linux-kernel - [PATCH AUTOSEL 6.14 13/18] cpufreq/amd-pstate: Invalidate cppc_req

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: <20250331143409.1682789-13-sashal@kernel.org>
Date: Mon, 31 Mar 2025 10:34:03 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Mario Limonciello <mario.limonciello@....com>,
	"Gautham R . Shenoy" <gautham.shenoy@....com>,
	Dhananjay Ugwekar <dhananjay.ugwekar@....com>,
	Miroslav Pavleski <miroslav@...leski.net>,
	Sasha Levin <sashal@...nel.org>,
	ray.huang@....com,
	rafael@...nel.org,
	linux-pm@...r.kernel.org
Subject: [PATCH AUTOSEL 6.14 13/18] cpufreq/amd-pstate: Invalidate cppc_req_cached during suspend

From: Mario Limonciello <mario.limonciello@....com>

[ Upstream commit b7a41156588ad03757bf0a2f0e05d6cbcebeaa9e ]

During resume it's possible the firmware didn't restore the CPPC request
MSR but the kernel thinks the values line up. This leads to incorrect
performance after resume from suspend.

To fix the issue invalidate the cached value at suspend. During resume use
the saved values programmed as cached limits.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@....com>
Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@....com>
Reported-by: Miroslav Pavleski <miroslav@...leski.net>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217931
Signed-off-by: Mario Limonciello <mario.limonciello@....com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/cpufreq/amd-pstate.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 313550fa62d41..340fb00aec6d7 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1617,7 +1617,7 @@ static int amd_pstate_epp_reenable(struct cpufreq_policy *policy)
 					  max_perf, policy->boost_enabled);
 	}
 
-	return amd_pstate_update_perf(cpudata, 0, 0, max_perf, cpudata->epp_cached, false);
+	return amd_pstate_epp_update_limit(policy);
 }
 
 static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
@@ -1666,6 +1666,9 @@ static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)
 	if (cppc_state != AMD_PSTATE_ACTIVE)
 		return 0;
 
+	/* invalidate to ensure it's rewritten during resume */
+	cpudata->cppc_req_cached = 0;
+
 	/* set this flag to avoid setting core offline*/
 	cpudata->suspended = true;
 
-- 
2.39.5