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>

1 files changed, 12 insertions, 8 deletions

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 106a22948aa9..4ba3a9a473dd 100644
--- 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++;