[Xen-devel] [PATCH 1/2] cpuidle: initialize default Cstate information

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

cpuidle: initialize default Cstate information

C0/C1 should be always available when cpuidle is enabled in Xen.
When there's case that Dom0 doesn't register ACPI Cstate information,
e.g. due to BIOS issue or acpi processor module  is not installed, 
this patch provides basic C0/C1 information available to xenpm tool.

Signed-off-by Kevin Tian <kevin.tian@xxxxxxxxx>

diff -r 33717472f37e xen/arch/x86/acpi/cpu_idle.c
--- a/xen/arch/x86/acpi/cpu_idle.c      Tue Jun 28 18:15:44 2011 +0100
+++ b/xen/arch/x86/acpi/cpu_idle.c      Tue Jul 05 14:36:04 2011 +0800
@@ -53,6 +53,8 @@
 #include <public/sysctl.h>
 #include <acpi/cpufreq/cpufreq.h>
 #include <asm/apic.h>
+#include <xen/notifier.h>
+#include <xen/cpu.h>
 
 /*#define DEBUG_PM_CX*/
 
@@ -592,23 +594,51 @@ default_halt:
         halt();
 }
 
-static int init_cx_pminfo(struct acpi_processor_power *acpi_power)
+static int cpuidle_init_cpu(int cpu)
 {
-    int i;
+    struct acpi_processor_power *acpi_power;
 
-    memset(acpi_power, 0, sizeof(*acpi_power));
+    acpi_power = processor_powers[cpu];
+    if ( !acpi_power )
+    {
+        int i;
+        acpi_power = xmalloc(struct acpi_processor_power);
+        if ( !acpi_power )
+            return -ENOMEM;
+        memset(acpi_power, 0, sizeof(*acpi_power));
 
-    for ( i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++ )
-        acpi_power->states[i].idx = i;
+        for ( i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++ )
+            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;
+     
+        acpi_power->count = 2;
+        acpi_power->safe_state = &acpi_power->states[ACPI_STATE_C1];
+        acpi_power->cpu = cpu;
+        processor_powers[cpu] = acpi_power;
+    }
 
-    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;
-
-    acpi_power->count = 2;
-    acpi_power->safe_state = &acpi_power->states[ACPI_STATE_C1];
+    if ( cpu == 0 )
+    {
+        if ( boot_cpu_has(X86_FEATURE_NONSTOP_TSC) )
+        {
+            get_tick = get_stime_tick;
+            ticks_elapsed = stime_ticks_elapsed;
+            tick_to_ns = stime_tick_to_ns;
+            ns_to_tick = ns_to_stime_tick;
+        }
+        else
+        {
+            get_tick = get_acpi_pm_tick;
+            ticks_elapsed = acpi_pm_ticks_elapsed;
+            tick_to_ns = acpi_pm_tick_to_ns;
+            ns_to_tick = ns_to_acpi_pm_tick;
+        }
+    }
 
     return 0;
 }
@@ -938,7 +968,7 @@ long set_cx_pminfo(uint32_t cpu, struct 
     XEN_GUEST_HANDLE(xen_processor_cx_t) states;
     xen_processor_cx_t xen_cx;
     struct acpi_processor_power *acpi_power;
-    int cpu_id, i;
+    int cpu_id, i, ret;
 
     if ( unlikely(!guest_handle_okay(power->states, power->count)) )
         return -EFAULT;
@@ -950,46 +980,19 @@ long set_cx_pminfo(uint32_t cpu, struct 
     if ( cpu_id == -1 )
     {
         printk(XENLOG_ERR "no cpu_id for acpi_id %d\n", cpu);
-        return -EFAULT;
+        return -EINVAL;
     }
 
-    if ( cpu_id == 0 )
-    {
-        if ( boot_cpu_has(X86_FEATURE_NONSTOP_TSC) )
-        {
-            get_tick = get_stime_tick;
-            ticks_elapsed = stime_ticks_elapsed;
-            tick_to_ns = stime_tick_to_ns;
-            ns_to_tick = ns_to_stime_tick;
-        }
-        else
-        {
-            get_tick = get_acpi_pm_tick;
-            ticks_elapsed = acpi_pm_ticks_elapsed;
-            tick_to_ns = acpi_pm_tick_to_ns;
-            ns_to_tick = ns_to_acpi_pm_tick;
-        }
-    }
-        
+    ret = cpuidle_init_cpu(cpu_id);
+    if ( ret < 0 )
+        return ret;
+
     acpi_power = processor_powers[cpu_id];
-    if ( !acpi_power )
-    {
-        acpi_power = xmalloc(struct acpi_processor_power);
-        if ( !acpi_power )
-            return -ENOMEM;
-        memset(acpi_power, 0, sizeof(*acpi_power));
-        processor_powers[cpu_id] = acpi_power;
-    }
-
-    init_cx_pminfo(acpi_power);
-
-    acpi_power->cpu = cpu_id;
     acpi_power->flags.bm_check = power->flags.bm_check;
     acpi_power->flags.bm_control = power->flags.bm_control;
     acpi_power->flags.has_cst = power->flags.has_cst;
 
     states = power->states;
-
     for ( i = 0; i < power->count; i++ )
     {
         if ( unlikely(copy_from_guest_offset(&xen_cx, states, i, 1)) )
@@ -1004,19 +1007,17 @@ long set_cx_pminfo(uint32_t cpu, struct 
 
     /* FIXME: C-state dependency is not supported by far */
 
-    /*print_acpi_power(cpu_id, acpi_power);*/
-
-    if ( cpu_id == 0 && pm_idle_save == NULL )
-    {
-        pm_idle_save = pm_idle;
-        pm_idle = acpi_processor_idle;
-    }
-
     if ( cpu_id == 0 )
     {
+        if ( pm_idle_save == NULL )
+        {
+            pm_idle_save = pm_idle;
+            pm_idle = acpi_processor_idle;
+        }
+
         dead_idle = acpi_dead_idle;
     }
-        
+ 
     return 0;
 }
 
@@ -1027,7 +1028,7 @@ uint32_t pmstat_get_cx_nr(uint32_t cpuid
 
 int pmstat_get_cx_stat(uint32_t cpuid, struct pm_cx_stat *stat)
 {
-    const struct acpi_processor_power *power = processor_powers[cpuid];
+    struct acpi_processor_power *power = processor_powers[cpuid];
     uint64_t usage, res, idle_usage = 0, idle_res = 0;
     int i;
     struct hw_residencies hw_res = {0};
@@ -1044,6 +1045,30 @@ int pmstat_get_cx_stat(uint32_t cpuid, s
     stat->nr = power->count;
     stat->idle_time = get_cpu_idle_time(cpuid);
 
+    /* mimic the stat when detail info hasn't been registered by dom0 */
+    if ( pm_idle_save == NULL )
+    {
+        /* C1 */
+        usage = 1;
+        res = stat->idle_time;
+        if ( copy_to_guest_offset(stat->triggers, 1, &usage, 1) ||
+             copy_to_guest_offset(stat->residencies, 1, &res, 1) )
+            return -EFAULT;
+
+        /* C0 */
+        res = NOW() - res;
+        if ( copy_to_guest_offset(stat->triggers, 0, &usage, 1) ||
+             copy_to_guest_offset(stat->residencies, 0, &res, 1) )
+            return -EFAULT;
+
+        stat->pc3 = 0;
+        stat->pc6 = 0;
+        stat->pc7 = 0;
+        stat->cc3 = 0;
+        stat->cc6 = 0;
+        return 0;
+    }
+
     for ( i = power->count - 1; i >= 0; i-- )
     {
         if ( i != 0 )
@@ -1098,3 +1123,36 @@ bool_t cpuidle_using_deep_cstate(void)
 {
     return xen_cpuidle && max_cstate > (local_apic_timer_c2_ok ? 2 : 1);
 }
+
+static int cpu_callback(
+    struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+    unsigned int cpu = (unsigned long)hcpu;
+
+    /* Only hook on CPU_ONLINE because a dead cpu may utilize the info to
+     * to enter deep C-state */
+    switch ( action )
+    {
+    case CPU_ONLINE:
+        (void)cpuidle_init_cpu(cpu);
+        break;
+    default:
+        break;
+    }
+
+    return NOTIFY_DONE;
+}
+
+static struct notifier_block cpu_nfb = {
+    .notifier_call = cpu_callback
+};
+
+static int __init cpuidle_presmp_init(void)
+{
+    void *cpu = (void *)(long)smp_processor_id();
+    cpu_callback(&cpu_nfb, CPU_ONLINE, cpu);
+    register_cpu_notifier(&cpu_nfb);
+    return 0;
+}
+presmp_initcall(cpuidle_presmp_init);
+
diff -r 33717472f37e xen/arch/x86/smpboot.c
--- a/xen/arch/x86/smpboot.c    Tue Jun 28 18:15:44 2011 +0100
+++ b/xen/arch/x86/smpboot.c    Tue Jul 05 14:36:04 2011 +0800
@@ -45,7 +45,6 @@
 #include <mach_apic.h>
 #include <mach_wakecpu.h>
 #include <smpboot_hooks.h>
-#include <acpi/cpufreq/processor_perf.h>
 
 #define setup_trampoline()    (bootsym_phys(trampoline_realmode_entry))

Attachment: 20110705_default_cstates.patch
Description: 20110705_default_cstates.patch

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel