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-rw-r--r--Documentation/power/runtime_pm.txt3
-rw-r--r--arch/x86/kernel/cpu/Makefile2
-rw-r--r--arch/x86/kernel/cpu/aperfmperf.c74
-rw-r--r--arch/x86/kernel/cpu/cpu.h3
-rw-r--r--arch/x86/kernel/cpu/proc.c6
-rw-r--r--drivers/base/power/runtime.c31
-rw-r--r--fs/proc/cpuinfo.c6
-rw-r--r--include/linux/cpufreq.h1
8 files changed, 80 insertions, 46 deletions
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 57af2f7963ee..937e33c46211 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -435,8 +435,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
       PM status to 'suspended' and update its parent's counter of 'active'
       children as appropriate (it is only valid to use this function if
       'power.runtime_error' is set or 'power.disable_depth' is greater than
-      zero); it will fail and return an error code if the device has a child
-      which is active and the 'power.ignore_children' flag is unset
+      zero)
 
   bool pm_runtime_active(struct device *dev);
     - return true if the device's runtime PM status is 'active' or its
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 90cb82dbba57..570e8bb1f386 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -22,7 +22,7 @@ obj-y			+= common.o
 obj-y			+= rdrand.o
 obj-y			+= match.o
 obj-y			+= bugs.o
-obj-$(CONFIG_CPU_FREQ)	+= aperfmperf.o
+obj-y			+= aperfmperf.o
 obj-y			+= cpuid-deps.o
 
 obj-$(CONFIG_PROC_FS)	+= proc.o
diff --git a/arch/x86/kernel/cpu/aperfmperf.c b/arch/x86/kernel/cpu/aperfmperf.c
index 957813e0180d..7eba34df54c3 100644
--- a/arch/x86/kernel/cpu/aperfmperf.c
+++ b/arch/x86/kernel/cpu/aperfmperf.c
@@ -14,6 +14,8 @@
 #include <linux/percpu.h>
 #include <linux/smp.h>
 
+#include "cpu.h"
+
 struct aperfmperf_sample {
 	unsigned int	khz;
 	ktime_t	time;
@@ -24,7 +26,7 @@ struct aperfmperf_sample {
 static DEFINE_PER_CPU(struct aperfmperf_sample, samples);
 
 #define APERFMPERF_CACHE_THRESHOLD_MS	10
-#define APERFMPERF_REFRESH_DELAY_MS	20
+#define APERFMPERF_REFRESH_DELAY_MS	10
 #define APERFMPERF_STALE_THRESHOLD_MS	1000
 
 /*
@@ -38,8 +40,6 @@ static void aperfmperf_snapshot_khz(void *dummy)
 	u64 aperf, aperf_delta;
 	u64 mperf, mperf_delta;
 	struct aperfmperf_sample *s = this_cpu_ptr(&samples);
-	ktime_t now = ktime_get();
-	s64 time_delta = ktime_ms_delta(now, s->time);
 	unsigned long flags;
 
 	local_irq_save(flags);
@@ -57,38 +57,68 @@ static void aperfmperf_snapshot_khz(void *dummy)
 	if (mperf_delta == 0)
 		return;
 
-	s->time = now;
+	s->time = ktime_get();
 	s->aperf = aperf;
 	s->mperf = mperf;
-
-	/* If the previous iteration was too long ago, discard it. */
-	if (time_delta > APERFMPERF_STALE_THRESHOLD_MS)
-		s->khz = 0;
-	else
-		s->khz = div64_u64((cpu_khz * aperf_delta), mperf_delta);
+	s->khz = div64_u64((cpu_khz * aperf_delta), mperf_delta);
 }
 
-unsigned int arch_freq_get_on_cpu(int cpu)
+static bool aperfmperf_snapshot_cpu(int cpu, ktime_t now, bool wait)
 {
-	s64 time_delta;
-	unsigned int khz;
+	s64 time_delta = ktime_ms_delta(now, per_cpu(samples.time, cpu));
+
+	/* Don't bother re-computing within the cache threshold time. */
+	if (time_delta < APERFMPERF_CACHE_THRESHOLD_MS)
+		return true;
+
+	smp_call_function_single(cpu, aperfmperf_snapshot_khz, NULL, wait);
+
+	/* Return false if the previous iteration was too long ago. */
+	return time_delta <= APERFMPERF_STALE_THRESHOLD_MS;
+}
 
+unsigned int aperfmperf_get_khz(int cpu)
+{
 	if (!cpu_khz)
 		return 0;
 
 	if (!static_cpu_has(X86_FEATURE_APERFMPERF))
 		return 0;
 
-	/* Don't bother re-computing within the cache threshold time. */
-	time_delta = ktime_ms_delta(ktime_get(), per_cpu(samples.time, cpu));
-	khz = per_cpu(samples.khz, cpu);
-	if (khz && time_delta < APERFMPERF_CACHE_THRESHOLD_MS)
-		return khz;
+	aperfmperf_snapshot_cpu(cpu, ktime_get(), true);
+	return per_cpu(samples.khz, cpu);
+}
 
-	smp_call_function_single(cpu, aperfmperf_snapshot_khz, NULL, 1);
-	khz = per_cpu(samples.khz, cpu);
-	if (khz)
-		return khz;
+void arch_freq_prepare_all(void)
+{
+	ktime_t now = ktime_get();
+	bool wait = false;
+	int cpu;
+
+	if (!cpu_khz)
+		return;
+
+	if (!static_cpu_has(X86_FEATURE_APERFMPERF))
+		return;
+
+	for_each_online_cpu(cpu)
+		if (!aperfmperf_snapshot_cpu(cpu, now, false))
+			wait = true;
+
+	if (wait)
+		msleep(APERFMPERF_REFRESH_DELAY_MS);
+}
+
+unsigned int arch_freq_get_on_cpu(int cpu)
+{
+	if (!cpu_khz)
+		return 0;
+
+	if (!static_cpu_has(X86_FEATURE_APERFMPERF))
+		return 0;
+
+	if (aperfmperf_snapshot_cpu(cpu, ktime_get(), true))
+		return per_cpu(samples.khz, cpu);
 
 	msleep(APERFMPERF_REFRESH_DELAY_MS);
 	smp_call_function_single(cpu, aperfmperf_snapshot_khz, NULL, 1);
diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h
index f52a370b6c00..e806b11a99af 100644
--- a/arch/x86/kernel/cpu/cpu.h
+++ b/arch/x86/kernel/cpu/cpu.h
@@ -47,4 +47,7 @@ extern const struct cpu_dev *const __x86_cpu_dev_start[],
 
 extern void get_cpu_cap(struct cpuinfo_x86 *c);
 extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c);
+
+unsigned int aperfmperf_get_khz(int cpu);
+
 #endif /* ARCH_X86_CPU_H */
diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c
index 6b7e17bf0b71..e7ecedafa1c8 100644
--- a/arch/x86/kernel/cpu/proc.c
+++ b/arch/x86/kernel/cpu/proc.c
@@ -5,6 +5,8 @@
 #include <linux/seq_file.h>
 #include <linux/cpufreq.h>
 
+#include "cpu.h"
+
 /*
  *	Get CPU information for use by the procfs.
  */
@@ -78,9 +80,11 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 		seq_printf(m, "microcode\t: 0x%x\n", c->microcode);
 
 	if (cpu_has(c, X86_FEATURE_TSC)) {
-		unsigned int freq = cpufreq_quick_get(cpu);
+		unsigned int freq = aperfmperf_get_khz(cpu);
 
 		if (!freq)
+			freq = cpufreq_quick_get(cpu);
+		if (!freq)
 			freq = cpu_khz;
 		seq_printf(m, "cpu MHz\t\t: %u.%03u\n",
 			   freq / 1000, (freq % 1000));
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 2362b9e9701e..027d159ac381 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1101,29 +1101,13 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status)
 		goto out;
 	}
 
-	if (dev->power.runtime_status == status)
+	if (dev->power.runtime_status == status || !parent)
 		goto out_set;
 
 	if (status == RPM_SUSPENDED) {
-		/*
-		 * It is invalid to suspend a device with an active child,
-		 * unless it has been set to ignore its children.
-		 */
-		if (!dev->power.ignore_children &&
-			atomic_read(&dev->power.child_count)) {
-			dev_err(dev, "runtime PM trying to suspend device but active child\n");
-			error = -EBUSY;
-			goto out;
-		}
-
-		if (parent) {
-			atomic_add_unless(&parent->power.child_count, -1, 0);
-			notify_parent = !parent->power.ignore_children;
-		}
-		goto out_set;
-	}
-
-	if (parent) {
+		atomic_add_unless(&parent->power.child_count, -1, 0);
+		notify_parent = !parent->power.ignore_children;
+	} else {
 		spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
 
 		/*
@@ -1307,6 +1291,13 @@ void pm_runtime_enable(struct device *dev)
 	else
 		dev_warn(dev, "Unbalanced %s!\n", __func__);
 
+	WARN(!dev->power.disable_depth &&
+	     dev->power.runtime_status == RPM_SUSPENDED &&
+	     !dev->power.ignore_children &&
+	     atomic_read(&dev->power.child_count) > 0,
+	     "Enabling runtime PM for inactive device (%s) with active children\n",
+	     dev_name(dev));
+
 	spin_unlock_irqrestore(&dev->power.lock, flags);
 }
 EXPORT_SYMBOL_GPL(pm_runtime_enable);
diff --git a/fs/proc/cpuinfo.c b/fs/proc/cpuinfo.c
index e0f867cd8553..96f1087e372c 100644
--- a/fs/proc/cpuinfo.c
+++ b/fs/proc/cpuinfo.c
@@ -1,12 +1,18 @@
 // SPDX-License-Identifier: GPL-2.0
+#include <linux/cpufreq.h>
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 
+__weak void arch_freq_prepare_all(void)
+{
+}
+
 extern const struct seq_operations cpuinfo_op;
 static int cpuinfo_open(struct inode *inode, struct file *file)
 {
+	arch_freq_prepare_all();
 	return seq_open(file, &cpuinfo_op);
 }
 
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 28734ee185a7..065f3a8eb486 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -917,6 +917,7 @@ static inline bool policy_has_boost_freq(struct cpufreq_policy *policy)
 }
 #endif
 
+extern void arch_freq_prepare_all(void);
 extern unsigned int arch_freq_get_on_cpu(int cpu);
 
 extern void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-10-17 05:30:08 +0000