mirror of
https://github.com/torvalds/linux
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115 lines
2.9 KiB
C
115 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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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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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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memcpy(sg + 1, SCp->buffer + 1,
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sizeof(struct scatterlist) * bufs);
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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++;
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SCp->buffers_residual--;
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SCp->ptr = (char *)
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(page_address(SCp->buffer->page) +
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SCp->buffer->offset);
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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(Scsi_Cmnd *SCpnt)
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{
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memset(&SCpnt->SCp, 0, sizeof(struct scsi_pointer));
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if (SCpnt->use_sg) {
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unsigned long len = 0;
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int buf;
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SCpnt->SCp.buffer = (struct scatterlist *) SCpnt->buffer;
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SCpnt->SCp.buffers_residual = SCpnt->use_sg - 1;
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SCpnt->SCp.ptr = (char *)
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(page_address(SCpnt->SCp.buffer->page) +
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SCpnt->SCp.buffer->offset);
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SCpnt->SCp.this_residual = SCpnt->SCp.buffer->length;
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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 request_bufflen.
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*/
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for (buf = 0; buf <= SCpnt->SCp.buffers_residual; buf++)
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len += SCpnt->SCp.buffer[buf].length;
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if (SCpnt->request_bufflen != len)
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printk(KERN_WARNING "scsi%d.%c: bad request buffer "
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"length %d, should be %ld\n", SCpnt->device->host->host_no,
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'0' + SCpnt->device->id, SCpnt->request_bufflen, len);
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SCpnt->request_bufflen = len;
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#endif
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} else {
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SCpnt->SCp.ptr = (unsigned char *)SCpnt->request_buffer;
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SCpnt->SCp.this_residual = SCpnt->request_bufflen;
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}
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/*
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* If the upper SCSI layers pass a buffer, but zero length,
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* we aren't interested in the buffer pointer.
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*/
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if (SCpnt->SCp.this_residual == 0 && SCpnt->SCp.ptr) {
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#if 0 //def BELT_AND_BRACES
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printk(KERN_WARNING "scsi%d.%c: zero length buffer passed for "
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"command ", SCpnt->host->host_no, '0' + SCpnt->target);
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__scsi_print_command(SCpnt->cmnd);
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#endif
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SCpnt->SCp.ptr = NULL;
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}
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}
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