tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * linux/drivers/acorn/scsi/scsi.h
3 *
4 * Copyright (C) 2002 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * Commonly used scsi driver functions.
11 */
12
13#include <linux/scatterlist.h>
14
15#define BELT_AND_BRACES
16
17/*
18 * The scatter-gather list handling. This contains all
19 * the yucky stuff that needs to be fixed properly.
20 */
21static inline int copy_SCp_to_sg(struct scatterlist *sg, struct scsi_pointer *SCp, int max)
22{
23 int bufs = SCp->buffers_residual;
24
25 BUG_ON(bufs + 1 > max);
26
27 sg_set_buf(sg, SCp->ptr, SCp->this_residual);
28
29 if (bufs)
30 memcpy(sg + 1, SCp->buffer + 1,
31 sizeof(struct scatterlist) * bufs);
32 return bufs + 1;
33}
34
35static inline int next_SCp(struct scsi_pointer *SCp)
36{
37 int ret = SCp->buffers_residual;
38 if (ret) {
39 SCp->buffer++;
40 SCp->buffers_residual--;
41 SCp->ptr = (char *)
42 (page_address(SCp->buffer->page) +
43 SCp->buffer->offset);
44 SCp->this_residual = SCp->buffer->length;
45 } else {
46 SCp->ptr = NULL;
47 SCp->this_residual = 0;
48 }
49 return ret;
50}
51
52static inline unsigned char get_next_SCp_byte(struct scsi_pointer *SCp)
53{
54 char c = *SCp->ptr;
55
56 SCp->ptr += 1;
57 SCp->this_residual -= 1;
58
59 return c;
60}
61
62static inline void put_next_SCp_byte(struct scsi_pointer *SCp, unsigned char c)
63{
64 *SCp->ptr = c;
65 SCp->ptr += 1;
66 SCp->this_residual -= 1;
67}
68
69static inline void init_SCp(Scsi_Cmnd *SCpnt)
70{
71 memset(&SCpnt->SCp, 0, sizeof(struct scsi_pointer));
72
73 if (SCpnt->use_sg) {
74 unsigned long len = 0;
75 int buf;
76
77 SCpnt->SCp.buffer = (struct scatterlist *) SCpnt->buffer;
78 SCpnt->SCp.buffers_residual = SCpnt->use_sg - 1;
79 SCpnt->SCp.ptr = (char *)
80 (page_address(SCpnt->SCp.buffer->page) +
81 SCpnt->SCp.buffer->offset);
82 SCpnt->SCp.this_residual = SCpnt->SCp.buffer->length;
83
84#ifdef BELT_AND_BRACES
85 /*
86 * Calculate correct buffer length. Some commands
87 * come in with the wrong request_bufflen.
88 */
89 for (buf = 0; buf <= SCpnt->SCp.buffers_residual; buf++)
90 len += SCpnt->SCp.buffer[buf].length;
91
92 if (SCpnt->request_bufflen != len)
93 printk(KERN_WARNING "scsi%d.%c: bad request buffer "
94 "length %d, should be %ld\n", SCpnt->device->host->host_no,
95 '0' + SCpnt->device->id, SCpnt->request_bufflen, len);
96 SCpnt->request_bufflen = len;
97#endif
98 } else {
99 SCpnt->SCp.ptr = (unsigned char *)SCpnt->request_buffer;
100 SCpnt->SCp.this_residual = SCpnt->request_bufflen;
101 }
102
103 /*
104 * If the upper SCSI layers pass a buffer, but zero length,
105 * we aren't interested in the buffer pointer.
106 */
107 if (SCpnt->SCp.this_residual == 0 && SCpnt->SCp.ptr) {
108#if 0 //def BELT_AND_BRACES
109 printk(KERN_WARNING "scsi%d.%c: zero length buffer passed for "
110 "command ", SCpnt->host->host_no, '0' + SCpnt->target);
111 __scsi_print_command(SCpnt->cmnd);
112#endif
113 SCpnt->SCp.ptr = NULL;
114 }
115}