linux-kernel - [PATCH] powercap: intel_rapl: Don't warn about BIOS locked limits during resume

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-next>] [day] [month] [year] [list]

Message-ID: <20231004183455.27797-1-ville.syrjala@linux.intel.com>
Date:   Wed,  4 Oct 2023 21:34:55 +0300
From:   Ville Syrjala <ville.syrjala@...ux.intel.com>
To:     linux-pm@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, intel-gfx@...ts.freedesktop.org,
        Zhang Rui <rui.zhang@...el.com>,
        Wang Wendy <wendy.wang@...el.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        Srinivas Pandruvada <srinivas.pandruvada@...el.com>
Subject: [PATCH] powercap: intel_rapl: Don't warn about BIOS locked limits during resume

From: Ville Syrjälä <ville.syrjala@...ux.intel.com>

Restore enough of the original behaviour to stop spamming
dmesg with warnings about BIOS locked limits when trying
to restore them during resume.

This still doesn't 100% match the original behaviour
as we no longer attempt to blindly restore the BIOS locked
limits. No idea if that makes any difference in practice.

Cc: Zhang Rui <rui.zhang@...el.com>
Cc: Wang Wendy <wendy.wang@...el.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@...el.com>
Fixes: 9050a9cd5e4c ("powercap: intel_rapl: Cleanup Power Limits support")
Signed-off-by: Ville Syrjälä <ville.syrjala@...ux.intel.com>
---
 drivers/powercap/intel_rapl_common.c | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c
index 40a2cc649c79..9a6a40c83f82 100644
--- a/drivers/powercap/intel_rapl_common.c
+++ b/drivers/powercap/intel_rapl_common.c
@@ -882,22 +882,34 @@ static int rapl_read_pl_data(struct rapl_domain *rd, int pl,
 	return rapl_read_data_raw(rd, prim, xlate, data);
 }
 
-static int rapl_write_pl_data(struct rapl_domain *rd, int pl,
-			       enum pl_prims pl_prim,
-			       unsigned long long value)
+static int rapl_write_pl_data_nowarn(struct rapl_domain *rd, int pl,
+				     enum pl_prims pl_prim,
+				     unsigned long long value)
 {
 	enum rapl_primitives prim = get_pl_prim(rd, pl, pl_prim);
 
 	if (!is_pl_valid(rd, pl))
 		return -EINVAL;
 
-	if (rd->rpl[pl].locked) {
-		pr_warn("%s:%s:%s locked by BIOS\n", rd->rp->name, rd->name, pl_names[pl]);
+	if (rd->rpl[pl].locked)
 		return -EACCES;
-	}
 
 	return rapl_write_data_raw(rd, prim, value);
 }
+
+static int rapl_write_pl_data(struct rapl_domain *rd, int pl,
+			      enum pl_prims pl_prim,
+			      unsigned long long value)
+{
+	int ret;
+
+	ret = rapl_write_pl_data_nowarn(rd, pl, pl_prim, value);
+	if (ret == -EACCES)
+		pr_warn("%s:%s:%s locked by BIOS\n", rd->rp->name, rd->name, pl_names[pl]);
+
+	return ret;
+}
+
 /*
  * Raw RAPL data stored in MSRs are in certain scales. We need to
  * convert them into standard units based on the units reported in
@@ -1634,8 +1646,8 @@ static void power_limit_state_restore(void)
 		rd = power_zone_to_rapl_domain(rp->power_zone);
 		for (i = POWER_LIMIT1; i < NR_POWER_LIMITS; i++)
 			if (rd->rpl[i].last_power_limit)
-				rapl_write_pl_data(rd, i, PL_LIMIT,
-					       rd->rpl[i].last_power_limit);
+				rapl_write_pl_data_nowarn(rd, i, PL_LIMIT,
+							  rd->rpl[i].last_power_limit);
 	}
 	cpus_read_unlock();
 }
-- 
2.41.0