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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/drivers/acorn/scsi/scsi.h
*
* Copyright (C) 2002 Russell King
*
* Commonly used scsi driver functions.
*/
#include <linux/scatterlist.h>
#define BELT_AND_BRACES
/*
* The scatter-gather list handling. This contains all
* the yucky stuff that needs to be fixed properly.
*/
/*
* copy_SCp_to_sg() Assumes contiguous allocation at @sg of at-most @max
* entries of uninitialized memory. SCp is from scsi-ml and has a valid
* (possibly chained) sg-list
*/
static inline int copy_SCp_to_sg(struct scatterlist *sg, struct scsi_pointer *SCp, int max)
{
int bufs = SCp->buffers_residual;
/* FIXME: It should be easy for drivers to loop on copy_SCp_to_sg().
* and to remove this BUG_ON. Use min() in-its-place
*/
BUG_ON(bufs + 1 > max);
sg_set_buf(sg, SCp->ptr, SCp->this_residual);
if (bufs) {
struct scatterlist *src_sg;
unsigned i;
for_each_sg(sg_next(SCp->buffer), src_sg, bufs, i)
*(++sg) = *src_sg;
sg_mark_end(sg);
}
return bufs + 1;
}
static inline int next_SCp(struct scsi_pointer *SCp)
{
int ret = SCp->buffers_residual;
if (ret) {
SCp->buffer = sg_next(SCp->buffer);
SCp->buffers_residual--;
SCp->ptr = sg_virt(SCp->buffer);
SCp->this_residual = SCp->buffer->length;
} else {
SCp->ptr = NULL;
SCp->this_residual = 0;
}
return ret;
}
static inline unsigned char get_next_SCp_byte(struct scsi_pointer *SCp)
{
char c = *SCp->ptr;
SCp->ptr += 1;
SCp->this_residual -= 1;
return c;
}
static inline void put_next_SCp_byte(struct scsi_pointer *SCp, unsigned char c)
{
*SCp->ptr = c;
SCp->ptr += 1;
SCp->this_residual -= 1;
}
static inline void init_SCp(struct scsi_cmnd *SCpnt)
{
memset(&SCpnt->SCp, 0, sizeof(struct scsi_pointer));
if (scsi_bufflen(SCpnt)) {
unsigned long len = 0;
SCpnt->SCp.buffer = scsi_sglist(SCpnt);
SCpnt->SCp.buffers_residual = scsi_sg_count(SCpnt) - 1;
SCpnt->SCp.ptr = sg_virt(SCpnt->SCp.buffer);
SCpnt->SCp.this_residual = SCpnt->SCp.buffer->length;
SCpnt->SCp.phase = scsi_bufflen(SCpnt);
#ifdef BELT_AND_BRACES
{ /*
* Calculate correct buffer length. Some commands
* come in with the wrong scsi_bufflen.
*/
struct scatterlist *sg;
unsigned i, sg_count = scsi_sg_count(SCpnt);
scsi_for_each_sg(SCpnt, sg, sg_count, i)
len += sg->length;
if (scsi_bufflen(SCpnt) != 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,
scsi_bufflen(SCpnt), len);
/*
* FIXME: Totaly naive fixup. We should abort
* with error
*/
SCpnt->SCp.phase =
min_t(unsigned long, len,
scsi_bufflen(SCpnt));
}
}
#endif
} else {
SCpnt->SCp.ptr = NULL;
SCpnt->SCp.this_residual = 0;
SCpnt->SCp.phase = 0;
}
}
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