linux-kernel - [PATCH] thermal/powerclamp: fix missing newer package c-states

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Date:	Thu,  7 May 2015 09:03:59 -0700
From:	Jacob Pan <jacob.jun.pan@...ux.intel.com>
To:	Zhang Rui <rui.zhang@...el.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Linux PM <linux-pm@...r.kernel.org>
Cc:	Rafael Wysocki <rafael.j.wysocki@...el.com>,
	Kristen Carlson Accardi <kristen.c.accardi@...el.com>,
	Arjan van de Ven <arjan@...ux.intel.com>,
	Jacob Pan <jacob.jun.pan@...ux.intel.com>
Subject: [PATCH] thermal/powerclamp: fix missing newer package c-states

Package C8 to C10 was introduced in newer Intel CPUs, we need to
include them in the package c-state residency calculation.
Otherwise, idle injection target is not accurately maintained by
the closed control loop.

Also cleaned up the code to make it scale better with large number
of c-states.

Reported-by: Kristen Carlson Accardi <kristen@...ux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@...ux.intel.com>
---
 drivers/thermal/intel_powerclamp.c | 80 ++++++++++++++++++++------------------
 1 file changed, 43 insertions(+), 37 deletions(-)

diff --git a/drivers/thermal/intel_powerclamp.c b/drivers/thermal/intel_powerclamp.c
index 12623bc..104058b 100644
--- a/drivers/thermal/intel_powerclamp.c
+++ b/drivers/thermal/intel_powerclamp.c
@@ -206,51 +206,57 @@ static void find_target_mwait(void)
 
 }
 
+struct pkg_cstate_info {
+	bool skip;
+	int msr_index;
+	int cstate_id;
+};
+
+#define PKG_CSTATE_INIT(id) {				\
+		.msr_index = MSR_PKG_C##id##_RESIDENCY, \
+		.cstate_id = id				\
+			}
+
+static struct pkg_cstate_info pkg_cstates[] = {
+	PKG_CSTATE_INIT(2),
+	PKG_CSTATE_INIT(3),
+	PKG_CSTATE_INIT(6),
+	PKG_CSTATE_INIT(7),
+	PKG_CSTATE_INIT(8),
+	PKG_CSTATE_INIT(9),
+	PKG_CSTATE_INIT(10),
+	{NULL},
+};
+
 static bool has_pkg_state_counter(void)
 {
-	u64 tmp;
-	return !rdmsrl_safe(MSR_PKG_C2_RESIDENCY, &tmp) ||
-	       !rdmsrl_safe(MSR_PKG_C3_RESIDENCY, &tmp) ||
-	       !rdmsrl_safe(MSR_PKG_C6_RESIDENCY, &tmp) ||
-	       !rdmsrl_safe(MSR_PKG_C7_RESIDENCY, &tmp);
+	u64 val;
+	struct pkg_cstate_info *info = pkg_cstates;
+
+	/* check if any one of the counter msrs exists */
+	while (info->msr_index) {
+		if (!rdmsrl_safe(info->msr_index, &val))
+			return true;
+		info++;
+	}
+
+	return false;
 }
 
 static u64 pkg_state_counter(void)
 {
 	u64 val;
 	u64 count = 0;
-
-	static bool skip_c2;
-	static bool skip_c3;
-	static bool skip_c6;
-	static bool skip_c7;
-
-	if (!skip_c2) {
-		if (!rdmsrl_safe(MSR_PKG_C2_RESIDENCY, &val))
-			count += val;
-		else
-			skip_c2 = true;
-	}
-
-	if (!skip_c3) {
-		if (!rdmsrl_safe(MSR_PKG_C3_RESIDENCY, &val))
-			count += val;
-		else
-			skip_c3 = true;
-	}
-
-	if (!skip_c6) {
-		if (!rdmsrl_safe(MSR_PKG_C6_RESIDENCY, &val))
-			count += val;
-		else
-			skip_c6 = true;
-	}
-
-	if (!skip_c7) {
-		if (!rdmsrl_safe(MSR_PKG_C7_RESIDENCY, &val))
-			count += val;
-		else
-			skip_c7 = true;
+	struct pkg_cstate_info *info = pkg_cstates;
+
+	while (info->msr_index) {
+		if (!info->skip) {
+			if (!rdmsrl_safe(info->msr_index, &val))
+				count += val;
+			else
+				info->skip = true;
+		}
+		info++;
 	}
 
 	return count;
-- 
1.9.1

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