Merge tag 'dma-mapping-6.6-2023-10-28' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fix from Christoph Hellwig:

 - reduce the initialy dynamic swiotlb size to remove an annoying but
   harmless warning from the page allocator (Petr Tesarik)

* tag 'dma-mapping-6.6-2023-10-28' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: do not try to allocate a TLB bigger than MAX_ORDER pages

Author: torvalds

kernel/dma/swiotlb.c

@@ -678,6 +678,11 @@ static struct io_tlb_pool *swiotlb_alloc_pool(struct device *dev,
 	size_t pool_size;
 	size_t tlb_size;
 
+	if (nslabs > SLABS_PER_PAGE << MAX_ORDER) {
+		nslabs = SLABS_PER_PAGE << MAX_ORDER;
+		nareas = limit_nareas(nareas, nslabs);
+	}
+
 	pool_size = sizeof(*pool) + array_size(sizeof(*pool->areas), nareas);
 	pool = kzalloc(pool_size, gfp);
 	if (!pool)