[ACPI] Add support for FADT P_LVL2_UP flag

[karo-tx-linux.git] / drivers / acpi / processor_idle.c

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 26a3a4016115364467b5feff71415c7e88f4d016..83fd1b6c10c41e7ddb62c271661523ef3affafc9 100644 (file)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -37,6 +37,7 @@
 #include <linux/acpi.h>
 #include <linux/dmi.h>
 #include <linux/moduleparam.h>
+#include <linux/sched.h>       /* need_resched() */
 
 #include <asm/io.h>
 #include <asm/uaccess.h>
@@ -166,6 +167,19 @@ acpi_processor_power_activate(struct acpi_processor *pr,
        return;
 }
 
+static void acpi_safe_halt(void)
+{
+       int polling = test_thread_flag(TIF_POLLING_NRFLAG);
+       if (polling) {
+               clear_thread_flag(TIF_POLLING_NRFLAG);
+               smp_mb__after_clear_bit();
+       }
+       if (!need_resched())
+               safe_halt();
+       if (polling)
+               set_thread_flag(TIF_POLLING_NRFLAG);
+}
+
 static atomic_t c3_cpu_count;
 
 static void acpi_processor_idle(void)
@@ -176,7 +190,7 @@ static void acpi_processor_idle(void)
        int sleep_ticks = 0;
        u32 t1, t2 = 0;
 
-       pr = processors[raw_smp_processor_id()];
+       pr = processors[smp_processor_id()];
        if (!pr)
                return;
 
@@ -196,8 +210,13 @@ static void acpi_processor_idle(void)
        }
 
        cx = pr->power.state;
-       if (!cx)
-               goto easy_out;
+       if (!cx) {
+               if (pm_idle_save)
+                       pm_idle_save();
+               else
+                       acpi_safe_halt();
+               return;
+       }
 
        /*
         * Check BM Activity
@@ -261,6 +280,16 @@ static void acpi_processor_idle(void)
 
        cx->usage++;
 
+#ifdef CONFIG_HOTPLUG_CPU
+       /*
+        * Check for P_LVL2_UP flag before entering C2 and above on
+        * an SMP system. We do it here instead of doing it at _CST/P_LVL
+        * detection phase, to work cleanly with logical CPU hotplug.
+        */
+       if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) && 
+           !pr->flags.has_cst && acpi_fadt.plvl2_up)
+               cx->type = ACPI_STATE_C1;
+#endif
        /*
         * Sleep:
         * ------
@@ -277,7 +306,8 @@ static void acpi_processor_idle(void)
                if (pm_idle_save)
                        pm_idle_save();
                else
-                       safe_halt();
+                       acpi_safe_halt();
+
                /*
                 * TBD: Can't get time duration while in C1, as resumes
                 *      go to an ISR rather than here.  Need to instrument
@@ -413,16 +443,6 @@ static void acpi_processor_idle(void)
         */
        if (next_state != pr->power.state)
                acpi_processor_power_activate(pr, next_state);
-
-       return;
-
-      easy_out:
-       /* do C1 instead of busy loop */
-       if (pm_idle_save)
-               pm_idle_save();
-       else
-               safe_halt();
-       return;
 }
 
 static int acpi_processor_set_power_policy(struct acpi_processor *pr)
@@ -504,8 +524,6 @@ static int acpi_processor_set_power_policy(struct acpi_processor *pr)
 
 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 {
-       int i;
-
        ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
 
        if (!pr)
@@ -514,8 +532,7 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
        if (!pr->pblk)
                return_VALUE(-ENODEV);
 
-       for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
-               memset(pr->power.states, 0, sizeof(struct acpi_processor_cx));
+       memset(pr->power.states, 0, sizeof(pr->power.states));
 
        /* if info is obtained from pblk/fadt, type equals state */
        pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
@@ -527,6 +544,15 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
        pr->power.states[ACPI_STATE_C0].valid = 1;
        pr->power.states[ACPI_STATE_C1].valid = 1;
 
+#ifndef CONFIG_HOTPLUG_CPU
+       /*
+        * Check for P_LVL2_UP flag before entering C2 and above on
+        * an SMP system. 
+        */
+       if ((num_online_cpus() > 1) && acpi_fadt.plvl2_up)
+               return_VALUE(-ENODEV);
+#endif
+
        /* determine C2 and C3 address from pblk */
        pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
        pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
@@ -545,13 +571,9 @@ static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 
 static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
 {
-       int i;
-
        ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_default_c1");
 
-       for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
-               memset(&(pr->power.states[i]), 0,
-                      sizeof(struct acpi_processor_cx));
+       memset(pr->power.states, 0, sizeof(pr->power.states));
 
        /* if info is obtained from pblk/fadt, type equals state */
        pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
@@ -687,7 +709,7 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 
        /* Validate number of power states discovered */
        if (pr->power.count < 2)
-               status = -ENODEV;
+               status = -EFAULT;
 
       end:
        acpi_os_free(buffer.pointer);
@@ -838,11 +860,11 @@ static int acpi_processor_get_power_info(struct acpi_processor *pr)
         * this function */
 
        result = acpi_processor_get_power_info_cst(pr);
-       if ((result) || (acpi_processor_power_verify(pr) < 2)) {
+       if (result == -ENODEV)
                result = acpi_processor_get_power_info_fadt(pr);
-               if ((result) || (acpi_processor_power_verify(pr) < 2))
-                       result = acpi_processor_get_power_info_default_c1(pr);
-       }
+
+       if ((result) || (acpi_processor_power_verify(pr) < 2))
+               result = acpi_processor_get_power_info_default_c1(pr);
 
        /*
         * Set Default Policy
@@ -863,7 +885,8 @@ static int acpi_processor_get_power_info(struct acpi_processor *pr)
        for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
                if (pr->power.states[i].valid) {
                        pr->power.count = i;
-                       pr->flags.power = 1;
+                       if (pr->power.states[i].type >= ACPI_STATE_C2)
+                               pr->flags.power = 1;
                }
        }