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| author |   Chris Wilson <chris@chris-wilson.co.uk> | 2016-03-18 10:42:59 +0200 |
|---|---|---|
| committer |   Joonas Lahtinen <joonas.lahtinen@linux.intel.com> | 2016-03-18 15:19:18 +0200 |
| commit | c890e2d5313e8e8f4fb54258dc2bbb2c7dd901ce (patch) | |
| tree | c876339d4a26b084e58e6f36f947e1df245568e6 /drivers | |
| parent | drm/i915/gtt: Clean up GGTT probing code (diff) | |
| download | linux-dev-c890e2d5313e8e8f4fb54258dc2bbb2c7dd901ce.tar.xz linux-dev-c890e2d5313e8e8f4fb54258dc2bbb2c7dd901ce.zip | |
drm/i915: Codify our assumption that the Global GTT is <= 4GiB
Throughout the code base, we use u32 for offsets into the global GTT. If
we ever see any hardware with a larger GGTT, then we run the real risk
of silent corruption. So test for our assumption up front so that we
have a nice reminder should the time come when it fails.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
[Rebased and changed 1ull -> 1ULL, cut 80 char line]
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458290579-27783-1-git-send-email-joonas.lahtinen@linux.intel.com
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem_gtt.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 799576e13f65..0715bb74d306 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -3191,6 +3191,14 @@ int i915_gem_gtt_init(struct drm_device *dev) if (ret) return ret; + if ((ggtt->base.total - 1) >> 32) { + DRM_ERROR("We never expected a Global GTT with more than 32bits" + "of address space! Found %lldM!\n", + ggtt->base.total >> 20); + ggtt->base.total = 1ULL << 32; + ggtt->mappable_end = min(ggtt->mappable_end, ggtt->base.total); + } + /* * Initialise stolen early so that we may reserve preallocated * objects for the BIOS to KMS transition. |