Re: [PATCH] gpu/buddy: Introduce gpu_buddy_assert() for kunit-aware assertions

[Arunpravin Paneer Selvam <arunpravin.paneerselvam@amd.com>]

Reviewed-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>

On 2/24/2026 6:55 PM, Sanjay Yadav wrote:
> Introduce gpu_buddy_assert(), a small helper that wraps WARN_ON() and,
> when CONFIG_KUNIT is enabled, also calls kunit_fail_current_test() so
> that any active KUnit test is marked as failed. In non-KUnit builds
> the macro reduces to WARN_ON(), preserving existing behaviour.
>
> Stringify the asserted condition in the failure message to make it easy
> to identify which assertion fired. Leave the WARN_ON() in
> gpu_buddy_block_trim() unchanged, as it returns -EINVAL and the caller
> already observes the failure via the return code.
>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
> Suggested-by: Matthew Auld <matthew.auld@intel.com>
> Signed-off-by: Sanjay Yadav <sanjay.kumar.yadav@intel.com>
> ---
>   drivers/gpu/buddy.c | 36 ++++++++++++++++++++++++++++--------
>   1 file changed, 28 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/buddy.c b/drivers/gpu/buddy.c
> index b27761246d4b..da5a1222f46b 100644
> --- a/drivers/gpu/buddy.c
> +++ b/drivers/gpu/buddy.c
> @@ -3,8 +3,7 @@
>    * Copyright © 2021 Intel Corporation
>    */
>   
> -#include <kunit/test-bug.h>
> -
> +#include <linux/bug.h>
>   #include <linux/export.h>
>   #include <linux/kmemleak.h>
>   #include <linux/module.h>
> @@ -12,6 +11,28 @@
>   
>   #include <linux/gpu_buddy.h>
>   
> +/**
> + * gpu_buddy_assert - assert a condition in the buddy allocator
> + * @condition: condition expected to be true
> + *
> + * When CONFIG_KUNIT is enabled, evaluates @condition and, if false, triggers
> + * a WARN_ON() and also calls kunit_fail_current_test() so that any running
> + * kunit test is properly marked as failed. The stringified condition is
> + * included in the failure message for easy identification.
> + *
> + * When CONFIG_KUNIT is not enabled, this reduces to WARN_ON() so production
> + * builds retain the same warning semantics as before.
> + */
> +#if IS_ENABLED(CONFIG_KUNIT)
> +#include <kunit/test-bug.h>
> +#define gpu_buddy_assert(condition) do {						\
> +	if (WARN_ON(!(condition)))						\
> +		kunit_fail_current_test("gpu_buddy_assert(" #condition ")");	\
> +} while (0)
> +#else
> +#define gpu_buddy_assert(condition) WARN_ON(!(condition))
> +#endif
> +
>   static struct kmem_cache *slab_blocks;
>   
>   static unsigned int
> @@ -268,8 +289,8 @@ static int __force_merge(struct gpu_buddy *mm,
>   				if (!gpu_buddy_block_is_free(buddy))
>   					continue;
>   
> -				WARN_ON(gpu_buddy_block_is_clear(block) ==
> -					gpu_buddy_block_is_clear(buddy));
> +				gpu_buddy_assert(gpu_buddy_block_is_clear(block) !=
> +						 gpu_buddy_block_is_clear(buddy));
>   
>   				/*
>   				 * Advance to the next node when the current node is the buddy,
> @@ -415,8 +436,7 @@ void gpu_buddy_fini(struct gpu_buddy *mm)
>   		start = gpu_buddy_block_offset(mm->roots[i]);
>   		__force_merge(mm, start, start + size, order);
>   
> -		if (WARN_ON(!gpu_buddy_block_is_free(mm->roots[i])))
> -			kunit_fail_current_test("buddy_fini() root");
> +		gpu_buddy_assert(gpu_buddy_block_is_free(mm->roots[i]));
>   
>   		gpu_block_free(mm, mm->roots[i]);
>   
> @@ -424,7 +444,7 @@ void gpu_buddy_fini(struct gpu_buddy *mm)
>   		size -= root_size;
>   	}
>   
> -	WARN_ON(mm->avail != mm->size);
> +	gpu_buddy_assert(mm->avail == mm->size);
>   
>   	for_each_free_tree(i)
>   		kfree(mm->free_trees[i]);
> @@ -541,7 +561,7 @@ static void __gpu_buddy_free_list(struct gpu_buddy *mm,
>   {
>   	struct gpu_buddy_block *block, *on;
>   
> -	WARN_ON(mark_dirty && mark_clear);
> +	gpu_buddy_assert(!(mark_dirty && mark_clear));
>   
>   	list_for_each_entry_safe(block, on, objects, link) {
>   		if (mark_clear)