diff options
| -rw-r--r-- | sys/kern/kern_cpu.c | 42 |
1 files changed, 38 insertions, 4 deletions
diff --git a/sys/kern/kern_cpu.c b/sys/kern/kern_cpu.c index ff1d006..85b33d1 100644 --- a/sys/kern/kern_cpu.c +++ b/sys/kern/kern_cpu.c @@ -57,9 +57,11 @@ __FBSDID("$FreeBSD$"); struct cpufreq_softc { struct cf_level curr_level; - int priority; - int all_count; + int curr_priority; + struct cf_level saved_level; + int saved_priority; struct cf_level_lst all_levels; + int all_count; device_t dev; struct sysctl_ctx_list sysctl_ctx; }; @@ -120,6 +122,7 @@ cpufreq_attach(device_t dev) sysctl_ctx_init(&sc->sysctl_ctx); TAILQ_INIT(&sc->all_levels); sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN; + sc->saved_level.total_set.freq = CPUFREQ_VAL_UNKNOWN; /* * Only initialize one set of sysctls for all CPUs. In the future, @@ -185,6 +188,21 @@ cf_set_method(device_t dev, const struct cf_level *level, int priority) if (strcmp(timecounter->tc_name, "TSC") == 0) return (EBUSY); + /* + * If the caller didn't specify a level and one is saved, prepare to + * restore the saved level. If none has been saved, return an error. + * If they did specify one, but the requested level has a lower + * priority, don't allow the new level right now. + */ + if (level == NULL) { + if (sc->saved_level.total_set.freq != CPUFREQ_VAL_UNKNOWN) { + level = &sc->saved_level; + priority = sc->saved_priority; + } else + return (ENXIO); + } else if (priority < sc->curr_priority) + return (EPERM); + /* If already at this level, just return. */ if (CPUFREQ_CMP(sc->curr_level.total_set.freq, level->total_set.freq)) return (0); @@ -226,9 +244,25 @@ cf_set_method(device_t dev, const struct cf_level *level, int priority) } } - /* Record the current level. */ + /* If we were restoring a saved state, reset it to "unused". */ + if (level == &sc->saved_level) { + sc->saved_level.total_set.freq = CPUFREQ_VAL_UNKNOWN; + sc->saved_priority = 0; + } + + /* + * Before recording the current level, check if we're going to a + * higher priority and have not saved a level yet. If so, save the + * previous level and priority. + */ + if (sc->curr_level.total_set.freq != CPUFREQ_VAL_UNKNOWN && + sc->saved_level.total_set.freq == CPUFREQ_VAL_UNKNOWN && + priority > sc->curr_priority) { + sc->saved_level = sc->curr_level; + sc->saved_priority = sc->curr_priority; + } sc->curr_level = *level; - sc->priority = priority; + sc->curr_priority = priority; error = 0; out: |
