Re: [PATCH V4 2/2] gpu/tests/gpu_buddy: Add KUnit test for gpu_buddy_allocated_addr_to_block

On 06/08/2026 10:46, Upadhyay, Tejas wrote:
> 
> 
>> -----Original Message-----
>> From: Auld, Matthew <[email protected]>
>> Sent: 06 August 2026 14:31
>> To: Upadhyay, Tejas <[email protected]>; intel-
>> [email protected]; [email protected]
>> Cc: [email protected]
>> Subject: Re: [PATCH V4 2/2] gpu/tests/gpu_buddy: Add KUnit test for
>> gpu_buddy_allocated_addr_to_block
>>
>> On 06/08/2026 06:36, 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
>>>
>>> v4(MattA):
>>> - Add test for unaligned address
>>> 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 <[email protected]>
>>
>> Reviewed-by: Matthew Auld <[email protected]>
> 
> Hi Matt,
> 
> Thanks for review. Since I don’t have merge rights on drm-tip, Would you please help merging this series.

I think Arun normally merges these. Arun, any objections? We need this 
for an upcoming driver feature (patches on the list), so wanted to land 
this API ahead of time. I don't think this will conflict much with the 
big rework you were doing.

> 
> Tejas
>>
>>> ---
>>>    drivers/gpu/tests/gpu_buddy_test.c | 45
>> ++++++++++++++++++++++++++++++
>>>    1 file changed, 45 insertions(+)
>>>
>>> diff --git a/drivers/gpu/tests/gpu_buddy_test.c
>>> b/drivers/gpu/tests/gpu_buddy_test.c
>>> index 7df5c2ae83bb..04e425eb8bdd 100644
>>> --- a/drivers/gpu/tests/gpu_buddy_test.c
>>> +++ b/drivers/gpu/tests/gpu_buddy_test.c
>>> @@ -1381,6 +1381,50 @@ 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);
>>> +
>>> +	/* Unaligned address inside the allocated block (should resolve to the
>> same block) */
>>> +	found_block = gpu_buddy_allocated_addr_to_block(&mm, alloc_start
>> + 16);
>>> +	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)
>>> @@ -1405,6 +1449,7 @@ 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),
>>>    	{}
>>>    };
>>>
>