Sanity check DRM_BUDDY_CONTIGUOUS_ALLOCATION.
References: https://gitlab.freedesktop.org/drm/amd/-/issues/3097
Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@xxxxxxx>
Cc: Limonciello <mario.limonciello@xxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
---
drivers/gpu/drm/tests/drm_buddy_test.c | 89 ++++++++++++++++++++++++++
1 file changed, 89 insertions(+)
diff --git a/drivers/gpu/drm/tests/drm_buddy_test.c b/drivers/gpu/drm/tests/drm_buddy_test.c
index ea2af6bd9abe..4215d8b5fcf0 100644
--- a/drivers/gpu/drm/tests/drm_buddy_test.c
+++ b/drivers/gpu/drm/tests/drm_buddy_test.c
@@ -8,6 +8,7 @@
#include <linux/prime_numbers.h>
#include <linux/sched/signal.h>
+#include <linux/sizes.h>
#include <drm/drm_buddy.h>
@@ -18,6 +19,93 @@ static inline u64 get_size(int order, u64 chunk_size)
return (1 << order) * chunk_size;
}
+static void drm_test_buddy_alloc_contiguous(struct kunit *test)
+{
+ u64 mm_size, ps = SZ_4K, i, n_pages, total;
+ struct drm_buddy_block *block;
+ struct drm_buddy mm;
+ LIST_HEAD(left);
+ LIST_HEAD(middle);
+ LIST_HEAD(right);
+ LIST_HEAD(allocated);
+
+ mm_size = 16 * 3 * SZ_4K;
+
+ KUNIT_EXPECT_FALSE(test, drm_buddy_init(&mm, mm_size, ps));
+
+ /*
+ * Idea is to fragment the address space by alternating block
+ * allocations between three different lists; one for left, middle and
+ * right. We can then free a list to simulate fragmentation. In
+ * particular we want to exercise the DRM_BUDDY_CONTIGUOUS_ALLOCATION,
+ * including the try_harder path.
+ */
+
+ i = 0;
+ n_pages = mm_size / ps;
+ do {
+ struct list_head *list;
+ int slot = i % 3;
+
+ if (slot == 0)
+ list = &left;
+ else if (slot == 1)
+ list = &middle;
+ else
+ list = &right;
+ KUNIT_ASSERT_FALSE_MSG(test,
+ drm_buddy_alloc_blocks(&mm, 0, mm_size,
+ ps, ps, list, 0),
+ "buddy_alloc hit an error size=%d\n",
+ ps);
+ } while (++i < n_pages);
+
+ KUNIT_ASSERT_TRUE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size,
+ 3 * ps, ps, &allocated,
+ DRM_BUDDY_CONTIGUOUS_ALLOCATION),
+ "buddy_alloc didn't error size=%d\n", 3 * ps);
+
+ drm_buddy_free_list(&mm, &middle);
+ KUNIT_ASSERT_TRUE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size,
+ 3 * ps, ps, &allocated,
+ DRM_BUDDY_CONTIGUOUS_ALLOCATION),
+ "buddy_alloc didn't error size=%llu\n", 3 * ps);
+ KUNIT_ASSERT_TRUE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size,
+ 2 * ps, ps, &allocated,
+ DRM_BUDDY_CONTIGUOUS_ALLOCATION),
+ "buddy_alloc didn't error size=%llu\n", 2 * ps);
+
+ drm_buddy_free_list(&mm, &right);
+ KUNIT_ASSERT_TRUE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size,
+ 3 * ps, ps, &allocated,
+ DRM_BUDDY_CONTIGUOUS_ALLOCATION),
+ "buddy_alloc didn't error size=%llu\n", 3 * ps);
+ /*
+ * At this point we should have enough contiguous space for 2 blocks,
+ * however they are never buddies (since we freed middle and right) so
+ * will require the try_harder logic to find them.
+ */
+ KUNIT_ASSERT_FALSE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size,
+ 2 * ps, ps, &allocated,
+ DRM_BUDDY_CONTIGUOUS_ALLOCATION),
+ "buddy_alloc hit an error size=%d\n", 2 * ps);
+
+ drm_buddy_free_list(&mm, &left);
+ KUNIT_ASSERT_FALSE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size,
+ 3 * ps, ps, &allocated,
+ DRM_BUDDY_CONTIGUOUS_ALLOCATION),
+ "buddy_alloc hit an error size=%d\n", 3 * ps);
+
+ total = 0;
+ list_for_each_entry(block, &allocated, link)
+ total += drm_buddy_block_size(&mm, block);
+
+ KUNIT_ASSERT_EQ(test, total, ps * 2 + ps * 3);
+
+ drm_buddy_free_list(&mm, &allocated);
+ drm_buddy_fini(&mm);
+}
+
static void drm_test_buddy_alloc_pathological(struct kunit *test)
{
u64 mm_size, size, start = 0;
@@ -280,6 +368,7 @@ static struct kunit_case drm_buddy_tests[] = {
KUNIT_CASE(drm_test_buddy_alloc_optimistic),
KUNIT_CASE(drm_test_buddy_alloc_pessimistic),
KUNIT_CASE(drm_test_buddy_alloc_pathological),
+ KUNIT_CASE(drm_test_buddy_alloc_contiguous),
{}
};
