drm/i915: Remove ironlake rc6 support

Apparently, this has never worked reliably and is currently disabled. Also, the
gains are not particularly impressive. Thus rather than try to keep unused code
from decaying and having to update it for other driver changes, it was decided
to simply remove it.

For: VIZ-5115
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -1831,18 +1831,6 @@ static int i915_context_status(struct seq_file *m, void *unused)
 	if (ret)
 		return ret;
 
-	if (dev_priv->ips.pwrctx) {
-		seq_puts(m, "power context ");
-		describe_obj(m, dev_priv->ips.pwrctx);
-		seq_putc(m, '\n');
-	}
-
-	if (dev_priv->ips.renderctx) {
-		seq_puts(m, "render context ");
-		describe_obj(m, dev_priv->ips.renderctx);
-		seq_putc(m, '\n');
-	}
-
 	list_for_each_entry(ctx, &dev_priv->context_list, link) {
 		if (!i915.enable_execlists &&
 		    ctx->legacy_hw_ctx.rcs_state == NULL)

drivers/gpu/drm/i915/i915_drv.h

@@ -1065,9 +1065,6 @@ struct intel_ilk_power_mgmt {
 
 	int c_m;
 	int r_t;
-
-	struct drm_i915_gem_object *pwrctx;
-	struct drm_i915_gem_object *renderctx;
 };
 
 struct drm_i915_private;

drivers/gpu/drm/i915/intel_display.c

@@ -13909,8 +13909,6 @@ void intel_modeset_cleanup(struct drm_device *dev)
 
 	intel_fbc_disable(dev);
 
-	ironlake_teardown_rc6(dev);
-
 	mutex_unlock(&dev->struct_mutex);
 
 	/* flush any delayed tasks or pending work */

drivers/gpu/drm/i915/intel_drv.h

@@ -1237,7 +1237,6 @@ void intel_enable_gt_powersave(struct drm_device *dev);
 void intel_disable_gt_powersave(struct drm_device *dev);
 void intel_suspend_gt_powersave(struct drm_device *dev);
 void intel_reset_gt_powersave(struct drm_device *dev);
-void ironlake_teardown_rc6(struct drm_device *dev);
 void gen6_update_ring_freq(struct drm_device *dev);
 void gen6_rps_idle(struct drm_i915_private *dev_priv);
 void gen6_rps_boost(struct drm_i915_private *dev_priv);

drivers/gpu/drm/i915/intel_pm.c

@@ -3538,41 +3538,6 @@ void intel_update_sprite_watermarks(struct drm_plane *plane,
 						   pixel_size, enabled, scaled);
 }
 
-static struct drm_i915_gem_object *
-intel_alloc_context_page(struct drm_device *dev)
-{
-	struct drm_i915_gem_object *ctx;
-	int ret;
-
-	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
-
-	ctx = i915_gem_alloc_object(dev, 4096);
-	if (!ctx) {
-		DRM_DEBUG("failed to alloc power context, RC6 disabled\n");
-		return NULL;
-	}
-
-	ret = i915_gem_obj_ggtt_pin(ctx, 4096, 0);
-	if (ret) {
-		DRM_ERROR("failed to pin power context: %d\n", ret);
-		goto err_unref;
-	}
-
-	ret = i915_gem_object_set_to_gtt_domain(ctx, 1);
-	if (ret) {
-		DRM_ERROR("failed to set-domain on power context: %d\n", ret);
-		goto err_unpin;
-	}
-
-	return ctx;
-
-err_unpin:
-	i915_gem_object_ggtt_unpin(ctx);
-err_unref:
-	drm_gem_object_unreference(&ctx->base);
-	return NULL;
-}
-
 /**
  * Lock protecting IPS related data structures
  */
@@ -4989,124 +4954,6 @@ static void valleyview_enable_rps(struct drm_device *dev)
 	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
 }
 
-void ironlake_teardown_rc6(struct drm_device *dev)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-
-	if (dev_priv->ips.renderctx) {
-		i915_gem_object_ggtt_unpin(dev_priv->ips.renderctx);
-		drm_gem_object_unreference(&dev_priv->ips.renderctx->base);
-		dev_priv->ips.renderctx = NULL;
-	}
-
-	if (dev_priv->ips.pwrctx) {
-		i915_gem_object_ggtt_unpin(dev_priv->ips.pwrctx);
-		drm_gem_object_unreference(&dev_priv->ips.pwrctx->base);
-		dev_priv->ips.pwrctx = NULL;
-	}
-}
-
-static void ironlake_disable_rc6(struct drm_device *dev)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-
-	if (I915_READ(PWRCTXA)) {
-		/* Wake the GPU, prevent RC6, then restore RSTDBYCTL */
-		I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) | RCX_SW_EXIT);
-		wait_for(((I915_READ(RSTDBYCTL) & RSX_STATUS_MASK) == RSX_STATUS_ON),
-			 50);
-
-		I915_WRITE(PWRCTXA, 0);
-		POSTING_READ(PWRCTXA);
-
-		I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) & ~RCX_SW_EXIT);
-		POSTING_READ(RSTDBYCTL);
-	}
-}
-
-static int ironlake_setup_rc6(struct drm_device *dev)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-
-	if (dev_priv->ips.renderctx == NULL)
-		dev_priv->ips.renderctx = intel_alloc_context_page(dev);
-	if (!dev_priv->ips.renderctx)
-		return -ENOMEM;
-
-	if (dev_priv->ips.pwrctx == NULL)
-		dev_priv->ips.pwrctx = intel_alloc_context_page(dev);
-	if (!dev_priv->ips.pwrctx) {
-		ironlake_teardown_rc6(dev);
-		return -ENOMEM;
-	}
-
-	return 0;
-}
-
-static void ironlake_enable_rc6(struct drm_device *dev)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_engine_cs *ring = &dev_priv->ring[RCS];
-	bool was_interruptible;
-	int ret;
-
-	/* rc6 disabled by default due to repeated reports of hanging during
-	 * boot and resume.
-	 */
-	if (!intel_enable_rc6(dev))
-		return;
-
-	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
-
-	ret = ironlake_setup_rc6(dev);
-	if (ret)
-		return;
-
-	was_interruptible = dev_priv->mm.interruptible;
-	dev_priv->mm.interruptible = false;
-
-	/*
-	 * GPU can automatically power down the render unit if given a page
-	 * to save state.
-	 */
-	ret = intel_ring_begin(ring, 6);
-	if (ret) {
-		ironlake_teardown_rc6(dev);
-		dev_priv->mm.interruptible = was_interruptible;
-		return;
-	}
-
-	intel_ring_emit(ring, MI_SUSPEND_FLUSH | MI_SUSPEND_FLUSH_EN);
-	intel_ring_emit(ring, MI_SET_CONTEXT);
-	intel_ring_emit(ring, i915_gem_obj_ggtt_offset(dev_priv->ips.renderctx) |
-			MI_MM_SPACE_GTT |
-			MI_SAVE_EXT_STATE_EN |
-			MI_RESTORE_EXT_STATE_EN |
-			MI_RESTORE_INHIBIT);
-	intel_ring_emit(ring, MI_SUSPEND_FLUSH);
-	intel_ring_emit(ring, MI_NOOP);
-	intel_ring_emit(ring, MI_FLUSH);
-	intel_ring_advance(ring);
-
-	/*
-	 * Wait for the command parser to advance past MI_SET_CONTEXT. The HW
-	 * does an implicit flush, combined with MI_FLUSH above, it should be
-	 * safe to assume that renderctx is valid
-	 */
-	ret = intel_ring_idle(ring);
-	dev_priv->mm.interruptible = was_interruptible;
-	if (ret) {
-		DRM_ERROR("failed to enable ironlake power savings\n");
-		ironlake_teardown_rc6(dev);
-		return;
-	}
-
-	I915_WRITE(PWRCTXA, i915_gem_obj_ggtt_offset(dev_priv->ips.pwrctx) | PWRCTX_EN);
-	I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) & ~RCX_SW_EXIT);
-
-	intel_print_rc6_info(dev, GEN6_RC_CTL_RC6_ENABLE);
-}
-
 static unsigned long intel_pxfreq(u32 vidfreq)
 {
 	unsigned long freq;
@@ -5654,7 +5501,6 @@ void intel_disable_gt_powersave(struct drm_device *dev)
 
 	if (IS_IRONLAKE_M(dev)) {
 		ironlake_disable_drps(dev);
-		ironlake_disable_rc6(dev);
 	} else if (INTEL_INFO(dev)->gen >= 6) {
 		intel_suspend_gt_powersave(dev);
 
@@ -5725,7 +5571,6 @@ void intel_enable_gt_powersave(struct drm_device *dev)
 	if (IS_IRONLAKE_M(dev)) {
 		mutex_lock(&dev->struct_mutex);
 		ironlake_enable_drps(dev);
-		ironlake_enable_rc6(dev);
 		intel_init_emon(dev);
 		mutex_unlock(&dev->struct_mutex);
 	} else if (INTEL_INFO(dev)->gen >= 6) {