drm/i915: Extend BIOS stolen mem handling to all platform

Based upon a patch from Deepak, but reworked to only apply on gen7+
and with the logic a bit clarified.

v2: Fix s/SHIFT/MASK/ fumble that Ville spotted.

Cc: Deepak S <deepak.s@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 19 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 21c025a209c0..85fda6b803e4 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -289,6 +289,7 @@ void i915_gem_cleanup_stolen(struct drm_device *dev)
 int i915_gem_init_stolen(struct drm_device *dev)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
+        u32 tmp;
         int bios_reserved = 0;
 
 #ifdef CONFIG_INTEL_IOMMU
@@ -308,8 +309,16 @@ int i915_gem_init_stolen(struct drm_device *dev)
         DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
                       dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
 
-        if (IS_VALLEYVIEW(dev))
-                bios_reserved = 1024*1024; /* top 1M on VLV/BYT */
+        if (INTEL_INFO(dev)->gen >= 8) {
+                tmp = I915_READ(GEN7_BIOS_RESERVED);
+                tmp >>= GEN8_BIOS_RESERVED_SHIFT;
+                tmp &= GEN8_BIOS_RESERVED_MASK;
+                bios_reserved = (1024*1024) << tmp;
+        } else if (IS_GEN7(dev)) {
+                tmp = I915_READ(GEN7_BIOS_RESERVED);
+                bios_reserved = tmp & GEN7_BIOS_RESERVED_256K ?
+                        256*1024 : 1024*1024;
+        }
 
         if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
                 return 0;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index b65bdfc23ccb..ad8179b40d19 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -143,6 +143,14 @@
 #define GAB_CTL                         0x24000
 #define   GAB_CTL_CONT_AFTER_PAGEFAULT  (1<<8)
 
+#define GEN7_BIOS_RESERVED              0x1082C0
+#define GEN7_BIOS_RESERVED_1M           (0 << 5)
+#define GEN7_BIOS_RESERVED_256K         (1 << 5)
+#define GEN8_BIOS_RESERVED_SHIFT       7
+#define GEN7_BIOS_RESERVED_MASK        0x1
+#define GEN8_BIOS_RESERVED_MASK        0x3
+
+
 /* VGA stuff */
 
 #define VGA_ST01_MDA 0x3ba