Commit 1892faa9 authored by Michel Thierry's avatar Michel Thierry Committed by Daniel Vetter

drm/i915/gen9: Set PIN_ZONE_4G end to 4GB - 1 page

Kernel and userspace are able to handle 4GB (1<<32) address space range,
but "A32 Stateless Model" is not. According to documentation, A32 accesses
are based on General State Base Address and bound checking is in place.
Because size field (instruction State Base Address) limitation, it is not
possible to address full 4GB memory region.

A32 Stateless Model is used by some libraries and without this patch, the
last page of 4GB address space is not accessible in 32bit processes.
Reported-by: default avatarArtur Harasimiuk <artur.harasimiuk@intel.com>
Signed-off-by: default avatarMichel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1452512367-23614-1-git-send-email-michel.thierry@intel.com
Cc: drm-intel-fixes@lists.freedesktop.org
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 0cd1262d
......@@ -3484,7 +3484,7 @@ i915_gem_object_bind_to_vm(struct drm_i915_gem_object *obj,
if (flags & PIN_MAPPABLE)
end = min_t(u64, end, dev_priv->gtt.mappable_end);
if (flags & PIN_ZONE_4G)
end = min_t(u64, end, (1ULL << 32));
end = min_t(u64, end, (1ULL << 32) - PAGE_SIZE);
if (alignment == 0)
alignment = flags & PIN_MAPPABLE ? fence_alignment :
......
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