linux-kernel - [PATCH v1.1 6/6] cpufreq: intel_pstate: Update the maximum CPU frequency consistently

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <6059426.lOV4Wx5bFT@kreacher>
Date: Thu, 28 Mar 2024 20:02:18 +0100
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Linux PM <linux-pm@...r.kernel.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
 Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Subject:
 [PATCH v1.1 6/6] cpufreq: intel_pstate: Update the maximum CPU frequency
 consistently

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

There are 3 places at which the maximum CPU frequency may change,
store_no_turbo(), intel_pstate_update_limits() (when called by the
cpufreq core) and intel_pstate_notify_work() (when handling a HWP
change notification).  Currently, cpuinfo.max_freq is only updated by
store_no_turbo() and intel_pstate_notify_work(), although it principle
it may be necessary to update it in intel_pstate_update_limits() either.

Make all of them mutually consistent.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---

v1 -> v1.1: Fix changelog (Srinivas).

---
 drivers/cpufreq/intel_pstate.c |   23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

Index: linux-pm/drivers/cpufreq/intel_pstate.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/intel_pstate.c
+++ linux-pm/drivers/cpufreq/intel_pstate.c
@@ -1153,18 +1153,32 @@ static void intel_pstate_update_policies
 static void __intel_pstate_update_max_freq(struct cpudata *cpudata,
 					   struct cpufreq_policy *policy)
 {
+	intel_pstate_get_hwp_cap(cpudata);
+
 	policy->cpuinfo.max_freq = READ_ONCE(global.no_turbo) ?
 			cpudata->pstate.max_freq : cpudata->pstate.turbo_freq;
+
 	refresh_frequency_limits(policy);
 }

 static void intel_pstate_update_limits(unsigned int cpu)
 {
-	mutex_lock(&intel_pstate_driver_lock);
+	struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);

-	cpufreq_update_policy(cpu);
+	if (!policy)
+		return;

-	mutex_unlock(&intel_pstate_driver_lock);
+	__intel_pstate_update_max_freq(all_cpu_data[cpu], policy);
+
+	cpufreq_cpu_release(policy);
+}
+
+static void intel_pstate_update_limits_for_all(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		intel_pstate_update_limits(cpu);
 }

 /************************** sysfs begin ************************/
@@ -1311,7 +1325,7 @@ static ssize_t store_no_turbo(struct kob

 	mutex_unlock(&intel_pstate_limits_lock);

-	intel_pstate_update_policies();
+	intel_pstate_update_limits_for_all();
 	arch_set_max_freq_ratio(no_turbo);

 unlock_driver:
@@ -1595,7 +1609,6 @@ static void intel_pstate_notify_work(str
 	struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpudata->cpu);

 	if (policy) {
-		intel_pstate_get_hwp_cap(cpudata);
 		__intel_pstate_update_max_freq(cpudata, policy);

 		cpufreq_cpu_release(policy);