diff --git a/sys/kern/kern_cpu.c b/sys/kern/kern_cpu.c
index 4bf9d3693e50..0688b499282c 100644
--- a/sys/kern/kern_cpu.c
+++ b/sys/kern/kern_cpu.c
@@ -32,6 +32,7 @@ __FBSDID("$FreeBSD$");
#include <sys/cpu.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
+#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/proc.h>
@@ -40,6 +41,7 @@ __FBSDID("$FreeBSD$");
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/sbuf.h>
+#include <sys/sx.h>
#include <sys/timetc.h>
#include "cpufreq_if.h"
@@ -56,6 +58,7 @@ __FBSDID("$FreeBSD$");
#define CF_MAX_LEVELS 64
struct cpufreq_softc {
+ struct sx lock;
struct cf_level curr_level;
int curr_priority;
struct cf_level saved_level;
@@ -75,6 +78,11 @@ struct cf_setting_array {
TAILQ_HEAD(cf_setting_lst, cf_setting_array);
+#define CF_MTX_INIT(x) sx_init((x), "cpufreq lock")
+#define CF_MTX_LOCK(x) sx_xlock((x))
+#define CF_MTX_UNLOCK(x) sx_xunlock((x))
+#define CF_MTX_ASSERT(x) sx_assert((x), SX_XLOCKED)
+
static int cpufreq_attach(device_t dev);
static int cpufreq_detach(device_t dev);
static void cpufreq_evaluate(void *arg);
@@ -129,6 +137,7 @@ cpufreq_attach(device_t dev)
sc->dev = dev;
sysctl_ctx_init(&sc->sysctl_ctx);
TAILQ_INIT(&sc->all_levels);
+ CF_MTX_INIT(&sc->lock);
sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
sc->saved_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
@@ -188,6 +197,8 @@ cf_set_method(device_t dev, const struct cf_level *level, int priority)
int cpu_id, error, i;
sc = device_get_softc(dev);
+ error = 0;
+ set = NULL;
/*
* Check that the TSC isn't being used as a timecounter.
@@ -203,22 +214,29 @@ cf_set_method(device_t dev, const struct cf_level *level, int priority)
* If they did specify one, but the requested level has a lower
* priority, don't allow the new level right now.
*/
+ CF_MTX_LOCK(&sc->lock);
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);
+ } else {
+ error = ENXIO;
+ goto out;
+ }
+ } else if (priority < sc->curr_priority) {
+ error = EPERM;
+ goto out;
+ }
/* Reject levels that are below our specified threshold. */
- if (level->total_set.freq <= cf_lowest_freq)
- return (EINVAL);
+ if (level->total_set.freq <= cf_lowest_freq) {
+ error = EINVAL;
+ goto out;
+ }
/* If already at this level, just return. */
if (CPUFREQ_CMP(sc->curr_level.total_set.freq, level->total_set.freq))
- return (0);
+ goto out;
/* First, set the absolute frequency via its driver. */
set = &level->abs_set;
@@ -297,7 +315,8 @@ cf_set_method(device_t dev, const struct cf_level *level, int priority)
error = 0;
out:
- if (error)
+ CF_MTX_UNLOCK(&sc->lock);
+ if (error && set)
device_printf(set->dev, "set freq failed, err %d\n", error);
return (error);
}
@@ -314,12 +333,15 @@ cf_get_method(device_t dev, struct cf_level *level)
uint64_t rate;
sc = device_get_softc(dev);
- curr_set = &sc->curr_level.total_set;
+ error = 0;
levels = NULL;
/* If we already know the current frequency, we're done. */
+ CF_MTX_LOCK(&sc->lock);
+ curr_set = &sc->curr_level.total_set;
if (curr_set->freq != CPUFREQ_VAL_UNKNOWN)
goto out;
+ CF_MTX_UNLOCK(&sc->lock);
/*
* We need to figure out the current level. Loop through every
@@ -334,11 +356,24 @@ cf_get_method(device_t dev, struct cf_level *level)
if (error) {
if (error == E2BIG)
printf("cpufreq: need to increase CF_MAX_LEVELS\n");
- goto out;
+ free(levels, M_TEMP);
+ return (error);
}
error = device_get_children(device_get_parent(dev), &devs, &numdevs);
- if (error)
- goto out;
+ if (error) {
+ free(levels, M_TEMP);
+ return (error);
+ }
+
+ /*
+ * Reacquire the lock and search for the given level.
+ *
+ * XXX Note: this is not quite right since we really need to go
+ * through each level and compare both absolute and relative
+ * settings for each driver in the system before making a match.
+ * The estimation code below catches this case though.
+ */
+ CF_MTX_LOCK(&sc->lock);
for (i = 0; i < numdevs && curr_set->freq == CPUFREQ_VAL_UNKNOWN; i++) {
if (!device_is_attached(devs[i]))
continue;
@@ -375,10 +410,13 @@ cf_get_method(device_t dev, struct cf_level *level)
}
out:
+ if (error == 0)
+ *level = sc->curr_level;
+
+ CF_MTX_UNLOCK(&sc->lock);
if (levels)
free(levels, M_TEMP);
- *level = sc->curr_level;
- return (0);
+ return (error);
}
static int
@@ -409,6 +447,7 @@ cf_levels_method(device_t dev, struct cf_level *levels, int *count)
}
/* Get settings from all cpufreq drivers. */
+ CF_MTX_LOCK(&sc->lock);
for (i = 0; i < numdevs; i++) {
/* Skip devices that aren't ready. */
if (!device_is_attached(devs[i]))
@@ -502,11 +541,13 @@ out:
TAILQ_REMOVE(&sc->all_levels, lev, link);
free(lev, M_TEMP);
}
+ sc->all_count = 0;
+
+ CF_MTX_UNLOCK(&sc->lock);
while ((set_arr = TAILQ_FIRST(&rel_sets)) != NULL) {
TAILQ_REMOVE(&rel_sets, set_arr, link);
free(set_arr, M_TEMP);
}
- sc->all_count = 0;
free(devs, M_TEMP);
free(sets, M_TEMP);
return (error);
@@ -524,6 +565,8 @@ cpufreq_insert_abs(struct cpufreq_softc *sc, struct cf_setting *sets,
struct cf_level *level, *search;
int i;
+ CF_MTX_ASSERT(&sc->lock);
+
list = &sc->all_levels;
for (i = 0; i < count; i++) {
level = malloc(sizeof(*level), M_TEMP, M_NOWAIT | M_ZERO);
@@ -559,6 +602,8 @@ cpufreq_expand_set(struct cpufreq_softc *sc, struct cf_setting_array *set_arr)
struct cf_setting *set;
int i;
+ CF_MTX_ASSERT(&sc->lock);
+
TAILQ_FOREACH(search, &sc->all_levels, link) {
/* Skip this level if we've already modified it. */
for (i = 0; i < search->rel_count; i++) {
@@ -608,6 +653,8 @@ cpufreq_dup_set(struct cpufreq_softc *sc, struct cf_level *dup,
struct cf_setting *fill_set, *itr_set;
int i;
+ CF_MTX_ASSERT(&sc->lock);
+
/*
* Create a new level, copy it from the old one, and update the
* total frequency and power by the percentage specified in the