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-rw-r--r--Documentation/ABI/testing/sysfs-devices-power4
-rw-r--r--drivers/base/cpu.c3
-rw-r--r--drivers/base/power/domain.c2
-rw-r--r--drivers/base/power/domain_governor.c40
-rw-r--r--drivers/base/power/qos.c5
-rw-r--r--drivers/base/power/runtime.c2
-rw-r--r--drivers/base/power/sysfs.c25
-rw-r--r--drivers/cpuidle/governors/menu.c4
-rw-r--r--include/linux/pm_qos.h26
9 files changed, 68 insertions, 43 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power
index f4b24c327665..80a00f7b6667 100644
--- a/Documentation/ABI/testing/sysfs-devices-power
+++ b/Documentation/ABI/testing/sysfs-devices-power
@@ -211,7 +211,9 @@ Description:
device, after it has been suspended at run time, from a resume
request to the moment the device will be ready to process I/O,
in microseconds. If it is equal to 0, however, this means that
- the PM QoS resume latency may be arbitrary.
+ the PM QoS resume latency may be arbitrary and the special value
+ "n/a" means that user space cannot accept any resume latency at
+ all for the given device.
Not all drivers support this attribute. If it isn't supported,
it is not present.
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 321cd7b4d817..227bac5f1191 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -377,7 +377,8 @@ int register_cpu(struct cpu *cpu, int num)
per_cpu(cpu_sys_devices, num) = &cpu->dev;
register_cpu_under_node(num, cpu_to_node(num));
- dev_pm_qos_expose_latency_limit(&cpu->dev, 0);
+ dev_pm_qos_expose_latency_limit(&cpu->dev,
+ PM_QOS_RESUME_LATENCY_NO_CONSTRAINT);
return 0;
}
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 679c79545e42..24e39ce27bd8 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1326,7 +1326,7 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
gpd_data->base.dev = dev;
gpd_data->td.constraint_changed = true;
- gpd_data->td.effective_constraint_ns = 0;
+ gpd_data->td.effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS;
gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
spin_lock_irq(&dev->power.lock);
diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c
index e4cca8adab32..99896fbf18e4 100644
--- a/drivers/base/power/domain_governor.c
+++ b/drivers/base/power/domain_governor.c
@@ -33,15 +33,10 @@ static int dev_update_qos_constraint(struct device *dev, void *data)
* known at this point anyway).
*/
constraint_ns = dev_pm_qos_read_value(dev);
- if (constraint_ns > 0)
- constraint_ns *= NSEC_PER_USEC;
+ constraint_ns *= NSEC_PER_USEC;
}
- /* 0 means "no constraint" */
- if (constraint_ns == 0)
- return 0;
-
- if (constraint_ns < *constraint_ns_p || *constraint_ns_p == 0)
+ if (constraint_ns < *constraint_ns_p)
*constraint_ns_p = constraint_ns;
return 0;
@@ -69,12 +64,12 @@ static bool default_suspend_ok(struct device *dev)
}
td->constraint_changed = false;
td->cached_suspend_ok = false;
- td->effective_constraint_ns = -1;
+ td->effective_constraint_ns = 0;
constraint_ns = __dev_pm_qos_read_value(dev);
spin_unlock_irqrestore(&dev->power.lock, flags);
- if (constraint_ns < 0)
+ if (constraint_ns == 0)
return false;
constraint_ns *= NSEC_PER_USEC;
@@ -87,25 +82,25 @@ static bool default_suspend_ok(struct device *dev)
device_for_each_child(dev, &constraint_ns,
dev_update_qos_constraint);
- if (constraint_ns == 0) {
+ if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS) {
/* "No restriction", so the device is allowed to suspend. */
- td->effective_constraint_ns = 0;
+ td->effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS;
td->cached_suspend_ok = true;
- } else if (constraint_ns < 0) {
+ } else if (constraint_ns == 0) {
/*
* This triggers if one of the children that don't belong to a
- * domain has a negative PM QoS constraint and it's better not
- * to suspend then. effective_constraint_ns is negative already
- * and cached_suspend_ok is false, so bail out.
+ * domain has a zero PM QoS constraint and it's better not to
+ * suspend then. effective_constraint_ns is zero already and
+ * cached_suspend_ok is false, so bail out.
*/
return false;
} else {
constraint_ns -= td->suspend_latency_ns +
td->resume_latency_ns;
/*
- * effective_constraint_ns is negative already and
- * cached_suspend_ok is false, so if the computed value is not
- * positive, return right away.
+ * effective_constraint_ns is zero already and cached_suspend_ok
+ * is false, so if the computed value is not positive, return
+ * right away.
*/
if (constraint_ns <= 0)
return false;
@@ -174,13 +169,10 @@ static bool __default_power_down_ok(struct dev_pm_domain *pd,
td = &to_gpd_data(pdd)->td;
constraint_ns = td->effective_constraint_ns;
/*
- * Negative values mean "no suspend at all" and this runs only
- * when all devices in the domain are suspended, so it must be
- * 0 at least.
- *
- * 0 means "no constraint"
+ * Zero means "no suspend at all" and this runs only when all
+ * devices in the domain are suspended, so it must be positive.
*/
- if (constraint_ns == 0)
+ if (constraint_ns == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS)
continue;
if (constraint_ns <= off_on_time_ns)
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 277d43a83f53..3382542b39b7 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -139,6 +139,9 @@ static int apply_constraint(struct dev_pm_qos_request *req,
switch(req->type) {
case DEV_PM_QOS_RESUME_LATENCY:
+ if (WARN_ON(action != PM_QOS_REMOVE_REQ && value < 0))
+ value = 0;
+
ret = pm_qos_update_target(&qos->resume_latency,
&req->data.pnode, action, value);
break;
@@ -189,7 +192,7 @@ static int dev_pm_qos_constraints_allocate(struct device *dev)
plist_head_init(&c->list);
c->target_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
c->default_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
- c->no_constraint_value = PM_QOS_RESUME_LATENCY_DEFAULT_VALUE;
+ c->no_constraint_value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
c->type = PM_QOS_MIN;
c->notifiers = n;
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 7bcf80fa9ada..13e015905543 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -253,7 +253,7 @@ static int rpm_check_suspend_allowed(struct device *dev)
|| (dev->power.request_pending
&& dev->power.request == RPM_REQ_RESUME))
retval = -EAGAIN;
- else if (__dev_pm_qos_read_value(dev) < 0)
+ else if (__dev_pm_qos_read_value(dev) == 0)
retval = -EPERM;
else if (dev->power.runtime_status == RPM_SUSPENDED)
retval = 1;
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 29bf28fef136..e153e28b1857 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -218,7 +218,14 @@ static ssize_t pm_qos_resume_latency_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
- return sprintf(buf, "%d\n", dev_pm_qos_requested_resume_latency(dev));
+ s32 value = dev_pm_qos_requested_resume_latency(dev);
+
+ if (value == 0)
+ return sprintf(buf, "n/a\n");
+ else if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
+ value = 0;
+
+ return sprintf(buf, "%d\n", value);
}
static ssize_t pm_qos_resume_latency_store(struct device *dev,
@@ -228,11 +235,21 @@ static ssize_t pm_qos_resume_latency_store(struct device *dev,
s32 value;
int ret;
- if (kstrtos32(buf, 0, &value))
- return -EINVAL;
+ if (!kstrtos32(buf, 0, &value)) {
+ /*
+ * Prevent users from writing negative or "no constraint" values
+ * directly.
+ */
+ if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
+ return -EINVAL;
- if (value < 0)
+ if (value == 0)
+ value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
+ } else if (!strcmp(buf, "n/a") || !strcmp(buf, "n/a\n")) {
+ value = 0;
+ } else {
return -EINVAL;
+ }
ret = dev_pm_qos_update_request(dev->power.qos->resume_latency_req,
value);
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 48eaf2879228..aa390404e85f 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -298,8 +298,8 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
data->needs_update = 0;
}
- /* resume_latency is 0 means no restriction */
- if (resume_latency && resume_latency < latency_req)
+ if (resume_latency < latency_req &&
+ resume_latency != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
latency_req = resume_latency;
/* Special case when user has set very strict latency requirement */
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index 51f0d7e0b15f..2a3b36da61b1 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -27,16 +27,19 @@ enum pm_qos_flags_status {
PM_QOS_FLAGS_ALL,
};
-#define PM_QOS_DEFAULT_VALUE -1
+#define PM_QOS_DEFAULT_VALUE (-1)
+#define PM_QOS_LATENCY_ANY S32_MAX
+#define PM_QOS_LATENCY_ANY_NS ((s64)PM_QOS_LATENCY_ANY * NSEC_PER_USEC)
#define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC)
#define PM_QOS_NETWORK_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC)
#define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0
#define PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE 0
-#define PM_QOS_RESUME_LATENCY_DEFAULT_VALUE 0
+#define PM_QOS_RESUME_LATENCY_DEFAULT_VALUE PM_QOS_LATENCY_ANY
+#define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT PM_QOS_LATENCY_ANY
+#define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS PM_QOS_LATENCY_ANY_NS
#define PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE 0
#define PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT (-1)
-#define PM_QOS_LATENCY_ANY ((s32)(~(__u32)0 >> 1))
#define PM_QOS_FLAG_NO_POWER_OFF (1 << 0)
@@ -173,7 +176,8 @@ static inline s32 dev_pm_qos_requested_flags(struct device *dev)
static inline s32 dev_pm_qos_raw_read_value(struct device *dev)
{
return IS_ERR_OR_NULL(dev->power.qos) ?
- 0 : pm_qos_read_value(&dev->power.qos->resume_latency);
+ PM_QOS_RESUME_LATENCY_NO_CONSTRAINT :
+ pm_qos_read_value(&dev->power.qos->resume_latency);
}
#else
static inline enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev,
@@ -183,9 +187,9 @@ static inline enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev,
s32 mask)
{ return PM_QOS_FLAGS_UNDEFINED; }
static inline s32 __dev_pm_qos_read_value(struct device *dev)
- { return 0; }
+ { return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; }
static inline s32 dev_pm_qos_read_value(struct device *dev)
- { return 0; }
+ { return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; }
static inline int dev_pm_qos_add_request(struct device *dev,
struct dev_pm_qos_request *req,
enum dev_pm_qos_req_type type,
@@ -231,9 +235,15 @@ static inline int dev_pm_qos_expose_latency_tolerance(struct device *dev)
{ return 0; }
static inline void dev_pm_qos_hide_latency_tolerance(struct device *dev) {}
-static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev) { return 0; }
+static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev)
+{
+ return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
+}
static inline s32 dev_pm_qos_requested_flags(struct device *dev) { return 0; }
-static inline s32 dev_pm_qos_raw_read_value(struct device *dev) { return 0; }
+static inline s32 dev_pm_qos_raw_read_value(struct device *dev)
+{
+ return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
+}
#endif
#endif
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.