| /* |
| * 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 MAX_PSTATE_SHIFT 32 |
| #define LPSTATE_SHIFT 48 |
| #define GPSTATE_SHIFT 56 |
| |
| #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]; |
| u32 pstate_sign_prefix; |
| 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; |
| |
| static inline int extract_pstate(u64 pmsr_val, unsigned int shift) |
| { |
| int ret = ((pmsr_val >> shift) & 0xFF); |
| |
| if (!ret) |
| return ret; |
| |
| return (pstate_sign_prefix | ret); |
| } |
| |
| #define extract_local_pstate(x) extract_pstate(x, LPSTATE_SHIFT) |
| #define extract_global_pstate(x) extract_pstate(x, GPSTATE_SHIFT) |
| #define extract_max_pstate(x) extract_pstate(x, MAX_PSTATE_SHIFT) |
| |
| /* 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); |
| |
| pstate_sign_prefix = pstate_min & ~0xFF; |
| |
| 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; |
| if (id == pstate_nominal) |
| powernv_pstate_info.nominal = i; |
| 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; |
| struct powernv_smp_call_data *freq_data = arg; |
| |
| pmspr_val = get_pmspr(SPRN_PMSR); |
| freq_data->pstate_id = extract_local_pstate(pmspr_val); |
| 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 = extract_max_pstate(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 the timer has migrated to the different cpu then bring |
| * it back to one of the policy->cpus |
| */ |
| if (!cpumask_test_cpu(raw_smp_processor_id(), policy->cpus)) { |
| gpstates->timer.expires = jiffies + msecs_to_jiffies(1); |
| add_timer_on(&gpstates->timer, cpumask_first(policy->cpus)); |
| spin_unlock(&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 = extract_global_pstate(val); |
| freq_data.pstate_id = extract_local_pstate(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); |
| |
| set_pstate(&freq_data); |
| spin_unlock(&gpstates->gpstate_lock); |
| } |
| |
| /* |
| * 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; |
| unsigned int cpu, i; |
| unsigned int prev_chip_id = UINT_MAX; |
| int ret = 0; |
| |
| chip = kcalloc(num_possible_cpus(), sizeof(*chip), GFP_KERNEL); |
| if (!chip) |
| return -ENOMEM; |
| |
| 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) { |
| ret = -ENOMEM; |
| goto free_and_return; |
| } |
| |
| 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]; |
| } |
| |
| free_and_return: |
| kfree(chip); |
| return ret; |
| } |
| |
| static inline void clean_chip_info(void) |
| { |
| int i; |
| |
| /* flush any pending work items */ |
| if (chips) |
| for (i = 0; i < nr_chips; i++) |
| cancel_work_sync(&chips[i].throttle); |
| 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>"); |