drm/i915/bdw: Create a separate BDW rps enable

This is mostly what we have for HSW with the exceptions of:
no writes:
  GEN6_RC1_WAKE_RATE_LIMIT
  GEN6_RC6pp_WAKE_RATE_LIMIT
  GEN6_RC1e_THRESHOLD
  GEN6_RC6p_THRESHOLD
  GEN6_RC6pp_THRESHOLD

GEN6_RP_DOWN_TIMEOUT - use 1s instead of 1.28s

Don't try to overclock, or program ring/IA frequency tables since we
don't quite have sufficient docs yet.

NOTE: These values do not reflect the changes made recently by Chris.
Since we have no evidence yet what the proper way to tweak for this
platform is, I think it is good to go, and can be optimized by Chris, or
whomever, later.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
[danvet: Drop spurious hunk and drop TODO - having per-platform rps
register frobbing code is in my opinion preferred, now that all the
infrastructure functions are extracted.]
Reviewed-by: Jesse Barnes <jbarnes@virtuosugeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -3762,6 +3762,78 @@ static void gen6_enable_rps_interrupts(struct drm_device *dev)
 	I915_WRITE(GEN6_PMINTRMSK, ~enabled_intrs);
 }
 
+static void gen8_enable_rps(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_ring_buffer *ring;
+	uint32_t rc6_mask = 0, rp_state_cap;
+	int unused;
+
+	/* 1a: Software RC state - RC0 */
+	I915_WRITE(GEN6_RC_STATE, 0);
+
+	/* 1c & 1d: Get forcewake during program sequence. Although the driver
+	 * hasn't enabled a state yet where we need forcewake, BIOS may have.*/
+	gen6_gt_force_wake_get(dev_priv);
+
+	/* 2a: Disable RC states. */
+	I915_WRITE(GEN6_RC_CONTROL, 0);
+
+	rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
+
+	/* 2b: Program RC6 thresholds.*/
+	I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
+	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
+	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
+	for_each_ring(ring, dev_priv, unused)
+		I915_WRITE(RING_MAX_IDLE(ring->mmio_base), 10);
+	I915_WRITE(GEN6_RC_SLEEP, 0);
+	I915_WRITE(GEN6_RC6_THRESHOLD, 50000); /* 50/125ms per EI */
+
+	/* 3: Enable RC6 */
+	if (intel_enable_rc6(dev) & INTEL_RC6_ENABLE)
+		rc6_mask = GEN6_RC_CTL_RC6_ENABLE;
+	DRM_INFO("RC6 %s\n", (rc6_mask & GEN6_RC_CTL_RC6_ENABLE) ? "on" : "off");
+	I915_WRITE(GEN6_RC_CONTROL, GEN6_RC_CTL_HW_ENABLE |
+			GEN6_RC_CTL_EI_MODE(1) |
+			rc6_mask);
+
+	/* 4 Program defaults and thresholds for RPS*/
+	I915_WRITE(GEN6_RPNSWREQ, HSW_FREQUENCY(10)); /* Request 500 MHz */
+	I915_WRITE(GEN6_RC_VIDEO_FREQ, HSW_FREQUENCY(12)); /* Request 600 MHz */
+	/* NB: Docs say 1s, and 1000000 - which aren't equivalent */
+	I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 100000000 / 128); /* 1 second timeout */
+
+	/* Docs recommend 900MHz, and 300 MHz respectively */
+	I915_WRITE(GEN6_RP_INTERRUPT_LIMITS,
+		   dev_priv->rps.max_delay << 24 |
+		   dev_priv->rps.min_delay << 16);
+
+	I915_WRITE(GEN6_RP_UP_THRESHOLD, 7600000 / 128); /* 76ms busyness per EI, 90% */
+	I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 31300000 / 128); /* 313ms busyness per EI, 70%*/
+	I915_WRITE(GEN6_RP_UP_EI, 66000); /* 84.48ms, XXX: random? */
+	I915_WRITE(GEN6_RP_DOWN_EI, 350000); /* 448ms, XXX: random? */
+
+	I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);
+
+	/* 5: Enable RPS */
+	I915_WRITE(GEN6_RP_CONTROL,
+		   GEN6_RP_MEDIA_TURBO |
+		   GEN6_RP_MEDIA_HW_NORMAL_MODE |
+		   GEN6_RP_MEDIA_IS_GFX |
+		   GEN6_RP_ENABLE |
+		   GEN6_RP_UP_BUSY_AVG |
+		   GEN6_RP_DOWN_IDLE_AVG);
+
+	/* 6: Ring frequency + overclocking (our driver does this later */
+
+	gen6_set_rps(dev, (I915_READ(GEN6_GT_PERF_STATUS) & 0xff00) >> 8);
+
+	gen6_enable_rps_interrupts(dev);
+
+	gen6_gt_force_wake_put(dev_priv);
+}
+
 static void gen6_enable_rps(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -4891,6 +4963,9 @@ static void intel_gen6_powersave_work(struct work_struct *work)
 
 	if (IS_VALLEYVIEW(dev)) {
 		valleyview_enable_rps(dev);
+	} else if (IS_BROADWELL(dev)) {
+		gen8_enable_rps(dev);
+		gen6_update_ring_freq(dev);
 	} else {
 		gen6_enable_rps(dev);
 		gen6_update_ring_freq(dev);