Merge tag 'pm+acpi-3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management fixes from Rafael Wysocki:
 "These three commits fix a recent intel_pstate regression and two old
  bugs that should be fixed in -stable too, one in the ACPI processor
  driver and one in the firmare loader.

  Specifics:

   - One of the recent intel_pstate driver fixes introduced a rounding
     error that on some systems causes the frequency to be stuck at the
     lowest level forever.  Fix from Dirk Brandewie.

   - The firmware_class driver's PM notifier doesn't handle the
     PM_RESTORE_PREPARE event during hibernation image restore and that
     leads to a deadlock on umhelper_sem in __usermodehelper_disable().
     Fix from Sebastian Capella.

   - acpi_processor_set_throttling() abuses set_cpus_allowed_ptr() in a
     nasty way which triggers the WARN_ON_ONCE() in wq_worker_waking_up()
     among other things.  Fix from Lan Tianyu"

* tag 'pm+acpi-3.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / processor: Rework processor throttling with work_on_cpu()
  PM / hibernate: Fix restore hang in freeze_processes()
  intel_pstate: Change busy calculation to use fixed point math.

3 files changed, 51 insertions, 47 deletions

diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index 28baa05b801..84243c32e29 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -56,6 +56,12 @@ struct throttling_tstate {
 	int target_state;		/* target T-state */
 };
 
+struct acpi_processor_throttling_arg {
+	struct acpi_processor *pr;
+	int target_state;
+	bool force;
+};
+
 #define THROTTLING_PRECHANGE       (1)
 #define THROTTLING_POSTCHANGE      (2)
 
@@ -1060,16 +1066,24 @@ static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
 	return 0;
 }
 
+static long acpi_processor_throttling_fn(void *data)
+{
+	struct acpi_processor_throttling_arg *arg = data;
+	struct acpi_processor *pr = arg->pr;
+
+	return pr->throttling.acpi_processor_set_throttling(pr,
+			arg->target_state, arg->force);
+}
+
 int acpi_processor_set_throttling(struct acpi_processor *pr,
 						int state, bool force)
 {
-	cpumask_var_t saved_mask;
 	int ret = 0;
 	unsigned int i;
 	struct acpi_processor *match_pr;
 	struct acpi_processor_throttling *p_throttling;
+	struct acpi_processor_throttling_arg arg;
 	struct throttling_tstate t_state;
-	cpumask_var_t online_throttling_cpus;
 
 	if (!pr)
 		return -EINVAL;
@@ -1080,14 +1094,6 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
 	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 		return -EINVAL;
 
-	if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
-		return -ENOMEM;
-
-	if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
-		free_cpumask_var(saved_mask);
-		return -ENOMEM;
-	}
-
 	if (cpu_is_offline(pr->id)) {
 		/*
 		 * the cpu pointed by pr->id is offline. Unnecessary to change
@@ -1096,17 +1102,15 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
 		return -ENODEV;
 	}
 
-	cpumask_copy(saved_mask, &current->cpus_allowed);
 	t_state.target_state = state;
 	p_throttling = &(pr->throttling);
-	cpumask_and(online_throttling_cpus, cpu_online_mask,
-		    p_throttling->shared_cpu_map);
+
 	/*
 	 * The throttling notifier will be called for every
 	 * affected cpu in order to get one proper T-state.
 	 * The notifier event is THROTTLING_PRECHANGE.
 	 */
-	for_each_cpu(i, online_throttling_cpus) {
+	for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
 		t_state.cpu = i;
 		acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
 							&t_state);
@@ -1118,21 +1122,18 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
 	 * it can be called only for the cpu pointed by pr.
 	 */
 	if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
-		/* FIXME: use work_on_cpu() */
-		if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
-			/* Can't migrate to the pr->id CPU. Exit */
-			ret = -ENODEV;
-			goto exit;
-		}
-		ret = p_throttling->acpi_processor_set_throttling(pr,
-						t_state.target_state, force);
+		arg.pr = pr;
+		arg.target_state = state;
+		arg.force = force;
+		ret = work_on_cpu(pr->id, acpi_processor_throttling_fn, &arg);
 	} else {
 		/*
 		 * When the T-state coordination is SW_ALL or HW_ALL,
 		 * it is necessary to set T-state for every affected
 		 * cpus.
 		 */
-		for_each_cpu(i, online_throttling_cpus) {
+		for_each_cpu_and(i, cpu_online_mask,
+		    p_throttling->shared_cpu_map) {
 			match_pr = per_cpu(processors, i);
 			/*
 			 * If the pointer is invalid, we will report the
@@ -1153,13 +1154,12 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
 					"on CPU %d\n", i));
 				continue;
 			}
-			t_state.cpu = i;
-			/* FIXME: use work_on_cpu() */
-			if (set_cpus_allowed_ptr(current, cpumask_of(i)))
-				continue;
-			ret = match_pr->throttling.
-				acpi_processor_set_throttling(
-				match_pr, t_state.target_state, force);
+
+			arg.pr = match_pr;
+			arg.target_state = state;
+			arg.force = force;
+			ret = work_on_cpu(pr->id, acpi_processor_throttling_fn,
+				&arg);
 		}
 	}
 	/*
@@ -1168,17 +1168,12 @@ int acpi_processor_set_throttling(struct acpi_processor *pr,
 	 * affected cpu to update the T-states.
 	 * The notifier event is THROTTLING_POSTCHANGE
 	 */
-	for_each_cpu(i, online_throttling_cpus) {
+	for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
 		t_state.cpu = i;
 		acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
 							&t_state);
 	}
-	/* restore the previous state */
-	/* FIXME: use work_on_cpu() */
-	set_cpus_allowed_ptr(current, saved_mask);
-exit:
-	free_cpumask_var(online_throttling_cpus);
-	free_cpumask_var(saved_mask);
+
 	return ret;
 }
 
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 8a97ddfa612..c30df50e444 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -1580,6 +1580,7 @@ static int fw_pm_notify(struct notifier_block *notify_block,
 	switch (mode) {
 	case PM_HIBERNATION_PREPARE:
 	case PM_SUSPEND_PREPARE:
+	case PM_RESTORE_PREPARE:
 		kill_requests_without_uevent();
 		device_cache_fw_images();
 		break;
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index e9081610592..2cd36b9297f 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -39,9 +39,10 @@
 #define BYT_TURBO_RATIOS	0x66c
 
 
-#define FRAC_BITS 8
+#define FRAC_BITS 6
 #define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
 #define fp_toint(X) ((X) >> FRAC_BITS)
+#define FP_ROUNDUP(X) ((X) += 1 << FRAC_BITS)
 
 static inline int32_t mul_fp(int32_t x, int32_t y)
 {
@@ -556,18 +557,20 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
 static inline void intel_pstate_calc_busy(struct cpudata *cpu,
 					struct sample *sample)
 {
-	u64 core_pct;
-	u64 c0_pct;
+	int32_t core_pct;
+	int32_t c0_pct;
 
-	core_pct = div64_u64(sample->aperf * 100, sample->mperf);
+	core_pct = div_fp(int_tofp((sample->aperf)),
+			int_tofp((sample->mperf)));
+	core_pct = mul_fp(core_pct, int_tofp(100));
+	FP_ROUNDUP(core_pct);
+
+	c0_pct = div_fp(int_tofp(sample->mperf), int_tofp(sample->tsc));
 
-	c0_pct = div64_u64(sample->mperf * 100, sample->tsc);
 	sample->freq = fp_toint(
-		mul_fp(int_tofp(cpu->pstate.max_pstate),
-			int_tofp(core_pct * 1000)));
+		mul_fp(int_tofp(cpu->pstate.max_pstate * 1000), core_pct));
 
-	sample->core_pct_busy = mul_fp(int_tofp(core_pct),
-				div_fp(int_tofp(c0_pct + 1), int_tofp(100)));
+	sample->core_pct_busy = mul_fp(core_pct, c0_pct);
 }
 
 static inline void intel_pstate_sample(struct cpudata *cpu)
@@ -579,6 +582,10 @@ static inline void intel_pstate_sample(struct cpudata *cpu)
 	rdmsrl(MSR_IA32_MPERF, mperf);
 	tsc = native_read_tsc();
 
+	aperf = aperf >> FRAC_BITS;
+	mperf = mperf >> FRAC_BITS;
+	tsc = tsc >> FRAC_BITS;
+
 	cpu->sample_ptr = (cpu->sample_ptr + 1) % SAMPLE_COUNT;
 	cpu->samples[cpu->sample_ptr].aperf = aperf;
 	cpu->samples[cpu->sample_ptr].mperf = mperf;
@@ -610,7 +617,8 @@ static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu)
 	core_busy = cpu->samples[cpu->sample_ptr].core_pct_busy;
 	max_pstate = int_tofp(cpu->pstate.max_pstate);
 	current_pstate = int_tofp(cpu->pstate.current_pstate);
-	return mul_fp(core_busy, div_fp(max_pstate, current_pstate));
+	core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate));
+	return FP_ROUNDUP(core_busy);
 }
 
 static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)