CPUIDLE: Support C1 FFH entry

Add support for C1 FFH (mwait) entry. Meanwhile add timing for C1. The
timing for C1 should be accurate for FFH case, but may not for halt case.

Signed-off-by: Wei Gang <gang.wei@intel.com>

diff --git a/xen/arch/x86/acpi/cpu_idle.c b/xen/arch/x86/acpi/cpu_idle.c
index eda2d9b21a2e7f108479a8782cceb3ecb0f27d5d..95f8bd4f8fd70c5d3aab11720e30d1c8cfec9402 100644 (file)
--- a/xen/arch/x86/acpi/cpu_idle.c
+++ b/xen/arch/x86/acpi/cpu_idle.c
@@ -140,20 +140,26 @@ static void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx *cx)
 
 static void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 {
-    if ( cx->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE )
+    int unused;
+
+    switch ( cx->entry_method )
     {
+    case ACPI_CSTATE_EM_FFH:
         /* Call into architectural FFH based C-state */
         acpi_processor_ffh_cstate_enter(cx);
-    }
-    else
-    {
-        int unused;
+        return;
+    case ACPI_CSTATE_EM_SYSIO:
         /* IO port based C-state */
         inb(cx->address);
         /* Dummy wait op - must do something useless after P_LVL2 read
            because chipsets cannot guarantee that STPCLK# signal
            gets asserted in time to freeze execution properly. */
         unused = inl(pmtmr_ioport);
+        return;
+    case ACPI_CSTATE_EM_HALT:
+        acpi_safe_halt();
+        local_irq_disable();
+        return;
     }
 }
 
@@ -253,35 +259,11 @@ static void acpi_processor_idle(void)
     switch ( cx->type )
     {
     case ACPI_STATE_C1:
-        /* Trace cpu idle entry */
-        TRACE_1D(TRC_PM_IDLE_ENTRY, 1);
-
-        /*
-         * Invoke C1.
-         * Use the appropriate idle routine, the one that would
-         * be used without acpi C-states.
-         */
-        if ( pm_idle_save )
-            pm_idle_save();
-        else 
-            acpi_safe_halt();
-
-        /* Trace cpu idle exit */
-        TRACE_1D(TRC_PM_IDLE_EXIT, 1);
-
-        /*
-         * TBD: Can't get time duration while in C1, as resumes
-         *      go to an ISR rather than here.  Need to instrument
-         *      base interrupt handler.
-         */
-        sleep_ticks = 0xFFFFFFFF;
-        break;
-
     case ACPI_STATE_C2:
-        if ( local_apic_timer_c2_ok )
+        if ( cx->type == ACPI_STATE_C1 || local_apic_timer_c2_ok )
         {
             /* Trace cpu idle entry */
-            TRACE_1D(TRC_PM_IDLE_ENTRY, 2);
+            TRACE_1D(TRC_PM_IDLE_ENTRY, cx->idx);
             /* Get start time (ticks) */
             t1 = inl(pmtmr_ioport);
             /* Invoke C2 */
@@ -289,7 +271,7 @@ static void acpi_processor_idle(void)
             /* Get end time (ticks) */
             t2 = inl(pmtmr_ioport);
             /* Trace cpu idle exit */
-            TRACE_1D(TRC_PM_IDLE_EXIT, 2);
+            TRACE_1D(TRC_PM_IDLE_EXIT, cx->idx);
 
             /* Re-enable interrupts */
             local_irq_enable();
@@ -396,6 +378,7 @@ static int init_cx_pminfo(struct acpi_processor_power *acpi_power)
         acpi_power->states[i].idx = i;
 
     acpi_power->states[ACPI_STATE_C1].type = ACPI_STATE_C1;
+    acpi_power->states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_EM_HALT;
 
     acpi_power->states[ACPI_STATE_C0].valid = 1;
     acpi_power->states[ACPI_STATE_C1].valid = 1;
@@ -492,16 +475,13 @@ static int check_cx(struct acpi_processor_power *power, xen_processor_cx_t *cx)
         break;
 
     case ACPI_ADR_SPACE_FIXED_HARDWARE:
-        if ( cx->type > ACPI_STATE_C1 )
-        {
-            if ( cx->reg.bit_width != VENDOR_INTEL || 
-                 cx->reg.bit_offset != NATIVE_CSTATE_BEYOND_HALT )
-                return -EINVAL;
+        if ( cx->reg.bit_width != VENDOR_INTEL || 
+             cx->reg.bit_offset != NATIVE_CSTATE_BEYOND_HALT )
+            return -EINVAL;
 
-            /* assume all logical cpu has the same support for mwait */
-            if ( acpi_processor_ffh_cstate_probe(cx) )
-                return -EINVAL;
-        }
+        /* assume all logical cpu has the same support for mwait */
+        if ( acpi_processor_ffh_cstate_probe(cx) )
+            return -EINVAL;
         break;
 
     default:
@@ -605,7 +585,23 @@ static void set_cx(
     cx->valid    = 1;
     cx->type     = xen_cx->type;
     cx->address  = xen_cx->reg.address;
-    cx->space_id = xen_cx->reg.space_id;
+
+    switch ( xen_cx->reg.space_id )
+    {
+    case ACPI_ADR_SPACE_FIXED_HARDWARE:
+        if ( xen_cx->reg.bit_width == VENDOR_INTEL &&
+             xen_cx->reg.bit_offset == NATIVE_CSTATE_BEYOND_HALT )
+            cx->entry_method = ACPI_CSTATE_EM_FFH;
+        else
+            cx->entry_method = ACPI_CSTATE_EM_HALT;
+        break;
+    case ACPI_ADR_SPACE_SYSTEM_IO:
+        cx->entry_method = ACPI_CSTATE_EM_SYSIO;
+        break;
+    default:
+        cx->entry_method = ACPI_CSTATE_EM_NONE;
+    }
+
     cx->latency  = xen_cx->latency;
     cx->power    = xen_cx->power;
     

diff --git a/xen/arch/x86/acpi/cpuidle_menu.c b/xen/arch/x86/acpi/cpuidle_menu.c
index 621d1bdae1584d06fa5daaa87792d8f7365fda93..683dc3bb16aa6af40357a09a85612391dccf8fa7 100644 (file)
--- a/xen/arch/x86/acpi/cpuidle_menu.c
+++ b/xen/arch/x86/acpi/cpuidle_menu.c
@@ -59,7 +59,7 @@ static int menu_select(struct acpi_processor_power *power)
     data->expected_us = (u32) get_sleep_length_ns() / 1000;
 
     /* find the deepest idle state that satisfies our constraints */
-    for ( i = 1; i < power->count; i++ )
+    for ( i = 2; i < power->count; i++ )
     {
         struct acpi_processor_cx *s = &power->states[i];
 
@@ -81,17 +81,7 @@ static void menu_reflect(struct acpi_processor_power *power)
     unsigned int last_residency; 
     unsigned int measured_us;
 
-    /*
-     * Ugh, this idle state doesn't support residency measurements, so we
-     * are basically lost in the dark.  As a compromise, assume we slept
-     * for one full standard timer tick.  However, be aware that this
-     * could potentially result in a suboptimal state transition.
-     */
-    if ( target->type == ACPI_STATE_C1 )
-        last_residency = USEC_PER_SEC / HZ;
-    else
-        last_residency = power->last_residency;
-
+    last_residency = power->last_residency;
     measured_us = last_residency + data->elapsed_us;
 
     /* if wrapping, set to max uint (-1) */

diff --git a/xen/include/xen/cpuidle.h b/xen/include/xen/cpuidle.h
index ccfae6c4d3624ae6be76b84f512330d47c57c105..559db769dcd234244a968d3fd11cbf39905330b7 100644 (file)
--- a/xen/include/xen/cpuidle.h
+++ b/xen/include/xen/cpuidle.h
@@ -30,13 +30,18 @@
 #define ACPI_PROCESSOR_MAX_POWER        8
 #define CPUIDLE_NAME_LEN                16
 
+#define ACPI_CSTATE_EM_NONE     0
+#define ACPI_CSTATE_EM_SYSIO    1
+#define ACPI_CSTATE_EM_FFH      2
+#define ACPI_CSTATE_EM_HALT     3
+
 struct acpi_processor_cx
 {
     u8 idx;
     u8 valid;
     u8 type;
     u32 address;
-    u8 space_id;
+    u8 entry_method; /* ACPI_CSTATE_EM_xxx */
     u32 latency;
     u32 latency_ticks;
     u32 power;