1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
2 | /* |
3 | * Copyright (C) 2002 Russell King |
4 | * |
5 | * Commonly used functions by the ARM SCSI-II drivers. |
6 | */ |
7 | |
8 | #include <linux/scatterlist.h> |
9 | |
10 | #define BELT_AND_BRACES |
11 | |
12 | struct arm_cmd_priv { |
13 | struct scsi_pointer scsi_pointer; |
14 | }; |
15 | |
16 | static inline struct scsi_pointer *arm_scsi_pointer(struct scsi_cmnd *cmd) |
17 | { |
18 | struct arm_cmd_priv *acmd = scsi_cmd_priv(cmd); |
19 | |
20 | return &acmd->scsi_pointer; |
21 | } |
22 | |
23 | /* |
24 | * The scatter-gather list handling. This contains all |
25 | * the yucky stuff that needs to be fixed properly. |
26 | */ |
27 | |
28 | /* |
29 | * copy_SCp_to_sg() Assumes contiguous allocation at @sg of at-most @max |
30 | * entries of uninitialized memory. SCp is from scsi-ml and has a valid |
31 | * (possibly chained) sg-list |
32 | */ |
33 | static inline int copy_SCp_to_sg(struct scatterlist *sg, struct scsi_pointer *SCp, int max) |
34 | { |
35 | int bufs = SCp->buffers_residual; |
36 | |
37 | /* FIXME: It should be easy for drivers to loop on copy_SCp_to_sg(). |
38 | * and to remove this BUG_ON. Use min() in-its-place |
39 | */ |
40 | BUG_ON(bufs + 1 > max); |
41 | |
42 | sg_set_buf(sg, buf: SCp->ptr, buflen: SCp->this_residual); |
43 | |
44 | if (bufs) { |
45 | struct scatterlist *src_sg; |
46 | unsigned i; |
47 | |
48 | for_each_sg(sg_next(SCp->buffer), src_sg, bufs, i) |
49 | *(++sg) = *src_sg; |
50 | sg_mark_end(sg); |
51 | } |
52 | |
53 | return bufs + 1; |
54 | } |
55 | |
56 | static inline int next_SCp(struct scsi_pointer *SCp) |
57 | { |
58 | int ret = SCp->buffers_residual; |
59 | if (ret) { |
60 | SCp->buffer = sg_next(SCp->buffer); |
61 | SCp->buffers_residual--; |
62 | SCp->ptr = sg_virt(sg: SCp->buffer); |
63 | SCp->this_residual = SCp->buffer->length; |
64 | } else { |
65 | SCp->ptr = NULL; |
66 | SCp->this_residual = 0; |
67 | } |
68 | return ret; |
69 | } |
70 | |
71 | static inline unsigned char get_next_SCp_byte(struct scsi_pointer *SCp) |
72 | { |
73 | char c = *SCp->ptr; |
74 | |
75 | SCp->ptr += 1; |
76 | SCp->this_residual -= 1; |
77 | |
78 | return c; |
79 | } |
80 | |
81 | static inline void put_next_SCp_byte(struct scsi_pointer *SCp, unsigned char c) |
82 | { |
83 | *SCp->ptr = c; |
84 | SCp->ptr += 1; |
85 | SCp->this_residual -= 1; |
86 | } |
87 | |
88 | static inline void init_SCp(struct scsi_cmnd *SCpnt) |
89 | { |
90 | struct scsi_pointer *scsi_pointer = arm_scsi_pointer(cmd: SCpnt); |
91 | |
92 | memset(scsi_pointer, 0, sizeof(struct scsi_pointer)); |
93 | |
94 | if (scsi_bufflen(cmd: SCpnt)) { |
95 | unsigned long len = 0; |
96 | |
97 | scsi_pointer->buffer = scsi_sglist(cmd: SCpnt); |
98 | scsi_pointer->buffers_residual = scsi_sg_count(cmd: SCpnt) - 1; |
99 | scsi_pointer->ptr = sg_virt(sg: scsi_pointer->buffer); |
100 | scsi_pointer->this_residual = scsi_pointer->buffer->length; |
101 | scsi_pointer->phase = scsi_bufflen(cmd: SCpnt); |
102 | |
103 | #ifdef BELT_AND_BRACES |
104 | { /* |
105 | * Calculate correct buffer length. Some commands |
106 | * come in with the wrong scsi_bufflen. |
107 | */ |
108 | struct scatterlist *sg; |
109 | unsigned i, sg_count = scsi_sg_count(cmd: SCpnt); |
110 | |
111 | scsi_for_each_sg(SCpnt, sg, sg_count, i) |
112 | len += sg->length; |
113 | |
114 | if (scsi_bufflen(cmd: SCpnt) != len) { |
115 | printk(KERN_WARNING |
116 | "scsi%d.%c: bad request buffer " |
117 | "length %d, should be %ld\n" , |
118 | SCpnt->device->host->host_no, |
119 | '0' + SCpnt->device->id, |
120 | scsi_bufflen(SCpnt), len); |
121 | /* |
122 | * FIXME: Totaly naive fixup. We should abort |
123 | * with error |
124 | */ |
125 | scsi_pointer->phase = |
126 | min_t(unsigned long, len, |
127 | scsi_bufflen(SCpnt)); |
128 | } |
129 | } |
130 | #endif |
131 | } else { |
132 | scsi_pointer->ptr = NULL; |
133 | scsi_pointer->this_residual = 0; |
134 | scsi_pointer->phase = 0; |
135 | } |
136 | } |
137 | |