/* * POWERNV cpufreq driver for the IBM POWER processors * * (C) Copyright IBM 2014 * * Author: Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com> * * 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, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * */ #define pr_fmt(fmt) "powernv-cpufreq: " fmt #include <linux/kernel.h> #include <linux/sysfs.h> #include <linux/cpumask.h> #include <linux/module.h> #include <linux/cpufreq.h> #include <linux/smp.h> #include <linux/of.h> #include <linux/reboot.h> #include <linux/slab.h> #include <linux/cpu.h> #include <trace/events/power.h> #include <asm/cputhreads.h> #include <asm/firmware.h> #include <asm/reg.h> #include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */ #include <asm/opal.h> #include <linux/timer.h> #define POWERNV_MAX_PSTATES 256 #define PMSR_PSAFE_ENABLE (1UL << 30) #define PMSR_SPR_EM_DISABLE (1UL << 31) #define PMSR_MAX(x) ((x >> 32) & 0xFF) #define LPSTATE_SHIFT 48 #define GPSTATE_SHIFT 56 #define GET_LPSTATE(x) (((x) >> LPSTATE_SHIFT) & 0xFF) #define GET_GPSTATE(x) (((x) >> GPSTATE_SHIFT) & 0xFF) #define MAX_RAMP_DOWN_TIME 5120 /* * On an idle system we want the global pstate to ramp-down from max value to * min over a span of ~5 secs. Also we want it to initially ramp-down slowly and * then ramp-down rapidly later on. * * This gives a percentage rampdown for time elapsed in milliseconds. * ramp_down_percentage = ((ms * ms) >> 18) * ~= 3.8 * (sec * sec) * * At 0 ms ramp_down_percent = 0 * At 5120 ms ramp_down_percent = 100 */ #define ramp_down_percent(time) ((time * time) >> 18) /* Interval after which the timer is queued to bring down global pstate */ #define GPSTATE_TIMER_INTERVAL 2000 /** * struct global_pstate_info - Per policy data structure to maintain history of * global pstates * @highest_lpstate_idx: The local pstate index from which we are * ramping down * @elapsed_time: Time in ms spent in ramping down from * highest_lpstate_idx * @last_sampled_time: Time from boot in ms when global pstates were * last set * @last_lpstate_idx, Last set value of local pstate and global * last_gpstate_idx pstate in terms of cpufreq table index * @timer: Is used for ramping down if cpu goes idle for * a long time with global pstate held high * @gpstate_lock: A spinlock to maintain synchronization between * routines called by the timer handler and * governer's target_index calls */ struct global_pstate_info { int highest_lpstate_idx; unsigned int elapsed_time; unsigned int last_sampled_time; int last_lpstate_idx; int last_gpstate_idx; spinlock_t gpstate_lock; struct timer_list timer; }; static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1]; static bool rebooting, throttled, occ_reset; static const char * const throttle_reason[] = { "No throttling", "Power Cap", "Processor Over Temperature", "Power Supply Failure", "Over Current", "OCC Reset" }; enum throttle_reason_type { NO_THROTTLE = 0, POWERCAP, CPU_OVERTEMP, POWER_SUPPLY_FAILURE, OVERCURRENT, OCC_RESET_THROTTLE, OCC_MAX_REASON }; static struct chip { unsigned int id; bool throttled; bool restore; u8 throttle_reason; cpumask_t mask; struct work_struct throttle; int throttle_turbo; int throttle_sub_turbo; int reason[OCC_MAX_REASON]; } *chips; static int nr_chips; static DEFINE_PER_CPU(struct chip *, chip_info); /* * Note: * The set of pstates consists of contiguous integers. * powernv_pstate_info stores the index of the frequency table for * max, min and nominal frequencies. It also stores number of * available frequencies. * * powernv_pstate_info.nominal indicates the index to the highest * non-turbo frequency. */ static struct powernv_pstate_info { unsigned int min; unsigned int max; unsigned int nominal; unsigned int nr_pstates; bool wof_enabled; } powernv_pstate_info; /* Use following macros for conversions between pstate_id and index */ static inline int idx_to_pstate(unsigned int i) { if (unlikely(i >= powernv_pstate_info.nr_pstates)) { pr_warn_once("index %u is out of bound\n", i); return powernv_freqs[powernv_pstate_info.nominal].driver_data; } return powernv_freqs[i].driver_data; } static inline unsigned int pstate_to_idx(int pstate) { int min = powernv_freqs[powernv_pstate_info.min].driver_data; int max = powernv_freqs[powernv_pstate_info.max].driver_data; if (min > 0) { if (unlikely((pstate < max) || (pstate > min))) { pr_warn_once("pstate %d is out of bound\n", pstate); return powernv_pstate_info.nominal; } } else { if (unlikely((pstate > max) || (pstate < min))) { pr_warn_once("pstate %d is out of bound\n", pstate); return powernv_pstate_info.nominal; } } /* * abs() is deliberately used so that is works with * both monotonically increasing and decreasing * pstate values */ return abs(pstate - idx_to_pstate(powernv_pstate_info.max)); } static inline void reset_gpstates(struct cpufreq_policy *policy) { struct global_pstate_info *gpstates = policy->driver_data; gpstates->highest_lpstate_idx = 0; gpstates->elapsed_time = 0; gpstates->last_sampled_time = 0; gpstates->last_lpstate_idx = 0; gpstates->last_gpstate_idx = 0; } /* * Initialize the freq table based on data obtained * from the firmware passed via device-tree */ static int init_powernv_pstates(void) { struct device_node *power_mgt; int i, nr_pstates = 0; const __be32 *pstate_ids, *pstate_freqs; u32 len_ids, len_freqs; u32 pstate_min, pstate_max, pstate_nominal; u32 pstate_turbo, pstate_ultra_turbo; power_mgt = of_find_node_by_path("/ibm,opal/power-mgt"); if (!power_mgt) { pr_warn("power-mgt node not found\n"); return -ENODEV; } if (of_property_read_u32(power_mgt, "ibm,pstate-min", &pstate_min)) { pr_warn("ibm,pstate-min node not found\n"); return -ENODEV; } if (of_property_read_u32(power_mgt, "ibm,pstate-max", &pstate_max)) { pr_warn("ibm,pstate-max node not found\n"); return -ENODEV; } if (of_property_read_u32(power_mgt, "ibm,pstate-nominal", &pstate_nominal)) { pr_warn("ibm,pstate-nominal not found\n"); return -ENODEV; } if (of_property_read_u32(power_mgt, "ibm,pstate-ultra-turbo", &pstate_ultra_turbo)) { powernv_pstate_info.wof_enabled = false; goto next; } if (of_property_read_u32(power_mgt, "ibm,pstate-turbo", &pstate_turbo)) { powernv_pstate_info.wof_enabled = false; goto next; } if (pstate_turbo == pstate_ultra_turbo) powernv_pstate_info.wof_enabled = false; else powernv_pstate_info.wof_enabled = true; next: pr_info("cpufreq pstate min %d nominal %d max %d\n", pstate_min, pstate_nominal, pstate_max); pr_info("Workload Optimized Frequency is %s in the platform\n", (powernv_pstate_info.wof_enabled) ? "enabled" : "disabled"); pstate_ids = of_get_property(power_mgt, "ibm,pstate-ids", &len_ids); if (!pstate_ids) { pr_warn("ibm,pstate-ids not found\n"); return -ENODEV; } pstate_freqs = of_get_property(power_mgt, "ibm,pstate-frequencies-mhz", &len_freqs); if (!pstate_freqs) { pr_warn("ibm,pstate-frequencies-mhz not found\n"); return -ENODEV; } if (len_ids != len_freqs) { pr_warn("Entries in ibm,pstate-ids and " "ibm,pstate-frequencies-mhz does not match\n"); } nr_pstates = min(len_ids, len_freqs) / sizeof(u32); if (!nr_pstates) { pr_warn("No PStates found\n"); return -ENODEV; } powernv_pstate_info.nr_pstates = nr_pstates; pr_debug("NR PStates %d\n", nr_pstates); for (i = 0; i < nr_pstates; i++) { u32 id = be32_to_cpu(pstate_ids[i]); u32 freq = be32_to_cpu(pstate_freqs[i]); pr_debug("PState id %d freq %d MHz\n", id, freq); powernv_freqs[i].frequency = freq * 1000; /* kHz */ powernv_freqs[i].driver_data = id; if (id == pstate_max) powernv_pstate_info.max = i; else if (id == pstate_nominal) powernv_pstate_info.nominal = i; else if (id == pstate_min) powernv_pstate_info.min = i; if (powernv_pstate_info.wof_enabled && id == pstate_turbo) { int j; for (j = i - 1; j >= (int)powernv_pstate_info.max; j--) powernv_freqs[j].flags = CPUFREQ_BOOST_FREQ; } } /* End of list marker entry */ powernv_freqs[i].frequency = CPUFREQ_TABLE_END; return 0; } /* Returns the CPU frequency corresponding to the pstate_id. */ static unsigned int pstate_id_to_freq(int pstate_id) { int i; i = pstate_to_idx(pstate_id); if (i >= powernv_pstate_info.nr_pstates || i < 0) { pr_warn("PState id %d outside of PState table, " "reporting nominal id %d instead\n", pstate_id, idx_to_pstate(powernv_pstate_info.nominal)); i = powernv_pstate_info.nominal; } return powernv_freqs[i].frequency; } /* * cpuinfo_nominal_freq_show - Show the nominal CPU frequency as indicated by * the firmware */ static ssize_t cpuinfo_nominal_freq_show(struct cpufreq_policy *policy, char *buf) { return sprintf(buf, "%u\n", powernv_freqs[powernv_pstate_info.nominal].frequency); } struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq = __ATTR_RO(cpuinfo_nominal_freq); #define SCALING_BOOST_FREQS_ATTR_INDEX 2 static struct freq_attr *powernv_cpu_freq_attr[] = { &cpufreq_freq_attr_scaling_available_freqs, &cpufreq_freq_attr_cpuinfo_nominal_freq, &cpufreq_freq_attr_scaling_boost_freqs, NULL, }; #define throttle_attr(name, member) \ static ssize_t name##_show(struct cpufreq_policy *policy, char *buf) \ { \ struct chip *chip = per_cpu(chip_info, policy->cpu); \ \ return sprintf(buf, "%u\n", chip->member); \ } \ \ static struct freq_attr throttle_attr_##name = __ATTR_RO(name) \ throttle_attr(unthrottle, reason[NO_THROTTLE]); throttle_attr(powercap, reason[POWERCAP]); throttle_attr(overtemp, reason[CPU_OVERTEMP]); throttle_attr(supply_fault, reason[POWER_SUPPLY_FAILURE]); throttle_attr(overcurrent, reason[OVERCURRENT]); throttle_attr(occ_reset, reason[OCC_RESET_THROTTLE]); throttle_attr(turbo_stat, throttle_turbo); throttle_attr(sub_turbo_stat, throttle_sub_turbo); static struct attribute *throttle_attrs[] = { &throttle_attr_unthrottle.attr, &throttle_attr_powercap.attr, &throttle_attr_overtemp.attr, &throttle_attr_supply_fault.attr, &throttle_attr_overcurrent.attr, &throttle_attr_occ_reset.attr, &throttle_attr_turbo_stat.attr, &throttle_attr_sub_turbo_stat.attr, NULL, }; static const struct attribute_group throttle_attr_grp = { .name = "throttle_stats", .attrs = throttle_attrs, }; /* Helper routines */ /* Access helpers to power mgt SPR */ static inline unsigned long get_pmspr(unsigned long sprn) { switch (sprn) { case SPRN_PMCR: return mfspr(SPRN_PMCR); case SPRN_PMICR: return mfspr(SPRN_PMICR); case SPRN_PMSR: return mfspr(SPRN_PMSR); } BUG(); } static inline void set_pmspr(unsigned long sprn, unsigned long val) { switch (sprn) { case SPRN_PMCR: mtspr(SPRN_PMCR, val); return; case SPRN_PMICR: mtspr(SPRN_PMICR, val); return; } BUG(); } /* * Use objects of this type to query/update * pstates on a remote CPU via smp_call_function. */ struct powernv_smp_call_data { unsigned int freq; int pstate_id; int gpstate_id; }; /* * powernv_read_cpu_freq: Reads the current frequency on this CPU. * * Called via smp_call_function. * * Note: The caller of the smp_call_function should pass an argument of * the type 'struct powernv_smp_call_data *' along with this function. * * The current frequency on this CPU will be returned via * ((struct powernv_smp_call_data *)arg)->freq; */ static void powernv_read_cpu_freq(void *arg) { unsigned long pmspr_val; s8 local_pstate_id; struct powernv_smp_call_data *freq_data = arg; pmspr_val = get_pmspr(SPRN_PMSR); /* * The local pstate id corresponds bits 48..55 in the PMSR. * Note: Watch out for the sign! */ local_pstate_id = (pmspr_val >> 48) & 0xFF; freq_data->pstate_id = local_pstate_id; freq_data->freq = pstate_id_to_freq(freq_data->pstate_id); pr_debug("cpu %d pmsr %016lX pstate_id %d frequency %d kHz\n", raw_smp_processor_id(), pmspr_val, freq_data->pstate_id, freq_data->freq); } /* * powernv_cpufreq_get: Returns the CPU frequency as reported by the * firmware for CPU 'cpu'. This value is reported through the sysfs * file cpuinfo_cur_freq. */ static unsigned int powernv_cpufreq_get(unsigned int cpu) { struct powernv_smp_call_data freq_data; smp_call_function_any(cpu_sibling_mask(cpu), powernv_read_cpu_freq, &freq_data, 1); return freq_data.freq; } /* * set_pstate: Sets the pstate on this CPU. * * This is called via an smp_call_function. * * The caller must ensure that freq_data is of the type * (struct powernv_smp_call_data *) and the pstate_id which needs to be set * on this CPU should be present in freq_data->pstate_id. */ static void set_pstate(void *data) { unsigned long val; struct powernv_smp_call_data *freq_data = data; unsigned long pstate_ul = freq_data->pstate_id; unsigned long gpstate_ul = freq_data->gpstate_id; val = get_pmspr(SPRN_PMCR); val = val & 0x0000FFFFFFFFFFFFULL; pstate_ul = pstate_ul & 0xFF; gpstate_ul = gpstate_ul & 0xFF; /* Set both global(bits 56..63) and local(bits 48..55) PStates */ val = val | (gpstate_ul << 56) | (pstate_ul << 48); pr_debug("Setting cpu %d pmcr to %016lX\n", raw_smp_processor_id(), val); set_pmspr(SPRN_PMCR, val); } /* * get_nominal_index: Returns the index corresponding to the nominal * pstate in the cpufreq table */ static inline unsigned int get_nominal_index(void) { return powernv_pstate_info.nominal; } static void powernv_cpufreq_throttle_check(void *data) { struct chip *chip; unsigned int cpu = smp_processor_id(); unsigned long pmsr; int pmsr_pmax; unsigned int pmsr_pmax_idx; pmsr = get_pmspr(SPRN_PMSR); chip = this_cpu_read(chip_info); /* Check for Pmax Capping */ pmsr_pmax = (s8)PMSR_MAX(pmsr); pmsr_pmax_idx = pstate_to_idx(pmsr_pmax); if (pmsr_pmax_idx != powernv_pstate_info.max) { if (chip->throttled) goto next; chip->throttled = true; if (pmsr_pmax_idx > powernv_pstate_info.nominal) { pr_warn_once("CPU %d on Chip %u has Pmax(%d) reduced below nominal frequency(%d)\n", cpu, chip->id, pmsr_pmax, idx_to_pstate(powernv_pstate_info.nominal)); chip->throttle_sub_turbo++; } else { chip->throttle_turbo++; } trace_powernv_throttle(chip->id, throttle_reason[chip->throttle_reason], pmsr_pmax); } else if (chip->throttled) { chip->throttled = false; trace_powernv_throttle(chip->id, throttle_reason[chip->throttle_reason], pmsr_pmax); } /* Check if Psafe_mode_active is set in PMSR. */ next: if (pmsr & PMSR_PSAFE_ENABLE) { throttled = true; pr_info("Pstate set to safe frequency\n"); } /* Check if SPR_EM_DISABLE is set in PMSR */ if (pmsr & PMSR_SPR_EM_DISABLE) { throttled = true; pr_info("Frequency Control disabled from OS\n"); } if (throttled) { pr_info("PMSR = %16lx\n", pmsr); pr_warn("CPU Frequency could be throttled\n"); } } /** * calc_global_pstate - Calculate global pstate * @elapsed_time: Elapsed time in milliseconds * @local_pstate_idx: New local pstate * @highest_lpstate_idx: pstate from which its ramping down * * Finds the appropriate global pstate based on the pstate from which its * ramping down and the time elapsed in ramping down. It follows a quadratic * equation which ensures that it reaches ramping down to pmin in 5sec. */ static inline int calc_global_pstate(unsigned int elapsed_time, int highest_lpstate_idx, int local_pstate_idx) { int index_diff; /* * Using ramp_down_percent we get the percentage of rampdown * that we are expecting to be dropping. Difference between * highest_lpstate_idx and powernv_pstate_info.min will give a absolute * number of how many pstates we will drop eventually by the end of * 5 seconds, then just scale it get the number pstates to be dropped. */ index_diff = ((int)ramp_down_percent(elapsed_time) * (powernv_pstate_info.min - highest_lpstate_idx)) / 100; /* Ensure that global pstate is >= to local pstate */ if (highest_lpstate_idx + index_diff >= local_pstate_idx) return local_pstate_idx; else return highest_lpstate_idx + index_diff; } static inline void queue_gpstate_timer(struct global_pstate_info *gpstates) { unsigned int timer_interval; /* * Setting up timer to fire after GPSTATE_TIMER_INTERVAL ms, But * if it exceeds MAX_RAMP_DOWN_TIME ms for ramp down time. * Set timer such that it fires exactly at MAX_RAMP_DOWN_TIME * seconds of ramp down time. */ if ((gpstates->elapsed_time + GPSTATE_TIMER_INTERVAL) > MAX_RAMP_DOWN_TIME) timer_interval = MAX_RAMP_DOWN_TIME - gpstates->elapsed_time; else timer_interval = GPSTATE_TIMER_INTERVAL; mod_timer(&gpstates->timer, jiffies + msecs_to_jiffies(timer_interval)); } /** * gpstate_timer_handler * * @data: pointer to cpufreq_policy on which timer was queued * * This handler brings down the global pstate closer to the local pstate * according quadratic equation. Queues a new timer if it is still not equal * to local pstate */ void gpstate_timer_handler(unsigned long data) { struct cpufreq_policy *policy = (struct cpufreq_policy *)data; struct global_pstate_info *gpstates = policy->driver_data; int gpstate_idx, lpstate_idx; unsigned long val; unsigned int time_diff = jiffies_to_msecs(jiffies) - gpstates->last_sampled_time; struct powernv_smp_call_data freq_data; if (!spin_trylock(&gpstates->gpstate_lock)) return; /* * If PMCR was last updated was using fast_swtich then * We may have wrong in gpstate->last_lpstate_idx * value. Hence, read from PMCR to get correct data. */ val = get_pmspr(SPRN_PMCR); freq_data.gpstate_id = (s8)GET_GPSTATE(val); freq_data.pstate_id = (s8)GET_LPSTATE(val); if (freq_data.gpstate_id == freq_data.pstate_id) { reset_gpstates(policy); spin_unlock(&gpstates->gpstate_lock); return; } gpstates->last_sampled_time += time_diff; gpstates->elapsed_time += time_diff; if (gpstates->elapsed_time > MAX_RAMP_DOWN_TIME) { gpstate_idx = pstate_to_idx(freq_data.pstate_id); lpstate_idx = gpstate_idx; reset_gpstates(policy); gpstates->highest_lpstate_idx = gpstate_idx; } else { lpstate_idx = pstate_to_idx(freq_data.pstate_id); gpstate_idx = calc_global_pstate(gpstates->elapsed_time, gpstates->highest_lpstate_idx, lpstate_idx); } freq_data.gpstate_id = idx_to_pstate(gpstate_idx); gpstates->last_gpstate_idx = gpstate_idx; gpstates->last_lpstate_idx = lpstate_idx; /* * If local pstate is equal to global pstate, rampdown is over * So timer is not required to be queued. */ if (gpstate_idx != gpstates->last_lpstate_idx) queue_gpstate_timer(gpstates); spin_unlock(&gpstates->gpstate_lock); /* Timer may get migrated to a different cpu on cpu hot unplug */ smp_call_function_any(policy->cpus, set_pstate, &freq_data, 1); } /* * powernv_cpufreq_target_index: Sets the frequency corresponding to * the cpufreq table entry indexed by new_index on the cpus in the * mask policy->cpus */ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy, unsigned int new_index) { struct powernv_smp_call_data freq_data; unsigned int cur_msec, gpstate_idx; struct global_pstate_info *gpstates = policy->driver_data; if (unlikely(rebooting) && new_index != get_nominal_index()) return 0; if (!throttled) { /* we don't want to be preempted while * checking if the CPU frequency has been throttled */ preempt_disable(); powernv_cpufreq_throttle_check(NULL); preempt_enable(); } cur_msec = jiffies_to_msecs(get_jiffies_64()); spin_lock(&gpstates->gpstate_lock); freq_data.pstate_id = idx_to_pstate(new_index); if (!gpstates->last_sampled_time) { gpstate_idx = new_index; gpstates->highest_lpstate_idx = new_index; goto gpstates_done; } if (gpstates->last_gpstate_idx < new_index) { gpstates->elapsed_time += cur_msec - gpstates->last_sampled_time; /* * If its has been ramping down for more than MAX_RAMP_DOWN_TIME * we should be resetting all global pstate related data. Set it * equal to local pstate to start fresh. */ if (gpstates->elapsed_time > MAX_RAMP_DOWN_TIME) { reset_gpstates(policy); gpstates->highest_lpstate_idx = new_index; gpstate_idx = new_index; } else { /* Elaspsed_time is less than 5 seconds, continue to rampdown */ gpstate_idx = calc_global_pstate(gpstates->elapsed_time, gpstates->highest_lpstate_idx, new_index); } } else { reset_gpstates(policy); gpstates->highest_lpstate_idx = new_index; gpstate_idx = new_index; } /* * If local pstate is equal to global pstate, rampdown is over * So timer is not required to be queued. */ if (gpstate_idx != new_index) queue_gpstate_timer(gpstates); else del_timer_sync(&gpstates->timer); gpstates_done: freq_data.gpstate_id = idx_to_pstate(gpstate_idx); gpstates->last_sampled_time = cur_msec; gpstates->last_gpstate_idx = gpstate_idx; gpstates->last_lpstate_idx = new_index; spin_unlock(&gpstates->gpstate_lock); /* * Use smp_call_function to send IPI and execute the * mtspr on target CPU. We could do that without IPI * if current CPU is within policy->cpus (core) */ smp_call_function_any(policy->cpus, set_pstate, &freq_data, 1); return 0; } static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy) { int base, i, ret; struct kernfs_node *kn; struct global_pstate_info *gpstates; base = cpu_first_thread_sibling(policy->cpu); for (i = 0; i < threads_per_core; i++) cpumask_set_cpu(base + i, policy->cpus); kn = kernfs_find_and_get(policy->kobj.sd, throttle_attr_grp.name); if (!kn) { int ret; ret = sysfs_create_group(&policy->kobj, &throttle_attr_grp); if (ret) { pr_info("Failed to create throttle stats directory for cpu %d\n", policy->cpu); return ret; } } else { kernfs_put(kn); } gpstates = kzalloc(sizeof(*gpstates), GFP_KERNEL); if (!gpstates) return -ENOMEM; policy->driver_data = gpstates; /* initialize timer */ init_timer_pinned_deferrable(&gpstates->timer); gpstates->timer.data = (unsigned long)policy; gpstates->timer.function = gpstate_timer_handler; gpstates->timer.expires = jiffies + msecs_to_jiffies(GPSTATE_TIMER_INTERVAL); spin_lock_init(&gpstates->gpstate_lock); ret = cpufreq_table_validate_and_show(policy, powernv_freqs); if (ret < 0) { kfree(policy->driver_data); return ret; } policy->fast_switch_possible = true; return ret; } static int powernv_cpufreq_cpu_exit(struct cpufreq_policy *policy) { /* timer is deleted in cpufreq_cpu_stop() */ kfree(policy->driver_data); return 0; } static int powernv_cpufreq_reboot_notifier(struct notifier_block *nb, unsigned long action, void *unused) { int cpu; struct cpufreq_policy cpu_policy; rebooting = true; for_each_online_cpu(cpu) { cpufreq_get_policy(&cpu_policy, cpu); powernv_cpufreq_target_index(&cpu_policy, get_nominal_index()); } return NOTIFY_DONE; } static struct notifier_block powernv_cpufreq_reboot_nb = { .notifier_call = powernv_cpufreq_reboot_notifier, }; void powernv_cpufreq_work_fn(struct work_struct *work) { struct chip *chip = container_of(work, struct chip, throttle); unsigned int cpu; cpumask_t mask; get_online_cpus(); cpumask_and(&mask, &chip->mask, cpu_online_mask); smp_call_function_any(&mask, powernv_cpufreq_throttle_check, NULL, 0); if (!chip->restore) goto out; chip->restore = false; for_each_cpu(cpu, &mask) { int index; struct cpufreq_policy policy; cpufreq_get_policy(&policy, cpu); index = cpufreq_table_find_index_c(&policy, policy.cur); powernv_cpufreq_target_index(&policy, index); cpumask_andnot(&mask, &mask, policy.cpus); } out: put_online_cpus(); } static int powernv_cpufreq_occ_msg(struct notifier_block *nb, unsigned long msg_type, void *_msg) { struct opal_msg *msg = _msg; struct opal_occ_msg omsg; int i; if (msg_type != OPAL_MSG_OCC) return 0; omsg.type = be64_to_cpu(msg->params[0]); switch (omsg.type) { case OCC_RESET: occ_reset = true; pr_info("OCC (On Chip Controller - enforces hard thermal/power limits) Resetting\n"); /* * powernv_cpufreq_throttle_check() is called in * target() callback which can detect the throttle state * for governors like ondemand. * But static governors will not call target() often thus * report throttling here. */ if (!throttled) { throttled = true; pr_warn("CPU frequency is throttled for duration\n"); } break; case OCC_LOAD: pr_info("OCC Loading, CPU frequency is throttled until OCC is started\n"); break; case OCC_THROTTLE: omsg.chip = be64_to_cpu(msg->params[1]); omsg.throttle_status = be64_to_cpu(msg->params[2]); if (occ_reset) { occ_reset = false; throttled = false; pr_info("OCC Active, CPU frequency is no longer throttled\n"); for (i = 0; i < nr_chips; i++) { chips[i].restore = true; schedule_work(&chips[i].throttle); } return 0; } for (i = 0; i < nr_chips; i++) if (chips[i].id == omsg.chip) break; if (omsg.throttle_status >= 0 && omsg.throttle_status <= OCC_MAX_THROTTLE_STATUS) { chips[i].throttle_reason = omsg.throttle_status; chips[i].reason[omsg.throttle_status]++; } if (!omsg.throttle_status) chips[i].restore = true; schedule_work(&chips[i].throttle); } return 0; } static struct notifier_block powernv_cpufreq_opal_nb = { .notifier_call = powernv_cpufreq_occ_msg, .next = NULL, .priority = 0, }; static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy) { struct powernv_smp_call_data freq_data; struct global_pstate_info *gpstates = policy->driver_data; freq_data.pstate_id = idx_to_pstate(powernv_pstate_info.min); freq_data.gpstate_id = idx_to_pstate(powernv_pstate_info.min); smp_call_function_single(policy->cpu, set_pstate, &freq_data, 1); del_timer_sync(&gpstates->timer); } static unsigned int powernv_fast_switch(struct cpufreq_policy *policy, unsigned int target_freq) { int index; struct powernv_smp_call_data freq_data; index = cpufreq_table_find_index_dl(policy, target_freq); freq_data.pstate_id = powernv_freqs[index].driver_data; freq_data.gpstate_id = powernv_freqs[index].driver_data; set_pstate(&freq_data); return powernv_freqs[index].frequency; } static struct cpufreq_driver powernv_cpufreq_driver = { .name = "powernv-cpufreq", .flags = CPUFREQ_CONST_LOOPS, .init = powernv_cpufreq_cpu_init, .exit = powernv_cpufreq_cpu_exit, .verify = cpufreq_generic_frequency_table_verify, .target_index = powernv_cpufreq_target_index, .fast_switch = powernv_fast_switch, .get = powernv_cpufreq_get, .stop_cpu = powernv_cpufreq_stop_cpu, .attr = powernv_cpu_freq_attr, }; static int init_chip_info(void) { unsigned int chip[256]; unsigned int cpu, i; unsigned int prev_chip_id = UINT_MAX; for_each_possible_cpu(cpu) { unsigned int id = cpu_to_chip_id(cpu); if (prev_chip_id != id) { prev_chip_id = id; chip[nr_chips++] = id; } } chips = kcalloc(nr_chips, sizeof(struct chip), GFP_KERNEL); if (!chips) return -ENOMEM; for (i = 0; i < nr_chips; i++) { chips[i].id = chip[i]; cpumask_copy(&chips[i].mask, cpumask_of_node(chip[i])); INIT_WORK(&chips[i].throttle, powernv_cpufreq_work_fn); for_each_cpu(cpu, &chips[i].mask) per_cpu(chip_info, cpu) = &chips[i]; } return 0; } static inline void clean_chip_info(void) { kfree(chips); } static inline void unregister_all_notifiers(void) { opal_message_notifier_unregister(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb); unregister_reboot_notifier(&powernv_cpufreq_reboot_nb); } static int __init powernv_cpufreq_init(void) { int rc = 0; /* Don't probe on pseries (guest) platforms */ if (!firmware_has_feature(FW_FEATURE_OPAL)) return -ENODEV; /* Discover pstates from device tree and init */ rc = init_powernv_pstates(); if (rc) goto out; /* Populate chip info */ rc = init_chip_info(); if (rc) goto out; register_reboot_notifier(&powernv_cpufreq_reboot_nb); opal_message_notifier_register(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb); if (powernv_pstate_info.wof_enabled) powernv_cpufreq_driver.boost_enabled = true; else powernv_cpu_freq_attr[SCALING_BOOST_FREQS_ATTR_INDEX] = NULL; rc = cpufreq_register_driver(&powernv_cpufreq_driver); if (rc) { pr_info("Failed to register the cpufreq driver (%d)\n", rc); goto cleanup_notifiers; } if (powernv_pstate_info.wof_enabled) cpufreq_enable_boost_support(); return 0; cleanup_notifiers: unregister_all_notifiers(); clean_chip_info(); out: pr_info("Platform driver disabled. System does not support PState control\n"); return rc; } module_init(powernv_cpufreq_init); static void __exit powernv_cpufreq_exit(void) { cpufreq_unregister_driver(&powernv_cpufreq_driver); unregister_all_notifiers(); clean_chip_info(); } module_exit(powernv_cpufreq_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>");