Re: [PATCH V3 2/2] gpu/tests/gpu_buddy: Add KUnit test for gpu_buddy_allocated_addr_to_block

[Matthew Auld <matthew.auld@intel.com>]

On 29/07/2026 16:38, Matthew Auld wrote:
> On 28/07/2026 13:44, Tejas Upadhyay wrote:
>> Add a new KUnit test gpu_test_buddy_addr_to_block() that validates the
>> gpu_buddy_allocated_addr_to_block() helper which traces a address back
>> to its allocated buddy block.
>>
>> The test covers:
>> - Exact address matching returns the correct allocated block
>> - An unallocated address inside the manager should return NULL
>> - An address outside the manager should return -ENXIO
> 
> Do we allow an unaligned addr? It looks like we do, but I would think 
> best to reject if not at least aligned to chunk size?

Or if that is a legit thing, then maybe also include it in the test 
coverage. And even if rejected, maybe also cover that in the test.

> 
>>
>> v3(Sashiko):
>> - remove unused target_addr variable
>> v2(Sashiko):
>> - Drop the mutex and lockdep annotation; standalone KUnit tests do
>>    not register a driver lock.
>>
>> Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
>> ---
>>   drivers/gpu/tests/gpu_buddy_test.c | 41 ++++++++++++++++++++++++++++++
>>   1 file changed, 41 insertions(+)
>>
>> diff --git a/drivers/gpu/tests/gpu_buddy_test.c b/drivers/gpu/tests/ 
>> gpu_buddy_test.c
>> index 89698563c61b..21c90e96ac13 100644
>> --- a/drivers/gpu/tests/gpu_buddy_test.c
>> +++ b/drivers/gpu/tests/gpu_buddy_test.c
>> @@ -1422,6 +1422,46 @@ static void 
>> gpu_test_buddy_alloc_exceeds_max_order(struct kunit *test)
>>       gpu_buddy_fini(&mm);
>>   }
>> +static void gpu_test_buddy_addr_to_block(struct kunit *test)
>> +{
>> +    struct gpu_buddy_block *allocated_block, *found_block;
>> +    LIST_HEAD(allocated_list);
>> +    const u64 test_size = SZ_4M + SZ_2M;
>> +    const u64 alloc_start = SZ_4M;
>> +    const u64 alloc_size = SZ_4K;
>> +    const u64 chunk_size = SZ_4K;
>> +    struct gpu_buddy mm;
>> +
>> +    KUNIT_ASSERT_FALSE_MSG(test, gpu_buddy_init(&mm, test_size, 
>> chunk_size),
>> +                   "buddy_init failed\n");
>> +
>> +    KUNIT_ASSERT_FALSE_MSG(test, gpu_buddy_alloc_blocks(&mm, 
>> alloc_start,
>> +                                alloc_start + alloc_size,
>> +                                alloc_size, chunk_size,
>> +                                &allocated_list, 0),
>> +                   "buddy_alloc failed\n");
>> +
>> +    allocated_block = list_first_entry(&allocated_list, struct 
>> gpu_buddy_block, link);
>> +    KUNIT_EXPECT_EQ(test, gpu_buddy_block_offset(allocated_block), 
>> alloc_start);
>> +    KUNIT_EXPECT_EQ(test, gpu_buddy_block_size(&mm, allocated_block), 
>> alloc_size);
>> +
>> +    found_block = gpu_buddy_allocated_addr_to_block(&mm, alloc_start);
>> +    KUNIT_EXPECT_PTR_EQ(test, found_block, allocated_block);
>> +
>> +    /* An unallocated address inside the manager should return NULL. */
>> +    found_block = gpu_buddy_allocated_addr_to_block(&mm,
>> +                            alloc_start - chunk_size);
>> +    KUNIT_EXPECT_NULL(test, found_block);
>> +
>> +    /* An address outside the manager should return -ENXIO. */
>> +    found_block = gpu_buddy_allocated_addr_to_block(&mm, test_size);
>> +    KUNIT_EXPECT_EQ(test, PTR_ERR(found_block), -ENXIO);
>> +
>> +    /* 3. Standard inline cleanup flow */
>> +    gpu_buddy_free_list(&mm, &allocated_list, 0);
>> +    gpu_buddy_fini(&mm);
>> +}
>> +
>>   static int gpu_buddy_suite_init(struct kunit_suite *suite)
>>   {
>>       while (!random_seed)
>> @@ -1446,6 +1486,7 @@ static struct kunit_case gpu_buddy_tests[] = {
>>       KUNIT_CASE(gpu_test_buddy_alloc_exceeds_max_order),
>>       KUNIT_CASE(gpu_test_buddy_offset_aligned_allocation),
>>       KUNIT_CASE(gpu_test_buddy_subtree_offset_alignment_stress),
>> +    KUNIT_CASE(gpu_test_buddy_addr_to_block),
>>       {}
>>   };
>