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

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

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 <tejas.upadhyay@intel.com>

Reviewed-by: Matthew Auld <matthew.auld@intel.com>

> ---
>   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),
>   	{}
>   };
>