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-rw-r--r--arch/powerpc/platforms/powernv/idle.c847
1 files changed, 847 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
new file mode 100644
index 000000000..e52f9b06d
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -0,0 +1,847 @@
+/*
+ * PowerNV cpuidle code
+ *
+ * Copyright 2015 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/device.h>
+#include <linux/cpu.h>
+
+#include <asm/firmware.h>
+#include <asm/machdep.h>
+#include <asm/opal.h>
+#include <asm/cputhreads.h>
+#include <asm/cpuidle.h>
+#include <asm/code-patching.h>
+#include <asm/smp.h>
+#include <asm/runlatch.h>
+#include <asm/dbell.h>
+
+#include "powernv.h"
+#include "subcore.h"
+
+/* Power ISA 3.0 allows for stop states 0x0 - 0xF */
+#define MAX_STOP_STATE 0xF
+
+#define P9_STOP_SPR_MSR 2000
+#define P9_STOP_SPR_PSSCR 855
+
+static u32 supported_cpuidle_states;
+struct pnv_idle_states_t *pnv_idle_states;
+int nr_pnv_idle_states;
+
+/*
+ * The default stop state that will be used by ppc_md.power_save
+ * function on platforms that support stop instruction.
+ */
+static u64 pnv_default_stop_val;
+static u64 pnv_default_stop_mask;
+static bool default_stop_found;
+
+/*
+ * First deep stop state. Used to figure out when to save/restore
+ * hypervisor context.
+ */
+u64 pnv_first_deep_stop_state = MAX_STOP_STATE;
+
+/*
+ * psscr value and mask of the deepest stop idle state.
+ * Used when a cpu is offlined.
+ */
+static u64 pnv_deepest_stop_psscr_val;
+static u64 pnv_deepest_stop_psscr_mask;
+static u64 pnv_deepest_stop_flag;
+static bool deepest_stop_found;
+
+static int pnv_save_sprs_for_deep_states(void)
+{
+ int cpu;
+ int rc;
+
+ /*
+ * hid0, hid1, hid4, hid5, hmeer and lpcr values are symmetric across
+ * all cpus at boot. Get these reg values of current cpu and use the
+ * same across all cpus.
+ */
+ uint64_t lpcr_val = mfspr(SPRN_LPCR);
+ uint64_t hid0_val = mfspr(SPRN_HID0);
+ uint64_t hid1_val = mfspr(SPRN_HID1);
+ uint64_t hid4_val = mfspr(SPRN_HID4);
+ uint64_t hid5_val = mfspr(SPRN_HID5);
+ uint64_t hmeer_val = mfspr(SPRN_HMEER);
+ uint64_t msr_val = MSR_IDLE;
+ uint64_t psscr_val = pnv_deepest_stop_psscr_val;
+
+ for_each_present_cpu(cpu) {
+ uint64_t pir = get_hard_smp_processor_id(cpu);
+ uint64_t hsprg0_val = (uint64_t)paca_ptrs[cpu];
+
+ rc = opal_slw_set_reg(pir, SPRN_HSPRG0, hsprg0_val);
+ if (rc != 0)
+ return rc;
+
+ rc = opal_slw_set_reg(pir, SPRN_LPCR, lpcr_val);
+ if (rc != 0)
+ return rc;
+
+ if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+ rc = opal_slw_set_reg(pir, P9_STOP_SPR_MSR, msr_val);
+ if (rc)
+ return rc;
+
+ rc = opal_slw_set_reg(pir,
+ P9_STOP_SPR_PSSCR, psscr_val);
+
+ if (rc)
+ return rc;
+ }
+
+ /* HIDs are per core registers */
+ if (cpu_thread_in_core(cpu) == 0) {
+
+ rc = opal_slw_set_reg(pir, SPRN_HMEER, hmeer_val);
+ if (rc != 0)
+ return rc;
+
+ rc = opal_slw_set_reg(pir, SPRN_HID0, hid0_val);
+ if (rc != 0)
+ return rc;
+
+ /* Only p8 needs to set extra HID regiters */
+ if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+
+ rc = opal_slw_set_reg(pir, SPRN_HID1, hid1_val);
+ if (rc != 0)
+ return rc;
+
+ rc = opal_slw_set_reg(pir, SPRN_HID4, hid4_val);
+ if (rc != 0)
+ return rc;
+
+ rc = opal_slw_set_reg(pir, SPRN_HID5, hid5_val);
+ if (rc != 0)
+ return rc;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static void pnv_alloc_idle_core_states(void)
+{
+ int i, j;
+ int nr_cores = cpu_nr_cores();
+ u32 *core_idle_state;
+
+ /*
+ * core_idle_state - The lower 8 bits track the idle state of
+ * each thread of the core.
+ *
+ * The most significant bit is the lock bit.
+ *
+ * Initially all the bits corresponding to threads_per_core
+ * are set. They are cleared when the thread enters deep idle
+ * state like sleep and winkle/stop.
+ *
+ * Initially the lock bit is cleared. The lock bit has 2
+ * purposes:
+ * a. While the first thread in the core waking up from
+ * idle is restoring core state, it prevents other
+ * threads in the core from switching to process
+ * context.
+ * b. While the last thread in the core is saving the
+ * core state, it prevents a different thread from
+ * waking up.
+ */
+ for (i = 0; i < nr_cores; i++) {
+ int first_cpu = i * threads_per_core;
+ int node = cpu_to_node(first_cpu);
+ size_t paca_ptr_array_size;
+
+ core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, node);
+ *core_idle_state = (1 << threads_per_core) - 1;
+ paca_ptr_array_size = (threads_per_core *
+ sizeof(struct paca_struct *));
+
+ for (j = 0; j < threads_per_core; j++) {
+ int cpu = first_cpu + j;
+
+ paca_ptrs[cpu]->core_idle_state_ptr = core_idle_state;
+ paca_ptrs[cpu]->thread_idle_state = PNV_THREAD_RUNNING;
+ paca_ptrs[cpu]->thread_mask = 1 << j;
+ }
+ }
+
+ update_subcore_sibling_mask();
+
+ if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT) {
+ int rc = pnv_save_sprs_for_deep_states();
+
+ if (likely(!rc))
+ return;
+
+ /*
+ * The stop-api is unable to restore hypervisor
+ * resources on wakeup from platform idle states which
+ * lose full context. So disable such states.
+ */
+ supported_cpuidle_states &= ~OPAL_PM_LOSE_FULL_CONTEXT;
+ pr_warn("cpuidle-powernv: Disabling idle states that lose full context\n");
+ pr_warn("cpuidle-powernv: Idle power-savings, CPU-Hotplug affected\n");
+
+ if (cpu_has_feature(CPU_FTR_ARCH_300) &&
+ (pnv_deepest_stop_flag & OPAL_PM_LOSE_FULL_CONTEXT)) {
+ /*
+ * Use the default stop state for CPU-Hotplug
+ * if available.
+ */
+ if (default_stop_found) {
+ pnv_deepest_stop_psscr_val =
+ pnv_default_stop_val;
+ pnv_deepest_stop_psscr_mask =
+ pnv_default_stop_mask;
+ pr_warn("cpuidle-powernv: Offlined CPUs will stop with psscr = 0x%016llx\n",
+ pnv_deepest_stop_psscr_val);
+ } else { /* Fallback to snooze loop for CPU-Hotplug */
+ deepest_stop_found = false;
+ pr_warn("cpuidle-powernv: Offlined CPUs will busy wait\n");
+ }
+ }
+ }
+}
+
+u32 pnv_get_supported_cpuidle_states(void)
+{
+ return supported_cpuidle_states;
+}
+EXPORT_SYMBOL_GPL(pnv_get_supported_cpuidle_states);
+
+static void pnv_fastsleep_workaround_apply(void *info)
+
+{
+ int rc;
+ int *err = info;
+
+ rc = opal_config_cpu_idle_state(OPAL_CONFIG_IDLE_FASTSLEEP,
+ OPAL_CONFIG_IDLE_APPLY);
+ if (rc)
+ *err = 1;
+}
+
+/*
+ * Used to store fastsleep workaround state
+ * 0 - Workaround applied/undone at fastsleep entry/exit path (Default)
+ * 1 - Workaround applied once, never undone.
+ */
+static u8 fastsleep_workaround_applyonce;
+
+static ssize_t show_fastsleep_workaround_applyonce(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%u\n", fastsleep_workaround_applyonce);
+}
+
+static ssize_t store_fastsleep_workaround_applyonce(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ cpumask_t primary_thread_mask;
+ int err;
+ u8 val;
+
+ if (kstrtou8(buf, 0, &val) || val != 1)
+ return -EINVAL;
+
+ if (fastsleep_workaround_applyonce == 1)
+ return count;
+
+ /*
+ * fastsleep_workaround_applyonce = 1 implies
+ * fastsleep workaround needs to be left in 'applied' state on all
+ * the cores. Do this by-
+ * 1. Patching out the call to 'undo' workaround in fastsleep exit path
+ * 2. Sending ipi to all the cores which have at least one online thread
+ * 3. Patching out the call to 'apply' workaround in fastsleep entry
+ * path
+ * There is no need to send ipi to cores which have all threads
+ * offlined, as last thread of the core entering fastsleep or deeper
+ * state would have applied workaround.
+ */
+ err = patch_instruction(
+ (unsigned int *)pnv_fastsleep_workaround_at_exit,
+ PPC_INST_NOP);
+ if (err) {
+ pr_err("fastsleep_workaround_applyonce change failed while patching pnv_fastsleep_workaround_at_exit");
+ goto fail;
+ }
+
+ get_online_cpus();
+ primary_thread_mask = cpu_online_cores_map();
+ on_each_cpu_mask(&primary_thread_mask,
+ pnv_fastsleep_workaround_apply,
+ &err, 1);
+ put_online_cpus();
+ if (err) {
+ pr_err("fastsleep_workaround_applyonce change failed while running pnv_fastsleep_workaround_apply");
+ goto fail;
+ }
+
+ err = patch_instruction(
+ (unsigned int *)pnv_fastsleep_workaround_at_entry,
+ PPC_INST_NOP);
+ if (err) {
+ pr_err("fastsleep_workaround_applyonce change failed while patching pnv_fastsleep_workaround_at_entry");
+ goto fail;
+ }
+
+ fastsleep_workaround_applyonce = 1;
+
+ return count;
+fail:
+ return -EIO;
+}
+
+static DEVICE_ATTR(fastsleep_workaround_applyonce, 0600,
+ show_fastsleep_workaround_applyonce,
+ store_fastsleep_workaround_applyonce);
+
+static unsigned long __power7_idle_type(unsigned long type)
+{
+ unsigned long srr1;
+
+ if (!prep_irq_for_idle_irqsoff())
+ return 0;
+
+ __ppc64_runlatch_off();
+ srr1 = power7_idle_insn(type);
+ __ppc64_runlatch_on();
+
+ fini_irq_for_idle_irqsoff();
+
+ return srr1;
+}
+
+void power7_idle_type(unsigned long type)
+{
+ unsigned long srr1;
+
+ srr1 = __power7_idle_type(type);
+ irq_set_pending_from_srr1(srr1);
+}
+
+void power7_idle(void)
+{
+ if (!powersave_nap)
+ return;
+
+ power7_idle_type(PNV_THREAD_NAP);
+}
+
+static unsigned long __power9_idle_type(unsigned long stop_psscr_val,
+ unsigned long stop_psscr_mask)
+{
+ unsigned long psscr;
+ unsigned long srr1;
+
+ if (!prep_irq_for_idle_irqsoff())
+ return 0;
+
+ psscr = mfspr(SPRN_PSSCR);
+ psscr = (psscr & ~stop_psscr_mask) | stop_psscr_val;
+
+ __ppc64_runlatch_off();
+ srr1 = power9_idle_stop(psscr);
+ __ppc64_runlatch_on();
+
+ fini_irq_for_idle_irqsoff();
+
+ return srr1;
+}
+
+void power9_idle_type(unsigned long stop_psscr_val,
+ unsigned long stop_psscr_mask)
+{
+ unsigned long srr1;
+
+ srr1 = __power9_idle_type(stop_psscr_val, stop_psscr_mask);
+ irq_set_pending_from_srr1(srr1);
+}
+
+/*
+ * Used for ppc_md.power_save which needs a function with no parameters
+ */
+void power9_idle(void)
+{
+ power9_idle_type(pnv_default_stop_val, pnv_default_stop_mask);
+}
+
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+/*
+ * This is used in working around bugs in thread reconfiguration
+ * on POWER9 (at least up to Nimbus DD2.2) relating to transactional
+ * memory and the way that XER[SO] is checkpointed.
+ * This function forces the core into SMT4 in order by asking
+ * all other threads not to stop, and sending a message to any
+ * that are in a stop state.
+ * Must be called with preemption disabled.
+ */
+void pnv_power9_force_smt4_catch(void)
+{
+ int cpu, cpu0, thr;
+ int awake_threads = 1; /* this thread is awake */
+ int poke_threads = 0;
+ int need_awake = threads_per_core;
+
+ cpu = smp_processor_id();
+ cpu0 = cpu & ~(threads_per_core - 1);
+ for (thr = 0; thr < threads_per_core; ++thr) {
+ if (cpu != cpu0 + thr)
+ atomic_inc(&paca_ptrs[cpu0+thr]->dont_stop);
+ }
+ /* order setting dont_stop vs testing requested_psscr */
+ mb();
+ for (thr = 0; thr < threads_per_core; ++thr) {
+ if (!paca_ptrs[cpu0+thr]->requested_psscr)
+ ++awake_threads;
+ else
+ poke_threads |= (1 << thr);
+ }
+
+ /* If at least 3 threads are awake, the core is in SMT4 already */
+ if (awake_threads < need_awake) {
+ /* We have to wake some threads; we'll use msgsnd */
+ for (thr = 0; thr < threads_per_core; ++thr) {
+ if (poke_threads & (1 << thr)) {
+ ppc_msgsnd_sync();
+ ppc_msgsnd(PPC_DBELL_MSGTYPE, 0,
+ paca_ptrs[cpu0+thr]->hw_cpu_id);
+ }
+ }
+ /* now spin until at least 3 threads are awake */
+ do {
+ for (thr = 0; thr < threads_per_core; ++thr) {
+ if ((poke_threads & (1 << thr)) &&
+ !paca_ptrs[cpu0+thr]->requested_psscr) {
+ ++awake_threads;
+ poke_threads &= ~(1 << thr);
+ }
+ }
+ } while (awake_threads < need_awake);
+ }
+}
+EXPORT_SYMBOL_GPL(pnv_power9_force_smt4_catch);
+
+void pnv_power9_force_smt4_release(void)
+{
+ int cpu, cpu0, thr;
+
+ cpu = smp_processor_id();
+ cpu0 = cpu & ~(threads_per_core - 1);
+
+ /* clear all the dont_stop flags */
+ for (thr = 0; thr < threads_per_core; ++thr) {
+ if (cpu != cpu0 + thr)
+ atomic_dec(&paca_ptrs[cpu0+thr]->dont_stop);
+ }
+}
+EXPORT_SYMBOL_GPL(pnv_power9_force_smt4_release);
+#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+void pnv_program_cpu_hotplug_lpcr(unsigned int cpu, u64 lpcr_val)
+{
+ u64 pir = get_hard_smp_processor_id(cpu);
+
+ mtspr(SPRN_LPCR, lpcr_val);
+
+ /*
+ * Program the LPCR via stop-api only if the deepest stop state
+ * can lose hypervisor context.
+ */
+ if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT)
+ opal_slw_set_reg(pir, SPRN_LPCR, lpcr_val);
+}
+
+/*
+ * pnv_cpu_offline: A function that puts the CPU into the deepest
+ * available platform idle state on a CPU-Offline.
+ * interrupts hard disabled and no lazy irq pending.
+ */
+unsigned long pnv_cpu_offline(unsigned int cpu)
+{
+ unsigned long srr1;
+ u32 idle_states = pnv_get_supported_cpuidle_states();
+
+ __ppc64_runlatch_off();
+
+ if (cpu_has_feature(CPU_FTR_ARCH_300) && deepest_stop_found) {
+ unsigned long psscr;
+
+ psscr = mfspr(SPRN_PSSCR);
+ psscr = (psscr & ~pnv_deepest_stop_psscr_mask) |
+ pnv_deepest_stop_psscr_val;
+ srr1 = power9_offline_stop(psscr);
+
+ } else if ((idle_states & OPAL_PM_WINKLE_ENABLED) &&
+ (idle_states & OPAL_PM_LOSE_FULL_CONTEXT)) {
+ srr1 = power7_idle_insn(PNV_THREAD_WINKLE);
+ } else if ((idle_states & OPAL_PM_SLEEP_ENABLED) ||
+ (idle_states & OPAL_PM_SLEEP_ENABLED_ER1)) {
+ srr1 = power7_idle_insn(PNV_THREAD_SLEEP);
+ } else if (idle_states & OPAL_PM_NAP_ENABLED) {
+ srr1 = power7_idle_insn(PNV_THREAD_NAP);
+ } else {
+ /* This is the fallback method. We emulate snooze */
+ while (!generic_check_cpu_restart(cpu)) {
+ HMT_low();
+ HMT_very_low();
+ }
+ srr1 = 0;
+ HMT_medium();
+ }
+
+ __ppc64_runlatch_on();
+
+ return srr1;
+}
+#endif
+
+/*
+ * Power ISA 3.0 idle initialization.
+ *
+ * POWER ISA 3.0 defines a new SPR Processor stop Status and Control
+ * Register (PSSCR) to control idle behavior.
+ *
+ * PSSCR layout:
+ * ----------------------------------------------------------
+ * | PLS | /// | SD | ESL | EC | PSLL | /// | TR | MTL | RL |
+ * ----------------------------------------------------------
+ * 0 4 41 42 43 44 48 54 56 60
+ *
+ * PSSCR key fields:
+ * Bits 0:3 - Power-Saving Level Status (PLS). This field indicates the
+ * lowest power-saving state the thread entered since stop instruction was
+ * last executed.
+ *
+ * Bit 41 - Status Disable(SD)
+ * 0 - Shows PLS entries
+ * 1 - PLS entries are all 0
+ *
+ * Bit 42 - Enable State Loss
+ * 0 - No state is lost irrespective of other fields
+ * 1 - Allows state loss
+ *
+ * Bit 43 - Exit Criterion
+ * 0 - Exit from power-save mode on any interrupt
+ * 1 - Exit from power-save mode controlled by LPCR's PECE bits
+ *
+ * Bits 44:47 - Power-Saving Level Limit
+ * This limits the power-saving level that can be entered into.
+ *
+ * Bits 60:63 - Requested Level
+ * Used to specify which power-saving level must be entered on executing
+ * stop instruction
+ */
+
+int validate_psscr_val_mask(u64 *psscr_val, u64 *psscr_mask, u32 flags)
+{
+ int err = 0;
+
+ /*
+ * psscr_mask == 0xf indicates an older firmware.
+ * Set remaining fields of psscr to the default values.
+ * See NOTE above definition of PSSCR_HV_DEFAULT_VAL
+ */
+ if (*psscr_mask == 0xf) {
+ *psscr_val = *psscr_val | PSSCR_HV_DEFAULT_VAL;
+ *psscr_mask = PSSCR_HV_DEFAULT_MASK;
+ return err;
+ }
+
+ /*
+ * New firmware is expected to set the psscr_val bits correctly.
+ * Validate that the following invariants are correctly maintained by
+ * the new firmware.
+ * - ESL bit value matches the EC bit value.
+ * - ESL bit is set for all the deep stop states.
+ */
+ if (GET_PSSCR_ESL(*psscr_val) != GET_PSSCR_EC(*psscr_val)) {
+ err = ERR_EC_ESL_MISMATCH;
+ } else if ((flags & OPAL_PM_LOSE_FULL_CONTEXT) &&
+ GET_PSSCR_ESL(*psscr_val) == 0) {
+ err = ERR_DEEP_STATE_ESL_MISMATCH;
+ }
+
+ return err;
+}
+
+/*
+ * pnv_arch300_idle_init: Initializes the default idle state, first
+ * deep idle state and deepest idle state on
+ * ISA 3.0 CPUs.
+ *
+ * @np: /ibm,opal/power-mgt device node
+ * @flags: cpu-idle-state-flags array
+ * @dt_idle_states: Number of idle state entries
+ * Returns 0 on success
+ */
+static int __init pnv_power9_idle_init(void)
+{
+ u64 max_residency_ns = 0;
+ int i;
+
+ /*
+ * Set pnv_first_deep_stop_state, pnv_deepest_stop_psscr_{val,mask},
+ * and the pnv_default_stop_{val,mask}.
+ *
+ * pnv_first_deep_stop_state should be set to the first stop
+ * level to cause hypervisor state loss.
+ *
+ * pnv_deepest_stop_{val,mask} should be set to values corresponding to
+ * the deepest stop state.
+ *
+ * pnv_default_stop_{val,mask} should be set to values corresponding to
+ * the shallowest (OPAL_PM_STOP_INST_FAST) loss-less stop state.
+ */
+ pnv_first_deep_stop_state = MAX_STOP_STATE;
+ for (i = 0; i < nr_pnv_idle_states; i++) {
+ int err;
+ struct pnv_idle_states_t *state = &pnv_idle_states[i];
+ u64 psscr_rl = state->psscr_val & PSSCR_RL_MASK;
+
+ if ((state->flags & OPAL_PM_LOSE_FULL_CONTEXT) &&
+ pnv_first_deep_stop_state > psscr_rl)
+ pnv_first_deep_stop_state = psscr_rl;
+
+ err = validate_psscr_val_mask(&state->psscr_val,
+ &state->psscr_mask,
+ state->flags);
+ if (err) {
+ report_invalid_psscr_val(state->psscr_val, err);
+ continue;
+ }
+
+ state->valid = true;
+
+ if (max_residency_ns < state->residency_ns) {
+ max_residency_ns = state->residency_ns;
+ pnv_deepest_stop_psscr_val = state->psscr_val;
+ pnv_deepest_stop_psscr_mask = state->psscr_mask;
+ pnv_deepest_stop_flag = state->flags;
+ deepest_stop_found = true;
+ }
+
+ if (!default_stop_found &&
+ (state->flags & OPAL_PM_STOP_INST_FAST)) {
+ pnv_default_stop_val = state->psscr_val;
+ pnv_default_stop_mask = state->psscr_mask;
+ default_stop_found = true;
+ }
+ }
+
+ if (unlikely(!default_stop_found)) {
+ pr_warn("cpuidle-powernv: No suitable default stop state found. Disabling platform idle.\n");
+ } else {
+ ppc_md.power_save = power9_idle;
+ pr_info("cpuidle-powernv: Default stop: psscr = 0x%016llx,mask=0x%016llx\n",
+ pnv_default_stop_val, pnv_default_stop_mask);
+ }
+
+ if (unlikely(!deepest_stop_found)) {
+ pr_warn("cpuidle-powernv: No suitable stop state for CPU-Hotplug. Offlined CPUs will busy wait");
+ } else {
+ pr_info("cpuidle-powernv: Deepest stop: psscr = 0x%016llx,mask=0x%016llx\n",
+ pnv_deepest_stop_psscr_val,
+ pnv_deepest_stop_psscr_mask);
+ }
+
+ pr_info("cpuidle-powernv: Requested Level (RL) value of first deep stop = 0x%llx\n",
+ pnv_first_deep_stop_state);
+
+ return 0;
+}
+
+/*
+ * Probe device tree for supported idle states
+ */
+static void __init pnv_probe_idle_states(void)
+{
+ int i;
+
+ if (nr_pnv_idle_states < 0) {
+ pr_warn("cpuidle-powernv: no idle states found in the DT\n");
+ return;
+ }
+
+ if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+ if (pnv_power9_idle_init())
+ return;
+ }
+
+ for (i = 0; i < nr_pnv_idle_states; i++)
+ supported_cpuidle_states |= pnv_idle_states[i].flags;
+}
+
+/*
+ * This function parses device-tree and populates all the information
+ * into pnv_idle_states structure. It also sets up nr_pnv_idle_states
+ * which is the number of cpuidle states discovered through device-tree.
+ */
+
+static int pnv_parse_cpuidle_dt(void)
+{
+ struct device_node *np;
+ int nr_idle_states, i;
+ int rc = 0;
+ u32 *temp_u32;
+ u64 *temp_u64;
+ const char **temp_string;
+
+ np = of_find_node_by_path("/ibm,opal/power-mgt");
+ if (!np) {
+ pr_warn("opal: PowerMgmt Node not found\n");
+ return -ENODEV;
+ }
+ nr_idle_states = of_property_count_u32_elems(np,
+ "ibm,cpu-idle-state-flags");
+
+ pnv_idle_states = kcalloc(nr_idle_states, sizeof(*pnv_idle_states),
+ GFP_KERNEL);
+ temp_u32 = kcalloc(nr_idle_states, sizeof(u32), GFP_KERNEL);
+ temp_u64 = kcalloc(nr_idle_states, sizeof(u64), GFP_KERNEL);
+ temp_string = kcalloc(nr_idle_states, sizeof(char *), GFP_KERNEL);
+
+ if (!(pnv_idle_states && temp_u32 && temp_u64 && temp_string)) {
+ pr_err("Could not allocate memory for dt parsing\n");
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ /* Read flags */
+ if (of_property_read_u32_array(np, "ibm,cpu-idle-state-flags",
+ temp_u32, nr_idle_states)) {
+ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-flags in DT\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ for (i = 0; i < nr_idle_states; i++)
+ pnv_idle_states[i].flags = temp_u32[i];
+
+ /* Read latencies */
+ if (of_property_read_u32_array(np, "ibm,cpu-idle-state-latencies-ns",
+ temp_u32, nr_idle_states)) {
+ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ for (i = 0; i < nr_idle_states; i++)
+ pnv_idle_states[i].latency_ns = temp_u32[i];
+
+ /* Read residencies */
+ if (of_property_read_u32_array(np, "ibm,cpu-idle-state-residency-ns",
+ temp_u32, nr_idle_states)) {
+ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ for (i = 0; i < nr_idle_states; i++)
+ pnv_idle_states[i].residency_ns = temp_u32[i];
+
+ /* For power9 */
+ if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+ /* Read pm_crtl_val */
+ if (of_property_read_u64_array(np, "ibm,cpu-idle-state-psscr",
+ temp_u64, nr_idle_states)) {
+ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-psscr in DT\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ for (i = 0; i < nr_idle_states; i++)
+ pnv_idle_states[i].psscr_val = temp_u64[i];
+
+ /* Read pm_crtl_mask */
+ if (of_property_read_u64_array(np, "ibm,cpu-idle-state-psscr-mask",
+ temp_u64, nr_idle_states)) {
+ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-psscr-mask in DT\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ for (i = 0; i < nr_idle_states; i++)
+ pnv_idle_states[i].psscr_mask = temp_u64[i];
+ }
+
+ /*
+ * power8 specific properties ibm,cpu-idle-state-pmicr-mask and
+ * ibm,cpu-idle-state-pmicr-val were never used and there is no
+ * plan to use it in near future. Hence, not parsing these properties
+ */
+
+ if (of_property_read_string_array(np, "ibm,cpu-idle-state-names",
+ temp_string, nr_idle_states) < 0) {
+ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-names in DT\n");
+ rc = -EINVAL;
+ goto out;
+ }
+ for (i = 0; i < nr_idle_states; i++)
+ strlcpy(pnv_idle_states[i].name, temp_string[i],
+ PNV_IDLE_NAME_LEN);
+ nr_pnv_idle_states = nr_idle_states;
+ rc = 0;
+out:
+ kfree(temp_u32);
+ kfree(temp_u64);
+ kfree(temp_string);
+ return rc;
+}
+
+static int __init pnv_init_idle_states(void)
+{
+ int rc = 0;
+ supported_cpuidle_states = 0;
+
+ /* In case we error out nr_pnv_idle_states will be zero */
+ nr_pnv_idle_states = 0;
+ if (cpuidle_disable != IDLE_NO_OVERRIDE)
+ goto out;
+ rc = pnv_parse_cpuidle_dt();
+ if (rc)
+ return rc;
+ pnv_probe_idle_states();
+
+ if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) {
+ patch_instruction(
+ (unsigned int *)pnv_fastsleep_workaround_at_entry,
+ PPC_INST_NOP);
+ patch_instruction(
+ (unsigned int *)pnv_fastsleep_workaround_at_exit,
+ PPC_INST_NOP);
+ } else {
+ /*
+ * OPAL_PM_SLEEP_ENABLED_ER1 is set. It indicates that
+ * workaround is needed to use fastsleep. Provide sysfs
+ * control to choose how this workaround has to be applied.
+ */
+ device_create_file(cpu_subsys.dev_root,
+ &dev_attr_fastsleep_workaround_applyonce);
+ }
+
+ pnv_alloc_idle_core_states();
+
+ if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED)
+ ppc_md.power_save = power7_idle;
+
+out:
+ return 0;
+}
+machine_subsys_initcall(powernv, pnv_init_idle_states);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 16:59:14 +0000