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path: root/drivers/cpuidle/cpuidle-powernv.c
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Diffstat (limited to 'drivers/cpuidle/cpuidle-powernv.c')
-rw-r--r--drivers/cpuidle/cpuidle-powernv.c107
1 files changed, 97 insertions, 10 deletions
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 78fd174c57e..719f6fb5b1c 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -11,9 +11,18 @@
#include <linux/cpuidle.h>
#include <linux/cpu.h>
#include <linux/notifier.h>
+#include <linux/clockchips.h>
+#include <linux/of.h>
#include <asm/machdep.h>
#include <asm/firmware.h>
+#include <asm/runlatch.h>
+
+/* Flags and constants used in PowerNV platform */
+
+#define MAX_POWERNV_IDLE_STATES 8
+#define IDLE_USE_INST_NAP 0x00010000 /* Use nap instruction */
+#define IDLE_USE_INST_SLEEP 0x00020000 /* Use sleep instruction */
struct cpuidle_driver powernv_idle_driver = {
.name = "powernv_idle",
@@ -30,12 +39,14 @@ static int snooze_loop(struct cpuidle_device *dev,
local_irq_enable();
set_thread_flag(TIF_POLLING_NRFLAG);
+ ppc64_runlatch_off();
while (!need_resched()) {
HMT_low();
HMT_very_low();
}
HMT_medium();
+ ppc64_runlatch_on();
clear_thread_flag(TIF_POLLING_NRFLAG);
smp_mb();
return index;
@@ -45,14 +56,42 @@ static int nap_loop(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
+ ppc64_runlatch_off();
power7_idle();
+ ppc64_runlatch_on();
+ return index;
+}
+
+static int fastsleep_loop(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ unsigned long old_lpcr = mfspr(SPRN_LPCR);
+ unsigned long new_lpcr;
+
+ if (unlikely(system_state < SYSTEM_RUNNING))
+ return index;
+
+ new_lpcr = old_lpcr;
+ new_lpcr &= ~(LPCR_MER | LPCR_PECE); /* lpcr[mer] must be 0 */
+
+ /* exit powersave upon external interrupt, but not decrementer
+ * interrupt.
+ */
+ new_lpcr |= LPCR_PECE0;
+
+ mtspr(SPRN_LPCR, new_lpcr);
+ power7_sleep();
+
+ mtspr(SPRN_LPCR, old_lpcr);
+
return index;
}
/*
* States for dedicated partition case.
*/
-static struct cpuidle_state powernv_states[] = {
+static struct cpuidle_state powernv_states[MAX_POWERNV_IDLE_STATES] = {
{ /* Snooze */
.name = "snooze",
.desc = "snooze",
@@ -60,13 +99,6 @@ static struct cpuidle_state powernv_states[] = {
.exit_latency = 0,
.target_residency = 0,
.enter = &snooze_loop },
- { /* NAP */
- .name = "NAP",
- .desc = "NAP",
- .flags = CPUIDLE_FLAG_TIME_VALID,
- .exit_latency = 10,
- .target_residency = 100,
- .enter = &nap_loop },
};
static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
@@ -127,19 +159,74 @@ static int powernv_cpuidle_driver_init(void)
return 0;
}
+static int powernv_add_idle_states(void)
+{
+ struct device_node *power_mgt;
+ struct property *prop;
+ int nr_idle_states = 1; /* Snooze */
+ int dt_idle_states;
+ u32 *flags;
+ int i;
+
+ /* Currently we have snooze statically defined */
+
+ power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
+ if (!power_mgt) {
+ pr_warn("opal: PowerMgmt Node not found\n");
+ return nr_idle_states;
+ }
+
+ prop = of_find_property(power_mgt, "ibm,cpu-idle-state-flags", NULL);
+ if (!prop) {
+ pr_warn("DT-PowerMgmt: missing ibm,cpu-idle-state-flags\n");
+ return nr_idle_states;
+ }
+
+ dt_idle_states = prop->length / sizeof(u32);
+ flags = (u32 *) prop->value;
+
+ for (i = 0; i < dt_idle_states; i++) {
+
+ if (flags[i] & IDLE_USE_INST_NAP) {
+ /* Add NAP state */
+ strcpy(powernv_states[nr_idle_states].name, "Nap");
+ strcpy(powernv_states[nr_idle_states].desc, "Nap");
+ powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIME_VALID;
+ powernv_states[nr_idle_states].exit_latency = 10;
+ powernv_states[nr_idle_states].target_residency = 100;
+ powernv_states[nr_idle_states].enter = &nap_loop;
+ nr_idle_states++;
+ }
+
+ if (flags[i] & IDLE_USE_INST_SLEEP) {
+ /* Add FASTSLEEP state */
+ strcpy(powernv_states[nr_idle_states].name, "FastSleep");
+ strcpy(powernv_states[nr_idle_states].desc, "FastSleep");
+ powernv_states[nr_idle_states].flags =
+ CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TIMER_STOP;
+ powernv_states[nr_idle_states].exit_latency = 300;
+ powernv_states[nr_idle_states].target_residency = 1000000;
+ powernv_states[nr_idle_states].enter = &fastsleep_loop;
+ nr_idle_states++;
+ }
+ }
+
+ return nr_idle_states;
+}
+
/*
* powernv_idle_probe()
* Choose state table for shared versus dedicated partition
*/
static int powernv_idle_probe(void)
{
-
if (cpuidle_disable != IDLE_NO_OVERRIDE)
return -ENODEV;
if (firmware_has_feature(FW_FEATURE_OPALv3)) {
cpuidle_state_table = powernv_states;
- max_idle_state = ARRAY_SIZE(powernv_states);
+ /* Device tree can indicate more idle states */
+ max_idle_state = powernv_add_idle_states();
} else
return -ENODEV;