[PATCH 06/11] drm/i915: add power context allocation and setup on VLV v4

[jbarnes at virtuousgeek.org (Jesse Barnes)]

The Gunit has a separate reg for this, so allocate some stolen space for
the power context and initialize the reg.

v2: check for allocation before freeing at cleanup (Jani)
v3: add comment about stolen allocation (Chris)
    check for lock bit before init (jbarnes)
v4: check for allocation before init (jbarnes)

Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/i915_drv.h        |    2 ++
 drivers/gpu/drm/i915/i915_gem_stolen.c |   55 ++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_reg.h        |    1 +
 3 files changed, 58 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 2832cdb..182c494 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1023,6 +1023,8 @@ typedef struct drm_i915_private {
 
 	struct i915_gpu_error gpu_error;
 
+	struct drm_mm_node *vlv_pctx;
+
 	/* list of fbdev register on this device */
 	struct intel_fbdev *fbdev;
 
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index efaaba5..36c9af4 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -171,11 +171,63 @@ void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
 	dev_priv->cfb_size = 0;
 }
 
+static void i915_setup_pctx(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_mm_node *pctx;
+	unsigned long pctx_paddr;
+	int pctx_size = 24*1024;
+
+	if (I915_READ(VLV_PCBR)) /* BIOS set it up already */
+		return;
+
+	/*
+	 * From the Gunit register HAS:
+	 * The Gfx driver is expected to program this register and ensure
+	 * proper allocation within Gfx stolen memory.  For example, this
+	 * register should be programmed such than the PCBR range does not
+	 * overlap with other ranges, such as the frame buffer, protected
+	 * memory, or any other relevant ranges.
+	 */
+	pctx = drm_mm_search_free(&dev_priv->mm.stolen, pctx_size, 4096, 0);
+	if (pctx)
+		pctx = drm_mm_get_block(pctx, pctx_size, 4096);
+	if (!pctx)
+		goto err;
+
+	pctx_paddr = dev_priv->mm.stolen_base + pctx->start;
+	if (!pctx_paddr)
+		goto err_free_pctx;
+
+	dev_priv->vlv_pctx = pctx;
+	I915_WRITE(VLV_PCBR, pctx_paddr);
+
+	return;
+
+err_free_pctx:
+	drm_mm_put_block(pctx);
+err:
+	DRM_DEBUG("not enough stolen space for PCTX, disabling\n");
+}
+
+static void i915_cleanup_pctx(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (!dev_priv->vlv_pctx)
+		return;
+
+	I915_WRITE(VLV_PCBR, 0);
+	drm_mm_put_block(dev_priv->vlv_pctx);
+}
+
 void i915_gem_cleanup_stolen(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
 	i915_gem_stolen_cleanup_compression(dev);
+	if (IS_VALLEYVIEW(dev) && i915_powersave)
+		i915_cleanup_pctx(dev);
 	drm_mm_takedown(&dev_priv->mm.stolen);
 }
 
@@ -193,6 +245,9 @@ int i915_gem_init_stolen(struct drm_device *dev)
 	/* Basic memrange allocator for stolen space */
 	drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size);
 
+	if (IS_VALLEYVIEW(dev) && i915_powersave)
+		i915_setup_pctx(dev);
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 834e79f..68051d6 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -677,6 +677,7 @@
 #define VLV_IIR		(VLV_DISPLAY_BASE + 0x20a4)
 #define VLV_IMR		(VLV_DISPLAY_BASE + 0x20a8)
 #define VLV_ISR		(VLV_DISPLAY_BASE + 0x20ac)
+#define VLV_PCBR	(VLV_DISPLAY_BASE + 0x2120)
 #define   I915_PIPE_CONTROL_NOTIFY_INTERRUPT		(1<<18)
 #define   I915_DISPLAY_PORT_INTERRUPT			(1<<17)
 #define   I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT	(1<<15)
-- 
1.7.10.4