thermal/intel: Introduce Intel TCC library

There are several different drivers that accesses the Intel TCC
(thermal control circuitry) MSRs, and each of them has its own
implementation for the same functionalities, e.g. getting the current
temperature, getting the tj_max, and getting/setting the tj_max offset.

Introduce a library to unify the code for Intel CPU TCC MSR access.

At the same time, ensure the temperature is got based on the updated
tjmax value because tjmax can be changed at runtime for cases like
the Intel SST-PP (Intel Speed Select Technology - Performance Profile)
level change.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/include/linux/intel_tcc.h b/include/linux/intel_tcc.h
new file mode 100644
index 000000000000..f422612c28d6
--- /dev/null
+++ b/include/linux/intel_tcc.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  header for Intel TCC (thermal control circuitry) library
+ *
+ *  Copyright (C) 2022  Intel Corporation.
+ */
+
+#ifndef __INTEL_TCC_H__
+#define __INTEL_TCC_H__
+
+#include <linux/types.h>
+
+int intel_tcc_get_tjmax(int cpu);
+int intel_tcc_get_offset(int cpu);
+int intel_tcc_set_offset(int cpu, int offset);
+int intel_tcc_get_temp(int cpu, bool pkg);
+
+#endif /* __INTEL_TCC_H__ */