diff options
Diffstat (limited to 'driver/gator_events_power.c')
| -rw-r--r-- | driver/gator_events_power.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/driver/gator_events_power.c b/driver/gator_events_power.c new file mode 100644 index 0000000..a0ae684 --- /dev/null +++ b/driver/gator_events_power.c @@ -0,0 +1,178 @@ +/** + * Copyright (C) ARM Limited 2011-2012. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include "gator.h" +#include <linux/slab.h> +#include <linux/cpufreq.h> +#include <trace/events/power.h> + +// cpu_frequency and cpu_idle trace points were introduced in Linux kernel v2.6.38 +// the now deprecated power_frequency trace point was available prior to 2.6.38, but only for x86 +// CPU Idle is currently disabled in the .xml +#if GATOR_CPU_FREQ_SUPPORT +enum { + POWER_CPU_FREQ, + POWER_CPU_IDLE, + POWER_TOTAL +}; + +static ulong power_cpu_enabled[POWER_TOTAL]; +static ulong power_cpu_key[POWER_TOTAL]; +static DEFINE_PER_CPU(ulong[POWER_TOTAL], power); +static DEFINE_PER_CPU(ulong[POWER_TOTAL], prev); +static DEFINE_PER_CPU(int *, powerGet); + +GATOR_DEFINE_PROBE(cpu_frequency, TP_PROTO(unsigned int frequency, unsigned int cpu)) +{ + per_cpu(power, cpu)[POWER_CPU_FREQ] = frequency * 1000; +} + +GATOR_DEFINE_PROBE(cpu_idle, TP_PROTO(unsigned int state, unsigned int cpu)) +{ + per_cpu(power, cpu)[POWER_CPU_IDLE] = state; +} + +static int gator_events_power_create_files(struct super_block *sb, struct dentry *root) +{ + struct dentry *dir; + + // cpu_frequency + dir = gatorfs_mkdir(sb, root, "Linux_power_cpu_freq"); + if (!dir) { + return -1; + } + gatorfs_create_ulong(sb, dir, "enabled", &power_cpu_enabled[POWER_CPU_FREQ]); + gatorfs_create_ro_ulong(sb, dir, "key", &power_cpu_key[POWER_CPU_FREQ]); + + // cpu_idle + dir = gatorfs_mkdir(sb, root, "Linux_power_cpu_idle"); + if (!dir) { + return -1; + } + gatorfs_create_ulong(sb, dir, "enabled", &power_cpu_enabled[POWER_CPU_IDLE]); + gatorfs_create_ro_ulong(sb, dir, "key", &power_cpu_key[POWER_CPU_IDLE]); + + return 0; +} + +static int gator_events_power_populate(int cpu, int** buffer) +{ + int i, len = 0; + + for (i = 0; i < POWER_TOTAL; i++) { + if (power_cpu_enabled[i]) { + if (per_cpu(power, cpu)[i] != per_cpu(prev, cpu)[i]) { + per_cpu(prev, cpu)[i] = per_cpu(power, cpu)[i]; + per_cpu(powerGet, cpu)[len++] = power_cpu_key[i]; + per_cpu(powerGet, cpu)[len++] = per_cpu(power, cpu)[i]; + } + } + } + + if (buffer) + *buffer = per_cpu(powerGet, cpu); + + return len; +} + +static int gator_events_power_online(int** buffer) +{ + int i, cpu = smp_processor_id(); + for (i = 0; i < POWER_TOTAL; i++) + per_cpu(prev, cpu)[i] = -1; + per_cpu(power, cpu)[POWER_CPU_FREQ] = cpufreq_quick_get(cpu) * 1000; + return gator_events_power_populate(cpu, buffer); +} + +static int gator_events_power_offline(int** buffer) +{ + int cpu = smp_processor_id(); + // Set frequency to zero on an offline + per_cpu(power, cpu)[POWER_CPU_FREQ] = 0; + return gator_events_power_populate(cpu, buffer); +} + +static int gator_events_power_start(void) +{ + int cpu; + + for_each_present_cpu(cpu) { + per_cpu(powerGet, cpu) = kmalloc(POWER_TOTAL * 2, GFP_KERNEL); + if (!per_cpu(powerGet, cpu)) + return -1; + } + + // register tracepoints + if (power_cpu_enabled[POWER_CPU_FREQ]) + if (GATOR_REGISTER_TRACE(cpu_frequency)) + goto fail_cpu_frequency_exit; + if (power_cpu_enabled[POWER_CPU_IDLE]) + if (GATOR_REGISTER_TRACE(cpu_idle)) + goto fail_cpu_idle_exit; + pr_debug("gator: registered power event tracepoints\n"); + + return 0; + + // unregister tracepoints on error +fail_cpu_idle_exit: + GATOR_UNREGISTER_TRACE(cpu_frequency); +fail_cpu_frequency_exit: + pr_err("gator: power event tracepoints failed to activate, please verify that tracepoints are enabled in the linux kernel\n"); + + return -1; +} + +static void gator_events_power_stop(void) +{ + int i, cpu; + if (power_cpu_enabled[POWER_CPU_FREQ]) + GATOR_UNREGISTER_TRACE(cpu_frequency); + if (power_cpu_enabled[POWER_CPU_IDLE]) + GATOR_UNREGISTER_TRACE(cpu_idle); + pr_debug("gator: unregistered power event tracepoints\n"); + + for (i = 0; i < POWER_TOTAL; i++) { + power_cpu_enabled[i] = 0; + } + + for_each_present_cpu(cpu) { + kfree(per_cpu(powerGet, cpu)); + } +} + +static int gator_events_power_read(int **buffer) +{ + return gator_events_power_populate(smp_processor_id(), buffer); +} + +static struct gator_interface gator_events_power_interface = { + .create_files = gator_events_power_create_files, + .online = gator_events_power_online, + .offline = gator_events_power_offline, + .start = gator_events_power_start, + .stop = gator_events_power_stop, + .read = gator_events_power_read, +}; +#endif + +int gator_events_power_init(void) +{ +#if (GATOR_CPU_FREQ_SUPPORT) + int i; + for (i = 0; i < POWER_TOTAL; i++) { + power_cpu_enabled[i] = 0; + power_cpu_key[i] = gator_events_get_key(); + } + + return gator_events_install(&gator_events_power_interface); +#else + return -1; +#endif +} +gator_events_init(gator_events_power_init); |