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drm/tests/drm_buddy: add alloc_contiguous test
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Sanity check DRM_BUDDY_CONTIGUOUS_ALLOCATION.

v2: Fix checkpatch warnings.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240214131853.5934-2-Arunpravin.PaneerSelvam@amd.com
Signed-off-by: Christian König <christian.koenig@amd.com>
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Matthew Auld authored and Christian König committed Feb 14, 2024
1 parent 8746c6c commit a64056b
Showing 1 changed file with 89 additions and 0 deletions.
89 changes: 89 additions & 0 deletions drivers/gpu/drm/tests/drm_buddy_test.c
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@

#include <linux/prime_numbers.h>
#include <linux/sched/signal.h>
#include <linux/sizes.h>

#include <drm/drm_buddy.h>

Expand All @@ -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;
Expand Down Expand Up @@ -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),
{}
};

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