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/*
* linux/drivers/acorn/scsi/scsi.h
*
* Copyright (C) 2002 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Commonly used scsi driver functions.
*/
#define BELT_AND_BRACES
/*
* The scatter-gather list handling. This contains all
* the yucky stuff that needs to be fixed properly.
*/
static inline int copy_SCp_to_sg(struct scatterlist *sg, Scsi_Pointer *SCp, int max)
{
int bufs = SCp->buffers_residual;
BUG_ON(bufs + 1 > max);
sg->page = virt_to_page(SCp->ptr);
sg->offset = offset_in_page(SCp->ptr);
sg->length = SCp->this_residual;
if (bufs)
memcpy(sg + 1, SCp->buffer + 1,
sizeof(struct scatterlist) * bufs);
return bufs + 1;
}
static inline int next_SCp(Scsi_Pointer *SCp)
{
int ret = SCp->buffers_residual;
if (ret) {
SCp->buffer++;
SCp->buffers_residual--;
SCp->ptr = (char *)
(page_address(SCp->buffer->page) +
SCp->buffer->offset);
SCp->this_residual = SCp->buffer->length;
} else {
SCp->ptr = NULL;
SCp->this_residual = 0;
}
return ret;
}
static inline unsigned char get_next_SCp_byte(Scsi_Pointer *SCp)
{
char c = *SCp->ptr;
SCp->ptr += 1;
SCp->this_residual -= 1;
return c;
}
static inline void put_next_SCp_byte(Scsi_Pointer *SCp, unsigned char c)
{
*SCp->ptr = c;
SCp->ptr += 1;
SCp->this_residual -= 1;
}
static inline void init_SCp(Scsi_Cmnd *SCpnt)
{
memset(&SCpnt->SCp, 0, sizeof(struct scsi_pointer));
if (SCpnt->use_sg) {
unsigned long len = 0;
int buf;
SCpnt->SCp.buffer = (struct scatterlist *) SCpnt->buffer;
SCpnt->SCp.buffers_residual = SCpnt->use_sg - 1;
SCpnt->SCp.ptr = (char *)
(page_address(SCpnt->SCp.buffer->page) +
SCpnt->SCp.buffer->offset);
SCpnt->SCp.this_residual = SCpnt->SCp.buffer->length;
#ifdef BELT_AND_BRACES
/*
* Calculate correct buffer length. Some commands
* come in with the wrong request_bufflen.
*/
for (buf = 0; buf <= SCpnt->SCp.buffers_residual; buf++)
len += SCpnt->SCp.buffer[buf].length;
if (SCpnt->request_bufflen != len)
printk(KERN_WARNING "scsi%d.%c: bad request buffer "
"length %d, should be %ld\n", SCpnt->device->host->host_no,
'0' + SCpnt->device->id, SCpnt->request_bufflen, len);
SCpnt->request_bufflen = len;
#endif
} else {
SCpnt->SCp.ptr = (unsigned char *)SCpnt->request_buffer;
SCpnt->SCp.this_residual = SCpnt->request_bufflen;
}
/*
* If the upper SCSI layers pass a buffer, but zero length,
* we aren't interested in the buffer pointer.
*/
if (SCpnt->SCp.this_residual == 0 && SCpnt->SCp.ptr) {
#if 0 //def BELT_AND_BRACES
printk(KERN_WARNING "scsi%d.%c: zero length buffer passed for "
"command ", SCpnt->host->host_no, '0' + SCpnt->target);
print_command(SCpnt->cmnd);
#endif
SCpnt->SCp.ptr = NULL;
}
}
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