diff options
Diffstat (limited to 'drivers/scsi/hpsa_cmd.h')
| -rw-r--r-- | drivers/scsi/hpsa_cmd.h | 12 |
1 files changed, 12 insertions, 0 deletions
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 |