drm/i915: Always convert incoming exec offsets to non-canonical

We're using non-canonical addresses in drm_mm, and we're making sure that
userspace is using canonical addressing - both in case of softpin
(verifying incoming offset) and when relocating (converting to canonical
when updating offset returned to userspace).
Unfortunately when considering the need for relocations, we're comparing
offset from userspace (in canonical form) with drm_mm node (in
non-canonical form), and as a result, we end up always relocating if our
offsets are in the "problematic" range.
Let's always convert the offsets to avoid the performance impact of
relocations.

Fixes: a5f0edf63bdf ("drm/i915: Avoid writing relocs with addresses in non-canonical form")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Reported-by: Michał Pyrzowski <michal.pyrzowski@intel.com>
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170207195559.18798-1-michal.winiarski@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
(cherry picked from commit 038c95a313e4ca954ee5ab8a0c7559a646b0f462)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 097d9d8c2315e061a3600615532c6d51531ee42c..b8b877c91b0a9b36b1a9ac318b2e5255b096a46e 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1181,14 +1181,14 @@ validate_exec_list(struct drm_device *dev,
                        if (exec[i].offset !=
                            gen8_canonical_addr(exec[i].offset & PAGE_MASK))
                                return -EINVAL;
-
-                       /* From drm_mm perspective address space is continuous,
-                        * so from this point we're always using non-canonical
-                        * form internally.
-                        */
-                       exec[i].offset = gen8_noncanonical_addr(exec[i].offset);
                }
 
+               /* From drm_mm perspective address space is continuous,
+                * so from this point we're always using non-canonical
+                * form internally.
+                */
+               exec[i].offset = gen8_noncanonical_addr(exec[i].offset);
+
                if (exec[i].alignment && !is_power_of_2(exec[i].alignment))
                        return -EINVAL;