| 1 | /* tty_subr.c 4.1 %G% */ |
| 2 | |
| 3 | #include "../h/param.h" |
| 4 | #include "../h/tty.h" |
| 5 | #include "../h/systm.h" |
| 6 | #include "../h/conf.h" |
| 7 | #include "../h/buf.h" |
| 8 | |
| 9 | struct cblock { |
| 10 | struct cblock *c_next; |
| 11 | char c_info[CBSIZE]; |
| 12 | }; |
| 13 | |
| 14 | struct cblock cfree[NCLIST]; |
| 15 | int cbad; |
| 16 | struct cblock *cfreelist; |
| 17 | |
| 18 | /* |
| 19 | * Character list get/put |
| 20 | */ |
| 21 | getc(p) |
| 22 | register struct clist *p; |
| 23 | { |
| 24 | register struct cblock *bp; |
| 25 | register int c, s; |
| 26 | |
| 27 | s = spl6(); |
| 28 | if (p->c_cc <= 0) { |
| 29 | c = -1; |
| 30 | p->c_cc = 0; |
| 31 | p->c_cf = p->c_cl = NULL; |
| 32 | } else { |
| 33 | c = *p->c_cf++ & 0377; |
| 34 | if (--p->c_cc<=0) { |
| 35 | bp = (struct cblock *)(p->c_cf-1); |
| 36 | bp = (struct cblock *) ((int)bp & ~CROUND); |
| 37 | p->c_cf = NULL; |
| 38 | p->c_cl = NULL; |
| 39 | bp->c_next = cfreelist; |
| 40 | cfreelist = bp; |
| 41 | } else if (((int)p->c_cf & CROUND) == 0){ |
| 42 | bp = (struct cblock *)(p->c_cf); |
| 43 | bp--; |
| 44 | p->c_cf = bp->c_next->c_info; |
| 45 | bp->c_next = cfreelist; |
| 46 | cfreelist = bp; |
| 47 | } |
| 48 | } |
| 49 | splx(s); |
| 50 | return(c); |
| 51 | } |
| 52 | |
| 53 | /* |
| 54 | * copy clist to buffer. |
| 55 | * return number of bytes moved. |
| 56 | */ |
| 57 | q_to_b(q, cp, cc) |
| 58 | register struct clist *q; |
| 59 | register char *cp; |
| 60 | { |
| 61 | register struct cblock *bp; |
| 62 | register int s; |
| 63 | char *acp; |
| 64 | |
| 65 | if (cc <= 0) |
| 66 | return(0); |
| 67 | s = spl6(); |
| 68 | if (q->c_cc <= 0) { |
| 69 | q->c_cc = 0; |
| 70 | q->c_cf = q->c_cl = NULL; |
| 71 | return(0); |
| 72 | } |
| 73 | acp = cp; |
| 74 | cc++; |
| 75 | |
| 76 | while (--cc) { |
| 77 | *cp++ = *q->c_cf++; |
| 78 | if (--q->c_cc <= 0) { |
| 79 | bp = (struct cblock *)(q->c_cf-1); |
| 80 | bp = (struct cblock *)((int)bp & ~CROUND); |
| 81 | q->c_cf = q->c_cl = NULL; |
| 82 | bp->c_next = cfreelist; |
| 83 | cfreelist = bp; |
| 84 | break; |
| 85 | } |
| 86 | if (((int)q->c_cf & CROUND) == 0) { |
| 87 | bp = (struct cblock *)(q->c_cf); |
| 88 | bp--; |
| 89 | q->c_cf = bp->c_next->c_info; |
| 90 | bp->c_next = cfreelist; |
| 91 | cfreelist = bp; |
| 92 | } |
| 93 | } |
| 94 | splx(s); |
| 95 | return(cp-acp); |
| 96 | } |
| 97 | |
| 98 | /* |
| 99 | * Return count of contiguous characters |
| 100 | * in clist starting at q->c_cf. |
| 101 | * Stop counting if flag&character is non-null. |
| 102 | */ |
| 103 | ndqb(q, flag) |
| 104 | register struct clist *q; |
| 105 | { |
| 106 | register cc; |
| 107 | int s; |
| 108 | |
| 109 | s = spl6(); |
| 110 | if (q->c_cc <= 0) { |
| 111 | cc = -q->c_cc; |
| 112 | goto out; |
| 113 | } |
| 114 | cc = ((int)q->c_cf + CBSIZE) & ~CROUND; |
| 115 | cc -= (int)q->c_cf; |
| 116 | if (q->c_cc < cc) |
| 117 | cc = q->c_cc; |
| 118 | if (flag) { |
| 119 | register char *p, *end; |
| 120 | |
| 121 | p = q->c_cf; |
| 122 | end = p; |
| 123 | end += cc; |
| 124 | while (p < end) { |
| 125 | if (*p & flag) { |
| 126 | cc = (int)p - (int)q->c_cf; |
| 127 | break; |
| 128 | } |
| 129 | p++; |
| 130 | } |
| 131 | } |
| 132 | out: |
| 133 | splx(s); |
| 134 | return(cc); |
| 135 | } |
| 136 | |
| 137 | /* |
| 138 | * Update clist to show that cc characters |
| 139 | * were removed. It is assumed that cc < CBSIZE. |
| 140 | */ |
| 141 | ndflush(q, cc) |
| 142 | register struct clist *q; |
| 143 | register cc; |
| 144 | { |
| 145 | register s; |
| 146 | |
| 147 | if (cc == 0) |
| 148 | return; |
| 149 | s = spl6(); |
| 150 | if (q->c_cc < 0) { |
| 151 | if (q->c_cf != NULL) { |
| 152 | q->c_cc += cc; |
| 153 | q->c_cf += cc; |
| 154 | goto out; |
| 155 | } |
| 156 | q->c_cc = 0; |
| 157 | goto out; |
| 158 | } |
| 159 | if (q->c_cc == 0) { |
| 160 | goto out; |
| 161 | } |
| 162 | if (cc > CBSIZE || cc <= 0) { |
| 163 | cbad++; |
| 164 | goto out; |
| 165 | } |
| 166 | q->c_cc -= cc; |
| 167 | q->c_cf += cc; |
| 168 | if (((int)q->c_cf & CROUND) == 0) { |
| 169 | register struct cblock *bp; |
| 170 | |
| 171 | bp = (struct cblock *)(q->c_cf) -1; |
| 172 | if (bp->c_next) { |
| 173 | q->c_cf = bp->c_next->c_info; |
| 174 | } else { |
| 175 | q->c_cf = q->c_cl = NULL; |
| 176 | } |
| 177 | bp->c_next = cfreelist; |
| 178 | cfreelist = bp; |
| 179 | } else |
| 180 | if (q->c_cc == 0) { |
| 181 | register struct cblock *bp; |
| 182 | q->c_cf = (char *)((int)q->c_cf & ~CROUND); |
| 183 | bp = (struct cblock *)(q->c_cf); |
| 184 | bp->c_next = cfreelist; |
| 185 | cfreelist = bp; |
| 186 | q->c_cf = q->c_cl = NULL; |
| 187 | } |
| 188 | out: |
| 189 | splx(s); |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * Put character c in queue p. |
| 194 | */ |
| 195 | putc(c, p) |
| 196 | register struct clist *p; |
| 197 | { |
| 198 | register struct cblock *bp; |
| 199 | register char *cp; |
| 200 | register s; |
| 201 | |
| 202 | s = spl6(); |
| 203 | if ((cp = p->c_cl) == NULL || p->c_cc < 0 ) { |
| 204 | if ((bp = cfreelist) == NULL) { |
| 205 | splx(s); |
| 206 | return(-1); |
| 207 | } |
| 208 | cfreelist = bp->c_next; |
| 209 | bp->c_next = NULL; |
| 210 | p->c_cf = cp = bp->c_info; |
| 211 | } else if (((int)cp & CROUND) == 0) { |
| 212 | bp = (struct cblock *)cp - 1; |
| 213 | if ((bp->c_next = cfreelist) == NULL) { |
| 214 | splx(s); |
| 215 | return(-1); |
| 216 | } |
| 217 | bp = bp->c_next; |
| 218 | cfreelist = bp->c_next; |
| 219 | bp->c_next = NULL; |
| 220 | cp = bp->c_info; |
| 221 | } |
| 222 | *cp++ = c; |
| 223 | p->c_cc++; |
| 224 | p->c_cl = cp; |
| 225 | splx(s); |
| 226 | return(0); |
| 227 | } |
| 228 | |
| 229 | /* |
| 230 | * copy buffer to clist. |
| 231 | * return number of bytes not transfered. |
| 232 | */ |
| 233 | b_to_q(cp, cc, q) |
| 234 | register char *cp; |
| 235 | struct clist *q; |
| 236 | register int cc; |
| 237 | { |
| 238 | register char *cq; |
| 239 | register struct cblock *bp; |
| 240 | register s, acc; |
| 241 | |
| 242 | if (cc <= 0) |
| 243 | return(0); |
| 244 | acc = cc; |
| 245 | s = spl6(); |
| 246 | if ((cq = q->c_cl) == NULL || q->c_cc < 0) { |
| 247 | if ((bp = cfreelist) == NULL) |
| 248 | goto out; |
| 249 | cfreelist = bp->c_next; |
| 250 | bp->c_next = NULL; |
| 251 | q->c_cf = cq = bp->c_info; |
| 252 | } |
| 253 | |
| 254 | while (cc) { |
| 255 | if (((int)cq & CROUND) == 0) { |
| 256 | bp = (struct cblock *) cq - 1; |
| 257 | if ((bp->c_next = cfreelist) == NULL) |
| 258 | goto out; |
| 259 | bp = bp->c_next; |
| 260 | cfreelist = bp->c_next; |
| 261 | bp->c_next = NULL; |
| 262 | cq = bp->c_info; |
| 263 | } |
| 264 | *cq++ = *cp++; |
| 265 | cc--; |
| 266 | } |
| 267 | out: |
| 268 | q->c_cl = cq; |
| 269 | q->c_cc += acc-cc; |
| 270 | splx(s); |
| 271 | return(cc); |
| 272 | } |
| 273 | |
| 274 | /* |
| 275 | * Given a non-NULL pointter into the list (like c_cf which |
| 276 | * always points to a real character if non-NULL) return the pointer |
| 277 | * to the next character in the list or return NULL if no more chars. |
| 278 | * |
| 279 | * Callers must not allow getc's to happen between nextc's so that the |
| 280 | * pointer becomes invalid. Note that interrupts are NOT masked. |
| 281 | */ |
| 282 | char * |
| 283 | nextc(p, cp) |
| 284 | register struct clist *p; |
| 285 | register char *cp; |
| 286 | { |
| 287 | |
| 288 | if (p->c_cc && ++cp != p->c_cl) { |
| 289 | if (((int)cp & CROUND) == 0) |
| 290 | return (((struct cblock *)cp)[-1].c_next->c_info); |
| 291 | return (cp); |
| 292 | } |
| 293 | return (0); |
| 294 | } |
| 295 | |
| 296 | /* |
| 297 | * Remove the last character in the list and return it. |
| 298 | */ |
| 299 | unputc(p) |
| 300 | register struct clist *p; |
| 301 | { |
| 302 | register struct cblock *bp; |
| 303 | register int c, s; |
| 304 | struct cblock *obp; |
| 305 | |
| 306 | s = spl6(); |
| 307 | if (p->c_cc <= 0) |
| 308 | c = -1; |
| 309 | else { |
| 310 | c = *--p->c_cl; |
| 311 | if (--p->c_cc <= 0) { |
| 312 | bp = (struct cblock *)p->c_cl; |
| 313 | bp = (struct cblock *)((int)bp & ~CROUND); |
| 314 | p->c_cl = p->c_cf = NULL; |
| 315 | bp->c_next = cfreelist; |
| 316 | cfreelist = bp; |
| 317 | } else if (((int)p->c_cl & CROUND) == sizeof(bp->c_next)) { |
| 318 | p->c_cl = (char *)((int)p->c_cl & ~CROUND); |
| 319 | bp = (struct cblock *)p->c_cf; |
| 320 | bp = (struct cblock *)((int)bp & ~CROUND); |
| 321 | while (bp->c_next != (struct cblock *)p->c_cl) |
| 322 | bp = bp->c_next; |
| 323 | obp = bp; |
| 324 | p->c_cl = (char *)(bp + 1); |
| 325 | bp = bp->c_next; |
| 326 | bp->c_next = cfreelist; |
| 327 | cfreelist = bp; |
| 328 | obp->c_next = NULL; |
| 329 | } |
| 330 | } |
| 331 | splx(s); |
| 332 | return (c); |
| 333 | } |
| 334 | |
| 335 | /* |
| 336 | * Put the chars in the from que |
| 337 | * on the end of the to que. |
| 338 | * |
| 339 | * SHOULD JUST USE q_to_b AND THEN b_to_q HERE. |
| 340 | */ |
| 341 | catq(from, to) |
| 342 | struct clist *from, *to; |
| 343 | { |
| 344 | register c; |
| 345 | |
| 346 | while ((c = getc(from)) >= 0) |
| 347 | (void) putc(c, to); |
| 348 | } |
| 349 | |
| 350 | /* |
| 351 | * Initialize clist by freeing all character blocks, then count |
| 352 | * number of character devices. (Once-only routine) |
| 353 | */ |
| 354 | cinit() |
| 355 | { |
| 356 | register int ccp; |
| 357 | register struct cblock *cp; |
| 358 | register struct cdevsw *cdp; |
| 359 | |
| 360 | ccp = (int)cfree; |
| 361 | ccp = (ccp+CROUND) & ~CROUND; |
| 362 | for(cp=(struct cblock *)ccp; cp <= &cfree[NCLIST-1]; cp++) { |
| 363 | cp->c_next = cfreelist; |
| 364 | cfreelist = cp; |
| 365 | } |
| 366 | ccp = 0; |
| 367 | for(cdp = cdevsw; cdp->d_open; cdp++) |
| 368 | ccp++; |
| 369 | nchrdev = ccp; |
| 370 | } |
| 371 | |
| 372 | /* |
| 373 | * integer (2-byte) get/put |
| 374 | * using clists |
| 375 | */ |
| 376 | /* |
| 377 | getw(p) |
| 378 | register struct clist *p; |
| 379 | { |
| 380 | register int s; |
| 381 | |
| 382 | if (p->c_cc <= 1) |
| 383 | return(-1); |
| 384 | s = getc(p); |
| 385 | return(s | (getc(p)<<8)); |
| 386 | } |
| 387 | */ |
| 388 | |
| 389 | putw(c, p) |
| 390 | register struct clist *p; |
| 391 | { |
| 392 | register s; |
| 393 | |
| 394 | s = spl6(); |
| 395 | if (cfreelist==NULL) { |
| 396 | splx(s); |
| 397 | return(-1); |
| 398 | } |
| 399 | (void) putc(c, p); |
| 400 | (void) putc(c>>8, p); |
| 401 | splx(s); |
| 402 | return(0); |
| 403 | } |