1 files changed, 75 insertions, 63 deletions

diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 757a98f6d7a2..4265814c74f8 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -53,6 +53,8 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 {
 	acpi_status status = 0;
 	unsigned long long ppc = 0;
+	s32 qos_value;
+	int index;
 	int ret;
 
 	if (!pr)
@@ -72,17 +74,30 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 		}
 	}
 
+	index = ppc;
+
+	if (pr->performance_platform_limit == index ||
+	    ppc >= pr->performance->state_count)
+		return 0;
+
 	pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id,
-		       (int)ppc, ppc ? "" : "not");
+		 index, index ? "is" : "is not");
 
-	pr->performance_platform_limit = (int)ppc;
+	pr->performance_platform_limit = index;
 
-	if (ppc >= pr->performance->state_count ||
-	    unlikely(!freq_qos_request_active(&pr->perflib_req)))
+	if (unlikely(!freq_qos_request_active(&pr->perflib_req)))
 		return 0;
 
-	ret = freq_qos_update_request(&pr->perflib_req,
-			pr->performance->states[ppc].core_frequency * 1000);
+	/*
+	 * If _PPC returns 0, it means that all of the available states can be
+	 * used ("no limit").
+	 */
+	if (index == 0)
+		qos_value = FREQ_QOS_MAX_DEFAULT_VALUE;
+	else
+		qos_value = pr->performance->states[index].core_frequency * 1000;
+
+	ret = freq_qos_update_request(&pr->perflib_req, qos_value);
 	if (ret < 0) {
 		pr_warn("Failed to update perflib freq constraint: CPU%d (%d)\n",
 			pr->id, ret);
@@ -142,6 +157,7 @@ int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
 	pr = per_cpu(processors, cpu);
 	if (!pr || !pr->performance || !pr->performance->state_count)
 		return -ENODEV;
+
 	*limit = pr->performance->states[pr->performance_platform_limit].
 		core_frequency * 1000;
 	return 0;
@@ -165,9 +181,16 @@ void acpi_processor_ppc_init(struct cpufreq_policy *policy)
 		if (!pr)
 			continue;
 
+		/*
+		 * Reset performance_platform_limit in case there is a stale
+		 * value in it, so as to make it match the "no limit" QoS value
+		 * below.
+		 */
+		pr->performance_platform_limit = 0;
+
 		ret = freq_qos_add_request(&policy->constraints,
-					   &pr->perflib_req,
-					   FREQ_QOS_MAX, INT_MAX);
+					   &pr->perflib_req, FREQ_QOS_MAX,
+					   FREQ_QOS_MAX_DEFAULT_VALUE);
 		if (ret < 0)
 			pr_err("Failed to add freq constraint for CPU%d (%d)\n",
 			       cpu, ret);
@@ -201,8 +224,7 @@ static int acpi_processor_get_performance_control(struct acpi_processor *pr)
 	}
 
 	pct = (union acpi_object *)buffer.pointer;
-	if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
-	    || (pct->package.count != 2)) {
+	if (!pct || pct->type != ACPI_TYPE_PACKAGE || pct->package.count != 2) {
 		pr_err("Invalid _PCT data\n");
 		result = -EFAULT;
 		goto end;
@@ -214,9 +236,8 @@ static int acpi_processor_get_performance_control(struct acpi_processor *pr)
 
 	obj = pct->package.elements[0];
 
-	if ((obj.type != ACPI_TYPE_BUFFER)
-	    || (obj.buffer.length < sizeof(struct acpi_pct_register))
-	    || (obj.buffer.pointer == NULL)) {
+	if (!obj.buffer.pointer || obj.type != ACPI_TYPE_BUFFER ||
+	    obj.buffer.length < sizeof(struct acpi_pct_register)) {
 		pr_err("Invalid _PCT data (control_register)\n");
 		result = -EFAULT;
 		goto end;
@@ -230,9 +251,8 @@ static int acpi_processor_get_performance_control(struct acpi_processor *pr)
 
 	obj = pct->package.elements[1];
 
-	if ((obj.type != ACPI_TYPE_BUFFER)
-	    || (obj.buffer.length < sizeof(struct acpi_pct_register))
-	    || (obj.buffer.pointer == NULL)) {
+	if (!obj.buffer.pointer || obj.type != ACPI_TYPE_BUFFER ||
+	    obj.buffer.length < sizeof(struct acpi_pct_register)) {
 		pr_err("Invalid _PCT data (status_register)\n");
 		result = -EFAULT;
 		goto end;
@@ -260,8 +280,8 @@ static void amd_fixup_frequency(struct acpi_processor_px *px, int i)
 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
 		return;
 
-	if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
-	    || boot_cpu_data.x86 == 0x11) {
+	if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10) ||
+	    boot_cpu_data.x86 == 0x11) {
 		rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi);
 		/*
 		 * MSR C001_0064+:
@@ -300,7 +320,7 @@ static int acpi_processor_get_performance_states(struct acpi_processor *pr)
 	}
 
 	pss = buffer.pointer;
-	if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
+	if (!pss || pss->type != ACPI_TYPE_PACKAGE) {
 		pr_err("Invalid _PSS data\n");
 		result = -EFAULT;
 		goto end;
@@ -353,8 +373,7 @@ static int acpi_processor_get_performance_states(struct acpi_processor *pr)
 		 * Check that ACPI's u64 MHz will be valid as u32 KHz in cpufreq
 		 */
 		if (!px->core_frequency ||
-		    ((u32)(px->core_frequency * 1000) !=
-		     (px->core_frequency * 1000))) {
+		    (u32)(px->core_frequency * 1000) != px->core_frequency * 1000) {
 			pr_err(FW_BUG
 			       "Invalid BIOS _PSS frequency found for processor %d: 0x%llx MHz\n",
 			       pr->id, px->core_frequency);
@@ -456,7 +475,7 @@ int acpi_processor_pstate_control(void)
 int acpi_processor_notify_smm(struct module *calling_module)
 {
 	static int is_done;
-	int result;
+	int result = 0;
 
 	if (!acpi_processor_cpufreq_init)
 		return -EBUSY;
@@ -464,42 +483,41 @@ int acpi_processor_notify_smm(struct module *calling_module)
 	if (!try_module_get(calling_module))
 		return -EINVAL;
 
-	/* is_done is set to negative if an error occurred,
-	 * and to postitive if _no_ error occurred, but SMM
-	 * was already notified. This avoids double notification
-	 * which might lead to unexpected results...
+	/*
+	 * is_done is set to negative if an error occurs and to 1 if no error
+	 * occurrs, but SMM has been notified already. This avoids repeated
+	 * notification which might lead to unexpected results.
 	 */
-	if (is_done > 0) {
-		module_put(calling_module);
-		return 0;
-	} else if (is_done < 0) {
-		module_put(calling_module);
-		return is_done;
-	}
+	if (is_done != 0) {
+		if (is_done < 0)
+			result = is_done;
 
-	is_done = -EIO;
+		goto out_put;
+	}
 
 	result = acpi_processor_pstate_control();
-	if (!result) {
-		pr_debug("No SMI port or pstate_control\n");
-		module_put(calling_module);
-		return 0;
-	}
-	if (result < 0) {
-		module_put(calling_module);
-		return result;
+	if (result <= 0) {
+		if (result) {
+			is_done = result;
+		} else {
+			pr_debug("No SMI port or pstate_control\n");
+			is_done = 1;
+		}
+		goto out_put;
 	}
 
-	/* Success. If there's no _PPC, we need to fear nothing, so
-	 * we can allow the cpufreq driver to be rmmod'ed. */
 	is_done = 1;
+	/*
+	 * Success. If there _PPC, unloading the cpufreq driver would be risky,
+	 * so disallow it in that case.
+	 */
+	if (acpi_processor_ppc_in_use)
+		return 0;
 
-	if (!acpi_processor_ppc_in_use)
-		module_put(calling_module);
-
-	return 0;
+out_put:
+	module_put(calling_module);
+	return result;
 }
-
 EXPORT_SYMBOL(acpi_processor_notify_smm);
 
 int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain)
@@ -517,7 +535,7 @@ int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain)
 	}
 
 	psd = buffer.pointer;
-	if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) {
+	if (!psd || psd->type != ACPI_TYPE_PACKAGE) {
 		pr_err("Invalid _PSD data\n");
 		result = -EFAULT;
 		goto end;
@@ -532,8 +550,7 @@ int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain)
 	state.length = sizeof(struct acpi_psd_package);
 	state.pointer = pdomain;
 
-	status = acpi_extract_package(&(psd->package.elements[0]),
-		&format, &state);
+	status = acpi_extract_package(&(psd->package.elements[0]), &format, &state);
 	if (ACPI_FAILURE(status)) {
 		pr_err("Invalid _PSD data\n");
 		result = -EFAULT;
@@ -716,9 +733,8 @@ err_out:
 }
 EXPORT_SYMBOL(acpi_processor_preregister_performance);
 
-int
-acpi_processor_register_performance(struct acpi_processor_performance
-				    *performance, unsigned int cpu)
+int acpi_processor_register_performance(struct acpi_processor_performance
+					*performance, unsigned int cpu)
 {
 	struct acpi_processor *pr;
 
@@ -751,7 +767,6 @@ acpi_processor_register_performance(struct acpi_processor_performance
 	mutex_unlock(&performance_mutex);
 	return 0;
 }
-
 EXPORT_SYMBOL(acpi_processor_register_performance);
 
 void acpi_processor_unregister_performance(unsigned int cpu)
@@ -761,18 +776,15 @@ void acpi_processor_unregister_performance(unsigned int cpu)
 	mutex_lock(&performance_mutex);
 
 	pr = per_cpu(processors, cpu);
-	if (!pr) {
-		mutex_unlock(&performance_mutex);
-		return;
-	}
+	if (!pr)
+		goto unlock;
 
 	if (pr->performance)
 		kfree(pr->performance->states);
+
 	pr->performance = NULL;
 
+unlock:
 	mutex_unlock(&performance_mutex);
-
-	return;
 }
-
 EXPORT_SYMBOL(acpi_processor_unregister_performance);