[PATCH 1/2] drm/i915: add SNB power monitoring

[Jesse Barnes <jbarnes@virtuousgeek.org>]

Use CPU package registers to monitor CPU and GPU power consumption.  Add
a trace point for package power as well, to simplify data collection.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
 drivers/gpu/drm/i915/i915_debugfs.c  |   50 +++++++++++++++++++++++++++------
 drivers/gpu/drm/i915/i915_drv.h      |    2 +
 drivers/gpu/drm/i915/i915_reg.h      |    3 ++
 drivers/gpu/drm/i915/i915_trace.h    |   14 +++++++++
 drivers/gpu/drm/i915/intel_display.c |    3 ++
 5 files changed, 63 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index d659f36..9094c71 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1088,27 +1088,59 @@ static int i915_sr_status(struct seq_file *m, void *unused)
 	return 0;
 }
 
+/* Return current power draw in mW */
+static unsigned long i915_cur_power(struct drm_device *dev)
+{
+	drm_i915_private_t *dev_priv = dev->dev_private;
+	u32 pkg_power, units, tunit, eunit, punit;
+	unsigned long energy, time;
+
+	units = I915_READ(GEN6_PKG_POWER_SKU_UNIT);
+	pkg_power = I915_READ(GEN6_PKG_ENERGY_STATUS);
+
+	tunit = (units >> 16) & 0xf; /* 1s / 2^tunit */
+	eunit = (units >> 8) & 0x1f; /* 1J / 2^enuit */
+	punit = units & 0xf; /* 1W / 2^punit */
+
+	energy = pkg_power - dev_priv->last_pkg_power;
+	time = jiffies_to_msecs(jiffies) - dev_priv->last_pkg_power_time;
+	energy /= (1 << (eunit - 10));
+
+	dev_priv->last_pkg_power = pkg_power;
+	dev_priv->last_pkg_power_time = jiffies_to_msecs(jiffies);
+
+	return (energy * 1000) / time;
+}
+
 static int i915_emon_status(struct seq_file *m, void *unused)
 {
 	struct drm_info_node *node = (struct drm_info_node *) m->private;
 	struct drm_device *dev = node->minor->dev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
-	unsigned long temp, chipset, gfx;
 	int ret;
 
 	ret = mutex_lock_interruptible(&dev->struct_mutex);
 	if (ret)
 		return ret;
 
-	temp = i915_mch_val(dev_priv);
-	chipset = i915_chipset_val(dev_priv);
-	gfx = i915_gfx_val(dev_priv);
-	mutex_unlock(&dev->struct_mutex);
+	if (IS_GEN5(dev)) {
+		unsigned long temp, chipset, gfx;
+
+		temp = i915_mch_val(dev_priv);
+		chipset = i915_chipset_val(dev_priv);
+		gfx = i915_gfx_val(dev_priv);
 
-	seq_printf(m, "GMCH temp: %ld\n", temp);
-	seq_printf(m, "Chipset power: %ld\n", chipset);
-	seq_printf(m, "GFX power: %ld\n", gfx);
-	seq_printf(m, "Total power: %ld\n", chipset + gfx);
+		seq_printf(m, "GMCH temp: %ld\n", temp);
+		seq_printf(m, "Chipset power: %ld\n", chipset);
+		seq_printf(m, "GFX power: %ld\n", gfx);
+		seq_printf(m, "Total power: %ld\n", chipset + gfx);
+	} else if (IS_GEN6(dev)) {
+		unsigned long power = i915_cur_power(dev);
+
+		trace_i915_pkg_power(power);
+		seq_printf(m, "Current power draw: %ldmW\n", power);
+	}
+	mutex_unlock(&dev->struct_mutex);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3d4fd01..c8a21ce 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -697,6 +697,8 @@ typedef struct drm_i915_private {
 	int r_t;
 	u8 corr;
 	spinlock_t *mchdev_lock;
+	u32 last_pkg_power;
+	unsigned long last_pkg_power_time;
 
 	enum no_fbc_reason no_fbc_reason;
 
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index e1be98f..acf786c 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1244,6 +1244,9 @@
 #define GEN6_RP_STATE_LIMITS	0x145994
 #define GEN6_RP_STATE_CAP	0x145998
 
+#define GEN6_PKG_POWER_SKU_UNIT	0x145938
+#define GEN6_PKG_ENERGY_STATUS	0x14593c
+
 /*
  * Logical Context regs
  */
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index d623fef..e102c76 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -410,6 +410,20 @@ TRACE_EVENT(i915_reg_rw,
 		     (u32)(__entry->val >> 32))
 );
 
+TRACE_EVENT(i915_pkg_power,
+	    TP_PROTO(unsigned long power),
+	    TP_ARGS(power),
+	    TP_STRUCT__entry(
+		    __field(unsigned long, power)
+		    ),
+
+	    TP_fast_assign(
+		    __entry->power = power;
+		    ),
+
+	    TP_printk("pkg power=%ld", __entry->power)
+);
+
 #endif /* _I915_TRACE_H_ */
 
 /* This part must be outside protection */
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f569841..6c7361e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6959,6 +6959,9 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
 	I915_WRITE(GEN6_PMINTRMSK, 0);
 
 	__gen6_force_wake_put(dev_priv);
+
+	dev_priv->last_pkg_power = I915_READ(GEN6_PKG_ENERGY_STATUS);
+	dev_priv->last_pkg_power_time = jiffies_to_msecs(jiffies);
 }
 
 void intel_enable_clock_gating(struct drm_device *dev)
-- 
1.7.1