Merge tag 'dma-mapping-5.20-2022-08-06' of git://git.infradead.org/users/hch/dma...

[platform/kernel/linux-starfive.git] / drivers / iommu / iova.c

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 9f00b58..47d1983 100644 (file)
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -619,7 +619,12 @@ EXPORT_SYMBOL_GPL(reserve_iova);
  * dynamic size tuning described in the paper.
  */
 
-#define IOVA_MAG_SIZE 128
+/*
+ * As kmalloc's buffer size is fixed to power of 2, 127 is chosen to
+ * assure size of 'iova_magazine' to be 1024 bytes, so that no memory
+ * will be wasted.
+ */
+#define IOVA_MAG_SIZE 127
 #define MAX_GLOBAL_MAGS 32     /* magazines per bin */
 
 struct iova_magazine {