[Intel-gfx] [RFC 01/10] drm/i915: Convert intel_rc6_residency_us to ns

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Will be used for exposing the PMU counters.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h |  8 +++++++-
 drivers/gpu/drm/i915/intel_pm.c | 23 +++++++++--------------
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6383940e8d55..d47215e73405 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -4009,9 +4009,15 @@ void vlv_phy_reset_lanes(struct intel_encoder *encoder);
 
 int intel_gpu_freq(struct drm_i915_private *dev_priv, int val);
 int intel_freq_opcode(struct drm_i915_private *dev_priv, int val);
-u64 intel_rc6_residency_us(struct drm_i915_private *dev_priv,
+u64 intel_rc6_residency_ns(struct drm_i915_private *dev_priv,
 			   const i915_reg_t reg);
 
+static inline u64 intel_rc6_residency_us(struct drm_i915_private *dev_priv,
+					 const i915_reg_t reg)
+{
+	return DIV_ROUND_UP_ULL(intel_rc6_residency_ns(dev_priv, reg), 1000);
+}
+
 #define I915_READ8(reg)		dev_priv->uncore.funcs.mmio_readb(dev_priv, (reg), true)
 #define I915_WRITE8(reg, val)	dev_priv->uncore.funcs.mmio_writeb(dev_priv, (reg), (val), true)
 
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 48785ef75d33..bfbce74a4013 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -9179,10 +9179,10 @@ static u64 vlv_residency_raw(struct drm_i915_private *dev_priv,
 	return lower | (u64)upper << 8;
 }
 
-u64 intel_rc6_residency_us(struct drm_i915_private *dev_priv,
+u64 intel_rc6_residency_ns(struct drm_i915_private *dev_priv,
 			   const i915_reg_t reg)
 {
-	u64 time_hw, units, div;
+	u64 res;
 
 	if (!intel_enable_rc6())
 		return 0;
@@ -9191,22 +9191,17 @@ u64 intel_rc6_residency_us(struct drm_i915_private *dev_priv,
 
 	/* On VLV and CHV, residency time is in CZ units rather than 1.28us */
 	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
-		units = 1000;
-		div = dev_priv->czclk_freq;
+		res = vlv_residency_raw(dev_priv, reg);
+		res = DIV_ROUND_UP_ULL(res * 1000000, dev_priv->czclk_freq);
 
-		time_hw = vlv_residency_raw(dev_priv, reg);
-	} else if (IS_GEN9_LP(dev_priv)) {
-		units = 1000;
-		div = 1200;		/* 833.33ns */
-
-		time_hw = I915_READ(reg);
 	} else {
-		units = 128000; /* 1.28us */
-		div = 100000;
+		/* 833.33ns units on Gen9LP, 1.28us elsewhere. */
+		unsigned int unit = IS_GEN9_LP(dev_priv) ? 833 : 1280;
 
-		time_hw = I915_READ(reg);
+		res = (u64)I915_READ(reg) * unit;
 	}
 
 	intel_runtime_pm_put(dev_priv);
-	return DIV_ROUND_UP_ULL(time_hw * units, div);
+
+	return res;
 }
-- 
2.9.4