drm/i915: remap l3 on hw init

If any l3 rows have been previously remapped, we must remap them after
GPU reset/resume too.

v2: Just return (no warn) on remapping init if not IVB (Jesse)
Move the check of schizo userspace to i915_gem_l3_remap (Jesse)
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -656,6 +656,8 @@ typedef struct drm_i915_private {
 		/** PPGTT used for aliasing the PPGTT with the GTT */
 		struct i915_hw_ppgtt *aliasing_ppgtt;
 
+		u32 *l3_remap_info;
+
 		struct shrinker inactive_shrinker;
 
 		/**
@@ -1309,6 +1311,7 @@ int __must_check i915_gem_object_set_domain(struct drm_i915_gem_object *obj,
 int __must_check i915_gem_object_finish_gpu(struct drm_i915_gem_object *obj);
 int __must_check i915_gem_init(struct drm_device *dev);
 int __must_check i915_gem_init_hw(struct drm_device *dev);
+void i915_gem_l3_remap(struct drm_device *dev);
 void i915_gem_init_swizzling(struct drm_device *dev);
 void i915_gem_init_ppgtt(struct drm_device *dev);
 void i915_gem_cleanup_ringbuffer(struct drm_device *dev);

drivers/gpu/drm/i915/i915_gem.c

@@ -3527,6 +3527,38 @@ i915_gem_idle(struct drm_device *dev)
 	return 0;
 }
 
+void i915_gem_l3_remap(struct drm_device *dev)
+{
+	drm_i915_private_t *dev_priv = dev->dev_private;
+	u32 misccpctl;
+	int i;
+
+	if (!IS_IVYBRIDGE(dev))
+		return;
+
+	if (!dev_priv->mm.l3_remap_info)
+		return;
+
+	misccpctl = I915_READ(GEN7_MISCCPCTL);
+	I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
+	POSTING_READ(GEN7_MISCCPCTL);
+
+	for (i = 0; i < GEN7_L3LOG_SIZE; i += 4) {
+		u32 remap = I915_READ(GEN7_L3LOG_BASE + i);
+		if (remap && remap != dev_priv->mm.l3_remap_info[i/4])
+			DRM_DEBUG("0x%x was already programmed to %x\n",
+				  GEN7_L3LOG_BASE + i, remap);
+		if (remap && !dev_priv->mm.l3_remap_info[i/4])
+			DRM_DEBUG_DRIVER("Clearing remapped register\n");
+		I915_WRITE(GEN7_L3LOG_BASE + i, dev_priv->mm.l3_remap_info[i/4]);
+	}
+
+	/* Make sure all the writes land before disabling dop clock gating */
+	POSTING_READ(GEN7_L3LOG_BASE);
+
+	I915_WRITE(GEN7_MISCCPCTL, misccpctl);
+}
+
 void i915_gem_init_swizzling(struct drm_device *dev)
 {
 	drm_i915_private_t *dev_priv = dev->dev_private;
@@ -3616,6 +3648,8 @@ i915_gem_init_hw(struct drm_device *dev)
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	int ret;
 
+	i915_gem_l3_remap(dev);
+
 	i915_gem_init_swizzling(dev);
 
 	ret = intel_init_render_ring_buffer(dev);

drivers/gpu/drm/i915/i915_reg.h

@@ -4111,6 +4111,9 @@
 		((reg & GEN7_L3CDERRST1_SUBBANK_MASK) >> 8)
 #define   GEN7_L3CDERRST1_ENABLE	(1<<7)
 
+#define GEN7_L3LOG_BASE			0xB070
+#define GEN7_L3LOG_SIZE			0x80
+
 #define G4X_AUD_VID_DID			0x62020
 #define INTEL_AUDIO_DEVCL		0x808629FB
 #define INTEL_AUDIO_DEVBLC		0x80862801