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42e9a92f RL |
1 | /* |
2 | * Copyright(c) 2007 Intel Corporation. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms and conditions of the GNU General Public License, | |
6 | * version 2, as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program; if not, write to the Free Software Foundation, Inc., | |
15 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | |
16 | * | |
17 | * Maintained at www.Open-FCoE.org | |
18 | */ | |
19 | ||
20 | #ifndef _FC_FRAME_H_ | |
21 | #define _FC_FRAME_H_ | |
22 | ||
23 | #include <linux/scatterlist.h> | |
24 | #include <linux/skbuff.h> | |
25 | #include <scsi/scsi_cmnd.h> | |
26 | ||
27 | #include <scsi/fc/fc_fs.h> | |
28 | #include <scsi/fc/fc_fcp.h> | |
29 | #include <scsi/fc/fc_encaps.h> | |
30 | ||
31 | /* | |
32 | * The fc_frame interface is used to pass frame data between functions. | |
33 | * The frame includes the data buffer, length, and SOF / EOF delimiter types. | |
34 | * A pointer to the port structure of the receiving port is also includeded. | |
35 | */ | |
36 | ||
37 | #define FC_FRAME_HEADROOM 32 /* headroom for VLAN + FCoE headers */ | |
38 | #define FC_FRAME_TAILROOM 8 /* trailer space for FCoE */ | |
39 | ||
40 | /* | |
41 | * Information about an individual fibre channel frame received or to be sent. | |
42 | * The buffer may be in up to 4 additional non-contiguous sections, | |
43 | * but the linear section must hold the frame header. | |
44 | */ | |
45 | #define FC_FRAME_SG_LEN 4 /* scatter/gather list maximum length */ | |
46 | ||
47 | #define fp_skb(fp) (&((fp)->skb)) | |
48 | #define fr_hdr(fp) ((fp)->skb.data) | |
49 | #define fr_len(fp) ((fp)->skb.len) | |
50 | #define fr_cb(fp) ((struct fcoe_rcv_info *)&((fp)->skb.cb[0])) | |
51 | #define fr_dev(fp) (fr_cb(fp)->fr_dev) | |
52 | #define fr_seq(fp) (fr_cb(fp)->fr_seq) | |
53 | #define fr_sof(fp) (fr_cb(fp)->fr_sof) | |
54 | #define fr_eof(fp) (fr_cb(fp)->fr_eof) | |
55 | #define fr_flags(fp) (fr_cb(fp)->fr_flags) | |
56 | #define fr_max_payload(fp) (fr_cb(fp)->fr_max_payload) | |
57 | #define fr_cmd(fp) (fr_cb(fp)->fr_cmd) | |
58 | #define fr_dir(fp) (fr_cmd(fp)->sc_data_direction) | |
59 | #define fr_crc(fp) (fr_cb(fp)->fr_crc) | |
60 | ||
61 | struct fc_frame { | |
62 | struct sk_buff skb; | |
63 | }; | |
64 | ||
65 | struct fcoe_rcv_info { | |
66 | struct packet_type *ptype; | |
67 | struct fc_lport *fr_dev; /* transport layer private pointer */ | |
68 | struct fc_seq *fr_seq; /* for use with exchange manager */ | |
69 | struct scsi_cmnd *fr_cmd; /* for use of scsi command */ | |
70 | u32 fr_crc; | |
71 | u16 fr_max_payload; /* max FC payload */ | |
72 | enum fc_sof fr_sof; /* start of frame delimiter */ | |
73 | enum fc_eof fr_eof; /* end of frame delimiter */ | |
74 | u8 fr_flags; /* flags - see below */ | |
75 | }; | |
76 | ||
77 | ||
78 | /* | |
79 | * Get fc_frame pointer for an skb that's already been imported. | |
80 | */ | |
81 | static inline struct fcoe_rcv_info *fcoe_dev_from_skb(const struct sk_buff *skb) | |
82 | { | |
83 | BUILD_BUG_ON(sizeof(struct fcoe_rcv_info) > sizeof(skb->cb)); | |
84 | return (struct fcoe_rcv_info *) skb->cb; | |
85 | } | |
86 | ||
87 | /* | |
88 | * fr_flags. | |
89 | */ | |
90 | #define FCPHF_CRC_UNCHECKED 0x01 /* CRC not computed, still appended */ | |
91 | ||
92 | /* | |
93 | * Initialize a frame. | |
94 | * We don't do a complete memset here for performance reasons. | |
95 | * The caller must set fr_free, fr_hdr, fr_len, fr_sof, and fr_eof eventually. | |
96 | */ | |
97 | static inline void fc_frame_init(struct fc_frame *fp) | |
98 | { | |
99 | fr_dev(fp) = NULL; | |
100 | fr_seq(fp) = NULL; | |
101 | fr_flags(fp) = 0; | |
102 | } | |
103 | ||
104 | struct fc_frame *fc_frame_alloc_fill(struct fc_lport *, size_t payload_len); | |
105 | ||
106 | struct fc_frame *__fc_frame_alloc(size_t payload_len); | |
107 | ||
108 | /* | |
109 | * Get frame for sending via port. | |
110 | */ | |
111 | static inline struct fc_frame *_fc_frame_alloc(struct fc_lport *dev, | |
112 | size_t payload_len) | |
113 | { | |
114 | return __fc_frame_alloc(payload_len); | |
115 | } | |
116 | ||
117 | /* | |
118 | * Allocate fc_frame structure and buffer. Set the initial length to | |
119 | * payload_size + sizeof (struct fc_frame_header). | |
120 | */ | |
121 | static inline struct fc_frame *fc_frame_alloc(struct fc_lport *dev, size_t len) | |
122 | { | |
123 | struct fc_frame *fp; | |
124 | ||
125 | /* | |
126 | * Note: Since len will often be a constant multiple of 4, | |
127 | * this check will usually be evaluated and eliminated at compile time. | |
128 | */ | |
129 | if ((len % 4) != 0) | |
130 | fp = fc_frame_alloc_fill(dev, len); | |
131 | else | |
132 | fp = _fc_frame_alloc(dev, len); | |
133 | return fp; | |
134 | } | |
135 | ||
136 | /* | |
137 | * Free the fc_frame structure and buffer. | |
138 | */ | |
139 | static inline void fc_frame_free(struct fc_frame *fp) | |
140 | { | |
141 | kfree_skb(fp_skb(fp)); | |
142 | } | |
143 | ||
144 | static inline int fc_frame_is_linear(struct fc_frame *fp) | |
145 | { | |
146 | return !skb_is_nonlinear(fp_skb(fp)); | |
147 | } | |
148 | ||
149 | /* | |
150 | * Get frame header from message in fc_frame structure. | |
151 | * This hides a cast and provides a place to add some checking. | |
152 | */ | |
153 | static inline | |
154 | struct fc_frame_header *fc_frame_header_get(const struct fc_frame *fp) | |
155 | { | |
156 | WARN_ON(fr_len(fp) < sizeof(struct fc_frame_header)); | |
157 | return (struct fc_frame_header *) fr_hdr(fp); | |
158 | } | |
159 | ||
160 | /* | |
161 | * Get frame payload from message in fc_frame structure. | |
162 | * This hides a cast and provides a place to add some checking. | |
163 | * The len parameter is the minimum length for the payload portion. | |
164 | * Returns NULL if the frame is too short. | |
165 | * | |
166 | * This assumes the interesting part of the payload is in the first part | |
167 | * of the buffer for received data. This may not be appropriate to use for | |
168 | * buffers being transmitted. | |
169 | */ | |
170 | static inline void *fc_frame_payload_get(const struct fc_frame *fp, | |
171 | size_t len) | |
172 | { | |
173 | void *pp = NULL; | |
174 | ||
175 | if (fr_len(fp) >= sizeof(struct fc_frame_header) + len) | |
176 | pp = fc_frame_header_get(fp) + 1; | |
177 | return pp; | |
178 | } | |
179 | ||
180 | /* | |
181 | * Get frame payload opcode (first byte) from message in fc_frame structure. | |
182 | * This hides a cast and provides a place to add some checking. Return 0 | |
183 | * if the frame has no payload. | |
184 | */ | |
185 | static inline u8 fc_frame_payload_op(const struct fc_frame *fp) | |
186 | { | |
187 | u8 *cp; | |
188 | ||
189 | cp = fc_frame_payload_get(fp, sizeof(u8)); | |
190 | if (!cp) | |
191 | return 0; | |
192 | return *cp; | |
193 | ||
194 | } | |
195 | ||
196 | /* | |
197 | * Get FC class from frame. | |
198 | */ | |
199 | static inline enum fc_class fc_frame_class(const struct fc_frame *fp) | |
200 | { | |
201 | return fc_sof_class(fr_sof(fp)); | |
202 | } | |
203 | ||
204 | /* | |
205 | * Check the CRC in a frame. | |
206 | * The CRC immediately follows the last data item *AFTER* the length. | |
207 | * The return value is zero if the CRC matches. | |
208 | */ | |
209 | u32 fc_frame_crc_check(struct fc_frame *); | |
210 | ||
211 | static inline u8 fc_frame_rctl(const struct fc_frame *fp) | |
212 | { | |
213 | return fc_frame_header_get(fp)->fh_r_ctl; | |
214 | } | |
215 | ||
216 | static inline bool fc_frame_is_cmd(const struct fc_frame *fp) | |
217 | { | |
218 | return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD; | |
219 | } | |
220 | ||
221 | static inline bool fc_frame_is_read(const struct fc_frame *fp) | |
222 | { | |
223 | if (fc_frame_is_cmd(fp) && fr_cmd(fp)) | |
224 | return fr_dir(fp) == DMA_FROM_DEVICE; | |
225 | return false; | |
226 | } | |
227 | ||
228 | static inline bool fc_frame_is_write(const struct fc_frame *fp) | |
229 | { | |
230 | if (fc_frame_is_cmd(fp) && fr_cmd(fp)) | |
231 | return fr_dir(fp) == DMA_TO_DEVICE; | |
232 | return false; | |
233 | } | |
234 | ||
235 | /* | |
236 | * Check for leaks. | |
237 | * Print the frame header of any currently allocated frame, assuming there | |
238 | * should be none at this point. | |
239 | */ | |
240 | void fc_frame_leak_check(void); | |
241 | ||
242 | #endif /* _FC_FRAME_H_ */ |