drm/i915/selftests: Move gpu energy measurement into its own little lib

Move the handy utility to measure the GPU energy consumption using RAPL
msr into a common lib so that it can be reused easily.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200417152018.13079-1-chris@chris-wilson.co.uk

2 files changed, 37 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/selftests/librapl.c b/drivers/gpu/drm/i915/selftests/librapl.c
new file mode 100644
index 000000000000..58710ac3f979
--- /dev/null
+++ b/drivers/gpu/drm/i915/selftests/librapl.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+
+#include <asm/msr.h>
+
+#include "librapl.h"
+
+u64 librapl_energy_uJ(void)
+{
+	unsigned long long power;
+	u32 units;
+
+	if (rdmsrl_safe(MSR_RAPL_POWER_UNIT, &power))
+		return 0;
+
+	units = (power & 0x1f00) >> 8;
+
+	if (rdmsrl_safe(MSR_PP1_ENERGY_STATUS, &power))
+		return 0;
+
+	return (1000000 * power) >> units; /* convert to uJ */
+}
diff --git a/drivers/gpu/drm/i915/selftests/librapl.h b/drivers/gpu/drm/i915/selftests/librapl.h
new file mode 100644
index 000000000000..887f3e91dd05
--- /dev/null
+++ b/drivers/gpu/drm/i915/selftests/librapl.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+
+#ifndef SELFTEST_LIBRAPL_H
+#define SELFTEST_LIBRAPL_H
+
+#include <linux/types.h>
+
+u64 librapl_energy_uJ(void);
+
+#endif /* SELFTEST_LIBRAPL_H */