[PATCH 6/8] drm/i915: Make l3 remapping use the ring

[Ben Widawsky <benjamin.widawsky@intel.com>]

Using LRI for setting the remapping registers allows us to stream l3
remapping information. This is necessary to handle per context remaps as
we'll see implemented in an upcoming patch.

Using the ring also means we don't need to frob the DOP clock gating
bits.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_drv.h   |  2 +-
 drivers/gpu/drm/i915/i915_gem.c   | 39 +++++++++++++++++----------------------
 drivers/gpu/drm/i915/i915_sysfs.c |  3 ++-
 3 files changed, 20 insertions(+), 24 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index eb90461..493a9cd 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1950,7 +1950,7 @@ bool i915_gem_clflush_object(struct drm_i915_gem_object *obj, bool force);
 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, int slice);
+int i915_gem_l3_remap(struct intel_ring_buffer *ring, int slice);
 void i915_gem_init_swizzling(struct drm_device *dev);
 void i915_gem_cleanup_ringbuffer(struct drm_device *dev);
 int __must_check i915_gpu_idle(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index b11f7d6c..fa01c69 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4256,41 +4256,36 @@ i915_gem_idle(struct drm_device *dev)
 	return 0;
 }
 
-void i915_gem_l3_remap(struct drm_device *dev, int slice)
+int i915_gem_l3_remap(struct intel_ring_buffer *ring, int slice)
 {
+	struct drm_device *dev = ring->dev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	u32 reg_base = GEN7_L3LOG_BASE + (slice * 0x200);
 	u32 *remap_info = dev_priv->l3_parity.remap_info[slice];
-	u32 misccpctl;
-	int i;
+	int i, ret;
 
 	if (!HAS_L3_GPU_CACHE(dev))
-		return;
+		return 0;
 
 	if (NUM_L3_SLICES(dev) < 2 && slice)
-		return;
+		return 0;
 
 	if (!remap_info)
-		return;
+		return 0;
 
-	misccpctl = I915_READ(GEN7_MISCCPCTL);
-	I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
-	POSTING_READ(GEN7_MISCCPCTL);
+	ret = intel_ring_begin(ring, GEN7_L3LOG_SIZE / 4 * 3);
+	if (ret)
+		return ret;
 
 	for (i = 0; i < GEN7_L3LOG_SIZE; i += 4) {
-		u32 remap = I915_READ(reg_base + i);
-		if (remap && remap != remap_info[i/4])
-			DRM_DEBUG("0x%x was already programmed to %x\n",
-				  reg_base + i, remap);
-		if (remap && !remap_info[i/4])
-			DRM_DEBUG_DRIVER("Clearing remapped register\n");
-		I915_WRITE(reg_base + i, remap_info[i/4]);
+		intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+		intel_ring_emit(ring, reg_base + i);
+		intel_ring_emit(ring, remap_info[i/4]);
 	}
 
-	/* Make sure all the writes land before disabling dop clock gating */
-	POSTING_READ(reg_base);
+	intel_ring_advance(ring);
 
-	I915_WRITE(GEN7_MISCCPCTL, misccpctl);
+	return ret;
 }
 
 void i915_gem_init_swizzling(struct drm_device *dev)
@@ -4401,15 +4396,15 @@ i915_gem_init_hw(struct drm_device *dev)
 		I915_WRITE(GEN7_MSG_CTL, temp);
 	}
 
-	for (i = 0; i < NUM_L3_SLICES(dev); i++)
-		i915_gem_l3_remap(dev, i);
-
 	i915_gem_init_swizzling(dev);
 
 	ret = i915_gem_init_rings(dev);
 	if (ret)
 		return ret;
 
+	for (i = 0; i < NUM_L3_SLICES(dev); i++)
+		i915_gem_l3_remap(&dev_priv->ring[RCS], i);
+
 	/*
 	 * XXX: There was some w/a described somewhere suggesting loading
 	 * contexts before PPGTT.
diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index d208f2d..65a7274 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -206,7 +206,8 @@ i915_l3_write(struct file *filp, struct kobject *kobj,
 
 	memcpy(dev_priv->l3_parity.remap_info[slice] + (offset/4), buf, count);
 
-	i915_gem_l3_remap(drm_dev, slice);
+	if (i915_gem_l3_remap(&dev_priv->ring[RCS], slice))
+		count = 0;
 
 	mutex_unlock(&drm_dev->struct_mutex);
 
-- 
1.8.4