[Intel-gfx] [PATCH 07/10] drm/i915: Calculate correct stolen size for GEN7+

[Ben Widawsky]

This bug existed in the old code, but was easier to fix here in the
rework. Unfortunately gen7 doesn't have a nice way to figure out the
size and we must use a lookup table.

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 14 +++++++++++++-
 drivers/gpu/drm/i915/i915_reg.h     |  2 ++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 7d3ec42..16fe960 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -528,6 +528,15 @@ static inline unsigned int gen6_get_stolen_size(u16 snb_gmch_ctl)
 	return snb_gmch_ctl << 25; /* 32 MB units */
 }
 
+static inline unsigned int gen7_get_stolen_size(u16 snb_gmch_ctl)
+{
+	static const int stolen_decoder[] = {
+		0, 0, 0, 0, 0, 32, 48, 64, 128, 256, 96, 160, 224, 352};
+	snb_gmch_ctl >>= IVB_GMCH_GMS_SHIFT;
+	snb_gmch_ctl &= IVB_GMCH_GMS_MASK;
+	return stolen_decoder[snb_gmch_ctl] << 20;
+}
+
 int i915_gem_gtt_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -575,7 +584,10 @@ int i915_gem_gtt_init(struct drm_device *dev)
 	pci_read_config_word(dev->pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
 	dev_priv->mm.gtt->gtt_total_entries =
 		gen6_get_total_gtt_size(snb_gmch_ctl) / sizeof(gtt_pte_t);
-	dev_priv->mm.gtt->stolen_size = gen6_get_stolen_size(snb_gmch_ctl);
+	if (INTEL_INFO(dev)->gen < 7)
+		dev_priv->mm.gtt->stolen_size = gen6_get_stolen_size(snb_gmch_ctl);
+	else
+		dev_priv->mm.gtt->stolen_size = gen7_get_stolen_size(snb_gmch_ctl);
 
 	ret = setup_scratch_page(dev);
 	if (ret)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 10a6e9b..1d54328 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -45,6 +45,8 @@
 #define    SNB_GMCH_GGMS_MASK	0x3
 #define    SNB_GMCH_GMS_SHIFT   3 /* Graphics Mode Select */
 #define    SNB_GMCH_GMS_MASK    0x1f
+#define    IVB_GMCH_GMS_SHIFT   4
+#define    IVB_GMCH_GMS_MASK    0xf
 
 
 /* PCI config space */
-- 
1.7.12.4