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path: root/drivers/acpi/processor_idle.c
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Diffstat (limited to 'drivers/acpi/processor_idle.c')
-rw-r--r--drivers/acpi/processor_idle.c99
1 files changed, 70 insertions, 29 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 26a3a401611..807b0df308f 100644
--- 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 +167,15 @@ acpi_processor_power_activate(struct acpi_processor *pr,
return;
}
+static void acpi_safe_halt(void)
+{
+ clear_thread_flag(TIF_POLLING_NRFLAG);
+ smp_mb__after_clear_bit();
+ if (!need_resched())
+ safe_halt();
+ set_thread_flag(TIF_POLLING_NRFLAG);
+}
+
static atomic_t c3_cpu_count;
static void acpi_processor_idle(void)
@@ -176,7 +186,7 @@ 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 +206,13 @@ 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
@@ -259,6 +274,17 @@ static void acpi_processor_idle(void)
}
}
+#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 = &pr->power.states[ACPI_STATE_C1];
+#endif
+
cx->usage++;
/*
@@ -266,6 +292,16 @@ static void acpi_processor_idle(void)
* ------
* Invoke the current Cx state to put the processor to sleep.
*/
+ if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
+ clear_thread_flag(TIF_POLLING_NRFLAG);
+ smp_mb__after_clear_bit();
+ if (need_resched()) {
+ set_thread_flag(TIF_POLLING_NRFLAG);
+ local_irq_enable();
+ return;
+ }
+ }
+
switch (cx->type) {
case ACPI_STATE_C1:
@@ -277,7 +313,8 @@ 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
@@ -297,6 +334,7 @@ static void acpi_processor_idle(void)
t2 = inl(acpi_fadt.xpm_tmr_blk.address);
/* Re-enable interrupts */
local_irq_enable();
+ set_thread_flag(TIF_POLLING_NRFLAG);
/* Compute time (ticks) that we were actually asleep */
sleep_ticks =
ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
@@ -336,6 +374,7 @@ static void acpi_processor_idle(void)
/* Re-enable interrupts */
local_irq_enable();
+ set_thread_flag(TIF_POLLING_NRFLAG);
/* Compute time (ticks) that we were actually asleep */
sleep_ticks =
ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
@@ -348,6 +387,15 @@ static void acpi_processor_idle(void)
next_state = pr->power.state;
+#ifdef CONFIG_HOTPLUG_CPU
+ /* Don't do promotion/demotion */
+ if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
+ !pr->flags.has_cst && !acpi_fadt.plvl2_up) {
+ next_state = cx;
+ goto end;
+ }
+#endif
+
/*
* Promotion?
* ----------
@@ -413,16 +461,6 @@ 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 +542,6 @@ 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 +550,7 @@ 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 +562,15 @@ 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 +589,9 @@ 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 +727,7 @@ 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 +878,11 @@ 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 +903,8 @@ 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;
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-01 22:39:15 +0000