CC: linux-ia64@xxxxxxxxxxxxxxx
CC: storagedev@xxxxxxxxxxxxx
CC: linux-scsi@xxxxxxxxxxxxxxx
CC: Joe Szczypek <jszczype@xxxxxxxxxx>
CC: Scott Benesh <scott.benesh@xxxxxxxxxxxxx>
CC: Scott Teel <scott.teel@xxxxxxxxxxxxx>
CC: Tomas Henzl <thenzl@xxxxxxxxxx>
CC: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
CC: Don Brace <don.brace@xxxxxxxxxxxxx>
Reported-by: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Suggested-by: Don Brace <don.brace@xxxxxxxxxxxxx>
Fixes: f749d8b7a "scsi: hpsa: Correct dev cmds outstanding for retried cmds"
Signed-off-by: Sergei Trofimovich <slyfox@xxxxxxxxxx>
---
drivers/scsi/hpsa_cmd.h | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/scsi/hpsa_cmd.h b/drivers/scsi/hpsa_cmd.h
index 885b1f1fb20a..ba6a3aa8d954 100644
--- a/drivers/scsi/hpsa_cmd.h
+++ b/drivers/scsi/hpsa_cmd.h
@@ -22,6 +22,9 @@
#include <linux/compiler.h>
+#include <linux/build_bug.h> /* static_assert */
+#include <linux/stddef.h> /* offsetof */
+
/* general boundary defintions */
#define SENSEINFOBYTES 32 /* may vary between hbas */
#define SG_ENTRIES_IN_CMD 32 /* Max SG entries excluding chain blocks */
@@ -454,6 +457,15 @@ struct CommandList {
atomic_t refcount; /* Must be last to avoid memset in hpsa_cmd_init() */
} __aligned(COMMANDLIST_ALIGNMENT);
+/*
+ * Make sure our embedded atomic variable is aligned. Otherwise we break atomic
+ * operations on architectures that don't support unaligned atomics like IA64.
+ *
+ * The assert guards against reintroductin against unwanted __packed to
+ * the struct CommandList.
+ */
+static_assert(offsetof(struct CommandList, refcount) % __alignof__(atomic_t) == 0);
+
/* Max S/G elements in I/O accelerator command */
#define IOACCEL1_MAXSGENTRIES 24
#define IOACCEL2_MAXSGENTRIES 28
--
2.31.1
