE_FFH;
-                       } else if (cx.type != ACPI_STATE_C1) {
+                               cx.entry_method = ACPI_CSTATE_FFH;
+                       } else if (cx.type == ACPI_STATE_C1) {
                                /*
                                 * C1 is a special case where FIXED_HARDWARE
                                 * can be handled in non-MWAIT way as well.
                                 * In that case, save this _CST entry info.
-                                * That is, we retain space_id of SYSTEM_IO for
-                                * halt based C1.
                                 * Otherwise, ignore this info and continue.
                                 */
+                               cx.entry_method = ACPI_CSTATE_HALT;
+                       } else {
                                continue;
                        }
                }
@@ -1376,12 +1376,16 @@ static inline void acpi_idle_update_bm_rld(struct acpi_processor *pr,
 /**
  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
  * @cx: cstate data
+ *
+ * Caller disables interrupt before call and enables interrupt after return.
  */
 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 {
-       if (cx->space_id == ACPI_CSTATE_FFH) {
+       if (cx->entry_method == ACPI_CSTATE_FFH) {
                /* Call into architectural FFH based C-state */
                acpi_processor_ffh_cstate_enter(cx);
+       } else if (cx->entry_method == ACPI_CSTATE_HALT) {
+               acpi_safe_halt();
        } else {
                int unused;
                /* IO port based C-state */
@@ -1414,7 +1418,7 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
        if (pr->flags.bm_check)
                acpi_idle_update_bm_rld(pr, cx);
 
-       acpi_safe_halt();
+       acpi_idle_do_entry(cx);
 
        local_irq_enable();
        cx->usage++;

diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 6e253b5..f6d7c50 100644 (file)
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -34,6 +34,7 @@
 
 #define ACPI_CSTATE_SYSTEMIO   (0)
 #define ACPI_CSTATE_FFH                (1)
+#define ACPI_CSTATE_HALT       (2)
 
 /* Power Management */
 
@@ -64,7 +65,7 @@ struct acpi_processor_cx {
        u8 valid;
        u8 type;
        u32 address;
-       u8 space_id;
+       u8 entry_method;
        u8 index;
        u32 latency;
        u32 latency_ticks;