drm/i915/gem: Only revoke the GGTT mmappings on aperture detiling changes

Only a GGTT mmapping will use the aperture detiling registers, so on a
tiling change for an object, we only need to revoke those mmappings and
not the CPU mmappings (which are always linear irrespective of the tiling).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200702163623.6402-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gem/i915_gem_mman.c

@@ -448,7 +448,7 @@ void __i915_gem_object_release_mmap_gtt(struct drm_i915_gem_object *obj)
  * mapping will then trigger a page fault on the next user access, allowing
  * fixup by vm_fault_gtt().
  */
-static void i915_gem_object_release_mmap_gtt(struct drm_i915_gem_object *obj)
+void i915_gem_object_release_mmap_gtt(struct drm_i915_gem_object *obj)
 {
 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 	intel_wakeref_t wakeref;

drivers/gpu/drm/i915/gem/i915_gem_mman.h

@@ -24,8 +24,11 @@ int i915_gem_dumb_mmap_offset(struct drm_file *file_priv,
 			      struct drm_device *dev,
 			      u32 handle, u64 *offset);
 
-void __i915_gem_object_release_mmap_gtt(struct drm_i915_gem_object *obj);
 void i915_gem_object_release_mmap(struct drm_i915_gem_object *obj);
+
+void __i915_gem_object_release_mmap_gtt(struct drm_i915_gem_object *obj);
+void i915_gem_object_release_mmap_gtt(struct drm_i915_gem_object *obj);
+
 void i915_gem_object_release_mmap_offset(struct drm_i915_gem_object *obj);
 
 #endif

drivers/gpu/drm/i915/gem/i915_gem_tiling.c

@@ -299,7 +299,7 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object *obj,
 	i915_gem_object_unlock(obj);
 
 	/* Force the fence to be reacquired for GTT access */
-	i915_gem_object_release_mmap(obj);
+	i915_gem_object_release_mmap_gtt(obj);
 
 	/* Try to preallocate memory required to save swizzling on put-pages */
 	if (i915_gem_object_needs_bit17_swizzle(obj)) {