From 58daa9ce96b847ed130453f5fdd63c579fb1f84f Mon Sep 17 00:00:00 2001 From: "Stephen M. Cameron" Date: Fri, 26 Feb 2010 16:01:12 -0600 Subject: [PATCH] cciss: clarify command list padding calculation cciss: clarify command list padding calculation Signed-off-by: Stephen M. Cameron Signed-off-by: Jens Axboe --- drivers/block/cciss_cmd.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/block/cciss_cmd.h b/drivers/block/cciss_cmd.h index 25f97623bacf..515c9f03c201 100644 --- a/drivers/block/cciss_cmd.h +++ b/drivers/block/cciss_cmd.h @@ -168,9 +168,14 @@ typedef struct _SGDescriptor_struct { #define CMD_MSG_STALE 0xff /* This structure needs to be divisible by 8 for new - * indexing method. + * indexing method. PAD_32 and PAD_64 can be adjusted + * independently as needed for 32-bit and 64-bits systems. */ -#define PADSIZE (sizeof(long) - 4) +#define IS_64_BIT ((sizeof(long) - 4)/4) +#define IS_32_BIT (!IS_64_BIT) +#define PAD_32 (0) +#define PAD_64 (4) +#define PADSIZE (IS_32_BIT * PAD_32 + IS_64_BIT * PAD_64) typedef struct _CommandList_struct { CommandListHeader_struct Header; RequestBlock_struct Request;