FAILED: patch "[PATCH] cpufreq: amd-pstate: Add ->fast_switch() callback" failed to apply to 6.1-stable tree

PATCH New [email protected] 2 participants 2 messages May 28, 2023 – May 30, 2023

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Stable branch CPU frequency scaling framework AMD pstate driver

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2023-05-28 16:55 UTC #0 lore raw

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 4badf2eb1e986bdbf34dd2f5d4c979553a86fe54
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023052858-overgrown-profile-8066@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

4badf2eb1e98 ("cpufreq: amd-pstate: Add ->fast_switch() callback")
2dd6d0ebf740 ("cpufreq: amd-pstate: Add guided autonomous mode")
3e6e07805764 ("Documentation: cpufreq: amd-pstate: Move amd_pstate param to alphabetical order") 5014603e409b ("Documentation: introduce amd pstate active mode kernel command line options") ffa5096a7c33 ("cpufreq: amd-pstate: implement Pstate EPP support for the AMD processors") 36c5014e5460 ("cpufreq: amd-pstate: optimize driver working mode selection in amd_pstate_param()") 4f3085f87b51 ("cpufreq: amd-pstate: fix kernel hang issue while amd-pstate unregistering")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 4badf2eb1e986bdbf34dd2f5d4c979553a86fe54 Mon Sep 17 00:00:00 2001
From: "Gautham R. Shenoy" <[email protected]>
Date: Wed, 17 May 2023 16:28:15 +0000
Subject: [PATCH] cpufreq: amd-pstate: Add ->fast_switch() callback

Schedutil normally calls the adjust_perf callback for drivers with adjust_perf callback available and fast_switch_possible flag set. However, when frequency invariance is disabled and schedutil tries to invoke fast_switch. So, there is a chance of kernel crash if this function pointer is not set. To protect against this scenario add fast_switch callback to amd_pstate driver.

Fixes 1d215f0319c2 ("cpufreq: amd-pstate: Add fast switch function for AMD P-State")

Signed-off-by Gautham R. Shenoy <[email protected]>

Signed-off-by Wyes Karny <[email protected]>

Signed-off-by Rafael J. Wysocki <[email protected]>

drivers/cpufreq/amd-pstate.c +30 -6

index 5a3d4aa0f45a..45711fc0a856 100644
@@ -444,9 +444,8 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy)
 	return 0;
 }
 
-static int amd_pstate_target(struct cpufreq_policy *policy,
-			     unsigned int target_freq,
-			     unsigned int relation)
+static int amd_pstate_update_freq(struct cpufreq_policy *policy,
+				  unsigned int target_freq, bool fast_switch)
 {
 	struct cpufreq_freqs freqs;
 	struct amd_cpudata *cpudata = policy->driver_data;

@@ -465,14 +464,37 @@ static int amd_pstate_target(struct cpufreq_policy *policy,
 	des_perf = DIV_ROUND_CLOSEST(target_freq * cap_perf,
 				     cpudata->max_freq);
 
-	cpufreq_freq_transition_begin(policy, &freqs);
+	WARN_ON(fast_switch && !policy->fast_switch_enabled);
+	/*
+	 * If fast_switch is desired, then there aren't any registered
+	 * transition notifiers. See comment for
+	 * cpufreq_enable_fast_switch().
+	 */
+	if (!fast_switch)
+		cpufreq_freq_transition_begin(policy, &freqs);
+
 	amd_pstate_update(cpudata, min_perf, des_perf,
-			  max_perf, false, policy->governor->flags);
-	cpufreq_freq_transition_end(policy, &freqs, false);
+			max_perf, fast_switch, policy->governor->flags);
+
+	if (!fast_switch)
+		cpufreq_freq_transition_end(policy, &freqs, false);
 
 	return 0;
 }
 
+static int amd_pstate_target(struct cpufreq_policy *policy,
+			     unsigned int target_freq,
+			     unsigned int relation)
+{
+	return amd_pstate_update_freq(policy, target_freq, false);
+}
+
+static unsigned int amd_pstate_fast_switch(struct cpufreq_policy *policy,
+				  unsigned int target_freq)
+{
+	return amd_pstate_update_freq(policy, target_freq, true);
+}
+
 static void amd_pstate_adjust_perf(unsigned int cpu,
 				   unsigned long _min_perf,
 				   unsigned long target_perf,

@@ -715,6 +737,7 @@ static int amd_pstate_cpu_exit(struct cpufreq_policy *policy)
 
 	freq_qos_remove_request(&cpudata->req[1]);
 	freq_qos_remove_request(&cpudata->req[0]);
+	policy->fast_switch_possible = false;
 	kfree(cpudata);
 
 	return 0;

@@ -1309,6 +1332,7 @@ static struct cpufreq_driver amd_pstate_driver = {
 	.flags		= CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS,
 	.verify		= amd_pstate_verify,
 	.target		= amd_pstate_target,
+	.fast_switch    = amd_pstate_fast_switch,
 	.init		= amd_pstate_cpu_init,
 	.exit		= amd_pstate_cpu_exit,
 	.suspend	= amd_pstate_cpu_suspend,

Wyes Karny

2023-05-30 11:05 UTC #1 lore raw

PATCH 1/1 cpufreq: amd-pstate: Add ->fast_switch() callback

From: "Gautham R. Shenoy" <[email protected]>

[ Upstream commit 4badf2eb1e986bdbf34dd2f5d4c979553a86fe54 ]

Fixes 1d215f0319c2 ("cpufreq: amd-pstate: Add fast switch function for AMD P-State")

Signed-off-by Gautham R. Shenoy <[email protected]>

Signed-off-by Wyes Karny <[email protected]>

Signed-off-by Rafael J. Wysocki <[email protected]>

(cherry picked from commit 4badf2eb1e986bdbf34dd2f5d4c979553a86fe54)

---
 drivers/cpufreq/amd-pstate.c | 37 +++++++++++++++++++++++++++++-------
 1 file changed, 30 insertions(+), 7 deletions(-)

drivers/cpufreq/amd-pstate.c +30 -7

index c17bd845f5fc..446edc0fd192 100644
@@ -249,9 +249,8 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy)
 	return 0;
 }
 
-static int amd_pstate_target(struct cpufreq_policy *policy,
-			     unsigned int target_freq,
-			     unsigned int relation)
+static int amd_pstate_update_freq(struct cpufreq_policy *policy,
+				  unsigned int target_freq, bool fast_switch)
 {
 	struct cpufreq_freqs freqs;
 	struct amd_cpudata *cpudata = policy->driver_data;

@@ -270,14 +269,36 @@ static int amd_pstate_target(struct cpufreq_policy *policy,
 	des_perf = DIV_ROUND_CLOSEST(target_freq * cap_perf,
 				     cpudata->max_freq);
 
-	cpufreq_freq_transition_begin(policy, &freqs);
-	amd_pstate_update(cpudata, min_perf, des_perf,
-			  max_perf, false);
-	cpufreq_freq_transition_end(policy, &freqs, false);
+	WARN_ON(fast_switch && !policy->fast_switch_enabled);
+	/*
+	 * If fast_switch is desired, then there aren't any registered
+	 * transition notifiers. See comment for
+	 * cpufreq_enable_fast_switch().
+	 */
+	if (!fast_switch)
+		cpufreq_freq_transition_begin(policy, &freqs);
+
+	amd_pstate_update(cpudata, min_perf, des_perf, max_perf, fast_switch);
+
+	if (!fast_switch)
+		cpufreq_freq_transition_end(policy, &freqs, false);
 
 	return 0;
 }
 
+static int amd_pstate_target(struct cpufreq_policy *policy,
+			     unsigned int target_freq,
+			     unsigned int relation)
+{
+	return amd_pstate_update_freq(policy, target_freq, false);
+}
+
+static unsigned int amd_pstate_fast_switch(struct cpufreq_policy *policy,
+				  unsigned int target_freq)
+{
+	return amd_pstate_update_freq(policy, target_freq, true);
+}
+
 static void amd_pstate_adjust_perf(unsigned int cpu,
 				   unsigned long _min_perf,
 				   unsigned long target_perf,

@@ -517,6 +538,7 @@ static int amd_pstate_cpu_exit(struct cpufreq_policy *policy)
 
 	freq_qos_remove_request(&cpudata->req[1]);
 	freq_qos_remove_request(&cpudata->req[0]);
+	policy->fast_switch_possible = false;
 	kfree(cpudata);
 
 	return 0;

@@ -608,6 +630,7 @@ static struct cpufreq_driver amd_pstate_driver = {
 	.flags		= CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS,
 	.verify		= amd_pstate_verify,
 	.target		= amd_pstate_target,
+	.fast_switch    = amd_pstate_fast_switch,
 	.init		= amd_pstate_cpu_init,
 	.exit		= amd_pstate_cpu_exit,
 	.suspend	= amd_pstate_cpu_suspend,

Signature · 1 line

2.34.1