drm/i915/gt: Add sysfs throttle frequency interfaces

Throttling here refers to the GT frequency being clipped. Each of
the throttle reason attributes will have a 0 or 1 value depending
upon whether there is throttling and also the specific reason for
it.

The following is a brief description of the sysfs throttle
frequency attributes added:

 - throttle_reason_status: when set indicates that there is GT
   frequency clipping.

 - throttle_reason_pl1: when set indicates that PBM PL1 (platform
   or package PL1) has caused GT frequency clipping.

 - throttle_reason_pl2: when set indicates that PBM PL2 or PL3
   (platform or package PL2 or PL3) has caused GT frequency
   clipping.

 - throttle_reason_pl4: when set indicates that PL4 or IccMax has
   caused GT frequency clipping.

 - throttle_reason_thermal: when set indicates that Thermal event
   has caused GT frequency clipping.

 - throttle_reason_prochot: when set indicates that PROCHOT# has
   caused GT frequency clipping.

 - throttle_reason_ratl: when set indicates that Running Average
   Thermal Limit has caused GT frequency clipping.

 - throttle_reason_vr_thermalert: when set indicates that Hot VR
   (any processor VR)  has caused GT frequency clipping.

 - throttle_reason_vr_tdc: when set indicates that VR TDC
   (Thermal Design Current)  has caused GT frequency clipping.

Signed-off-by: Sujaritha Sundaresan <sujaritha.sundaresan@intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Dale B Stimson <dale.b.stimson@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220318233938.149744-8-andi.shyti@linux.intel.com
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 3cdcd25..8d6ffd2 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1837,6 +1837,17 @@
 #define GEN9_RP_STATE_LIMITS	_MMIO(0x138148)
 #define XEHPSDV_RP_STATE_CAP	_MMIO(0x250014)
 
+#define GT0_PERF_LIMIT_REASONS		_MMIO(0x1381a8)
+#define   GT0_PERF_LIMIT_REASONS_MASK	0xde3
+#define   PROCHOT_MASK			REG_BIT(1)
+#define   THERMAL_LIMIT_MASK		REG_BIT(2)
+#define   RATL_MASK			REG_BIT(6)
+#define   VR_THERMALERT_MASK		REG_BIT(7)
+#define   VR_TDC_MASK			REG_BIT(8)
+#define   POWER_LIMIT_4_MASK		REG_BIT(9)
+#define   POWER_LIMIT_1_MASK		REG_BIT(11)
+#define   POWER_LIMIT_2_MASK		REG_BIT(12)
+
 #define CHV_CLK_CTL1			_MMIO(0x101100)
 #define VLV_CLK_CTL2			_MMIO(0x101104)
 #define   CLK_CTL2_CZCOUNT_30NS_SHIFT	28