From 053819e0bf8407746cc5febf7a4947bee50377b4 Mon Sep 17 00:00:00 2001 From: Shilpasri G Bhat Date: Thu, 16 Jul 2015 13:34:18 +0530 Subject: [PATCH] cpufreq: powernv: Handle throttling due to Pmax capping at chip level The On-Chip-Controller(OCC) can throttle cpu frequency by reducing the max allowed frequency for that chip if the chip exceeds its power or temperature limits. As Pmax capping is a chip level condition report this throttling behavior at chip level and also do not set the global 'throttled' on Pmax capping instead set the per-chip throttled variable. Report unthrottling if Pmax is restored after throttling. This patch adds a structure to store chip id and throttled state of the chip. Signed-off-by: Shilpasri G Bhat Reviewed-by: Preeti U Murthy Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/powernv-cpufreq.c | 59 ++++++++++++++++++++++++++++--- 1 file changed, 55 insertions(+), 4 deletions(-) diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index ebef0d8279c7..d0c18c9ce1ff 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -42,6 +43,13 @@ static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1]; static bool rebooting, throttled; +static struct chip { + unsigned int id; + bool throttled; +} *chips; + +static int nr_chips; + /* * Note: The set of pstates consists of contiguous integers, the * smallest of which is indicated by powernv_pstate_info.min, the @@ -301,22 +309,33 @@ static inline unsigned int get_nominal_index(void) static void powernv_cpufreq_throttle_check(unsigned int cpu) { unsigned long pmsr; - int pmsr_pmax, pmsr_lp; + int pmsr_pmax, pmsr_lp, i; pmsr = get_pmspr(SPRN_PMSR); + for (i = 0; i < nr_chips; i++) + if (chips[i].id == cpu_to_chip_id(cpu)) + break; + /* Check for Pmax Capping */ pmsr_pmax = (s8)PMSR_MAX(pmsr); if (pmsr_pmax != powernv_pstate_info.max) { - throttled = true; - pr_info("CPU %d Pmax is reduced to %d\n", cpu, pmsr_pmax); - pr_info("Max allowed Pstate is capped\n"); + if (chips[i].throttled) + goto next; + chips[i].throttled = true; + pr_info("CPU %d on Chip %u has Pmax reduced to %d\n", cpu, + chips[i].id, pmsr_pmax); + } else if (chips[i].throttled) { + chips[i].throttled = false; + pr_info("CPU %d on Chip %u has Pmax restored to %d\n", cpu, + chips[i].id, pmsr_pmax); } /* * Check for Psafe by reading LocalPstate * or check if Psafe_mode_active is set in PMSR. */ +next: pmsr_lp = (s8)PMSR_LP(pmsr); if ((pmsr_lp < powernv_pstate_info.min) || (pmsr & PMSR_PSAFE_ENABLE)) { @@ -414,6 +433,33 @@ static struct cpufreq_driver powernv_cpufreq_driver = { .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 = kmalloc_array(nr_chips, sizeof(struct chip), GFP_KERNEL); + if (!chips) + return -ENOMEM; + + for (i = 0; i < nr_chips; i++) { + chips[i].id = chip[i]; + chips[i].throttled = false; + } + + return 0; +} + static int __init powernv_cpufreq_init(void) { int rc = 0; @@ -429,6 +475,11 @@ static int __init powernv_cpufreq_init(void) return rc; } + /* Populate chip info */ + rc = init_chip_info(); + if (rc) + return rc; + register_reboot_notifier(&powernv_cpufreq_reboot_nb); return cpufreq_register_driver(&powernv_cpufreq_driver); } -- 2.30.2