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* FAILED: patch "[PATCH] cpufreq: amd-pstate: Add ->fast_switch() callback" failed to apply to 6.3-stable tree
@ 2023-05-28 16:53 gregkh
  2023-05-30 11:55 ` [PATCH 6.3.y] cpufreq: amd-pstate: Add ->fast_switch() callback Wyes Karny
  0 siblings, 1 reply; 5+ messages in thread
From: gregkh @ 2023-05-28 16:53 UTC (permalink / raw)
  To: gautham.shenoy, rafael.j.wysocki, wyes.karny; +Cc: stable


The patch below does not apply to the 6.3-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 <stable@vger.kernel.org>.

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-6.3.y
git checkout FETCH_HEAD
git cherry-pick -x 4badf2eb1e986bdbf34dd2f5d4c979553a86fe54
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023052858-danger-kilowatt-29cc@gregkh' --subject-prefix 'PATCH 6.3.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")

thanks,

greg k-h

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

From 4badf2eb1e986bdbf34dd2f5d4c979553a86fe54 Mon Sep 17 00:00:00 2001
From: "Gautham R. Shenoy" <gautham.shenoy@amd.com>
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 <gautham.shenoy@amd.com>
Signed-off-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 5a3d4aa0f45a..45711fc0a856 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -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,


^ permalink raw reply related	[flat|nested] 5+ messages in thread
* FAILED: patch "[PATCH] cpufreq: amd-pstate: Update policy->cur in" failed to apply to 6.3-stable tree
@ 2023-05-28 16:54 gregkh
  2023-05-30 11:16 ` [PATCH 6.3.y] cpufreq: amd-pstate: Add ->fast_switch() callback Wyes Karny
  0 siblings, 1 reply; 5+ messages in thread
From: gregkh @ 2023-05-28 16:54 UTC (permalink / raw)
  To: wyes.karny, rafael.j.wysocki, stable; +Cc: stable


The patch below does not apply to the 6.3-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 <stable@vger.kernel.org>.

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-6.3.y
git checkout FETCH_HEAD
git cherry-pick -x 3bf8c6307bad5c0cc09cde982e146d847859b651
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023052834-enlighten-vacate-bfd6@gregkh' --subject-prefix 'PATCH 6.3.y' HEAD^..

Possible dependencies:

3bf8c6307bad ("cpufreq: amd-pstate: Update policy->cur in amd_pstate_adjust_perf()")
2dd6d0ebf740 ("cpufreq: amd-pstate: Add guided autonomous mode")
3e6e07805764 ("Documentation: cpufreq: amd-pstate: Move amd_pstate param to alphabetical order")

thanks,

greg k-h

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

From 3bf8c6307bad5c0cc09cde982e146d847859b651 Mon Sep 17 00:00:00 2001
From: Wyes Karny <wyes.karny@amd.com>
Date: Thu, 18 May 2023 05:58:19 +0000
Subject: [PATCH] cpufreq: amd-pstate: Update policy->cur in
 amd_pstate_adjust_perf()

Driver should update policy->cur after updating the frequency.
Currently amd_pstate doesn't update policy->cur when `adjust_perf`
is used. Which causes /proc/cpuinfo to show wrong cpu frequency.
Fix this by updating policy->cur with correct frequency value in
adjust_perf function callback.

- Before the fix: (setting min freq to 1.5 MHz)

[root@amd]# cat /proc/cpuinfo | grep "cpu MHz" | sort | uniq --count
      1 cpu MHz         : 1777.016
      1 cpu MHz         : 1797.160
      1 cpu MHz         : 1797.270
    189 cpu MHz         : 400.000

- After the fix: (setting min freq to 1.5 MHz)

[root@amd]# cat /proc/cpuinfo | grep "cpu MHz" | sort | uniq --count
      1 cpu MHz         : 1753.353
      1 cpu MHz         : 1756.838
      1 cpu MHz         : 1776.466
      1 cpu MHz         : 1776.873
      1 cpu MHz         : 1777.308
      1 cpu MHz         : 1779.900
    183 cpu MHz         : 1805.231
      1 cpu MHz         : 1956.815
      1 cpu MHz         : 2246.203
      1 cpu MHz         : 2259.984

Fixes: 1d215f0319c2 ("cpufreq: amd-pstate: Add fast switch function for AMD P-State")
Signed-off-by: Wyes Karny <wyes.karny@amd.com>
[ rjw: Subject edits ]
Cc: 5.17+ <stable@vger.kernel.org> # 5.17+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index ac54779f5a49..ddd346a239e0 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -501,12 +501,14 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 				   unsigned long capacity)
 {
 	unsigned long max_perf, min_perf, des_perf,
-		      cap_perf, lowest_nonlinear_perf;
+		      cap_perf, lowest_nonlinear_perf, max_freq;
 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
 	struct amd_cpudata *cpudata = policy->driver_data;
+	unsigned int target_freq;
 
 	cap_perf = READ_ONCE(cpudata->highest_perf);
 	lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
+	max_freq = READ_ONCE(cpudata->max_freq);
 
 	des_perf = cap_perf;
 	if (target_perf < capacity)
@@ -523,6 +525,10 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 	if (max_perf < min_perf)
 		max_perf = min_perf;
 
+	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
+	target_freq = div_u64(des_perf * max_freq, max_perf);
+	policy->cur = target_freq;
+
 	amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true,
 			policy->governor->flags);
 	cpufreq_cpu_put(policy);


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2023-06-01 10:26 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-05-28 16:53 FAILED: patch "[PATCH] cpufreq: amd-pstate: Add ->fast_switch() callback" failed to apply to 6.3-stable tree gregkh
2023-05-30 11:55 ` [PATCH 6.3.y] cpufreq: amd-pstate: Add ->fast_switch() callback Wyes Karny
2023-06-01 10:22   ` Greg KH
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2023-05-28 16:54 FAILED: patch "[PATCH] cpufreq: amd-pstate: Update policy->cur in" failed to apply to 6.3-stable tree gregkh
2023-05-30 11:16 ` [PATCH 6.3.y] cpufreq: amd-pstate: Add ->fast_switch() callback Wyes Karny
2023-05-30 11:28   ` Wyes Karny

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