diff options
Diffstat (limited to 'drivers/cpufreq/powernv-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/powernv-cpufreq.c | 62 |
1 files changed, 60 insertions, 2 deletions
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index bb1d08dc8cc8..2dfd4fdb5a52 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -26,14 +26,17 @@ #include <linux/cpufreq.h> #include <linux/smp.h> #include <linux/of.h> +#include <linux/reboot.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 */ #define POWERNV_MAX_PSTATES 256 static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1]; +static bool rebooting; /* * Note: The set of pstates consists of contiguous integers, the @@ -98,7 +101,11 @@ static int init_powernv_pstates(void) return -ENODEV; } - WARN_ON(len_ids != len_freqs); + 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"); @@ -131,7 +138,12 @@ static unsigned int pstate_id_to_freq(int pstate_id) int i; i = powernv_pstate_info.max - pstate_id; - BUG_ON(i >= powernv_pstate_info.nr_pstates || i < 0); + 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, powernv_pstate_info.nominal); + i = powernv_pstate_info.max - powernv_pstate_info.nominal; + } return powernv_freqs[i].frequency; } @@ -274,6 +286,15 @@ static void set_pstate(void *freq_data) } /* + * 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.max - powernv_pstate_info.nominal; +} + +/* * 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 @@ -283,6 +304,9 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy, { struct powernv_smp_call_data freq_data; + if (unlikely(rebooting) && new_index != get_nominal_index()) + return 0; + freq_data.pstate_id = powernv_freqs[new_index].driver_data; /* @@ -307,6 +331,33 @@ static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy) return cpufreq_table_validate_and_show(policy, powernv_freqs); } +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, +}; + +static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy) +{ + struct powernv_smp_call_data freq_data; + + freq_data.pstate_id = powernv_pstate_info.min; + smp_call_function_single(policy->cpu, set_pstate, &freq_data, 1); +} + static struct cpufreq_driver powernv_cpufreq_driver = { .name = "powernv-cpufreq", .flags = CPUFREQ_CONST_LOOPS, @@ -314,6 +365,7 @@ static struct cpufreq_driver powernv_cpufreq_driver = { .verify = cpufreq_generic_frequency_table_verify, .target_index = powernv_cpufreq_target_index, .get = powernv_cpufreq_get, + .stop_cpu = powernv_cpufreq_stop_cpu, .attr = powernv_cpu_freq_attr, }; @@ -321,6 +373,10 @@ static int __init powernv_cpufreq_init(void) { int rc = 0; + /* Don't probe on pseries (guest) platforms */ + if (!firmware_has_feature(FW_FEATURE_OPALv3)) + return -ENODEV; + /* Discover pstates from device tree and init */ rc = init_powernv_pstates(); if (rc) { @@ -328,12 +384,14 @@ static int __init powernv_cpufreq_init(void) return rc; } + register_reboot_notifier(&powernv_cpufreq_reboot_nb); return cpufreq_register_driver(&powernv_cpufreq_driver); } module_init(powernv_cpufreq_init); static void __exit powernv_cpufreq_exit(void) { + unregister_reboot_notifier(&powernv_cpufreq_reboot_nb); cpufreq_unregister_driver(&powernv_cpufreq_driver); } module_exit(powernv_cpufreq_exit); |