--- /dev/null
+/*
+ * cpuidle-powernv - idle state cpuidle driver.
+ * Adapted from drivers/cpuidle/cpuidle-pseries
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/cpuidle.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+#include <linux/clockchips.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#include <asm/machdep.h>
+#include <asm/firmware.h>
+#include <asm/opal.h>
+#include <asm/runlatch.h>
+
+#define MAX_POWERNV_IDLE_STATES 8
+
+struct cpuidle_driver powernv_idle_driver = {
+ .name = "powernv_idle",
+ .owner = THIS_MODULE,
+};
+
+static int max_idle_state;
+static struct cpuidle_state *cpuidle_state_table;
+
+static int snooze_loop(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ 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;
+}
+
+static int nap_loop(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ ppc64_runlatch_off();
+ power7_idle();
+ ppc64_runlatch_on();
+ return index;
+}
+
+/* Register for fastsleep only in oneshot mode of broadcast */
+#ifdef CONFIG_TICK_ONESHOT
+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;
+ /* Do not exit powersave upon decrementer as we've setup the timer
+ * offload.
+ */
+ new_lpcr &= ~LPCR_PECE1;
+
+ mtspr(SPRN_LPCR, new_lpcr);
+ power7_sleep();
+
+ mtspr(SPRN_LPCR, old_lpcr);
+
+ return index;
+}
+#endif
+/*
+ * States for dedicated partition case.
+ */
+static struct cpuidle_state powernv_states[MAX_POWERNV_IDLE_STATES] = {
+ { /* Snooze */
+ .name = "snooze",
+ .desc = "snooze",
+ .exit_latency = 0,
+ .target_residency = 0,
+ .enter = &snooze_loop },
+};
+
+static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
+ unsigned long action, void *hcpu)
+{
+ int hotcpu = (unsigned long)hcpu;
+ struct cpuidle_device *dev =
+ per_cpu(cpuidle_devices, hotcpu);
+
+ if (dev && cpuidle_get_driver()) {
+ switch (action) {
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ cpuidle_pause_and_lock();
+ cpuidle_enable_device(dev);
+ cpuidle_resume_and_unlock();
+ break;
+
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ cpuidle_pause_and_lock();
+ cpuidle_disable_device(dev);
+ cpuidle_resume_and_unlock();
+ break;
+
+ default:
+ return NOTIFY_DONE;
+ }
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block setup_hotplug_notifier = {
+ .notifier_call = powernv_cpuidle_add_cpu_notifier,
+};
+
+/*
+ * powernv_cpuidle_driver_init()
+ */
+static int powernv_cpuidle_driver_init(void)
+{
+ int idle_state;
+ struct cpuidle_driver *drv = &powernv_idle_driver;
+
+ drv->state_count = 0;
+
+ for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
+ /* Is the state not enabled? */
+ if (cpuidle_state_table[idle_state].enter == NULL)
+ continue;
+
+ drv->states[drv->state_count] = /* structure copy */
+ cpuidle_state_table[idle_state];
+
+ drv->state_count += 1;
+ }
+
+ return 0;
+}
+
+static int powernv_add_idle_states(void)
+{
+ struct device_node *power_mgt;
+ int nr_idle_states = 1; /* Snooze */
+ int dt_idle_states;
+ u32 *latency_ns, *residency_ns, *flags;
+ int i, rc;
+
+ /* 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");
+ goto out;
+ }
+
+ /* Read values of any property to determine the num of idle states */
+ dt_idle_states = of_property_count_u32_elems(power_mgt, "ibm,cpu-idle-state-flags");
+ if (dt_idle_states < 0) {
+ pr_warn("cpuidle-powernv: no idle states found in the DT\n");
+ goto out;
+ }
+
+ flags = kzalloc(sizeof(*flags) * dt_idle_states, GFP_KERNEL);
+ if (of_property_read_u32_array(power_mgt,
+ "ibm,cpu-idle-state-flags", flags, dt_idle_states)) {
+ pr_warn("cpuidle-powernv : missing ibm,cpu-idle-state-flags in DT\n");
+ goto out_free_flags;
+ }
+
+ latency_ns = kzalloc(sizeof(*latency_ns) * dt_idle_states, GFP_KERNEL);
+ rc = of_property_read_u32_array(power_mgt,
+ "ibm,cpu-idle-state-latencies-ns", latency_ns, dt_idle_states);
+ if (rc) {
+ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
+ goto out_free_latency;
+ }
+
+ residency_ns = kzalloc(sizeof(*residency_ns) * dt_idle_states, GFP_KERNEL);
+ rc = of_property_read_u32_array(power_mgt,
+ "ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);
+
+ for (i = 0; i < dt_idle_states; i++) {
+
+ /*
+ * Cpuidle accepts exit_latency and target_residency in us.
+ * Use default target_residency values if f/w does not expose it.
+ */
+ if (flags[i] & OPAL_PM_NAP_ENABLED) {
+ /* 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 = 0;
+ powernv_states[nr_idle_states].target_residency = 100;
+ powernv_states[nr_idle_states].enter = &nap_loop;
+ }
+
+ /*
+ * All cpuidle states with CPUIDLE_FLAG_TIMER_STOP set must come
+ * within this config dependency check.
+ */
+#ifdef CONFIG_TICK_ONESHOT
+ if (flags[i] & OPAL_PM_SLEEP_ENABLED ||
+ flags[i] & OPAL_PM_SLEEP_ENABLED_ER1) {
+ /* 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_TIMER_STOP;
+ powernv_states[nr_idle_states].target_residency = 300000;
+ powernv_states[nr_idle_states].enter = &fastsleep_loop;
+ }
+#endif
+ powernv_states[nr_idle_states].exit_latency =
+ ((unsigned int)latency_ns[i]) / 1000;
+
+ if (!rc) {
+ powernv_states[nr_idle_states].target_residency =
+ ((unsigned int)residency_ns[i]) / 1000;
+ }
+
+ nr_idle_states++;
+ }
+
+ kfree(residency_ns);
+out_free_latency:
+ kfree(latency_ns);
+out_free_flags:
+ kfree(flags);
+out:
+ 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;
+ /* Device tree can indicate more idle states */
+ max_idle_state = powernv_add_idle_states();
+ } else
+ return -ENODEV;
+
+ return 0;
+}
+
+static int __init powernv_processor_idle_init(void)
+{
+ int retval;
+
+ retval = powernv_idle_probe();
+ if (retval)
+ return retval;
+
+ powernv_cpuidle_driver_init();
+ retval = cpuidle_register(&powernv_idle_driver, NULL);
+ if (retval) {
+ printk(KERN_DEBUG "Registration of powernv driver failed.\n");
+ return retval;
+ }
+
+ register_cpu_notifier(&setup_hotplug_notifier);
+ printk(KERN_DEBUG "powernv_idle_driver registered\n");
+ return 0;
+}
+
+device_initcall(powernv_processor_idle_init);
Code Review / kvmfornfv.git / blobdiff