1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2010 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #include "bge_impl.h" 28 29 30 /* 31 * The transmit-side code uses an allocation process which is similar 32 * to some theme park roller-coaster rides, where riders sit in cars 33 * that can go individually, but work better in a train. 34 * 35 * 1) RESERVE a place - this doesn't refer to any specific car or 36 * seat, just that you will get a ride. The attempt to RESERVE a 37 * place can fail if all spaces in all cars are already committed. 38 * 39 * 2) Prepare yourself; this may take an arbitrary (but not unbounded) 40 * time, and you can back out at this stage, in which case you must 41 * give up (RENOUNCE) your place. 42 * 43 * 3) CLAIM your space - a specific car (the next sequentially 44 * numbered one) is allocated at this stage, and is guaranteed 45 * to be part of the next train to depart. Once you've done 46 * this, you can't back out, nor wait for any external event 47 * or resource. 48 * 49 * 4) Occupy your car - when all CLAIMED cars are OCCUPIED, they 50 * all depart together as a single train! 51 * 52 * 5) At the end of the ride, you climb out of the car and RENOUNCE 53 * your right to it, so that it can be recycled for another rider. 54 * 55 * For each rider, these have to occur in this order, but the riders 56 * don't have to stay in the same order at each stage. In particular, 57 * they may overtake each other between RESERVING a place and CLAIMING 58 * it, or between CLAIMING and OCCUPYING a space. 59 * 60 * Once a car is CLAIMED, the train currently being assembled can't go 61 * without that car (this guarantees that the cars in a single train 62 * make up a consecutively-numbered set). Therefore, when any train 63 * leaves, we know there can't be any riders in transit between CLAIMING 64 * and OCCUPYING their cars. There can be some who have RESERVED but 65 * not yet CLAIMED their places. That's OK, though, because they'll go 66 * into the next train. 67 */ 68 69 #define BGE_DBG BGE_DBG_SEND /* debug flag for this code */ 70 71 /* 72 * ========== Send-side recycle routines ========== 73 */ 74 75 /* 76 * Recycle all the completed buffers in the specified send ring up to 77 * (but not including) the consumer index in the status block. 78 * 79 * This function must advance (srp->tc_next) AND adjust (srp->tx_free) 80 * to account for the packets it has recycled. 81 * 82 * This is a trivial version that just does that and nothing more, but 83 * it suffices while there's only one method for sending messages (by 84 * copying) and that method doesn't need any special per-buffer action 85 * for recycling. 86 */ 87 static void bge_recycle_ring(bge_t *bgep, send_ring_t *srp); 88 #pragma inline(bge_recycle_ring) 89 90 static void 91 bge_recycle_ring(bge_t *bgep, send_ring_t *srp) 92 { 93 sw_sbd_t *ssbdp; 94 bge_queue_item_t *buf_item; 95 bge_queue_item_t *buf_item_head; 96 bge_queue_item_t *buf_item_tail; 97 bge_queue_t *txbuf_queue; 98 uint64_t slot; 99 uint64_t n; 100 101 ASSERT(mutex_owned(srp->tc_lock)); 102 103 /* 104 * We're about to release one or more places :-) 105 * These ASSERTions check that our invariants still hold: 106 * there must always be at least one free place 107 * at this point, there must be at least one place NOT free 108 * we're not about to free more places than were claimed! 109 */ 110 ASSERT(srp->tx_free <= srp->desc.nslots); 111 112 buf_item_head = buf_item_tail = NULL; 113 for (n = 0, slot = srp->tc_next; slot != *srp->cons_index_p; 114 slot = NEXT(slot, srp->desc.nslots)) { 115 ssbdp = &srp->sw_sbds[slot]; 116 ASSERT(ssbdp->pbuf != NULL); 117 buf_item = ssbdp->pbuf; 118 if (buf_item_head == NULL) 119 buf_item_head = buf_item_tail = buf_item; 120 else { 121 buf_item_tail->next = buf_item; 122 buf_item_tail = buf_item; 123 } 124 ssbdp->pbuf = NULL; 125 n++; 126 } 127 if (n == 0) 128 return; 129 130 /* 131 * Update recycle index and free tx BD number 132 */ 133 srp->tc_next = slot; 134 ASSERT(srp->tx_free + n <= srp->desc.nslots); 135 bge_atomic_renounce(&srp->tx_free, n); 136 137 /* 138 * Reset the watchdog count: to 0 if all buffers are 139 * now free, or to 1 if some are still outstanding. 140 * Note: non-synchonised access here means we may get 141 * the "wrong" answer, but only in a harmless fashion 142 * (i.e. we deactivate the watchdog because all buffers 143 * are apparently free, even though another thread may 144 * have claimed one before we leave here; in this case 145 * the watchdog will restart on the next send() call). 146 */ 147 bgep->watchdog = srp->tx_free == srp->desc.nslots ? 0 : 1; 148 149 /* 150 * Return tx buffers to buffer push queue 151 */ 152 txbuf_queue = srp->txbuf_push_queue; 153 mutex_enter(txbuf_queue->lock); 154 buf_item_tail->next = txbuf_queue->head; 155 txbuf_queue->head = buf_item_head; 156 txbuf_queue->count += n; 157 mutex_exit(txbuf_queue->lock); 158 159 /* 160 * Check if we need exchange the tx buffer push and pop queue 161 */ 162 if ((srp->txbuf_pop_queue->count < srp->tx_buffers_low) && 163 (srp->txbuf_pop_queue->count < txbuf_queue->count)) { 164 srp->txbuf_push_queue = srp->txbuf_pop_queue; 165 srp->txbuf_pop_queue = txbuf_queue; 166 } 167 168 if (srp->tx_flow != 0 || bgep->tx_resched_needed) 169 ddi_trigger_softintr(bgep->drain_id); 170 } 171 172 /* 173 * Recycle all returned slots in all rings. 174 * 175 * To give priority to low-numbered rings, whenever we have recycled any 176 * slots in any ring except 0, we restart scanning again from ring 0. 177 * Thus, for example, if rings 0, 3, and 10 are carrying traffic, the 178 * pattern of recycles might go 0, 3, 10, 3, 0, 10, 0: 179 * 180 * 0 found some - recycle them 181 * 1..2 none found 182 * 3 found some - recycle them and restart scan 183 * 0..9 none found 184 * 10 found some - recycle them and restart scan 185 * 0..2 none found 186 * 3 found some more - recycle them and restart scan 187 * 0 found some more - recycle them 188 * 0..9 none found 189 * 10 found some more - recycle them and restart scan 190 * 0 found some more - recycle them 191 * 1..15 none found 192 * 193 * The routine returns only when a complete scan has been performed 194 * without finding any slots to recycle. 195 * 196 * Note: the expression (BGE_SEND_RINGS_USED > 1) yields a compile-time 197 * constant and allows the compiler to optimise away the outer do-loop 198 * if only one send ring is being used. 199 */ 200 void bge_recycle(bge_t *bgep, bge_status_t *bsp); 201 #pragma no_inline(bge_recycle) 202 203 void 204 bge_recycle(bge_t *bgep, bge_status_t *bsp) 205 { 206 send_ring_t *srp; 207 uint64_t ring; 208 uint64_t tx_rings = bgep->chipid.tx_rings; 209 210 restart: 211 ring = 0; 212 srp = &bgep->send[ring]; 213 do { 214 /* 215 * For each ring, (srp->cons_index_p) points to the 216 * proper index within the status block (which has 217 * already been sync'd by the caller). 218 */ 219 ASSERT(srp->cons_index_p == SEND_INDEX_P(bsp, ring)); 220 221 if (*srp->cons_index_p == srp->tc_next) 222 continue; /* no slots to recycle */ 223 if (mutex_tryenter(srp->tc_lock) == 0) 224 continue; /* already in process */ 225 bge_recycle_ring(bgep, srp); 226 mutex_exit(srp->tc_lock); 227 228 /* 229 * Restart from ring 0, if we're not on ring 0 already. 230 * As H/W selects send BDs totally based on priority and 231 * available BDs on the higher priority ring are always 232 * selected first, driver should keep consistence with H/W 233 * and gives lower-numbered ring with higher priority. 234 */ 235 if (tx_rings > 1 && ring > 0) 236 goto restart; 237 238 /* 239 * Loop over all rings (if there *are* multiple rings) 240 */ 241 } while (++srp, ++ring < tx_rings); 242 } 243 244 245 /* 246 * ========== Send-side transmit routines ========== 247 */ 248 #define TCP_CKSUM_OFFSET 16 249 #define UDP_CKSUM_OFFSET 6 250 251 static void 252 bge_pseudo_cksum(uint8_t *buf) 253 { 254 uint32_t cksum; 255 uint16_t iphl; 256 uint16_t proto; 257 258 /* 259 * Point it to the ip header. 260 */ 261 buf += sizeof (struct ether_header); 262 263 /* 264 * Calculate the pseudo-header checksum. 265 */ 266 iphl = 4 * (buf[0] & 0xF); 267 cksum = (((uint16_t)buf[2])<<8) + buf[3] - iphl; 268 cksum += proto = buf[9]; 269 cksum += (((uint16_t)buf[12])<<8) + buf[13]; 270 cksum += (((uint16_t)buf[14])<<8) + buf[15]; 271 cksum += (((uint16_t)buf[16])<<8) + buf[17]; 272 cksum += (((uint16_t)buf[18])<<8) + buf[19]; 273 cksum = (cksum>>16) + (cksum & 0xFFFF); 274 cksum = (cksum>>16) + (cksum & 0xFFFF); 275 276 /* 277 * Point it to the TCP/UDP header, and 278 * update the checksum field. 279 */ 280 buf += iphl + ((proto == IPPROTO_TCP) ? 281 TCP_CKSUM_OFFSET : UDP_CKSUM_OFFSET); 282 283 /* 284 * A real possibility that pointer cast is a problem. 285 * Should be fixed when we know the code better. 286 * E_BAD_PTR_CAST_ALIGN is added to make it temporarily clean. 287 */ 288 *(uint16_t *)buf = htons((uint16_t)cksum); 289 } 290 291 static bge_queue_item_t * 292 bge_get_txbuf(bge_t *bgep, send_ring_t *srp) 293 { 294 bge_queue_item_t *txbuf_item; 295 bge_queue_t *txbuf_queue; 296 297 txbuf_queue = srp->txbuf_pop_queue; 298 mutex_enter(txbuf_queue->lock); 299 if (txbuf_queue->count == 0) { 300 mutex_exit(txbuf_queue->lock); 301 txbuf_queue = srp->txbuf_push_queue; 302 mutex_enter(txbuf_queue->lock); 303 if (txbuf_queue->count == 0) { 304 mutex_exit(txbuf_queue->lock); 305 /* Try to allocate more tx buffers */ 306 if (srp->tx_array < srp->tx_array_max) { 307 mutex_enter(srp->tx_lock); 308 txbuf_item = bge_alloc_txbuf_array(bgep, srp); 309 mutex_exit(srp->tx_lock); 310 } else 311 txbuf_item = NULL; 312 return (txbuf_item); 313 } 314 } 315 txbuf_item = txbuf_queue->head; 316 txbuf_queue->head = (bge_queue_item_t *)txbuf_item->next; 317 txbuf_queue->count--; 318 mutex_exit(txbuf_queue->lock); 319 txbuf_item->next = NULL; 320 321 return (txbuf_item); 322 } 323 324 static void bge_send_fill_txbd(send_ring_t *srp, send_pkt_t *pktp); 325 #pragma inline(bge_send_fill_txbd) 326 327 static void 328 bge_send_fill_txbd(send_ring_t *srp, send_pkt_t *pktp) 329 { 330 bge_sbd_t *hw_sbd_p; 331 sw_sbd_t *ssbdp; 332 bge_queue_item_t *txbuf_item; 333 sw_txbuf_t *txbuf; 334 uint64_t slot; 335 336 ASSERT(mutex_owned(srp->tx_lock)); 337 338 /* 339 * Go straight to claiming our already-reserved places 340 * on the train! 341 */ 342 ASSERT(pktp->txbuf_item != NULL); 343 txbuf_item = pktp->txbuf_item; 344 txbuf = txbuf_item->item; 345 slot = srp->tx_next; 346 ssbdp = &srp->sw_sbds[slot]; 347 hw_sbd_p = DMA_VPTR(ssbdp->desc); 348 hw_sbd_p->flags = 0; 349 ASSERT(txbuf->copy_len != 0); 350 (void) ddi_dma_sync(txbuf->buf.dma_hdl, 0, 351 txbuf->copy_len, DDI_DMA_SYNC_FORDEV); 352 ASSERT(ssbdp->pbuf == NULL); 353 ssbdp->pbuf = txbuf_item; 354 srp->tx_next = NEXT(slot, srp->desc.nslots); 355 pktp->txbuf_item = NULL; 356 357 /* 358 * Setting hardware send buffer descriptor 359 */ 360 hw_sbd_p->host_buf_addr = txbuf->buf.cookie.dmac_laddress; 361 hw_sbd_p->len = txbuf->copy_len; 362 if (pktp->vlan_tci != 0) { 363 hw_sbd_p->vlan_tci = pktp->vlan_tci; 364 hw_sbd_p->host_buf_addr += VLAN_TAGSZ; 365 hw_sbd_p->flags |= SBD_FLAG_VLAN_TAG; 366 } 367 if (pktp->pflags & HCK_IPV4_HDRCKSUM) 368 hw_sbd_p->flags |= SBD_FLAG_IP_CKSUM; 369 if (pktp->pflags & HCK_FULLCKSUM) 370 hw_sbd_p->flags |= SBD_FLAG_TCP_UDP_CKSUM; 371 hw_sbd_p->flags |= SBD_FLAG_PACKET_END; 372 } 373 374 /* 375 * Send a message by copying it into a preallocated (and premapped) buffer 376 */ 377 static void bge_send_copy(bge_t *bgep, sw_txbuf_t *txbuf, mblk_t *mp); 378 #pragma inline(bge_send_copy) 379 380 static void 381 bge_send_copy(bge_t *bgep, sw_txbuf_t *txbuf, mblk_t *mp) 382 { 383 mblk_t *bp; 384 uint32_t mblen; 385 char *pbuf; 386 387 txbuf->copy_len = 0; 388 pbuf = DMA_VPTR(txbuf->buf); 389 for (bp = mp; bp != NULL; bp = bp->b_cont) { 390 if ((mblen = MBLKL(bp)) == 0) 391 continue; 392 ASSERT(txbuf->copy_len + mblen <= 393 bgep->chipid.snd_buff_size); 394 bcopy(bp->b_rptr, pbuf, mblen); 395 pbuf += mblen; 396 txbuf->copy_len += mblen; 397 } 398 } 399 400 /* 401 * Fill the Tx buffer descriptors and trigger the h/w transmission 402 */ 403 static void 404 bge_send_serial(bge_t *bgep, send_ring_t *srp) 405 { 406 send_pkt_t *pktp; 407 uint64_t txfill_next; 408 uint32_t count; 409 uint32_t tx_next; 410 sw_sbd_t *ssbdp; 411 bge_status_t *bsp; 412 413 /* 414 * Try to hold the tx lock: 415 * If we are in an interrupt context, use mutex_enter() to 416 * ensure quick response for tx in interrupt context; 417 * Otherwise, use mutex_tryenter() to serialize this h/w tx 418 * BD filling and transmission triggering task. 419 */ 420 if (servicing_interrupt() != 0) 421 mutex_enter(srp->tx_lock); 422 else if (mutex_tryenter(srp->tx_lock) == 0) 423 return; /* already in process */ 424 425 bsp = DMA_VPTR(bgep->status_block); 426 txfill_next = srp->txfill_next; 427 start_tx: 428 tx_next = srp->tx_next; 429 ssbdp = &srp->sw_sbds[tx_next]; 430 for (count = 0; count < bgep->param_drain_max; ++count) { 431 pktp = &srp->pktp[txfill_next]; 432 if (!pktp->tx_ready) { 433 if (count == 0) 434 srp->tx_block++; 435 break; 436 } 437 438 /* 439 * If there are no enough BDs: try to recycle more 440 */ 441 if (srp->tx_free <= 1) 442 bge_recycle(bgep, bsp); 443 444 /* 445 * Reserved required BDs: 1 is enough 446 */ 447 if (!bge_atomic_reserve(&srp->tx_free, 1)) { 448 srp->tx_nobd++; 449 break; 450 } 451 452 /* 453 * Filling the tx BD 454 */ 455 bge_send_fill_txbd(srp, pktp); 456 txfill_next = NEXT(txfill_next, BGE_SEND_BUF_MAX); 457 pktp->tx_ready = B_FALSE; 458 } 459 460 /* 461 * Trigger h/w to start transmission. 462 */ 463 if (count != 0) { 464 bge_atomic_sub64(&srp->tx_flow, count); 465 if (tx_next + count > srp->desc.nslots) { 466 (void) ddi_dma_sync(ssbdp->desc.dma_hdl, 0, 467 (srp->desc.nslots - tx_next) * sizeof (bge_sbd_t), 468 DDI_DMA_SYNC_FORDEV); 469 count -= srp->desc.nslots - tx_next; 470 ssbdp = &srp->sw_sbds[0]; 471 } 472 (void) ddi_dma_sync(ssbdp->desc.dma_hdl, 0, 473 count*sizeof (bge_sbd_t), DDI_DMA_SYNC_FORDEV); 474 bge_mbx_put(bgep, srp->chip_mbx_reg, srp->tx_next); 475 srp->txfill_next = txfill_next; 476 bgep->watchdog++; 477 if (srp->tx_flow != 0 && srp->tx_free > 1) 478 goto start_tx; 479 } 480 481 mutex_exit(srp->tx_lock); 482 } 483 484 mblk_t * 485 bge_ring_tx(void *arg, mblk_t *mp) 486 { 487 send_ring_t *srp = arg; 488 bge_t *bgep = srp->bgep; 489 struct ether_vlan_header *ehp; 490 bge_queue_item_t *txbuf_item; 491 sw_txbuf_t *txbuf; 492 send_pkt_t *pktp; 493 uint64_t pkt_slot; 494 uint16_t vlan_tci; 495 uint32_t pflags; 496 char *pbuf; 497 498 ASSERT(mp->b_next == NULL); 499 500 /* 501 * Get a s/w tx buffer first 502 */ 503 txbuf_item = bge_get_txbuf(bgep, srp); 504 if (txbuf_item == NULL) { 505 /* no tx buffer available */ 506 srp->tx_nobuf++; 507 bgep->tx_resched_needed = B_TRUE; 508 bge_send_serial(bgep, srp); 509 return (mp); 510 } 511 512 /* 513 * Copy all mp fragments to the pkt buffer 514 */ 515 txbuf = txbuf_item->item; 516 bge_send_copy(bgep, txbuf, mp); 517 518 /* 519 * Determine if the packet is VLAN tagged. 520 */ 521 ASSERT(txbuf->copy_len >= sizeof (struct ether_header)); 522 pbuf = DMA_VPTR(txbuf->buf); 523 524 ehp = (void *)pbuf; 525 if (ehp->ether_tpid == htons(ETHERTYPE_VLAN)) { 526 /* Strip the vlan tag */ 527 vlan_tci = ntohs(ehp->ether_tci); 528 pbuf = memmove(pbuf + VLAN_TAGSZ, pbuf, 2 * ETHERADDRL); 529 txbuf->copy_len -= VLAN_TAGSZ; 530 } else 531 vlan_tci = 0; 532 533 /* 534 * Retrieve checksum offloading info. 535 */ 536 mac_hcksum_get(mp, NULL, NULL, NULL, NULL, &pflags); 537 538 /* 539 * Calculate pseudo checksum if needed. 540 */ 541 if ((pflags & HCK_FULLCKSUM) && 542 (bgep->chipid.flags & CHIP_FLAG_PARTIAL_CSUM)) 543 bge_pseudo_cksum((uint8_t *)pbuf); 544 545 /* 546 * Packet buffer is ready to send: get and fill pkt info 547 */ 548 pkt_slot = bge_atomic_next(&srp->txpkt_next, BGE_SEND_BUF_MAX); 549 pktp = &srp->pktp[pkt_slot]; 550 ASSERT(pktp->txbuf_item == NULL); 551 pktp->txbuf_item = txbuf_item; 552 pktp->vlan_tci = vlan_tci; 553 pktp->pflags = pflags; 554 atomic_inc_64(&srp->tx_flow); 555 ASSERT(pktp->tx_ready == B_FALSE); 556 pktp->tx_ready = B_TRUE; 557 558 /* 559 * Filling the h/w bd and trigger the h/w to start transmission 560 */ 561 bge_send_serial(bgep, srp); 562 563 srp->pushed_bytes += MBLKL(mp); 564 565 /* 566 * We've copied the contents, the message can be freed right away 567 */ 568 freemsg(mp); 569 return (NULL); 570 } 571 572 static mblk_t * 573 bge_send(bge_t *bgep, mblk_t *mp) 574 { 575 send_ring_t *ring; 576 577 ring = &bgep->send[0]; /* ring 0 */ 578 579 return (bge_ring_tx(ring, mp)); 580 } 581 582 uint_t 583 bge_send_drain(caddr_t arg) 584 { 585 uint_t ring = 0; /* use ring 0 */ 586 bge_t *bgep; 587 send_ring_t *srp; 588 589 bgep = (void *)arg; 590 BGE_TRACE(("bge_send_drain($%p)", (void *)bgep)); 591 592 srp = &bgep->send[ring]; 593 bge_send_serial(bgep, srp); 594 595 if (bgep->tx_resched_needed && 596 (srp->tx_flow < srp->tx_buffers_low) && 597 (bgep->bge_mac_state == BGE_MAC_STARTED)) { 598 mac_tx_update(bgep->mh); 599 bgep->tx_resched_needed = B_FALSE; 600 bgep->tx_resched++; 601 } 602 603 return (DDI_INTR_CLAIMED); 604 } 605 606 /* 607 * bge_m_tx() - send a chain of packets 608 */ 609 mblk_t * 610 bge_m_tx(void *arg, mblk_t *mp) 611 { 612 bge_t *bgep = arg; /* private device info */ 613 mblk_t *next; 614 615 BGE_TRACE(("bge_m_tx($%p, $%p)", arg, (void *)mp)); 616 617 ASSERT(mp != NULL); 618 ASSERT(bgep->bge_mac_state == BGE_MAC_STARTED); 619 620 rw_enter(bgep->errlock, RW_READER); 621 if (bgep->bge_chip_state != BGE_CHIP_RUNNING) { 622 BGE_DEBUG(("bge_m_tx: chip not running")); 623 freemsgchain(mp); 624 mp = NULL; 625 } 626 627 while (mp != NULL) { 628 next = mp->b_next; 629 mp->b_next = NULL; 630 631 if ((mp = bge_send(bgep, mp)) != NULL) { 632 mp->b_next = next; 633 break; 634 } 635 636 mp = next; 637 } 638 rw_exit(bgep->errlock); 639 640 return (mp); 641 } 642