Merge tag 'dma-mapping-5.8-3' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:
 "Fixes for the SEV atomic pool (Geert Uytterhoeven and David Rientjes)"

* tag 'dma-mapping-5.8-3' of git://git.infradead.org/users/hch/dma-mapping:
  dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL
  dma-pool: fix too large DMA pools on medium memory size systems

kernel/dma/Kconfig

@@ -73,18 +73,18 @@ config SWIOTLB
 config DMA_NONCOHERENT_MMAP
 	bool
 
+config DMA_COHERENT_POOL
+	bool
+
 config DMA_REMAP
+	bool
 	depends on MMU
 	select GENERIC_ALLOCATOR
 	select DMA_NONCOHERENT_MMAP
-	bool
-
-config DMA_COHERENT_POOL
-	bool
-	select DMA_REMAP
 
 config DMA_DIRECT_REMAP
 	bool
+	select DMA_REMAP
 	select DMA_COHERENT_POOL
 
 config DMA_CMA

kernel/dma/pool.c

@@ -175,10 +175,9 @@ static int __init dma_atomic_pool_init(void)
 	 * sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER-1.
 	 */
 	if (!atomic_pool_size) {
-		atomic_pool_size = max(totalram_pages() >> PAGE_SHIFT, 1UL) *
-					SZ_128K;
-		atomic_pool_size = min_t(size_t, atomic_pool_size,
-					 1 << (PAGE_SHIFT + MAX_ORDER-1));
+		unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K);
+		pages = min_t(unsigned long, pages, MAX_ORDER_NR_PAGES);
+		atomic_pool_size = max_t(size_t, pages << PAGE_SHIFT, SZ_128K);
 	}
 	INIT_WORK(&atomic_pool_work, atomic_pool_work_fn);