129 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 *  linux/drivers/acorn/scsi/scsi.h
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 *
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 *  Copyright (C) 2002 Russell King
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published by the Free Software Foundation.
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 *
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 *  Commonly used scsi driver functions.
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 */
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#include <linux/scatterlist.h>
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#define BELT_AND_BRACES
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/*
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 * The scatter-gather list handling.  This contains all
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 * the yucky stuff that needs to be fixed properly.
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 */
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/*
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 * copy_SCp_to_sg() Assumes contiguous allocation at @sg of at-most @max
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 * entries of uninitialized memory. SCp is from scsi-ml and has a valid
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 * (possibly chained) sg-list
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 */
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static inline int copy_SCp_to_sg(struct scatterlist *sg, struct scsi_pointer *SCp, int max)
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{
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	int bufs = SCp->buffers_residual;
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	/* FIXME: It should be easy for drivers to loop on copy_SCp_to_sg().
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	 * and to remove this BUG_ON. Use min() in-its-place
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	 */
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	BUG_ON(bufs + 1 > max);
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	sg_set_buf(sg, SCp->ptr, SCp->this_residual);
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	if (bufs) {
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		struct scatterlist *src_sg;
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		unsigned i;
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		for_each_sg(sg_next(SCp->buffer), src_sg, bufs, i)
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			*(++sg) = *src_sg;
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		sg_mark_end(sg);
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	}
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	return bufs + 1;
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}
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static inline int next_SCp(struct scsi_pointer *SCp)
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{
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	int ret = SCp->buffers_residual;
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	if (ret) {
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		SCp->buffer = sg_next(SCp->buffer);
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		SCp->buffers_residual--;
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		SCp->ptr = sg_virt(SCp->buffer);
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		SCp->this_residual = SCp->buffer->length;
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	} else {
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		SCp->ptr = NULL;
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		SCp->this_residual = 0;
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	}
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	return ret;
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}
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static inline unsigned char get_next_SCp_byte(struct scsi_pointer *SCp)
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{
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	char c = *SCp->ptr;
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	SCp->ptr += 1;
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	SCp->this_residual -= 1;
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	return c;
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}
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static inline void put_next_SCp_byte(struct scsi_pointer *SCp, unsigned char c)
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{
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	*SCp->ptr = c;
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	SCp->ptr += 1;
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	SCp->this_residual -= 1;
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}
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static inline void init_SCp(struct scsi_cmnd *SCpnt)
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{
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	memset(&SCpnt->SCp, 0, sizeof(struct scsi_pointer));
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	if (scsi_bufflen(SCpnt)) {
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		unsigned long len = 0;
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		SCpnt->SCp.buffer = scsi_sglist(SCpnt);
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		SCpnt->SCp.buffers_residual = scsi_sg_count(SCpnt) - 1;
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		SCpnt->SCp.ptr = sg_virt(SCpnt->SCp.buffer);
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		SCpnt->SCp.this_residual = SCpnt->SCp.buffer->length;
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		SCpnt->SCp.phase = scsi_bufflen(SCpnt);
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#ifdef BELT_AND_BRACES
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		{	/*
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			 * Calculate correct buffer length.  Some commands
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			 * come in with the wrong scsi_bufflen.
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			 */
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			struct scatterlist *sg;
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			unsigned i, sg_count = scsi_sg_count(SCpnt);
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			scsi_for_each_sg(SCpnt, sg, sg_count, i)
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				len += sg->length;
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			if (scsi_bufflen(SCpnt) != len) {
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				printk(KERN_WARNING
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				       "scsi%d.%c: bad request buffer "
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				       "length %d, should be %ld\n",
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					SCpnt->device->host->host_no,
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					'0' + SCpnt->device->id,
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					scsi_bufflen(SCpnt), len);
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				/*
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				 * FIXME: Totaly naive fixup. We should abort
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				 * with error
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				 */
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				SCpnt->SCp.phase =
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					min_t(unsigned long, len,
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					      scsi_bufflen(SCpnt));
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			}
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		}
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#endif
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	} else {
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		SCpnt->SCp.ptr = NULL;
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		SCpnt->SCp.this_residual = 0;
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		SCpnt->SCp.phase = 0;
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	}
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}
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