3 * ===================================
4 * HARP | Host ATM Research Platform
5 * ===================================
8 * This Host ATM Research Platform ("HARP") file (the "Software") is
9 * made available by Network Computing Services, Inc. ("NetworkCS")
10 * "AS IS". NetworkCS does not provide maintenance, improvements or
11 * support of any kind.
13 * NETWORKCS MAKES NO WARRANTIES OR REPRESENTATIONS, EXPRESS OR IMPLIED,
14 * INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY
15 * AND FITNESS FOR A PARTICULAR PURPOSE, AS TO ANY ELEMENT OF THE
16 * SOFTWARE OR ANY SUPPORT PROVIDED IN CONNECTION WITH THIS SOFTWARE.
17 * In no event shall NetworkCS be responsible for any damages, including
18 * but not limited to consequential damages, arising from or relating to
19 * any use of the Software or related support.
21 * Copyright 1994-1998 Network Computing Services, Inc.
23 * Copies of this Software may be made, however, the above copyright
24 * notice must be reproduced on all copies.
26 * @(#) $FreeBSD: src/sys/dev/hea/eni_receive.c,v 1.5 1999/08/28 00:41:45 peter Exp $
27 * @(#) $DragonFly: src/sys/dev/atm/hea/eni_receive.c,v 1.10 2008/03/01 22:03:13 swildner Exp $
31 * Efficient ENI Adapter Support
32 * -----------------------------
38 #include <netproto/atm/kern_include.h>
40 #include "eni_stats.h"
44 static void eni_recv_stack (void *, KBuffer *);
47 extern int eni_pdu_print;
51 * Procedure to remove VCs from the Service List and generate DMA
52 * requests to move the associated PDUs into host memory. As PDUs
53 * are completed in adapter memory, the adapter examines the IN_SERVICE
54 * bit for the VC in the VC table. If this bit is not set, the adapter
55 * will place the VC number at the end of the service list queue, set
56 * the IN_SERVICE bit in the VC table, and interrupt the host. The host
57 * will remove VCs from the service list, clear the IN_SERVICE bit in
58 * the VC table, and create a DMA list to move the PDU into host buffers.
61 * eup pointer to per unit structure
68 eni_do_service(Eni_unit *eup)
77 u_long dma[TEMP_DMA_SIZE];
79 u_long dma_rd, dma_wr;
86 * Where is the adapter currently inserting entries?
88 servwrite = eup->eu_midway[MIDWAY_SVCWR] & SVC_SIZE_MASK;
90 * As long as we're not caught up with the adapter, keep
91 * removing VCs from the service list.
93 while ( servwrite != eup->eu_servread ) {
98 * Get VC number and find VC table entry.
100 vcc = eup->eu_svclist[eup->eu_servread];
101 vct = &eup->eu_vcitbl[vcc];
102 vci_hdr = vct->vci_control; /* Current status */
105 * Check that this VCC still needs servicing. We
106 * might have closed this VCC down in between
107 * the adapter setting the flag and our checking
108 * the flag. Also check that we haven't placed the
109 * VCC into TRASH mode.
111 if ( ( vci_hdr & VCI_IN_SERVICE ) == 0 ||
112 ( (vci_hdr & ~VCI_MODE_MASK) ==
113 (VCI_MODE_TRASH << VCI_MODE_SHIFT) ) )
117 * Find the size of this VCs buffer
119 mask = (vci_hdr >> VCI_SIZE_SHIFT) & VCI_SIZE_MASK;
120 mask = 1 << (ENI_LOC_PREDIV + mask);
121 /* Turn byte count into word count */
124 * Find the start of the adapter buffer for this VC.
127 ((int)(((vci_hdr >> VCI_LOC_SHIFT ) & VCI_LOC_MASK)
128 << ENI_LOC_PREDIV) + (int)eup->eu_ram);
130 * Locate incoming VCC for this PDU and find where we
131 * should next read from.
133 evp = (Eni_vcc *) atm_dev_vcc_find ( (Cmn_unit *)eup,
135 if ( evp == (Eni_vcc *)NULL )
136 goto next_vcc; /* VCI no longer active */
137 rdptr = evp->ev_rxpos;
139 * Find out where the adapter is currently reassembling.
140 * The PDU which starts at descr is not yet complete so we
143 descr = ( vct->vci_descr >> 16 ) & 0x7FFF;
145 * As long as we haven't processed all the completed PDUs on
146 * this VC, keep going...
148 while ( rdptr != descr )
155 * Ensure that the following are reset for every new
162 * Fisrt build a DMA with JK to skip the descriptor word.
163 * We must always skip the descriptor even if it turns out
164 * that there isn't any PDU here.
167 dma[j++] = (((rdptr + 1) & (mask-1)) << DMA_COUNT_SHIFT ) |
168 ( vcc << DMA_VCC_SHIFT ) | DMA_JK;
172 * We'll use some of the values below for skipping
173 * bad PDUs or counting statistics so compute them
178 * Grab a copy of the descriptor word
180 pdu_descr = rxp[rdptr];
183 * Strip out cell count from descriptor word.
184 * At this point, we still don't know if there
185 * is any real data until after we check for
188 n_cells = pdu_descr & DESCR_CELL_COUNT;
191 * Is this an AAL5 PDU? Check MODE in vci_hdr.
193 aal5 = ( ( vci_hdr & ~VCI_MODE_MASK ) ==
194 VCI_MODE_AAL5 << VCI_MODE_SHIFT );
197 * Now check to see if we're trashing on this vcc.
198 * If so, there is no data with this VC and the
199 * next word after the current descriptor is the
200 * descriptor for the next PDU.
202 if ( ( pdu_descr & DESCR_TRASH_BIT ) != 0 ) {
205 * Count as number of AAL5 cells dropped
207 eup->eu_stats.eni_st_aal5.aal5_drops += n_cells;
210 * Count as number of AAL0 cells dropped
212 eup->eu_stats.eni_st_aal0.aal0_drops += n_cells;
213 eup->eu_pif.pif_ierrors++;
215 * When cells have been trashed, all we have in the
216 * buffer is a descriptor word. There are no data
217 * words. Set the number of cells to zero so that
218 * we correctly skip to the next word which will
219 * be the descriptor for the next PDU.
223 * Go issue the DMA to skip this descriptor word.
229 * Data length: number of cells * cell size
231 pdulen = n_cells * BYTES_PER_CELL;
234 * If this is an AAL5 PDU, then we need to check
235 * for the presence of any CRC errors. If there
236 * is one or more CRC errors, then we are going to
239 if ( aal5 && ( pdu_descr & DESCR_CRC_ERR ) ) {
243 eup->eu_pif.pif_ierrors++;
244 eup->eu_stats.eni_st_aal5.aal5_pdu_crc++;
245 if ( evp->ev_connvc->cvc_vcc )
246 evp->ev_connvc->cvc_vcc->vc_ierrors++;
248 * Build a DMA entry to skip the rest of this
252 (((rdptr + n_cells*WORDS_PER_CELL + 1)
253 & (mask-1)) << DMA_COUNT_SHIFT ) |
254 (vcc << DMA_VCC_SHIFT ) | DMA_JK;
257 * All done with this PDU. Get a buffer to save some
258 * data for reclamation services.
260 KB_ALLOCPKT ( m, ENI_SMALL_BSIZE, KB_F_NOWAIT,
265 KB_DATASTART ( m, up, u_long * );
271 * Set buffer length - only driver overhead
273 KB_LEN ( m ) = 3 * sizeof ( u_long );
275 * Insert vcc, space for DMA pointers,
279 upp = up; /* Remember location */
280 up++; /* And skip it */
281 /* - to be filled later */
282 *up = pdulen; /* Actual PDU length if it */
286 * We've a real problem here as now we can't
287 * reclaim/advance resources/safety pointers.
289 eup->eu_stats.eni_st_drv.drv_rv_norsc++;
292 "eni_do_service: No drain buffers available. Receiver about to lock.\n" );
299 * Do we need to strip the AAL layer? Yes if this
304 * Grab the CS-PDU length. Find the address of the
305 * last word, back up one word to skip CRC, and
306 * then mask the whole thing to handle circular wraps.
308 pdulen = rxp[(rdptr + n_cells*WORDS_PER_CELL - 1)
314 * We now have a valid PDU of some length. Build
315 * the necessary DMA list to move it into host
320 * Get an initial buffer.
322 KB_ALLOCPKT ( m, ENI_SMALL_BSIZE, KB_F_NOWAIT, KB_T_DATA );
324 * Do we have a valid buffer?
326 if ( m != (KBuffer *)NULL )
332 KB_DATASTART ( m, up, u_long * );
334 * Fill in pdulen in PKTHDR structure (for IP).
336 KB_PLENSET ( m, pdulen );
338 * We're going to save the VCI nuber, the start
339 * and stop DMA pointers, and the PDU length at
340 * the head of the buffer. We'll pull this out
341 * later after the DMA has completed.
343 * Insert VCI number as first word in first buffer,
344 * remeber where we want to store the start/stop
345 * pointers, and store the PDU length.
347 *up++ = vcc; /* PDU's VCC */
348 upp = up; /* Remember where we are */
349 up++; /* To stuff start/stop pointers in */
350 *up++ = pdulen; /* PDU's length */
352 * Leave some extra room in case a higher protocol
353 * (IP) wants to do a pullup. Maybe we can keep
354 * someone from having to allocate another buffer
355 * a do a larger memory copy.
357 len = MIN ( ENI_SMALL_BSIZE, pdulen );
358 (void) eni_set_dma ( eup, 1, dma, TEMP_DMA_SIZE, &j,
359 vcc, (u_long)up, len );
361 * Adjust length of remaining data in PDU
365 * Set buffer length, including our overhead
367 KB_LEN ( m ) = len + 3 * sizeof ( u_long );
369 * Finish by moving anything which won't fit in
380 KB_ALLOCEXT ( m1, ENI_LARGE_BSIZE, KB_F_NOWAIT,
388 * Figure out how much we can move into
391 len = MIN ( ENI_LARGE_BSIZE, pdulen );
393 * Setup DMA list for this buffer
395 KB_DATASTART ( m1, data_addr, u_long );
397 ( eup, 1, dma, TEMP_DMA_SIZE, &j, vcc,
400 * Adjust remaining length
408 * Link new buffer onto end and advance
415 * Either we were unable to grab another
416 * buffer or there are no large buffers
417 * available. We know that the first
418 * buffer is valid, so drop everything
419 * else, build a JK DMA to skip/drop this
420 * PDU, set the pointers to reclaim
421 * resources/advance pointers, and
422 * finish this PDU now.
425 KB_FREEALL ( KB_NEXT ( m ) );
426 eup->eu_pif.pif_ierrors++;
429 (((rdptr + n_cells*WORDS_PER_CELL + 1)
430 & (mask-1)) << DMA_COUNT_SHIFT ) |
431 (vcc << DMA_VCC_SHIFT ) |
435 * Reset PDU length to zero
439 * Count some statistics
442 * Count this as dropped cells
445 eup->eu_stats.eni_st_aal5.aal5_drops +=
447 eup->eu_stats.eni_st_aal5.aal5_pdu_drops++;
449 eup->eu_stats.eni_st_aal0.aal0_drops +=
458 * If necessary, skip AAL layer
462 (((rdptr + n_cells*WORDS_PER_CELL + 1)
463 & (mask-1)) << DMA_COUNT_SHIFT)
464 | (vcc << DMA_VCC_SHIFT) | DMA_JK;
469 * We failed to get an initial buffer. Since we
470 * haven't changed anything for this PDU yet and the
471 * PDU is still valid, exit now and try to service it
472 * next time around. We're not very likely to get
473 * another buffer right now anyways.
475 eup->eu_stats.eni_st_drv.drv_rv_nobufs++;
478 "eni_do_service: No buffers available. Exiting without servicing service list.\n" );
481 * Clear the IN_SERVICE indicator for this VCC
483 vct->vci_control &= ~VCI_IN_SERVICE;
489 * Set the end bit on the last DMA for this PDU
491 dma[j-2] |= DMA_END_BIT;
494 * Where are the current DMA pointers
496 dma_rd = eup->eu_midway[MIDWAY_RX_RD];
497 dma_wr = eup->eu_midway[MIDWAY_RX_WR];
500 * Check how much space is available
502 if ( dma_rd == dma_wr )
503 dma_avail = DMA_LIST_SIZE;
505 dma_avail = ( dma_rd + DMA_LIST_SIZE - dma_wr )
509 * Check for queue full or wrap past write okay pointer
511 if ( dma_avail < j ||
512 ( dma_wr + j > eup->eu_rxdmawr + DMA_LIST_SIZE ) ) {
514 * There's no room in the DMA list to insert
515 * this request. Since we haven't changed anything
516 * yet and the PDU is good, exit now and service
517 * it next time around. What we really need to do
518 * is wait for the RX list to drain and that won't
519 * happen if we keep trying to process PDUs here.
521 eup->eu_stats.eni_st_drv.drv_rv_nodma++;
524 "eni_do_service: No room in receive DMA list. Postponing service request.\n" );
527 * Free the local buffer chain
531 * Clear the IN_SERVICE indicator for this VCC.
533 vct->vci_control &= ~VCI_IN_SERVICE;
538 * If we have a buffer chain, save the starting
549 for ( i = 0; i < j; i++ ) {
550 eup->eu_rxdma[dma_wr*2] = dma[i*2];
551 eup->eu_rxdma[dma_wr*2+1] = dma[i*2+1];
552 dma_wr = (dma_wr+1) & (DMA_LIST_SIZE-1);
555 * If we have a buffer chain, save the location of
556 * the ending dma_list location and queue the chain
557 * so that we can recover the resources later.
562 * Place buffer on receive queue waiting for RX_DMA
564 if ( IF_QFULL ( &eup->eu_rxqueue ) ) {
566 * We haven't done anything we can't back out
567 * of. Drop request and service it next time.
568 * We've inserted the DMA list but it's not
569 * valid until we advance the RX_WR pointer,
570 * thus it's okay to bail here...
572 eup->eu_stats.eni_st_drv.drv_rv_rxq++;
575 "eni_do_service: RX drain queue full. Postponing servicing.\n" );
579 * Clear the IN_SERVICE indicator for this VCC.
581 vct->vci_control &= ~VCI_IN_SERVICE;
584 IF_ENQUEUE ( &eup->eu_rxqueue, m );
586 * Advance the RX_WR pointer to cause
587 * the adapter to work on this DMA list.
589 eup->eu_midway[MIDWAY_RX_WR] = dma_wr;
593 * Advance our notion of where the next PDU
596 rdptr = (rdptr + n_cells*WORDS_PER_CELL + 1)
598 evp->ev_rxpos = rdptr;
601 * Increment cells/pdu received stats.
603 eup->eu_stats.eni_st_atm.atm_rcvd += n_cells;
605 eup->eu_stats.eni_st_aal5.aal5_rcvd += n_cells;
606 eup->eu_stats.eni_st_aal5.aal5_pdu_rcvd++;
608 eup->eu_stats.eni_st_aal0.aal0_rcvd += n_cells;
612 * Continue processing PDUs on this same VCI
618 * Advance to next entry in the service_list.
620 eup->eu_servread = (eup->eu_servread + 1) & SVC_SIZE_MASK;
623 * And clear the IN_SERVICE indicator for this VCC.
625 vct->vci_control &= ~VCI_IN_SERVICE;
631 * Drain Receive queue
633 * As we build DMA lists to move PDUs from adapter buffers into host
634 * buffers, we place the request on a private ifqueue so that we can
635 * free any resources AFTER we know they've been successfully DMAed.
636 * As part of the service processing, we record the PDUs start and stop
637 * entries in the DMA list, and prevent wrapping. When we pull the top
638 * entry off, we simply check that the current DMA location is outside
639 * this PDU and if so, it's okay to free things.
642 * eup pointer to device unit structure
649 eni_recv_drain(Eni_unit *eup)
660 /* Pop first buffer */
661 IF_DEQUEUE ( &eup->eu_rxqueue, m );
666 KB_DATASTART ( m, up, u_long * );
669 * Grab the VCI number
674 * Check to see if we can process this buffer yet.
676 /* Get current DMA_Rdptr */
677 DMA_Rdptr = eup->eu_midway[MIDWAY_RX_RD];
678 /* Boundaries for first buffer */
680 start = dma_wrp >> 16;
681 stop = dma_wrp & 0xffff;
683 * Start should not equal stop because that would
684 * mean we tried inserting a NULL DMA list.
686 if ( start > stop ) { /* We wrapped */
687 if ( !(DMA_Rdptr >= stop && DMA_Rdptr < start) ) {
688 IF_PREPEND ( &eup->eu_rxqueue, m );
692 if ( DMA_Rdptr < stop && DMA_Rdptr >= start ) {
693 IF_PREPEND ( &eup->eu_rxqueue, m );
698 * Adapter is finished with this buffer, we can
699 * continue processing it now.
703 * Locate incoming VCC for this PDU
705 evp = (Eni_vcc *) atm_dev_vcc_find ( (Cmn_unit *)eup,
709 eup->eu_stats.eni_st_drv.drv_rv_novcc++;
716 atm_dev_pdu_print ( (Cmn_unit *)eup, (Cmn_vcc *)evp, m,
721 * Grab theoretical PDU length
726 * Quick, count the PDU
728 eup->eu_pif.pif_ipdus++;
729 eup->eu_pif.pif_ibytes += pdulen;
731 vcp = evp->ev_connvc->cvc_vcc;
734 vcp->vc_ibytes += pdulen;
736 vcp->vc_nif->nif_ibytes += pdulen;
737 vcp->vc_nif->nif_if.if_ipackets++;
738 vcp->vc_nif->nif_if.if_ibytes += pdulen;
744 * Advance DMA write allowable pointer
746 eup->eu_rxdmawr = stop;
749 * Get packet PDU length
751 KB_PLENGET ( m, pdulen );
754 * Only try queueing this if there is data
755 * to be handed up to the next layer. Errors
756 * such as CRC and VC trashing will get us this
757 * far to advance pointers, etc., but the PDU
758 * length will be zero.
762 * We saved three words back in eni_do_service()
763 * to use for callback. Since the core only
764 * expects two words, skip over the first one.
765 * Then, reset up pointer to start of buffer data
766 * area and write the callback info.
768 KB_HEADADJ ( m, -sizeof(u_long) );
769 KB_DATASTART ( m, up, u_long * );
770 *((int *)up) = (int)eni_recv_stack;
772 *((int *)up) = (int)evp;
776 if (netisr_queue(NETISR_ATM, m)) {
777 eup->eu_stats.eni_st_drv.drv_rv_intrq++;
778 eup->eu_pif.pif_ierrors++;
781 "eni_receive_drain: ATM_INTRQ is full. Unable to pass up stack.\n" );
787 * Free zero-length buffer
794 * Look for next buffer
796 IF_DEQUEUE ( &eup->eu_rxqueue, m );
803 * Pass incoming PDU up Stack
805 * This function is called via the core ATM interrupt queue callback
806 * set in eni_recv_drain(). It will pass the supplied incoming
807 * PDU up the incoming VCC's stack.
810 * tok token to identify stack instantiation
811 * m pointer to incoming PDU buffer chain
817 eni_recv_stack(void *tok, KBuffer *m)
819 Eni_vcc *evp = (Eni_vcc *)tok;
823 * This should never happen now but if it does and we don't stop it,
824 * we end up panic'ing in netatm when trying to pull a function
825 * pointer and token value out of a buffer with address zero.
830 "eni_recv_stack: NULL buffer, tok = %p\n", tok );
836 * Send the data up the stack
838 STACK_CALL ( CPCS_UNITDATA_SIG, evp->ev_upper,
839 (void *)evp->ev_toku, evp->ev_connvc, (int)m, 0, err );