1 /* uipc_mbuf.c 1.30 82/03/09 */ 2 3 #include "../h/param.h" 4 #include "../h/dir.h" 5 #include "../h/user.h" 6 #include "../h/proc.h" 7 #include "../h/pte.h" 8 #include "../h/cmap.h" 9 #include "../h/map.h" 10 #include "../h/mbuf.h" 11 #include "../net/in_systm.h" /* XXX */ 12 #include "../h/vm.h" 13 14 mbinit() 15 { 16 17 COUNT(MBINIT); 18 if (m_reserve(32) == 0) 19 goto bad; 20 if (m_clalloc(4, MPG_MBUFS) == 0) 21 goto bad; 22 if (m_clalloc(32, MPG_CLUSTERS) == 0) 23 goto bad; 24 return; 25 bad: 26 panic("mbinit"); 27 } 28 29 caddr_t 30 m_clalloc(ncl, how) 31 register int ncl; 32 int how; 33 { 34 int npg, mbx; 35 register struct mbuf *m; 36 register int i; 37 int s; 38 39 COUNT(M_CLALLOC); 40 npg = ncl * CLSIZE; 41 s = splimp(); /* careful: rmalloc isn't reentrant */ 42 mbx = rmalloc(mbmap, npg); 43 splx(s); 44 if (mbx == 0) 45 return (0); 46 m = cltom(mbx / CLSIZE); 47 if (memall(&Mbmap[mbx], ncl * CLSIZE, proc, CSYS) == 0) 48 return (0); 49 vmaccess(&Mbmap[mbx], (caddr_t)m, npg); 50 switch (how) { 51 52 case MPG_CLUSTERS: 53 s = splimp(); 54 for (i = 0; i < ncl; i++) { 55 m->m_off = 0; 56 m->m_next = mclfree; 57 mclfree = m; 58 m += CLBYTES / sizeof (*m); 59 nmclfree++; 60 } 61 mbstat.m_clusters += ncl; 62 splx(s); 63 break; 64 65 case MPG_MBUFS: 66 for (i = ncl * CLBYTES / sizeof (*m); i > 0; i--) { 67 m->m_off = 0; 68 m->m_free = 0; 69 (void) m_free(m); 70 m++; 71 } 72 mbstat.m_clusters += ncl; 73 break; 74 } 75 return ((caddr_t)m); 76 } 77 78 m_pgfree(addr, n) 79 caddr_t addr; 80 int n; 81 { 82 83 COUNT(M_PGFREE); 84 } 85 86 m_expand() 87 { 88 89 COUNT(M_EXPAND); 90 if (mbstat.m_bufs >= mbstat.m_hiwat) 91 return (0); 92 if (m_clalloc(1, MPG_MBUFS) == 0) 93 goto steal; 94 return (1); 95 steal: 96 /* should ask protocols to free code */ 97 return (0); 98 } 99 100 /* NEED SOME WAY TO RELEASE SPACE */ 101 102 /* 103 * Space reservation routines 104 */ 105 m_reserve(mbufs) 106 int mbufs; 107 { 108 109 if (mbstat.m_lowat + (mbufs>>1) > (NMBCLUSTERS-32) * CLBYTES) 110 return (0); 111 mbstat.m_hiwat += mbufs; 112 mbstat.m_lowat = mbstat.m_hiwat >> 1; 113 return (1); 114 } 115 116 m_release(mbufs) 117 int mbufs; 118 { 119 120 mbstat.m_hiwat -= mbufs; 121 mbstat.m_lowat = mbstat.m_hiwat >> 1; 122 } 123 124 /* 125 * Space allocation routines. 126 * These are also available as macros 127 * for critical paths. 128 */ 129 struct mbuf * 130 m_get(canwait) 131 int canwait; 132 { 133 register struct mbuf *m; 134 135 COUNT(M_GET); 136 MGET(m, canwait); 137 return (m); 138 } 139 140 struct mbuf * 141 m_getclr(canwait) 142 int canwait; 143 { 144 register struct mbuf *m; 145 146 COUNT(M_GETCLR); 147 m = m_get(canwait); 148 if (m == 0) 149 return (0); 150 m->m_off = MMINOFF; 151 bzero(mtod(m, caddr_t), MLEN); 152 return (m); 153 } 154 155 struct mbuf * 156 m_free(m) 157 struct mbuf *m; 158 { 159 register struct mbuf *n; 160 161 COUNT(M_FREE); 162 MFREE(m, n); 163 return (n); 164 } 165 166 /*ARGSUSED*/ 167 struct mbuf * 168 m_more(type) 169 int type; 170 { 171 register struct mbuf *m; 172 173 COUNT(M_MORE); 174 if (!m_expand()) { 175 mbstat.m_drops++; 176 return (NULL); 177 } 178 #define m_more(x) (panic("m_more"), (struct mbuf *)0) 179 MGET(m, type); 180 #undef m_more 181 return (m); 182 } 183 184 m_freem(m) 185 register struct mbuf *m; 186 { 187 register struct mbuf *n; 188 register int s; 189 190 COUNT(M_FREEM); 191 if (m == NULL) 192 return; 193 s = splimp(); 194 do { 195 MFREE(m, n); 196 } while (m = n); 197 splx(s); 198 } 199 200 /* 201 * Mbuffer utility routines. 202 */ 203 struct mbuf * 204 m_copy(m, off, len) 205 register struct mbuf *m; 206 int off; 207 register int len; 208 { 209 register struct mbuf *n, **np; 210 struct mbuf *top, *p; 211 COUNT(M_COPY); 212 213 if (len == 0) 214 return (0); 215 if (off < 0 || len < 0) 216 panic("m_copy"); 217 while (off > 0) { 218 if (m == 0) 219 panic("m_copy"); 220 if (off < m->m_len) 221 break; 222 off -= m->m_len; 223 m = m->m_next; 224 } 225 np = ⊤ 226 top = 0; 227 while (len > 0) { 228 if (m == 0) { 229 if (len != M_COPYALL) 230 panic("m_copy"); 231 break; 232 } 233 MGET(n, 1); 234 *np = n; 235 if (n == 0) 236 goto nospace; 237 n->m_len = MIN(len, m->m_len - off); 238 if (m->m_off > MMAXOFF) { 239 p = mtod(m, struct mbuf *); 240 n->m_off = ((int)p - (int)n) + off; 241 mclrefcnt[mtocl(p)]++; 242 } else { 243 n->m_off = MMINOFF; 244 bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), 245 (unsigned)n->m_len); 246 } 247 if (len != M_COPYALL) 248 len -= n->m_len; 249 off = 0; 250 m = m->m_next; 251 np = &n->m_next; 252 } 253 return (top); 254 nospace: 255 m_freem(top); 256 return (0); 257 } 258 259 m_cat(m, n) 260 register struct mbuf *m, *n; 261 { 262 while (m->m_next) 263 m = m->m_next; 264 while (n) { 265 if (m->m_off >= MMAXOFF || 266 m->m_off + m->m_len + n->m_len > MMAXOFF) { 267 /* just join the two chains */ 268 m->m_next = n; 269 return; 270 } 271 /* splat the data from one into the other */ 272 bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, 273 (u_int)n->m_len); 274 m->m_len += n->m_len; 275 n = m_free(n); 276 } 277 } 278 279 m_adj(mp, len) 280 struct mbuf *mp; 281 register int len; 282 { 283 register struct mbuf *m, *n; 284 285 COUNT(M_ADJ); 286 if ((m = mp) == NULL) 287 return; 288 if (len >= 0) { 289 while (m != NULL && len > 0) { 290 if (m->m_len <= len) { 291 len -= m->m_len; 292 m->m_len = 0; 293 m = m->m_next; 294 } else { 295 m->m_len -= len; 296 m->m_off += len; 297 break; 298 } 299 } 300 } else { 301 /* a 2 pass algorithm might be better */ 302 len = -len; 303 while (len > 0 && m->m_len != 0) { 304 while (m != NULL && m->m_len != 0) { 305 n = m; 306 m = m->m_next; 307 } 308 if (n->m_len <= len) { 309 len -= n->m_len; 310 n->m_len = 0; 311 m = mp; 312 } else { 313 n->m_len -= len; 314 break; 315 } 316 } 317 } 318 } 319 320 struct mbuf * 321 m_pullup(m0, len) 322 struct mbuf *m0; 323 int len; 324 { 325 register struct mbuf *m, *n; 326 int cnt; 327 328 n = m0; 329 if (len > MLEN) 330 goto bad; 331 MGET(m, 0); 332 if (m == 0) 333 goto bad; 334 m->m_off = MMINOFF; 335 m->m_len = 0; 336 do { 337 cnt = MIN(MLEN - m->m_len, len); 338 if (cnt > n->m_len) 339 cnt = n->m_len; 340 bcopy(mtod(n, caddr_t), mtod(m, caddr_t)+m->m_len, cnt); 341 len -= cnt; 342 m->m_len += cnt; 343 n->m_off += cnt; 344 n->m_len -= cnt; 345 if (n->m_len) 346 break; 347 n = m_free(n); 348 } while (n); 349 if (len) { 350 (void) m_free(m); 351 goto bad; 352 } 353 m->m_next = n; 354 return (m); 355 bad: 356 m_freem(n); 357 return (0); 358 } 359