[Intel-gfx] [PATCH v6 2/3] drm/i915/hwmon: Add hwmon support in libpower for dgfx

[Riana Tauro]

Add an interface to obtain hwmon energy values. The function returns
per-gt energy if gt level energy is available else returns the package
level energy if there is a single gt.

Use this function in libpower to verify power consumption in
different subtests

v2 : use i915_hwmon prefix (Anshuman)
v3 : re-use is_visible function of energy to remove
     redundant code (Anshuman)
v4 : fix kernel-doc (Anshuman)
     add per-gt hwmon support (Ashutosh)
v5 : add check to return package level energy only when there
     is a single gt and gt level energy is not available.
     add libpower library changes (Ashutosh)

Signed-off-by: Riana Tauro <riana.tauro at intel.com>
Co-developed-by: Tilak Tangudu <tilak.tangudu at intel.com>
Signed-off-by: Tilak Tangudu <tilak.tangudu at intel.com>
Reviewed-by: Anshuman Gupta <anshuman.gupta at intel.com>
---
 drivers/gpu/drm/i915/i915_hwmon.c         | 28 ++++++++++++++++++++
 drivers/gpu/drm/i915/i915_hwmon.h         |  3 +++
 drivers/gpu/drm/i915/selftests/libpower.c | 31 +++++++++++------------
 drivers/gpu/drm/i915/selftests/libpower.h | 10 +++++---
 4 files changed, 52 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c
index c588a17f97e9..e1a33ea65458 100644
--- a/drivers/gpu/drm/i915/i915_hwmon.c
+++ b/drivers/gpu/drm/i915/i915_hwmon.c
@@ -442,6 +442,34 @@ hwm_energy_read(struct hwm_drvdata *ddat, u32 attr, long *val)
 	}
 }
 
+/**
+ * i915_hwmon_get_energy - obtains energy value
+ * @gt: intel_gt structure
+ * @energy: pointer to store energy in uJ
+ *
+ * This function checks for the validity of the underlying energy
+ * hardware register and obtains per-gt level energy
+ * values.
+ *
+ * Return: 0 on success, -EOPNOTSUPP if register is invalid
+ */
+int
+i915_hwmon_get_energy(struct intel_gt *gt, long *energy)
+{
+	struct i915_hwmon *hwmon = gt->i915->hwmon;
+	struct hwm_drvdata *ddat = &hwmon->ddat;
+	struct hwm_drvdata *ddat_gt = hwmon->ddat_gt + gt->info.id;
+
+	if (hwm_energy_is_visible(ddat_gt, hwmon_energy_input))
+		hwm_energy(ddat_gt, energy);
+	else if (!HAS_EXTRA_GT_LIST(gt->i915) && hwm_energy_is_visible(ddat, hwmon_energy_input))
+		hwm_energy(ddat, energy);
+	else
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
 static umode_t
 hwm_curr_is_visible(const struct hwm_drvdata *ddat, u32 attr)
 {
diff --git a/drivers/gpu/drm/i915/i915_hwmon.h b/drivers/gpu/drm/i915/i915_hwmon.h
index 7ca9cf2c34c9..1c38cfdbb7e9 100644
--- a/drivers/gpu/drm/i915/i915_hwmon.h
+++ b/drivers/gpu/drm/i915/i915_hwmon.h
@@ -8,13 +8,16 @@
 #define __I915_HWMON_H__
 
 struct drm_i915_private;
+struct intel_gt;
 
 #if IS_REACHABLE(CONFIG_HWMON)
 void i915_hwmon_register(struct drm_i915_private *i915);
 void i915_hwmon_unregister(struct drm_i915_private *i915);
+int i915_hwmon_get_energy(struct intel_gt *gt, long *energy);
 #else
 static inline void i915_hwmon_register(struct drm_i915_private *i915) { };
 static inline void i915_hwmon_unregister(struct drm_i915_private *i915) { };
+static inline int i915_hwmon_get_energy(struct intel_gt *gt, long *energy) { return -EOPNOTSUPP; }
 #endif
 
 #endif /* __I915_HWMON_H__ */
diff --git a/drivers/gpu/drm/i915/selftests/libpower.c b/drivers/gpu/drm/i915/selftests/libpower.c
index c66e993c5f85..3d4d2dc74a54 100644
--- a/drivers/gpu/drm/i915/selftests/libpower.c
+++ b/drivers/gpu/drm/i915/selftests/libpower.c
@@ -6,29 +6,28 @@
 #include <asm/msr.h>
 
 #include "i915_drv.h"
+#include "i915_hwmon.h"
 #include "libpower.h"
 
-bool libpower_supported(const struct drm_i915_private *i915)
-{
-	/* Discrete cards require hwmon integration */
-	if (IS_DGFX(i915))
-		return false;
-
-	return libpower_get_energy_uJ();
-}
-
-u64 libpower_get_energy_uJ(void)
+u64 libpower_get_energy_uJ(struct intel_gt *gt)
 {
 	unsigned long long power;
 	u32 units;
+	long energy_uJ = 0;
 
-	if (rdmsrl_safe(MSR_RAPL_POWER_UNIT, &power))
-		return 0;
+	if (IS_DGFX(gt->i915)) {
+		if (i915_hwmon_get_energy(gt, &energy_uJ))
+			return 0;
+	} else {
+		if (rdmsrl_safe(MSR_RAPL_POWER_UNIT, &power))
+			return 0;
 
-	units = (power & 0x1f00) >> 8;
+		units = (power & 0x1f00) >> 8;
 
-	if (rdmsrl_safe(MSR_PP1_ENERGY_STATUS, &power))
-		return 0;
+		if (rdmsrl_safe(MSR_PP1_ENERGY_STATUS, &power))
+			return 0;
 
-	return (1000000 * power) >> units; /* convert to uJ */
+		energy_uJ = (1000000 * power) >> units; /* convert to uJ */
+	}
+	return energy_uJ;
 }
diff --git a/drivers/gpu/drm/i915/selftests/libpower.h b/drivers/gpu/drm/i915/selftests/libpower.h
index 5352981eb946..e4410a886654 100644
--- a/drivers/gpu/drm/i915/selftests/libpower.h
+++ b/drivers/gpu/drm/i915/selftests/libpower.h
@@ -8,10 +8,12 @@
 
 #include <linux/types.h>
 
-struct drm_i915_private;
+struct intel_gt;
 
-bool libpower_supported(const struct drm_i915_private *i915);
-
-u64 libpower_get_energy_uJ(void);
+u64 libpower_get_energy_uJ(struct intel_gt *gt);
 
+static inline bool libpower_supported(struct intel_gt *gt)
+{
+	return libpower_get_energy_uJ(gt);
+}
 #endif /* SELFTEST_LIBPOWER_H */
-- 
2.25.1