Hansjoerg Lipp | 76bb468 | 2006-03-26 01:38:36 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Common data handling layer for bas_gigaset |
| 3 | * |
| 4 | * Copyright (c) 2005 by Tilman Schmidt <tilman@imap.cc>, |
| 5 | * Hansjoerg Lipp <hjlipp@web.de>. |
| 6 | * |
| 7 | * ===================================================================== |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License as |
| 10 | * published by the Free Software Foundation; either version 2 of |
| 11 | * the License, or (at your option) any later version. |
| 12 | * ===================================================================== |
| 13 | * ToDo: ... |
| 14 | * ===================================================================== |
| 15 | * Version: $Id: isocdata.c,v 1.2.2.5 2005/11/13 23:05:19 hjlipp Exp $ |
| 16 | * ===================================================================== |
| 17 | */ |
| 18 | |
| 19 | #include "gigaset.h" |
| 20 | #include <linux/crc-ccitt.h> |
| 21 | |
| 22 | /* access methods for isowbuf_t */ |
| 23 | /* ============================ */ |
| 24 | |
| 25 | /* initialize buffer structure |
| 26 | */ |
| 27 | void gigaset_isowbuf_init(struct isowbuf_t *iwb, unsigned char idle) |
| 28 | { |
| 29 | atomic_set(&iwb->read, 0); |
| 30 | atomic_set(&iwb->nextread, 0); |
| 31 | atomic_set(&iwb->write, 0); |
| 32 | atomic_set(&iwb->writesem, 1); |
| 33 | iwb->wbits = 0; |
| 34 | iwb->idle = idle; |
| 35 | memset(iwb->data + BAS_OUTBUFSIZE, idle, BAS_OUTBUFPAD); |
| 36 | } |
| 37 | |
| 38 | /* compute number of bytes which can be appended to buffer |
| 39 | * so that there is still room to append a maximum frame of flags |
| 40 | */ |
| 41 | static inline int isowbuf_freebytes(struct isowbuf_t *iwb) |
| 42 | { |
| 43 | int read, write, freebytes; |
| 44 | |
| 45 | read = atomic_read(&iwb->read); |
| 46 | write = atomic_read(&iwb->write); |
| 47 | if ((freebytes = read - write) > 0) { |
| 48 | /* no wraparound: need padding space within regular area */ |
| 49 | return freebytes - BAS_OUTBUFPAD; |
| 50 | } else if (read < BAS_OUTBUFPAD) { |
| 51 | /* wraparound: can use space up to end of regular area */ |
| 52 | return BAS_OUTBUFSIZE - write; |
| 53 | } else { |
| 54 | /* following the wraparound yields more space */ |
| 55 | return freebytes + BAS_OUTBUFSIZE - BAS_OUTBUFPAD; |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | /* compare two offsets within the buffer |
| 60 | * The buffer is seen as circular, with the read position as start |
| 61 | * returns -1/0/1 if position a </=/> position b without crossing 'read' |
| 62 | */ |
| 63 | static inline int isowbuf_poscmp(struct isowbuf_t *iwb, int a, int b) |
| 64 | { |
| 65 | int read; |
| 66 | if (a == b) |
| 67 | return 0; |
| 68 | read = atomic_read(&iwb->read); |
| 69 | if (a < b) { |
| 70 | if (a < read && read <= b) |
| 71 | return +1; |
| 72 | else |
| 73 | return -1; |
| 74 | } else { |
| 75 | if (b < read && read <= a) |
| 76 | return -1; |
| 77 | else |
| 78 | return +1; |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | /* start writing |
| 83 | * acquire the write semaphore |
| 84 | * return true if acquired, false if busy |
| 85 | */ |
| 86 | static inline int isowbuf_startwrite(struct isowbuf_t *iwb) |
| 87 | { |
| 88 | if (!atomic_dec_and_test(&iwb->writesem)) { |
| 89 | atomic_inc(&iwb->writesem); |
| 90 | dbg(DEBUG_ISO, |
| 91 | "%s: couldn't acquire iso write semaphore", __func__); |
| 92 | return 0; |
| 93 | } |
| 94 | #ifdef CONFIG_GIGASET_DEBUG |
| 95 | dbg(DEBUG_ISO, |
| 96 | "%s: acquired iso write semaphore, data[write]=%02x, nbits=%d", |
| 97 | __func__, iwb->data[atomic_read(&iwb->write)], iwb->wbits); |
| 98 | #endif |
| 99 | return 1; |
| 100 | } |
| 101 | |
| 102 | /* finish writing |
| 103 | * release the write semaphore and update the maximum buffer fill level |
| 104 | * returns the current write position |
| 105 | */ |
| 106 | static inline int isowbuf_donewrite(struct isowbuf_t *iwb) |
| 107 | { |
| 108 | int write = atomic_read(&iwb->write); |
| 109 | atomic_inc(&iwb->writesem); |
| 110 | return write; |
| 111 | } |
| 112 | |
| 113 | /* append bits to buffer without any checks |
| 114 | * - data contains bits to append, starting at LSB |
| 115 | * - nbits is number of bits to append (0..24) |
| 116 | * must be called with the write semaphore held |
| 117 | * If more than nbits bits are set in data, the extraneous bits are set in the |
| 118 | * buffer too, but the write position is only advanced by nbits. |
| 119 | */ |
| 120 | static inline void isowbuf_putbits(struct isowbuf_t *iwb, u32 data, int nbits) |
| 121 | { |
| 122 | int write = atomic_read(&iwb->write); |
| 123 | data <<= iwb->wbits; |
| 124 | data |= iwb->data[write]; |
| 125 | nbits += iwb->wbits; |
| 126 | while (nbits >= 8) { |
| 127 | iwb->data[write++] = data & 0xff; |
| 128 | write %= BAS_OUTBUFSIZE; |
| 129 | data >>= 8; |
| 130 | nbits -= 8; |
| 131 | } |
| 132 | iwb->wbits = nbits; |
| 133 | iwb->data[write] = data & 0xff; |
| 134 | atomic_set(&iwb->write, write); |
| 135 | } |
| 136 | |
| 137 | /* put final flag on HDLC bitstream |
| 138 | * also sets the idle fill byte to the correspondingly shifted flag pattern |
| 139 | * must be called with the write semaphore held |
| 140 | */ |
| 141 | static inline void isowbuf_putflag(struct isowbuf_t *iwb) |
| 142 | { |
| 143 | int write; |
| 144 | |
| 145 | /* add two flags, thus reliably covering one byte */ |
| 146 | isowbuf_putbits(iwb, 0x7e7e, 8); |
| 147 | /* recover the idle flag byte */ |
| 148 | write = atomic_read(&iwb->write); |
| 149 | iwb->idle = iwb->data[write]; |
| 150 | dbg(DEBUG_ISO, "idle fill byte %02x", iwb->idle); |
| 151 | /* mask extraneous bits in buffer */ |
| 152 | iwb->data[write] &= (1 << iwb->wbits) - 1; |
| 153 | } |
| 154 | |
| 155 | /* retrieve a block of bytes for sending |
| 156 | * The requested number of bytes is provided as a contiguous block. |
| 157 | * If necessary, the frame is filled to the requested number of bytes |
| 158 | * with the idle value. |
| 159 | * returns offset to frame, < 0 on busy or error |
| 160 | */ |
| 161 | int gigaset_isowbuf_getbytes(struct isowbuf_t *iwb, int size) |
| 162 | { |
| 163 | int read, write, limit, src, dst; |
| 164 | unsigned char pbyte; |
| 165 | |
| 166 | read = atomic_read(&iwb->nextread); |
| 167 | write = atomic_read(&iwb->write); |
| 168 | if (likely(read == write)) { |
| 169 | //dbg(DEBUG_STREAM, "%s: send buffer empty", __func__); |
| 170 | /* return idle frame */ |
| 171 | return read < BAS_OUTBUFPAD ? |
| 172 | BAS_OUTBUFSIZE : read - BAS_OUTBUFPAD; |
| 173 | } |
| 174 | |
| 175 | limit = read + size; |
| 176 | dbg(DEBUG_STREAM, |
| 177 | "%s: read=%d write=%d limit=%d", __func__, read, write, limit); |
| 178 | #ifdef CONFIG_GIGASET_DEBUG |
| 179 | if (unlikely(size < 0 || size > BAS_OUTBUFPAD)) { |
| 180 | err("invalid size %d", size); |
| 181 | return -EINVAL; |
| 182 | } |
| 183 | src = atomic_read(&iwb->read); |
| 184 | if (unlikely(limit > BAS_OUTBUFSIZE + BAS_OUTBUFPAD || |
| 185 | (read < src && limit >= src))) { |
| 186 | err("isoc write buffer frame reservation violated"); |
| 187 | return -EFAULT; |
| 188 | } |
| 189 | #endif |
| 190 | |
| 191 | if (read < write) { |
| 192 | /* no wraparound in valid data */ |
| 193 | if (limit >= write) { |
| 194 | /* append idle frame */ |
| 195 | if (!isowbuf_startwrite(iwb)) |
| 196 | return -EBUSY; |
| 197 | /* write position could have changed */ |
| 198 | if (limit >= (write = atomic_read(&iwb->write))) { |
| 199 | pbyte = iwb->data[write]; /* save partial byte */ |
| 200 | limit = write + BAS_OUTBUFPAD; |
| 201 | dbg(DEBUG_STREAM, |
| 202 | "%s: filling %d->%d with %02x", |
| 203 | __func__, write, limit, iwb->idle); |
| 204 | if (write + BAS_OUTBUFPAD < BAS_OUTBUFSIZE) |
| 205 | memset(iwb->data + write, iwb->idle, |
| 206 | BAS_OUTBUFPAD); |
| 207 | else { |
| 208 | /* wraparound, fill entire pad area */ |
| 209 | memset(iwb->data + write, iwb->idle, |
| 210 | BAS_OUTBUFSIZE + BAS_OUTBUFPAD |
| 211 | - write); |
| 212 | limit = 0; |
| 213 | } |
| 214 | dbg(DEBUG_STREAM, "%s: restoring %02x at %d", |
| 215 | __func__, pbyte, limit); |
| 216 | iwb->data[limit] = pbyte; /* restore partial byte */ |
| 217 | atomic_set(&iwb->write, limit); |
| 218 | } |
| 219 | isowbuf_donewrite(iwb); |
| 220 | } |
| 221 | } else { |
| 222 | /* valid data wraparound */ |
| 223 | if (limit >= BAS_OUTBUFSIZE) { |
| 224 | /* copy wrapped part into pad area */ |
| 225 | src = 0; |
| 226 | dst = BAS_OUTBUFSIZE; |
| 227 | while (dst < limit && src < write) |
| 228 | iwb->data[dst++] = iwb->data[src++]; |
| 229 | if (dst <= limit) { |
| 230 | /* fill pad area with idle byte */ |
| 231 | memset(iwb->data + dst, iwb->idle, |
| 232 | BAS_OUTBUFSIZE + BAS_OUTBUFPAD - dst); |
| 233 | } |
| 234 | limit = src; |
| 235 | } |
| 236 | } |
| 237 | atomic_set(&iwb->nextread, limit); |
| 238 | return read; |
| 239 | } |
| 240 | |
| 241 | /* dump_bytes |
| 242 | * write hex bytes to syslog for debugging |
| 243 | */ |
| 244 | static inline void dump_bytes(enum debuglevel level, const char *tag, |
| 245 | unsigned char *bytes, int count) |
| 246 | { |
| 247 | #ifdef CONFIG_GIGASET_DEBUG |
| 248 | unsigned char c; |
| 249 | static char dbgline[3 * 32 + 1]; |
| 250 | static const char hexdigit[] = "0123456789abcdef"; |
| 251 | int i = 0; |
| 252 | IFNULLRET(tag); |
| 253 | IFNULLRET(bytes); |
| 254 | while (count-- > 0) { |
| 255 | if (i > sizeof(dbgline) - 4) { |
| 256 | dbgline[i] = '\0'; |
| 257 | dbg(level, "%s:%s", tag, dbgline); |
| 258 | i = 0; |
| 259 | } |
| 260 | c = *bytes++; |
| 261 | dbgline[i] = (i && !(i % 12)) ? '-' : ' '; |
| 262 | i++; |
| 263 | dbgline[i++] = hexdigit[(c >> 4) & 0x0f]; |
| 264 | dbgline[i++] = hexdigit[c & 0x0f]; |
| 265 | } |
| 266 | dbgline[i] = '\0'; |
| 267 | dbg(level, "%s:%s", tag, dbgline); |
| 268 | #endif |
| 269 | } |
| 270 | |
| 271 | /*============================================================================*/ |
| 272 | |
| 273 | /* bytewise HDLC bitstuffing via table lookup |
| 274 | * lookup table: 5 subtables for 0..4 preceding consecutive '1' bits |
| 275 | * index: 256*(number of preceding '1' bits) + (next byte to stuff) |
| 276 | * value: bit 9.. 0 = result bits |
| 277 | * bit 12..10 = number of trailing '1' bits in result |
| 278 | * bit 14..13 = number of bits added by stuffing |
| 279 | */ |
| 280 | static u16 stufftab[5 * 256] = { |
| 281 | // previous 1s = 0: |
| 282 | 0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f, |
| 283 | 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x201f, |
| 284 | 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f, |
| 285 | 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x205f, |
| 286 | 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f, |
| 287 | 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x209f, |
| 288 | 0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f, |
| 289 | 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20df, |
| 290 | 0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x0487, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x048f, |
| 291 | 0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x0497, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x251f, |
| 292 | 0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x04a7, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x04af, |
| 293 | 0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x04b7, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x255f, |
| 294 | 0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x08c7, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x08cf, |
| 295 | 0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x08d7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x299f, |
| 296 | 0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x0ce7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x0cef, |
| 297 | 0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x10f7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x2ddf, |
| 298 | |
| 299 | // previous 1s = 1: |
| 300 | 0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x200f, |
| 301 | 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x202f, |
| 302 | 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x204f, |
| 303 | 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x206f, |
| 304 | 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x208f, |
| 305 | 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x20af, |
| 306 | 0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x20cf, |
| 307 | 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20ef, |
| 308 | 0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x0487, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x250f, |
| 309 | 0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x0497, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x252f, |
| 310 | 0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x04a7, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x254f, |
| 311 | 0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x04b7, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x256f, |
| 312 | 0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x08c7, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x298f, |
| 313 | 0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x08d7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x29af, |
| 314 | 0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x0ce7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x2dcf, |
| 315 | 0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x10f7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x31ef, |
| 316 | |
| 317 | // previous 1s = 2: |
| 318 | 0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x2007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x2017, |
| 319 | 0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x2027, 0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x2037, |
| 320 | 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x2047, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x2057, |
| 321 | 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x2067, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x203e, 0x2077, |
| 322 | 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x2087, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x2097, |
| 323 | 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x20a7, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x20b7, |
| 324 | 0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x20c7, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x20d7, |
| 325 | 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x20e7, 0x0078, 0x0079, 0x007a, 0x007b, 0x207c, 0x207d, 0x20be, 0x20f7, |
| 326 | 0x0480, 0x0481, 0x0482, 0x0483, 0x0484, 0x0485, 0x0486, 0x2507, 0x0488, 0x0489, 0x048a, 0x048b, 0x048c, 0x048d, 0x048e, 0x2517, |
| 327 | 0x0490, 0x0491, 0x0492, 0x0493, 0x0494, 0x0495, 0x0496, 0x2527, 0x0498, 0x0499, 0x049a, 0x049b, 0x049c, 0x049d, 0x049e, 0x2537, |
| 328 | 0x04a0, 0x04a1, 0x04a2, 0x04a3, 0x04a4, 0x04a5, 0x04a6, 0x2547, 0x04a8, 0x04a9, 0x04aa, 0x04ab, 0x04ac, 0x04ad, 0x04ae, 0x2557, |
| 329 | 0x04b0, 0x04b1, 0x04b2, 0x04b3, 0x04b4, 0x04b5, 0x04b6, 0x2567, 0x04b8, 0x04b9, 0x04ba, 0x04bb, 0x04bc, 0x04bd, 0x253e, 0x2577, |
| 330 | 0x08c0, 0x08c1, 0x08c2, 0x08c3, 0x08c4, 0x08c5, 0x08c6, 0x2987, 0x08c8, 0x08c9, 0x08ca, 0x08cb, 0x08cc, 0x08cd, 0x08ce, 0x2997, |
| 331 | 0x08d0, 0x08d1, 0x08d2, 0x08d3, 0x08d4, 0x08d5, 0x08d6, 0x29a7, 0x08d8, 0x08d9, 0x08da, 0x08db, 0x08dc, 0x08dd, 0x08de, 0x29b7, |
| 332 | 0x0ce0, 0x0ce1, 0x0ce2, 0x0ce3, 0x0ce4, 0x0ce5, 0x0ce6, 0x2dc7, 0x0ce8, 0x0ce9, 0x0cea, 0x0ceb, 0x0cec, 0x0ced, 0x0cee, 0x2dd7, |
| 333 | 0x10f0, 0x10f1, 0x10f2, 0x10f3, 0x10f4, 0x10f5, 0x10f6, 0x31e7, 0x20f8, 0x20f9, 0x20fa, 0x20fb, 0x257c, 0x257d, 0x29be, 0x41f7, |
| 334 | |
| 335 | // previous 1s = 3: |
| 336 | 0x0000, 0x0001, 0x0002, 0x2003, 0x0004, 0x0005, 0x0006, 0x200b, 0x0008, 0x0009, 0x000a, 0x2013, 0x000c, 0x000d, 0x000e, 0x201b, |
| 337 | 0x0010, 0x0011, 0x0012, 0x2023, 0x0014, 0x0015, 0x0016, 0x202b, 0x0018, 0x0019, 0x001a, 0x2033, 0x001c, 0x001d, 0x001e, 0x203b, |
| 338 | 0x0020, 0x0021, 0x0022, 0x2043, 0x0024, 0x0025, 0x0026, 0x204b, 0x0028, 0x0029, 0x002a, 0x2053, 0x002c, 0x002d, 0x002e, 0x205b, |
| 339 | 0x0030, 0x0031, 0x0032, 0x2063, 0x0034, 0x0035, 0x0036, 0x206b, 0x0038, 0x0039, 0x003a, 0x2073, 0x003c, 0x003d, 0x203e, 0x207b, |
| 340 | 0x0040, 0x0041, 0x0042, 0x2083, 0x0044, 0x0045, 0x0046, 0x208b, 0x0048, 0x0049, 0x004a, 0x2093, 0x004c, 0x004d, 0x004e, 0x209b, |
| 341 | 0x0050, 0x0051, 0x0052, 0x20a3, 0x0054, 0x0055, 0x0056, 0x20ab, 0x0058, 0x0059, 0x005a, 0x20b3, 0x005c, 0x005d, 0x005e, 0x20bb, |
| 342 | 0x0060, 0x0061, 0x0062, 0x20c3, 0x0064, 0x0065, 0x0066, 0x20cb, 0x0068, 0x0069, 0x006a, 0x20d3, 0x006c, 0x006d, 0x006e, 0x20db, |
| 343 | 0x0070, 0x0071, 0x0072, 0x20e3, 0x0074, 0x0075, 0x0076, 0x20eb, 0x0078, 0x0079, 0x007a, 0x20f3, 0x207c, 0x207d, 0x20be, 0x40fb, |
| 344 | 0x0480, 0x0481, 0x0482, 0x2503, 0x0484, 0x0485, 0x0486, 0x250b, 0x0488, 0x0489, 0x048a, 0x2513, 0x048c, 0x048d, 0x048e, 0x251b, |
| 345 | 0x0490, 0x0491, 0x0492, 0x2523, 0x0494, 0x0495, 0x0496, 0x252b, 0x0498, 0x0499, 0x049a, 0x2533, 0x049c, 0x049d, 0x049e, 0x253b, |
| 346 | 0x04a0, 0x04a1, 0x04a2, 0x2543, 0x04a4, 0x04a5, 0x04a6, 0x254b, 0x04a8, 0x04a9, 0x04aa, 0x2553, 0x04ac, 0x04ad, 0x04ae, 0x255b, |
| 347 | 0x04b0, 0x04b1, 0x04b2, 0x2563, 0x04b4, 0x04b5, 0x04b6, 0x256b, 0x04b8, 0x04b9, 0x04ba, 0x2573, 0x04bc, 0x04bd, 0x253e, 0x257b, |
| 348 | 0x08c0, 0x08c1, 0x08c2, 0x2983, 0x08c4, 0x08c5, 0x08c6, 0x298b, 0x08c8, 0x08c9, 0x08ca, 0x2993, 0x08cc, 0x08cd, 0x08ce, 0x299b, |
| 349 | 0x08d0, 0x08d1, 0x08d2, 0x29a3, 0x08d4, 0x08d5, 0x08d6, 0x29ab, 0x08d8, 0x08d9, 0x08da, 0x29b3, 0x08dc, 0x08dd, 0x08de, 0x29bb, |
| 350 | 0x0ce0, 0x0ce1, 0x0ce2, 0x2dc3, 0x0ce4, 0x0ce5, 0x0ce6, 0x2dcb, 0x0ce8, 0x0ce9, 0x0cea, 0x2dd3, 0x0cec, 0x0ced, 0x0cee, 0x2ddb, |
| 351 | 0x10f0, 0x10f1, 0x10f2, 0x31e3, 0x10f4, 0x10f5, 0x10f6, 0x31eb, 0x20f8, 0x20f9, 0x20fa, 0x41f3, 0x257c, 0x257d, 0x29be, 0x46fb, |
| 352 | |
| 353 | // previous 1s = 4: |
| 354 | 0x0000, 0x2001, 0x0002, 0x2005, 0x0004, 0x2009, 0x0006, 0x200d, 0x0008, 0x2011, 0x000a, 0x2015, 0x000c, 0x2019, 0x000e, 0x201d, |
| 355 | 0x0010, 0x2021, 0x0012, 0x2025, 0x0014, 0x2029, 0x0016, 0x202d, 0x0018, 0x2031, 0x001a, 0x2035, 0x001c, 0x2039, 0x001e, 0x203d, |
| 356 | 0x0020, 0x2041, 0x0022, 0x2045, 0x0024, 0x2049, 0x0026, 0x204d, 0x0028, 0x2051, 0x002a, 0x2055, 0x002c, 0x2059, 0x002e, 0x205d, |
| 357 | 0x0030, 0x2061, 0x0032, 0x2065, 0x0034, 0x2069, 0x0036, 0x206d, 0x0038, 0x2071, 0x003a, 0x2075, 0x003c, 0x2079, 0x203e, 0x407d, |
| 358 | 0x0040, 0x2081, 0x0042, 0x2085, 0x0044, 0x2089, 0x0046, 0x208d, 0x0048, 0x2091, 0x004a, 0x2095, 0x004c, 0x2099, 0x004e, 0x209d, |
| 359 | 0x0050, 0x20a1, 0x0052, 0x20a5, 0x0054, 0x20a9, 0x0056, 0x20ad, 0x0058, 0x20b1, 0x005a, 0x20b5, 0x005c, 0x20b9, 0x005e, 0x20bd, |
| 360 | 0x0060, 0x20c1, 0x0062, 0x20c5, 0x0064, 0x20c9, 0x0066, 0x20cd, 0x0068, 0x20d1, 0x006a, 0x20d5, 0x006c, 0x20d9, 0x006e, 0x20dd, |
| 361 | 0x0070, 0x20e1, 0x0072, 0x20e5, 0x0074, 0x20e9, 0x0076, 0x20ed, 0x0078, 0x20f1, 0x007a, 0x20f5, 0x207c, 0x40f9, 0x20be, 0x417d, |
| 362 | 0x0480, 0x2501, 0x0482, 0x2505, 0x0484, 0x2509, 0x0486, 0x250d, 0x0488, 0x2511, 0x048a, 0x2515, 0x048c, 0x2519, 0x048e, 0x251d, |
| 363 | 0x0490, 0x2521, 0x0492, 0x2525, 0x0494, 0x2529, 0x0496, 0x252d, 0x0498, 0x2531, 0x049a, 0x2535, 0x049c, 0x2539, 0x049e, 0x253d, |
| 364 | 0x04a0, 0x2541, 0x04a2, 0x2545, 0x04a4, 0x2549, 0x04a6, 0x254d, 0x04a8, 0x2551, 0x04aa, 0x2555, 0x04ac, 0x2559, 0x04ae, 0x255d, |
| 365 | 0x04b0, 0x2561, 0x04b2, 0x2565, 0x04b4, 0x2569, 0x04b6, 0x256d, 0x04b8, 0x2571, 0x04ba, 0x2575, 0x04bc, 0x2579, 0x253e, 0x467d, |
| 366 | 0x08c0, 0x2981, 0x08c2, 0x2985, 0x08c4, 0x2989, 0x08c6, 0x298d, 0x08c8, 0x2991, 0x08ca, 0x2995, 0x08cc, 0x2999, 0x08ce, 0x299d, |
| 367 | 0x08d0, 0x29a1, 0x08d2, 0x29a5, 0x08d4, 0x29a9, 0x08d6, 0x29ad, 0x08d8, 0x29b1, 0x08da, 0x29b5, 0x08dc, 0x29b9, 0x08de, 0x29bd, |
| 368 | 0x0ce0, 0x2dc1, 0x0ce2, 0x2dc5, 0x0ce4, 0x2dc9, 0x0ce6, 0x2dcd, 0x0ce8, 0x2dd1, 0x0cea, 0x2dd5, 0x0cec, 0x2dd9, 0x0cee, 0x2ddd, |
| 369 | 0x10f0, 0x31e1, 0x10f2, 0x31e5, 0x10f4, 0x31e9, 0x10f6, 0x31ed, 0x20f8, 0x41f1, 0x20fa, 0x41f5, 0x257c, 0x46f9, 0x29be, 0x4b7d |
| 370 | }; |
| 371 | |
| 372 | /* hdlc_bitstuff_byte |
| 373 | * perform HDLC bitstuffing for one input byte (8 bits, LSB first) |
| 374 | * parameters: |
| 375 | * cin input byte |
| 376 | * ones number of trailing '1' bits in result before this step |
| 377 | * iwb pointer to output buffer structure (write semaphore must be held) |
| 378 | * return value: |
| 379 | * number of trailing '1' bits in result after this step |
| 380 | */ |
| 381 | |
| 382 | static inline int hdlc_bitstuff_byte(struct isowbuf_t *iwb, unsigned char cin, |
| 383 | int ones) |
| 384 | { |
| 385 | u16 stuff; |
| 386 | int shiftinc, newones; |
| 387 | |
| 388 | /* get stuffing information for input byte |
| 389 | * value: bit 9.. 0 = result bits |
| 390 | * bit 12..10 = number of trailing '1' bits in result |
| 391 | * bit 14..13 = number of bits added by stuffing |
| 392 | */ |
| 393 | stuff = stufftab[256 * ones + cin]; |
| 394 | shiftinc = (stuff >> 13) & 3; |
| 395 | newones = (stuff >> 10) & 7; |
| 396 | stuff &= 0x3ff; |
| 397 | |
| 398 | /* append stuffed byte to output stream */ |
| 399 | isowbuf_putbits(iwb, stuff, 8 + shiftinc); |
| 400 | return newones; |
| 401 | } |
| 402 | |
| 403 | /* hdlc_buildframe |
| 404 | * Perform HDLC framing with bitstuffing on a byte buffer |
| 405 | * The input buffer is regarded as a sequence of bits, starting with the least |
| 406 | * significant bit of the first byte and ending with the most significant bit |
| 407 | * of the last byte. A 16 bit FCS is appended as defined by RFC 1662. |
| 408 | * Whenever five consecutive '1' bits appear in the resulting bit sequence, a |
| 409 | * '0' bit is inserted after them. |
| 410 | * The resulting bit string and a closing flag pattern (PPP_FLAG, '01111110') |
| 411 | * are appended to the output buffer starting at the given bit position, which |
| 412 | * is assumed to already contain a leading flag. |
| 413 | * The output buffer must have sufficient length; count + count/5 + 6 bytes |
| 414 | * starting at *out are safe and are verified to be present. |
| 415 | * parameters: |
| 416 | * in input buffer |
| 417 | * count number of bytes in input buffer |
| 418 | * iwb pointer to output buffer structure (write semaphore must be held) |
| 419 | * return value: |
| 420 | * position of end of packet in output buffer on success, |
| 421 | * -EAGAIN if write semaphore busy or buffer full |
| 422 | */ |
| 423 | |
| 424 | static inline int hdlc_buildframe(struct isowbuf_t *iwb, |
| 425 | unsigned char *in, int count) |
| 426 | { |
| 427 | int ones; |
| 428 | u16 fcs; |
| 429 | int end; |
| 430 | unsigned char c; |
| 431 | |
| 432 | if (isowbuf_freebytes(iwb) < count + count / 5 + 6 || |
| 433 | !isowbuf_startwrite(iwb)) { |
| 434 | dbg(DEBUG_ISO, "%s: %d bytes free -> -EAGAIN", |
| 435 | __func__, isowbuf_freebytes(iwb)); |
| 436 | return -EAGAIN; |
| 437 | } |
| 438 | |
| 439 | dump_bytes(DEBUG_STREAM, "snd data", in, count); |
| 440 | |
| 441 | /* bitstuff and checksum input data */ |
| 442 | fcs = PPP_INITFCS; |
| 443 | ones = 0; |
| 444 | while (count-- > 0) { |
| 445 | c = *in++; |
| 446 | ones = hdlc_bitstuff_byte(iwb, c, ones); |
| 447 | fcs = crc_ccitt_byte(fcs, c); |
| 448 | } |
| 449 | |
| 450 | /* bitstuff and append FCS (complemented, least significant byte first) */ |
| 451 | fcs ^= 0xffff; |
| 452 | ones = hdlc_bitstuff_byte(iwb, fcs & 0x00ff, ones); |
| 453 | ones = hdlc_bitstuff_byte(iwb, (fcs >> 8) & 0x00ff, ones); |
| 454 | |
| 455 | /* put closing flag and repeat byte for flag idle */ |
| 456 | isowbuf_putflag(iwb); |
| 457 | end = isowbuf_donewrite(iwb); |
| 458 | dump_bytes(DEBUG_STREAM_DUMP, "isowbuf", iwb->data, end + 1); |
| 459 | return end; |
| 460 | } |
| 461 | |
| 462 | /* trans_buildframe |
| 463 | * Append a block of 'transparent' data to the output buffer, |
| 464 | * inverting the bytes. |
| 465 | * The output buffer must have sufficient length; count bytes |
| 466 | * starting at *out are safe and are verified to be present. |
| 467 | * parameters: |
| 468 | * in input buffer |
| 469 | * count number of bytes in input buffer |
| 470 | * iwb pointer to output buffer structure (write semaphore must be held) |
| 471 | * return value: |
| 472 | * position of end of packet in output buffer on success, |
| 473 | * -EAGAIN if write semaphore busy or buffer full |
| 474 | */ |
| 475 | |
| 476 | static inline int trans_buildframe(struct isowbuf_t *iwb, |
| 477 | unsigned char *in, int count) |
| 478 | { |
| 479 | int write; |
| 480 | unsigned char c; |
| 481 | |
| 482 | if (unlikely(count <= 0)) |
| 483 | return atomic_read(&iwb->write); /* better ideas? */ |
| 484 | |
| 485 | if (isowbuf_freebytes(iwb) < count || |
| 486 | !isowbuf_startwrite(iwb)) { |
| 487 | dbg(DEBUG_ISO, "can't put %d bytes", count); |
| 488 | return -EAGAIN; |
| 489 | } |
| 490 | |
| 491 | dbg(DEBUG_STREAM, "put %d bytes", count); |
| 492 | write = atomic_read(&iwb->write); |
| 493 | do { |
| 494 | c = gigaset_invtab[*in++]; |
| 495 | iwb->data[write++] = c; |
| 496 | write %= BAS_OUTBUFSIZE; |
| 497 | } while (--count > 0); |
| 498 | atomic_set(&iwb->write, write); |
| 499 | iwb->idle = c; |
| 500 | |
| 501 | return isowbuf_donewrite(iwb); |
| 502 | } |
| 503 | |
| 504 | int gigaset_isoc_buildframe(struct bc_state *bcs, unsigned char *in, int len) |
| 505 | { |
| 506 | int result; |
| 507 | |
| 508 | switch (bcs->proto2) { |
| 509 | case ISDN_PROTO_L2_HDLC: |
| 510 | result = hdlc_buildframe(bcs->hw.bas->isooutbuf, in, len); |
| 511 | dbg(DEBUG_ISO, "%s: %d bytes HDLC -> %d", __func__, len, result); |
| 512 | break; |
| 513 | default: /* assume transparent */ |
| 514 | result = trans_buildframe(bcs->hw.bas->isooutbuf, in, len); |
| 515 | dbg(DEBUG_ISO, "%s: %d bytes trans -> %d", __func__, len, result); |
| 516 | } |
| 517 | return result; |
| 518 | } |
| 519 | |
| 520 | /* hdlc_putbyte |
| 521 | * append byte c to current skb of B channel structure *bcs, updating fcs |
| 522 | */ |
| 523 | static inline void hdlc_putbyte(unsigned char c, struct bc_state *bcs) |
| 524 | { |
| 525 | bcs->fcs = crc_ccitt_byte(bcs->fcs, c); |
| 526 | if (unlikely(bcs->skb == NULL)) { |
| 527 | /* skipping */ |
| 528 | return; |
| 529 | } |
| 530 | if (unlikely(bcs->skb->len == SBUFSIZE)) { |
| 531 | warn("received oversized packet discarded"); |
| 532 | bcs->hw.bas->giants++; |
| 533 | dev_kfree_skb_any(bcs->skb); |
| 534 | bcs->skb = NULL; |
| 535 | return; |
| 536 | } |
| 537 | *gigaset_skb_put_quick(bcs->skb, 1) = c; |
| 538 | } |
| 539 | |
| 540 | /* hdlc_flush |
| 541 | * drop partial HDLC data packet |
| 542 | */ |
| 543 | static inline void hdlc_flush(struct bc_state *bcs) |
| 544 | { |
| 545 | /* clear skb or allocate new if not skipping */ |
| 546 | if (likely(bcs->skb != NULL)) |
| 547 | skb_trim(bcs->skb, 0); |
| 548 | else if (!bcs->ignore) { |
| 549 | if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL) |
| 550 | skb_reserve(bcs->skb, HW_HDR_LEN); |
| 551 | else |
| 552 | err("could not allocate skb"); |
| 553 | } |
| 554 | |
| 555 | /* reset packet state */ |
| 556 | bcs->fcs = PPP_INITFCS; |
| 557 | } |
| 558 | |
| 559 | /* hdlc_done |
| 560 | * process completed HDLC data packet |
| 561 | */ |
| 562 | static inline void hdlc_done(struct bc_state *bcs) |
| 563 | { |
| 564 | struct sk_buff *procskb; |
| 565 | |
| 566 | if (unlikely(bcs->ignore)) { |
| 567 | bcs->ignore--; |
| 568 | hdlc_flush(bcs); |
| 569 | return; |
| 570 | } |
| 571 | |
| 572 | if ((procskb = bcs->skb) == NULL) { |
| 573 | /* previous error */ |
| 574 | dbg(DEBUG_ISO, "%s: skb=NULL", __func__); |
| 575 | gigaset_rcv_error(NULL, bcs->cs, bcs); |
| 576 | } else if (procskb->len < 2) { |
| 577 | notice("received short frame (%d octets)", procskb->len); |
| 578 | bcs->hw.bas->runts++; |
| 579 | gigaset_rcv_error(procskb, bcs->cs, bcs); |
| 580 | } else if (bcs->fcs != PPP_GOODFCS) { |
| 581 | notice("frame check error (0x%04x)", bcs->fcs); |
| 582 | bcs->hw.bas->fcserrs++; |
| 583 | gigaset_rcv_error(procskb, bcs->cs, bcs); |
| 584 | } else { |
| 585 | procskb->len -= 2; /* subtract FCS */ |
| 586 | procskb->tail -= 2; |
| 587 | dbg(DEBUG_ISO, |
| 588 | "%s: good frame (%d octets)", __func__, procskb->len); |
| 589 | dump_bytes(DEBUG_STREAM, |
| 590 | "rcv data", procskb->data, procskb->len); |
| 591 | bcs->hw.bas->goodbytes += procskb->len; |
| 592 | gigaset_rcv_skb(procskb, bcs->cs, bcs); |
| 593 | } |
| 594 | |
| 595 | if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL) |
| 596 | skb_reserve(bcs->skb, HW_HDR_LEN); |
| 597 | else |
| 598 | err("could not allocate skb"); |
| 599 | bcs->fcs = PPP_INITFCS; |
| 600 | } |
| 601 | |
| 602 | /* hdlc_frag |
| 603 | * drop HDLC data packet with non-integral last byte |
| 604 | */ |
| 605 | static inline void hdlc_frag(struct bc_state *bcs, unsigned inbits) |
| 606 | { |
| 607 | if (unlikely(bcs->ignore)) { |
| 608 | bcs->ignore--; |
| 609 | hdlc_flush(bcs); |
| 610 | return; |
| 611 | } |
| 612 | |
| 613 | notice("received partial byte (%d bits)", inbits); |
| 614 | bcs->hw.bas->alignerrs++; |
| 615 | gigaset_rcv_error(bcs->skb, bcs->cs, bcs); |
| 616 | |
| 617 | if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL) |
| 618 | skb_reserve(bcs->skb, HW_HDR_LEN); |
| 619 | else |
| 620 | err("could not allocate skb"); |
| 621 | bcs->fcs = PPP_INITFCS; |
| 622 | } |
| 623 | |
| 624 | /* bit counts lookup table for HDLC bit unstuffing |
| 625 | * index: input byte |
| 626 | * value: bit 0..3 = number of consecutive '1' bits starting from LSB |
| 627 | * bit 4..6 = number of consecutive '1' bits starting from MSB |
| 628 | * (replacing 8 by 7 to make it fit; the algorithm won't care) |
| 629 | * bit 7 set if there are 5 or more "interior" consecutive '1' bits |
| 630 | */ |
| 631 | static unsigned char bitcounts[256] = { |
| 632 | 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04, |
| 633 | 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x05, |
| 634 | 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04, |
| 635 | 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x80, 0x06, |
| 636 | 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04, |
| 637 | 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x05, |
| 638 | 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x04, |
| 639 | 0x00, 0x01, 0x00, 0x02, 0x00, 0x01, 0x00, 0x03, 0x00, 0x01, 0x00, 0x02, 0x80, 0x81, 0x80, 0x07, |
| 640 | 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x14, |
| 641 | 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x15, |
| 642 | 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x14, |
| 643 | 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x10, 0x13, 0x10, 0x11, 0x10, 0x12, 0x10, 0x11, 0x90, 0x16, |
| 644 | 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x23, 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x24, |
| 645 | 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x23, 0x20, 0x21, 0x20, 0x22, 0x20, 0x21, 0x20, 0x25, |
| 646 | 0x30, 0x31, 0x30, 0x32, 0x30, 0x31, 0x30, 0x33, 0x30, 0x31, 0x30, 0x32, 0x30, 0x31, 0x30, 0x34, |
| 647 | 0x40, 0x41, 0x40, 0x42, 0x40, 0x41, 0x40, 0x43, 0x50, 0x51, 0x50, 0x52, 0x60, 0x61, 0x70, 0x78 |
| 648 | }; |
| 649 | |
| 650 | /* hdlc_unpack |
| 651 | * perform HDLC frame processing (bit unstuffing, flag detection, FCS calculation) |
| 652 | * on a sequence of received data bytes (8 bits each, LSB first) |
| 653 | * pass on successfully received, complete frames as SKBs via gigaset_rcv_skb |
| 654 | * notify of errors via gigaset_rcv_error |
| 655 | * tally frames, errors etc. in BC structure counters |
| 656 | * parameters: |
| 657 | * src received data |
| 658 | * count number of received bytes |
| 659 | * bcs receiving B channel structure |
| 660 | */ |
| 661 | static inline void hdlc_unpack(unsigned char *src, unsigned count, |
| 662 | struct bc_state *bcs) |
| 663 | { |
| 664 | struct bas_bc_state *ubc; |
| 665 | int inputstate; |
| 666 | unsigned seqlen, inbyte, inbits; |
| 667 | |
| 668 | IFNULLRET(bcs); |
| 669 | ubc = bcs->hw.bas; |
| 670 | IFNULLRET(ubc); |
| 671 | |
| 672 | /* load previous state: |
| 673 | * inputstate = set of flag bits: |
| 674 | * - INS_flag_hunt: no complete opening flag received since connection setup or last abort |
| 675 | * - INS_have_data: at least one complete data byte received since last flag |
| 676 | * seqlen = number of consecutive '1' bits in last 7 input stream bits (0..7) |
| 677 | * inbyte = accumulated partial data byte (if !INS_flag_hunt) |
| 678 | * inbits = number of valid bits in inbyte, starting at LSB (0..6) |
| 679 | */ |
| 680 | inputstate = bcs->inputstate; |
| 681 | seqlen = ubc->seqlen; |
| 682 | inbyte = ubc->inbyte; |
| 683 | inbits = ubc->inbits; |
| 684 | |
| 685 | /* bit unstuffing a byte a time |
| 686 | * Take your time to understand this; it's straightforward but tedious. |
| 687 | * The "bitcounts" lookup table is used to speed up the counting of |
| 688 | * leading and trailing '1' bits. |
| 689 | */ |
| 690 | while (count--) { |
| 691 | unsigned char c = *src++; |
| 692 | unsigned char tabentry = bitcounts[c]; |
| 693 | unsigned lead1 = tabentry & 0x0f; |
| 694 | unsigned trail1 = (tabentry >> 4) & 0x0f; |
| 695 | |
| 696 | seqlen += lead1; |
| 697 | |
| 698 | if (unlikely(inputstate & INS_flag_hunt)) { |
| 699 | if (c == PPP_FLAG) { |
| 700 | /* flag-in-one */ |
| 701 | inputstate &= ~(INS_flag_hunt | INS_have_data); |
| 702 | inbyte = 0; |
| 703 | inbits = 0; |
| 704 | } else if (seqlen == 6 && trail1 != 7) { |
| 705 | /* flag completed & not followed by abort */ |
| 706 | inputstate &= ~(INS_flag_hunt | INS_have_data); |
| 707 | inbyte = c >> (lead1 + 1); |
| 708 | inbits = 7 - lead1; |
| 709 | if (trail1 >= 8) { |
| 710 | /* interior stuffing: omitting the MSB handles most cases */ |
| 711 | inbits--; |
| 712 | /* correct the incorrectly handled cases individually */ |
| 713 | switch (c) { |
| 714 | case 0xbe: |
| 715 | inbyte = 0x3f; |
| 716 | break; |
| 717 | } |
| 718 | } |
| 719 | } |
| 720 | /* else: continue flag-hunting */ |
| 721 | } else if (likely(seqlen < 5 && trail1 < 7)) { |
| 722 | /* streamlined case: 8 data bits, no stuffing */ |
| 723 | inbyte |= c << inbits; |
| 724 | hdlc_putbyte(inbyte & 0xff, bcs); |
| 725 | inputstate |= INS_have_data; |
| 726 | inbyte >>= 8; |
| 727 | /* inbits unchanged */ |
| 728 | } else if (likely(seqlen == 6 && inbits == 7 - lead1 && |
| 729 | trail1 + 1 == inbits && |
| 730 | !(inputstate & INS_have_data))) { |
| 731 | /* streamlined case: flag idle - state unchanged */ |
| 732 | } else if (unlikely(seqlen > 6)) { |
| 733 | /* abort sequence */ |
| 734 | ubc->aborts++; |
| 735 | hdlc_flush(bcs); |
| 736 | inputstate |= INS_flag_hunt; |
| 737 | } else if (seqlen == 6) { |
| 738 | /* closing flag, including (6 - lead1) '1's and one '0' from inbits */ |
| 739 | if (inbits > 7 - lead1) { |
| 740 | hdlc_frag(bcs, inbits + lead1 - 7); |
| 741 | inputstate &= ~INS_have_data; |
| 742 | } else { |
| 743 | if (inbits < 7 - lead1) |
| 744 | ubc->stolen0s ++; |
| 745 | if (inputstate & INS_have_data) { |
| 746 | hdlc_done(bcs); |
| 747 | inputstate &= ~INS_have_data; |
| 748 | } |
| 749 | } |
| 750 | |
| 751 | if (c == PPP_FLAG) { |
| 752 | /* complete flag, LSB overlaps preceding flag */ |
| 753 | ubc->shared0s ++; |
| 754 | inbits = 0; |
| 755 | inbyte = 0; |
| 756 | } else if (trail1 != 7) { |
| 757 | /* remaining bits */ |
| 758 | inbyte = c >> (lead1 + 1); |
| 759 | inbits = 7 - lead1; |
| 760 | if (trail1 >= 8) { |
| 761 | /* interior stuffing: omitting the MSB handles most cases */ |
| 762 | inbits--; |
| 763 | /* correct the incorrectly handled cases individually */ |
| 764 | switch (c) { |
| 765 | case 0xbe: |
| 766 | inbyte = 0x3f; |
| 767 | break; |
| 768 | } |
| 769 | } |
| 770 | } else { |
| 771 | /* abort sequence follows, skb already empty anyway */ |
| 772 | ubc->aborts++; |
| 773 | inputstate |= INS_flag_hunt; |
| 774 | } |
| 775 | } else { /* (seqlen < 6) && (seqlen == 5 || trail1 >= 7) */ |
| 776 | |
| 777 | if (c == PPP_FLAG) { |
| 778 | /* complete flag */ |
| 779 | if (seqlen == 5) |
| 780 | ubc->stolen0s++; |
| 781 | if (inbits) { |
| 782 | hdlc_frag(bcs, inbits); |
| 783 | inbits = 0; |
| 784 | inbyte = 0; |
| 785 | } else if (inputstate & INS_have_data) |
| 786 | hdlc_done(bcs); |
| 787 | inputstate &= ~INS_have_data; |
| 788 | } else if (trail1 == 7) { |
| 789 | /* abort sequence */ |
| 790 | ubc->aborts++; |
| 791 | hdlc_flush(bcs); |
| 792 | inputstate |= INS_flag_hunt; |
| 793 | } else { |
| 794 | /* stuffed data */ |
| 795 | if (trail1 < 7) { /* => seqlen == 5 */ |
| 796 | /* stuff bit at position lead1, no interior stuffing */ |
| 797 | unsigned char mask = (1 << lead1) - 1; |
| 798 | c = (c & mask) | ((c & ~mask) >> 1); |
| 799 | inbyte |= c << inbits; |
| 800 | inbits += 7; |
| 801 | } else if (seqlen < 5) { /* trail1 >= 8 */ |
| 802 | /* interior stuffing: omitting the MSB handles most cases */ |
| 803 | /* correct the incorrectly handled cases individually */ |
| 804 | switch (c) { |
| 805 | case 0xbe: |
| 806 | c = 0x7e; |
| 807 | break; |
| 808 | } |
| 809 | inbyte |= c << inbits; |
| 810 | inbits += 7; |
| 811 | } else { /* seqlen == 5 && trail1 >= 8 */ |
| 812 | |
| 813 | /* stuff bit at lead1 *and* interior stuffing */ |
| 814 | switch (c) { /* unstuff individually */ |
| 815 | case 0x7d: |
| 816 | c = 0x3f; |
| 817 | break; |
| 818 | case 0xbe: |
| 819 | c = 0x3f; |
| 820 | break; |
| 821 | case 0x3e: |
| 822 | c = 0x1f; |
| 823 | break; |
| 824 | case 0x7c: |
| 825 | c = 0x3e; |
| 826 | break; |
| 827 | } |
| 828 | inbyte |= c << inbits; |
| 829 | inbits += 6; |
| 830 | } |
| 831 | if (inbits >= 8) { |
| 832 | inbits -= 8; |
| 833 | hdlc_putbyte(inbyte & 0xff, bcs); |
| 834 | inputstate |= INS_have_data; |
| 835 | inbyte >>= 8; |
| 836 | } |
| 837 | } |
| 838 | } |
| 839 | seqlen = trail1 & 7; |
| 840 | } |
| 841 | |
| 842 | /* save new state */ |
| 843 | bcs->inputstate = inputstate; |
| 844 | ubc->seqlen = seqlen; |
| 845 | ubc->inbyte = inbyte; |
| 846 | ubc->inbits = inbits; |
| 847 | } |
| 848 | |
| 849 | /* trans_receive |
| 850 | * pass on received USB frame transparently as SKB via gigaset_rcv_skb |
| 851 | * invert bytes |
| 852 | * tally frames, errors etc. in BC structure counters |
| 853 | * parameters: |
| 854 | * src received data |
| 855 | * count number of received bytes |
| 856 | * bcs receiving B channel structure |
| 857 | */ |
| 858 | static inline void trans_receive(unsigned char *src, unsigned count, |
| 859 | struct bc_state *bcs) |
| 860 | { |
| 861 | struct sk_buff *skb; |
| 862 | int dobytes; |
| 863 | unsigned char *dst; |
| 864 | |
| 865 | if (unlikely(bcs->ignore)) { |
| 866 | bcs->ignore--; |
| 867 | hdlc_flush(bcs); |
| 868 | return; |
| 869 | } |
| 870 | if (unlikely((skb = bcs->skb) == NULL)) { |
| 871 | bcs->skb = skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN); |
| 872 | if (!skb) { |
| 873 | err("could not allocate skb"); |
| 874 | return; |
| 875 | } |
| 876 | skb_reserve(skb, HW_HDR_LEN); |
| 877 | } |
| 878 | bcs->hw.bas->goodbytes += skb->len; |
| 879 | dobytes = TRANSBUFSIZE - skb->len; |
| 880 | while (count > 0) { |
| 881 | dst = skb_put(skb, count < dobytes ? count : dobytes); |
| 882 | while (count > 0 && dobytes > 0) { |
| 883 | *dst++ = gigaset_invtab[*src++]; |
| 884 | count--; |
| 885 | dobytes--; |
| 886 | } |
| 887 | if (dobytes == 0) { |
| 888 | gigaset_rcv_skb(skb, bcs->cs, bcs); |
| 889 | bcs->skb = skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN); |
| 890 | if (!skb) { |
| 891 | err("could not allocate skb"); |
| 892 | return; |
| 893 | } |
| 894 | skb_reserve(bcs->skb, HW_HDR_LEN); |
| 895 | dobytes = TRANSBUFSIZE; |
| 896 | } |
| 897 | } |
| 898 | } |
| 899 | |
| 900 | void gigaset_isoc_receive(unsigned char *src, unsigned count, struct bc_state *bcs) |
| 901 | { |
| 902 | switch (bcs->proto2) { |
| 903 | case ISDN_PROTO_L2_HDLC: |
| 904 | hdlc_unpack(src, count, bcs); |
| 905 | break; |
| 906 | default: /* assume transparent */ |
| 907 | trans_receive(src, count, bcs); |
| 908 | } |
| 909 | } |
| 910 | |
| 911 | /* == data input =========================================================== */ |
| 912 | |
| 913 | static void cmd_loop(unsigned char *src, int numbytes, struct inbuf_t *inbuf) |
| 914 | { |
| 915 | struct cardstate *cs = inbuf->cs; |
| 916 | unsigned cbytes = cs->cbytes; |
| 917 | |
| 918 | while (numbytes--) { |
| 919 | /* copy next character, check for end of line */ |
| 920 | switch (cs->respdata[cbytes] = *src++) { |
| 921 | case '\r': |
| 922 | case '\n': |
| 923 | /* end of line */ |
| 924 | dbg(DEBUG_TRANSCMD, "%s: End of Command (%d Bytes)", |
| 925 | __func__, cbytes); |
| 926 | cs->cbytes = cbytes; |
| 927 | gigaset_handle_modem_response(cs); |
| 928 | cbytes = 0; |
| 929 | break; |
| 930 | default: |
| 931 | /* advance in line buffer, checking for overflow */ |
| 932 | if (cbytes < MAX_RESP_SIZE - 1) |
| 933 | cbytes++; |
| 934 | else |
| 935 | warn("response too large"); |
| 936 | } |
| 937 | } |
| 938 | |
| 939 | /* save state */ |
| 940 | cs->cbytes = cbytes; |
| 941 | } |
| 942 | |
| 943 | |
| 944 | /* process a block of data received through the control channel |
| 945 | */ |
| 946 | void gigaset_isoc_input(struct inbuf_t *inbuf) |
| 947 | { |
| 948 | struct cardstate *cs = inbuf->cs; |
| 949 | unsigned tail, head, numbytes; |
| 950 | unsigned char *src; |
| 951 | |
| 952 | head = atomic_read(&inbuf->head); |
| 953 | while (head != (tail = atomic_read(&inbuf->tail))) { |
| 954 | dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail); |
| 955 | if (head > tail) |
| 956 | tail = RBUFSIZE; |
| 957 | src = inbuf->data + head; |
| 958 | numbytes = tail - head; |
| 959 | dbg(DEBUG_INTR, "processing %u bytes", numbytes); |
| 960 | |
| 961 | if (atomic_read(&cs->mstate) == MS_LOCKED) { |
| 962 | gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response", |
| 963 | numbytes, src, 0); |
| 964 | gigaset_if_receive(inbuf->cs, src, numbytes); |
| 965 | } else { |
| 966 | gigaset_dbg_buffer(DEBUG_CMD, "received response", |
| 967 | numbytes, src, 0); |
| 968 | cmd_loop(src, numbytes, inbuf); |
| 969 | } |
| 970 | |
| 971 | head += numbytes; |
| 972 | if (head == RBUFSIZE) |
| 973 | head = 0; |
| 974 | dbg(DEBUG_INTR, "setting head to %u", head); |
| 975 | atomic_set(&inbuf->head, head); |
| 976 | } |
| 977 | } |
| 978 | |
| 979 | |
| 980 | /* == data output ========================================================== */ |
| 981 | |
| 982 | /* gigaset_send_skb |
| 983 | * called by common.c to queue an skb for sending |
| 984 | * and start transmission if necessary |
| 985 | * parameters: |
| 986 | * B Channel control structure |
| 987 | * skb |
| 988 | * return value: |
| 989 | * number of bytes accepted for sending |
| 990 | * (skb->len if ok, 0 if out of buffer space) |
| 991 | * or error code (< 0, eg. -EINVAL) |
| 992 | */ |
| 993 | int gigaset_isoc_send_skb(struct bc_state *bcs, struct sk_buff *skb) |
| 994 | { |
| 995 | int len; |
| 996 | |
| 997 | IFNULLRETVAL(bcs, -EFAULT); |
| 998 | IFNULLRETVAL(skb, -EFAULT); |
| 999 | len = skb->len; |
| 1000 | |
| 1001 | skb_queue_tail(&bcs->squeue, skb); |
| 1002 | dbg(DEBUG_ISO, |
| 1003 | "%s: skb queued, qlen=%d", __func__, skb_queue_len(&bcs->squeue)); |
| 1004 | |
| 1005 | /* tasklet submits URB if necessary */ |
| 1006 | tasklet_schedule(&bcs->hw.bas->sent_tasklet); |
| 1007 | |
| 1008 | return len; /* ok so far */ |
| 1009 | } |