From: Stephen M. Cameron Date: Thu, 25 Feb 2010 20:03:22 +0000 (-0600) Subject: [SCSI] hpsa: Clarify calculation of padding for commandlist structure X-Git-Tag: firefly_0821_release~9833^2~2561^2~43 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=db61bfcfe2a68dc71402c270686cd73b80971efc;p=firefly-linux-kernel-4.4.55.git [SCSI] hpsa: Clarify calculation of padding for commandlist structure Signed-off-by: Stephen M. Cameron Signed-off-by: James Bottomley --- diff --git a/drivers/scsi/hpsa_cmd.h b/drivers/scsi/hpsa_cmd.h index 3e0abdf76689..43b6f1cffe34 100644 --- a/drivers/scsi/hpsa_cmd.h +++ b/drivers/scsi/hpsa_cmd.h @@ -313,12 +313,18 @@ struct CommandList { void *scsi_cmd; /* on 64 bit architectures, to get this to be 32-byte-aligned - * it so happens we need no padding, on 32 bit systems, - * we need 8 bytes of padding. This does that. + * it so happens we need PAD_64 bytes of padding, on 32 bit systems, + * we need PAD_32 bytes of padding (see below). This does that. + * If it happens that 64 bit and 32 bit systems need different + * padding, PAD_32 and PAD_64 can be set independently, and. + * the code below will do the right thing. */ -#define COMMANDLIST_PAD ((8 - sizeof(long))/4 * 8) +#define IS_32_BIT ((8 - sizeof(long))/4) +#define IS_64_BIT (!IS_32_BIT) +#define PAD_32 (8) +#define PAD_64 (0) +#define COMMANDLIST_PAD (IS_32_BIT * PAD_32 + IS_64_BIT * PAD_64) u8 pad[COMMANDLIST_PAD]; - }; /* Configuration Table Structure */