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

> -----Original Message-----
> From: Auld, Matthew <[email protected]>
> Sent: 29 July 2026 21:37
> To: Upadhyay, Tejas <[email protected]>; intel-
> [email protected]; [email protected]
> Cc: [email protected]
> Subject: Re: [PATCH V3 2/2] gpu/tests/gpu_buddy: Add KUnit test for
> gpu_buddy_allocated_addr_to_block
> 
> 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.

No we expect aligned address. I will put a check to validate if address is aligned.

Tejas
> 
> >
> >>
> >> 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]>
> >> ---
> >>   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),
> >>       {}
> >>   };
> >