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authorStephen M. Cameron <scameron@beardog.cce.hp.com>2010-02-26 23:01:17 +0100
committerJens Axboe <jens.axboe@oracle.com>2010-02-28 19:42:31 +0100
commit1b7d0d28ad82cbd5650c26ec8e370176b112e407 (patch)
tree5b7cd9a673ad2fe6c28d141d8822b0ea80095bd4 /drivers/block/cciss_cmd.h
parentcciss: clarify command list padding calculation (diff)
downloadlinux-1b7d0d28ad82cbd5650c26ec8e370176b112e407.tar.xz
linux-1b7d0d28ad82cbd5650c26ec8e370176b112e407.zip
cciss: detect bad alignment of scsi commands at build time
cciss: detect bad alignment of scsi commands at build time Incidentally fix some nearby c++ style comments. Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'drivers/block/cciss_cmd.h')
-rw-r--r--drivers/block/cciss_cmd.h9
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/block/cciss_cmd.h b/drivers/block/cciss_cmd.h
index 515c9f03c201..e624ff959cb6 100644
--- a/drivers/block/cciss_cmd.h
+++ b/drivers/block/cciss_cmd.h
@@ -167,10 +167,13 @@ typedef struct _SGDescriptor_struct {
#define CMD_MSG_TIMEOUT 0x05
#define CMD_MSG_STALE 0xff
-/* This structure needs to be divisible by 8 for new
- * indexing method. PAD_32 and PAD_64 can be adjusted
- * independently as needed for 32-bit and 64-bits systems.
+/* This structure needs to be divisible by COMMANDLIST_ALIGNMENT
+ * because low bits of the address are used to to indicate that
+ * whether the tag contains an index or an address. PAD_32 and
+ * PAD_64 can be adjusted independently as needed for 32-bit
+ * and 64-bits systems.
*/
+#define COMMANDLIST_ALIGNMENT (8)
#define IS_64_BIT ((sizeof(long) - 4)/4)
#define IS_32_BIT (!IS_64_BIT)
#define PAD_32 (0)