Merge tag 'mvebu-dt-3.17-2' of git://git.infradead.org/linux-mvebu into next/dt

[cascardo/linux.git] / drivers / gpu / drm / i915 / i915_gem_stolen.c

diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 62ef55b..7465ab0 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -74,6 +74,50 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev)
        if (base == 0)
                return 0;
 
+       /* make sure we don't clobber the GTT if it's within stolen memory */
+       if (INTEL_INFO(dev)->gen <= 4 && !IS_G33(dev) && !IS_G4X(dev)) {
+               struct {
+                       u32 start, end;
+               } stolen[2] = {
+                       { .start = base, .end = base + dev_priv->gtt.stolen_size, },
+                       { .start = base, .end = base + dev_priv->gtt.stolen_size, },
+               };
+               u64 gtt_start, gtt_end;
+
+               gtt_start = I915_READ(PGTBL_CTL);
+               if (IS_GEN4(dev))
+                       gtt_start = (gtt_start & PGTBL_ADDRESS_LO_MASK) |
+                               (gtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
+               else
+                       gtt_start &= PGTBL_ADDRESS_LO_MASK;
+               gtt_end = gtt_start + gtt_total_entries(dev_priv->gtt) * 4;
+
+               if (gtt_start >= stolen[0].start && gtt_start < stolen[0].end)
+                       stolen[0].end = gtt_start;
+               if (gtt_end > stolen[1].start && gtt_end <= stolen[1].end)
+                       stolen[1].start = gtt_end;
+
+               /* pick the larger of the two chunks */
+               if (stolen[0].end - stolen[0].start >
+                   stolen[1].end - stolen[1].start) {
+                       base = stolen[0].start;
+                       dev_priv->gtt.stolen_size = stolen[0].end - stolen[0].start;
+               } else {
+                       base = stolen[1].start;
+                       dev_priv->gtt.stolen_size = stolen[1].end - stolen[1].start;
+               }
+
+               if (stolen[0].start != stolen[1].start ||
+                   stolen[0].end != stolen[1].end) {
+                       DRM_DEBUG_KMS("GTT within stolen memory at 0x%llx-0x%llx\n",
+                                     (unsigned long long) gtt_start,
+                                     (unsigned long long) gtt_end - 1);
+                       DRM_DEBUG_KMS("Stolen memory adjusted to 0x%x-0x%x\n",
+                                     base, base + (u32) dev_priv->gtt.stolen_size - 1);
+               }
+       }
+
+
        /* Verify that nothing else uses this physical address. Stolen
         * memory should be reserved by the BIOS and hidden from the
         * kernel. So if the region is already marked as busy, something