Revert "drm/i915: Kill GTT mappings when moving from GTT domain"

This reverts commit 4a684a4117abd756291969336af454e8a958802f.
Userland has always been required to set the object's domain to GTT
before using it through a GTT mapping, it's not something that the
kernel is supposed to enforce.  (The pagefault support is so that we
can handle multiple mappings without userland having to pin across
them, not so that userland can use GTT after GPU domains without
telling the kernel).

Fixes 19.2% +/- 0.8% (n=6) performance regression in cairo-gl
firefox-talos-gfx on my T420 latop.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 94c84d7441007f029ebad7b7d87eb158de5f971a..c6389de531612c11d78439207ebd051ba804e3a1 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1219,11 +1219,11 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
                ret = i915_gem_object_bind_to_gtt(obj, 0, true);
                if (ret)
                        goto unlock;
-       }
 
-       ret = i915_gem_object_set_to_gtt_domain(obj, write);
-       if (ret)
-               goto unlock;
+               ret = i915_gem_object_set_to_gtt_domain(obj, write);
+               if (ret)
+                       goto unlock;
+       }
 
        if (obj->tiling_mode == I915_TILING_NONE)
                ret = i915_gem_object_put_fence(obj);
@@ -2926,8 +2926,6 @@ i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj)
         */
        wmb();
 
-       i915_gem_release_mmap(obj);
-
        old_write_domain = obj->base.write_domain;
        obj->base.write_domain = 0;
 

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 20a4cc5b818f51632ad50a94bdfa4092c3f1a454..4934cf84c320336aa84320da544cc1e0d091da1c 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -187,10 +187,6 @@ i915_gem_object_set_to_gpu_domain(struct drm_i915_gem_object *obj,
        if ((flush_domains | invalidate_domains) & I915_GEM_DOMAIN_CPU)
                i915_gem_clflush_object(obj);
 
-       /* blow away mappings if mapped through GTT */
-       if ((flush_domains | invalidate_domains) & I915_GEM_DOMAIN_GTT)
-               i915_gem_release_mmap(obj);
-
        if (obj->base.pending_write_domain)
                cd->flips |= atomic_read(&obj->pending_flip);