drm/i915: Exercise crossing pot boundaries in the GTT

As the page-table trees within the GTT are naturally aligned to
power-of-two boundaries, by inserting an object that crosses a
power-of-two (and the power-of-two intervals) we can quickly check the
code for errors in switching between levels in the tree.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-46-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index 36e5cb5..5af9339 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -582,6 +582,82 @@ err:
        return 0;
 }
 
+static int pot_hole(struct drm_i915_private *i915,
+                   struct i915_address_space *vm,
+                   u64 hole_start, u64 hole_end,
+                   unsigned long end_time)
+{
+       struct drm_i915_gem_object *obj;
+       struct i915_vma *vma;
+       unsigned long flags;
+       unsigned int pot;
+       int err;
+
+       flags = PIN_OFFSET_FIXED | PIN_USER;
+       if (i915_is_ggtt(vm))
+               flags |= PIN_GLOBAL;
+
+       obj = i915_gem_object_create_internal(i915, 2 * I915_GTT_PAGE_SIZE);
+       if (IS_ERR(obj))
+               return PTR_ERR(obj);
+
+       vma = i915_vma_instance(obj, vm, NULL);
+       if (IS_ERR(vma)) {
+               err = PTR_ERR(vma);
+               goto err_obj;
+       }
+
+       /* Insert a pair of pages across every pot boundary within the hole */
+       for (pot = fls64(hole_end - 1) - 1;
+            pot > ilog2(2 * I915_GTT_PAGE_SIZE);
+            pot--) {
+               u64 step = BIT_ULL(pot);
+               u64 addr;
+
+               for (addr = round_up(hole_start + I915_GTT_PAGE_SIZE, step) - I915_GTT_PAGE_SIZE;
+                    addr + vma->size <= hole_end;
+                    addr += step) {
+                       err = i915_vma_pin(vma, 0, 0, addr | flags);
+                       if (err) {
+                               pr_err("%s failed to pin object at %llx in hole [%llx - %llx], with err=%d\n",
+                                      __func__,
+                                      addr,
+                                      hole_start, hole_end,
+                                      err);
+                               goto err;
+                       }
+
+                       if (!drm_mm_node_allocated(&vma->node) ||
+                           i915_vma_misplaced(vma, 0, 0, addr | flags)) {
+                               pr_err("%s incorrect at %llx + %llx\n",
+                                      __func__, addr, vma->size);
+                               i915_vma_unpin(vma);
+                               err = i915_vma_unbind(vma);
+                               err = -EINVAL;
+                               goto err;
+                       }
+
+                       i915_vma_unpin(vma);
+                       err = i915_vma_unbind(vma);
+                       GEM_BUG_ON(err);
+               }
+
+               if (igt_timeout(end_time,
+                               "%s timed out after %d/%d\n",
+                               __func__, pot, fls64(hole_end - 1) - 1)) {
+                       err = -EINTR;
+                       goto err;
+               }
+       }
+
+err:
+       if (!i915_vma_is_ggtt(vma))
+               i915_vma_close(vma);
+err_obj:
+       i915_gem_object_put(obj);
+       return err;
+}
+
 static int drunk_hole(struct drm_i915_private *i915,
                      struct i915_address_space *vm,
                      u64 hole_start, u64 hole_end,
@@ -819,6 +895,11 @@ static int igt_ppgtt_walk(void *arg)
        return exercise_ppgtt(arg, walk_hole);
 }
 
+static int igt_ppgtt_pot(void *arg)
+{
+       return exercise_ppgtt(arg, pot_hole);
+}
+
 static int igt_ppgtt_drunk(void *arg)
 {
        return exercise_ppgtt(arg, drunk_hole);
@@ -893,6 +974,11 @@ static int igt_ggtt_walk(void *arg)
        return exercise_ggtt(arg, walk_hole);
 }
 
+static int igt_ggtt_pot(void *arg)
+{
+       return exercise_ggtt(arg, pot_hole);
+}
+
 static int igt_ggtt_drunk(void *arg)
 {
        return exercise_ggtt(arg, drunk_hole);
@@ -1038,6 +1124,11 @@ static int igt_mock_walk(void *arg)
        return exercise_mock(arg, walk_hole);
 }
 
+static int igt_mock_pot(void *arg)
+{
+       return exercise_mock(arg, pot_hole);
+}
+
 static int igt_mock_drunk(void *arg)
 {
        return exercise_mock(arg, drunk_hole);
@@ -1418,6 +1509,7 @@ int i915_gem_gtt_mock_selftests(void)
        static const struct i915_subtest tests[] = {
                SUBTEST(igt_mock_drunk),
                SUBTEST(igt_mock_walk),
+               SUBTEST(igt_mock_pot),
                SUBTEST(igt_mock_fill),
                SUBTEST(igt_gtt_reserve),
                SUBTEST(igt_gtt_insert),
@@ -1444,11 +1536,13 @@ int i915_gem_gtt_live_selftests(struct drm_i915_private *i915)
                SUBTEST(igt_ppgtt_lowlevel),
                SUBTEST(igt_ppgtt_drunk),
                SUBTEST(igt_ppgtt_walk),
+               SUBTEST(igt_ppgtt_pot),
                SUBTEST(igt_ppgtt_fill),
                SUBTEST(igt_ppgtt_shrink),
                SUBTEST(igt_ggtt_lowlevel),
                SUBTEST(igt_ggtt_drunk),
                SUBTEST(igt_ggtt_walk),
+               SUBTEST(igt_ggtt_pot),
                SUBTEST(igt_ggtt_fill),
                SUBTEST(igt_ggtt_page),
        };