[SCSI] hpsa: Clarify calculation of padding for commandlist structure
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
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@ -313,12 +313,18 @@ struct CommandList {
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void *scsi_cmd;
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/* on 64 bit architectures, to get this to be 32-byte-aligned
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* it so happens we need no padding, on 32 bit systems,
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* we need 8 bytes of padding. This does that.
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* it so happens we need PAD_64 bytes of padding, on 32 bit systems,
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* we need PAD_32 bytes of padding (see below). This does that.
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* If it happens that 64 bit and 32 bit systems need different
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* padding, PAD_32 and PAD_64 can be set independently, and.
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* the code below will do the right thing.
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*/
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#define COMMANDLIST_PAD ((8 - sizeof(long))/4 * 8)
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#define IS_32_BIT ((8 - sizeof(long))/4)
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#define IS_64_BIT (!IS_32_BIT)
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#define PAD_32 (8)
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#define PAD_64 (0)
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#define COMMANDLIST_PAD (IS_32_BIT * PAD_32 + IS_64_BIT * PAD_64)
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u8 pad[COMMANDLIST_PAD];
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};
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/* Configuration Table Structure */
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