[PATCH 11/13] s390/qdio_setup: Use kzalloc() for the storage list

[Mike Rapoport (Microsoft)]

__qdio_allocate_qs() allocates the storage list information block of a
queue.

This memory can be allocated with kmalloc() as there's nothing special
about it to go directly to the page allocator.

kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.

Performance difference between kmalloc() and __get_free_pages() is not
measurable as both allocators take an object/page from a per-CPU list for
fast path allocations.

For the slow path the performance is anyway determined by the amount of
reclaim involved rather than by what allocator is used.

Replace use of __get_free_page() with kzalloc() and free_page() with
kfree().

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@xxxxxxxxxx
Assisted-by: copilot:claude-opus
Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
---
 drivers/s390/cio/qdio_setup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c
index b6f2ff202fe64..7ca8f61a2387b 100644
--- a/drivers/s390/cio/qdio_setup.c
+++ b/drivers/s390/cio/qdio_setup.c
@@ -83,7 +83,7 @@ static void __qdio_free_queues(struct qdio_q **queues, unsigned int count)
 
 	for (i = 0; i < count; i++) {
 		q = queues[i];
-		free_page((unsigned long)q->sl_page);
+		kfree(q->sl_page);
 		kmem_cache_free(qdio_q_cache, q);
 	}
 }
@@ -109,7 +109,7 @@ static int __qdio_allocate_qs(struct qdio_q **irq_ptr_qs, int nr_queues)
 			return -ENOMEM;
 		}
 
-		q->sl_page = (void *)__get_free_page(GFP_KERNEL);
+		q->sl_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
 		if (!q->sl_page) {
 			kmem_cache_free(qdio_q_cache, q);
 			__qdio_free_queues(irq_ptr_qs, i);

-- 
2.53.0