Merge tag 'dma-mapping-5.8-5' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - add a warning when the atomic pool is depleted (David Rientjes)

 - protect the parameters of the new scatterlist helper macros (Marek
   Szyprowski )

* tag 'dma-mapping-5.8-5' of git://git.infradead.org/users/hch/dma-mapping:
  scatterlist: protect parameters of the sg_table related macros
  dma-mapping: warn when coherent pool is depleted

1 files changed, 5 insertions, 1 deletions

diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
index 8cfa01243ed2..39ca26fa41b5 100644
--- a/kernel/dma/pool.c
+++ b/kernel/dma/pool.c
@@ -239,12 +239,16 @@ void *dma_alloc_from_pool(struct device *dev, size_t size,
 	}
 
 	val = gen_pool_alloc(pool, size);
-	if (val) {
+	if (likely(val)) {
 		phys_addr_t phys = gen_pool_virt_to_phys(pool, val);
 
 		*ret_page = pfn_to_page(__phys_to_pfn(phys));
 		ptr = (void *)val;
 		memset(ptr, 0, size);
+	} else {
+		WARN_ONCE(1, "DMA coherent pool depleted, increase size "
+			     "(recommended min coherent_pool=%zuK)\n",
+			  gen_pool_size(pool) >> 9);
 	}
 	if (gen_pool_avail(pool) < atomic_pool_size)
 		schedule_work(&atomic_pool_work);