[Intel-gfx] [PATCH 15/19] drm/i915: Remove pinned check from madvise ioctl

[Chris Wilson]

We don't need to incur the overhead of checking whether the object is
pinned prior to changing its madvise. If the object is pinned, the
madvise will not take effect until it is unpinned and so we cannot free
the pages being pointed at by hardware. Marking a pinned object with
allocated pages as DONTNEED will not trigger any undue warnings. The check
is therefore superfluous, and by removing it we can remove a linear walk
over all the vma the object has.

Still despite it being an overzealous check, that error code is part of
the current ABI and so we must proceed with caution.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_gem.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e18e30dfac4d..eb7b0f4d8a53 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3876,11 +3876,6 @@ i915_gem_madvise_ioctl(struct drm_device *dev, void *data,
 		goto unlock;
 	}
 
-	if (i915_gem_obj_is_pinned(obj)) {
-		ret = -EINVAL;
-		goto out;
-	}
-
 	if (obj->pages &&
 	    obj->tiling_mode != I915_TILING_NONE &&
 	    dev_priv->quirks & QUIRK_PIN_SWIZZLED_PAGES) {
@@ -3899,7 +3894,6 @@ i915_gem_madvise_ioctl(struct drm_device *dev, void *data,
 
 	args->retained = obj->madv != __I915_MADV_PURGED;
 
-out:
 	i915_gem_object_put(obj);
 unlock:
 	mutex_unlock(&dev->struct_mutex);
-- 
2.8.1