[PATCH v4 16/38] drm: kselftest for drm_mm and top-down allocation

Chris Wilson
2016-12-22T08:36:19Z

Check that if we request top-down allocation from drm_mm_insert_node()
we receive the next available hole from the top.

v2: Flip sign on conditional assert.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
---
drivers/gpu/drm/selftests/drm_mm_selftests.h | 1 +
drivers/gpu/drm/selftests/test-drm_mm.c | 119 +++++++++++++++++++++++++++
2 files changed, 120 insertions(+)

diff --git a/drivers/gpu/drm/selftests/drm_mm_selftests.h b/drivers/gpu/drm/selftests/drm_mm_selftests.h
index 965aca65c160..cd508e3d6538 100644
--- a/drivers/gpu/drm/selftests/drm_mm_selftests.h
+++ b/drivers/gpu/drm/selftests/drm_mm_selftests.h
@@ -17,3 +17,4 @@ selftest(align32, igt_align32)
selftest(align64, igt_align64)
selftest(evict, igt_evict)
selftest(evict_range, igt_evict_range)
+selftest(topdown, igt_topdown)
diff --git a/drivers/gpu/drm/selftests/test-drm_mm.c b/drivers/gpu/drm/selftests/test-drm_mm.c
index d49115186967..d3d4e4f39042 100644
--- a/drivers/gpu/drm/selftests/test-drm_mm.c
+++ b/drivers/gpu/drm/selftests/test-drm_mm.c
@@ -1552,6 +1552,125 @@ static int igt_evict_range(void *ignored)
return ret;
}

+static unsigned int node_index(const struct drm_mm_node *node)
+{
+ return div64_u64(node->start, node->size);
+}
+
+static int igt_topdown(void *ignored)
+{
+ const struct insert_mode *topdown = &insert_modes[TOPDOWN];
+ DRM_RND_STATE(prng, random_seed);
+ const unsigned int count = 8192;
+ unsigned int size;
+ unsigned long *bitmap = NULL;
+ struct drm_mm mm;
+ struct drm_mm_node *nodes, *node, *next;
+ unsigned int *order, n, m, o = 0;
+ int ret;
+
+ /* When allocating top-down, we expect to be returned a node
+ * from a suitable hole at the top of the drm_mm. We check that
+ * the returned node does match the highest available slot.
+ */
+
+ ret = -ENOMEM;
+ nodes = vzalloc(count * sizeof(*nodes));
+ if (!nodes)
+ goto err;
+
+ bitmap = kzalloc(count / BITS_PER_LONG * sizeof(unsigned long),
+ GFP_TEMPORARY);
+ if (!bitmap)
+ goto err_nodes;
+
+ order = drm_random_order(count, &prng);
+ if (!order)
+ goto err_bitmap;
+
+ ret = -EINVAL;
+ for (size = 1; size <= 64; size <<= 1) {
+ drm_mm_init(&mm, 0, size*count);
+ for (n = 0; n < count; n++) {
+ if (!expect_insert(&mm, &nodes[n],
+ size, 0, n,
+ topdown)) {
+ pr_err("insert failed, size %u step %d\n", size, n);
+ goto out;
+ }
+
+ if (nodes[n].hole_follows) {
+ pr_err("hole after topdown insert %d, start=%llx\n, size=%u",
+ n, nodes[n].start, size);
+ goto out;
+ }
+
+ if (!assert_one_hole(&mm, 0, size*(count - n - 1)))
+ goto out;
+ }
+
+ if (!assert_continuous(&mm, size))
+ goto out;
+
+ drm_random_reorder(order, count, &prng);
+ for_each_prime_number_from(n, 1, min(count, max_prime)) {
+ for (m = 0; m < n; m++) {
+ node = &nodes[order[(o + m) % count]];
+ drm_mm_remove_node(node);
+ __set_bit(node_index(node), bitmap);
+ }
+
+ for (m = 0; m < n; m++) {
+ unsigned int last;
+
+ node = &nodes[order[(o + m) % count]];
+ if (!expect_insert(&mm, node,
+ size, 0, 0,
+ topdown)) {
+ pr_err("insert failed, step %d/%d\n", m, n);
+ goto out;
+ }
+
+ if (node->hole_follows) {
+ pr_err("hole after topdown insert %d/%d, start=%llx\n",
+ m, n, node->start);
+ goto out;
+ }
+
+ last = find_last_bit(bitmap, count);
+ if (node_index(node) != last) {
+ pr_err("node %d/%d, size %d, not inserted into upmost hole, expected %d, found %d\n",
+ m, n, size, last, node_index(node));
+ goto out;
+ }
+
+ __clear_bit(last, bitmap);
+ }
+
+ DRM_MM_BUG_ON(find_first_bit(bitmap, count) != count);
+
+ o += n;
+ }
+
+ drm_mm_for_each_node_safe(node, next, &mm)
+ drm_mm_remove_node(node);
+ DRM_MM_BUG_ON(!drm_mm_clean(&mm));
+ }
+
+ ret = 0;
+out:
+ drm_mm_for_each_node_safe(node, next, &mm)
+ drm_mm_remove_node(node);
+ drm_mm_takedown(&mm);
+ kfree(order);
+err_bitmap:
+ kfree(bitmap);
+err_nodes:
+ vfree(nodes);
+err:
+ return ret;
+}
+
#include "drm_selftest.c"

static int __init test_drm_mm_init(void)