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1/*
2 * Copyright (c) 2006, 2007, 2008 QLogic Corporation. All rights reserved.
3 * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
4 *
5 * This software is available to you under a choice of one of two
6 * licenses.  You may choose to be licensed under the terms of the GNU
7 * General Public License (GPL) Version 2, available from the file
8 * COPYING in the main directory of this source tree, or the
9 * OpenIB.org BSD license below:
10 *
11 *     Redistribution and use in source and binary forms, with or
12 *     without modification, are permitted provided that the following
13 *     conditions are met:
14 *
15 *      - Redistributions of source code must retain the above
16 *        copyright notice, this list of conditions and the following
17 *        disclaimer.
18 *
19 *      - Redistributions in binary form must reproduce the above
20 *        copyright notice, this list of conditions and the following
21 *        disclaimer in the documentation and/or other materials
22 *        provided with the distribution.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31 * SOFTWARE.
32 */
33
34#include <linux/sched.h>
35#include <rdma/ib_smi.h>
36
37#include "ipath_verbs.h"
38#include "ipath_kernel.h"
39
40/**
41 * ipath_ud_loopback - handle send on loopback QPs
42 * @sqp: the sending QP
43 * @swqe: the send work request
44 *
45 * This is called from ipath_make_ud_req() to forward a WQE addressed
46 * to the same HCA.
47 * Note that the receive interrupt handler may be calling ipath_ud_rcv()
48 * while this is being called.
49 */
50static void ipath_ud_loopback(struct ipath_qp *sqp, struct ipath_swqe *swqe)
51{
52	struct ipath_ibdev *dev = to_idev(sqp->ibqp.device);
53	struct ipath_qp *qp;
54	struct ib_ah_attr *ah_attr;
55	unsigned long flags;
56	struct ipath_rq *rq;
57	struct ipath_srq *srq;
58	struct ipath_sge_state rsge;
59	struct ipath_sge *sge;
60	struct ipath_rwq *wq;
61	struct ipath_rwqe *wqe;
62	void (*handler)(struct ib_event *, void *);
63	struct ib_wc wc;
64	u32 tail;
65	u32 rlen;
66	u32 length;
67
68	qp = ipath_lookup_qpn(&dev->qp_table, swqe->wr.wr.ud.remote_qpn);
69	if (!qp || !(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK)) {
70		dev->n_pkt_drops++;
71		goto done;
72	}
73
74	/*
75	 * Check that the qkey matches (except for QP0, see 9.6.1.4.1).
76	 * Qkeys with the high order bit set mean use the
77	 * qkey from the QP context instead of the WR (see 10.2.5).
78	 */
79	if (unlikely(qp->ibqp.qp_num &&
80		     ((int) swqe->wr.wr.ud.remote_qkey < 0 ?
81		      sqp->qkey : swqe->wr.wr.ud.remote_qkey) != qp->qkey)) {
82		/* XXX OK to lose a count once in a while. */
83		dev->qkey_violations++;
84		dev->n_pkt_drops++;
85		goto drop;
86	}
87
88	/*
89	 * A GRH is expected to precede the data even if not
90	 * present on the wire.
91	 */
92	length = swqe->length;
93	memset(&wc, 0, sizeof wc);
94	wc.byte_len = length + sizeof(struct ib_grh);
95
96	if (swqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
97		wc.wc_flags = IB_WC_WITH_IMM;
98		wc.ex.imm_data = swqe->wr.ex.imm_data;
99	}
100
101	/*
102	 * This would be a lot simpler if we could call ipath_get_rwqe()
103	 * but that uses state that the receive interrupt handler uses
104	 * so we would need to lock out receive interrupts while doing
105	 * local loopback.
106	 */
107	if (qp->ibqp.srq) {
108		srq = to_isrq(qp->ibqp.srq);
109		handler = srq->ibsrq.event_handler;
110		rq = &srq->rq;
111	} else {
112		srq = NULL;
113		handler = NULL;
114		rq = &qp->r_rq;
115	}
116
117	/*
118	 * Get the next work request entry to find where to put the data.
119	 * Note that it is safe to drop the lock after changing rq->tail
120	 * since ipath_post_receive() won't fill the empty slot.
121	 */
122	spin_lock_irqsave(&rq->lock, flags);
123	wq = rq->wq;
124	tail = wq->tail;
125	/* Validate tail before using it since it is user writable. */
126	if (tail >= rq->size)
127		tail = 0;
128	if (unlikely(tail == wq->head)) {
129		spin_unlock_irqrestore(&rq->lock, flags);
130		dev->n_pkt_drops++;
131		goto drop;
132	}
133	wqe = get_rwqe_ptr(rq, tail);
134	rsge.sg_list = qp->r_ud_sg_list;
135	if (!ipath_init_sge(qp, wqe, &rlen, &rsge)) {
136		spin_unlock_irqrestore(&rq->lock, flags);
137		dev->n_pkt_drops++;
138		goto drop;
139	}
140	/* Silently drop packets which are too big. */
141	if (wc.byte_len > rlen) {
142		spin_unlock_irqrestore(&rq->lock, flags);
143		dev->n_pkt_drops++;
144		goto drop;
145	}
146	if (++tail >= rq->size)
147		tail = 0;
148	wq->tail = tail;
149	wc.wr_id = wqe->wr_id;
150	if (handler) {
151		u32 n;
152
153		/*
154		 * validate head pointer value and compute
155		 * the number of remaining WQEs.
156		 */
157		n = wq->head;
158		if (n >= rq->size)
159			n = 0;
160		if (n < tail)
161			n += rq->size - tail;
162		else
163			n -= tail;
164		if (n < srq->limit) {
165			struct ib_event ev;
166
167			srq->limit = 0;
168			spin_unlock_irqrestore(&rq->lock, flags);
169			ev.device = qp->ibqp.device;
170			ev.element.srq = qp->ibqp.srq;
171			ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
172			handler(&ev, srq->ibsrq.srq_context);
173		} else
174			spin_unlock_irqrestore(&rq->lock, flags);
175	} else
176		spin_unlock_irqrestore(&rq->lock, flags);
177
178	ah_attr = &to_iah(swqe->wr.wr.ud.ah)->attr;
179	if (ah_attr->ah_flags & IB_AH_GRH) {
180		ipath_copy_sge(&rsge, &ah_attr->grh, sizeof(struct ib_grh));
181		wc.wc_flags |= IB_WC_GRH;
182	} else
183		ipath_skip_sge(&rsge, sizeof(struct ib_grh));
184	sge = swqe->sg_list;
185	while (length) {
186		u32 len = sge->length;
187
188		if (len > length)
189			len = length;
190		if (len > sge->sge_length)
191			len = sge->sge_length;
192		BUG_ON(len == 0);
193		ipath_copy_sge(&rsge, sge->vaddr, len);
194		sge->vaddr += len;
195		sge->length -= len;
196		sge->sge_length -= len;
197		if (sge->sge_length == 0) {
198			if (--swqe->wr.num_sge)
199				sge++;
200		} else if (sge->length == 0 && sge->mr != NULL) {
201			if (++sge->n >= IPATH_SEGSZ) {
202				if (++sge->m >= sge->mr->mapsz)
203					break;
204				sge->n = 0;
205			}
206			sge->vaddr =
207				sge->mr->map[sge->m]->segs[sge->n].vaddr;
208			sge->length =
209				sge->mr->map[sge->m]->segs[sge->n].length;
210		}
211		length -= len;
212	}
213	wc.status = IB_WC_SUCCESS;
214	wc.opcode = IB_WC_RECV;
215	wc.qp = &qp->ibqp;
216	wc.src_qp = sqp->ibqp.qp_num;
217	/* XXX do we know which pkey matched? Only needed for GSI. */
218	wc.pkey_index = 0;
219	wc.slid = dev->dd->ipath_lid |
220		(ah_attr->src_path_bits &
221		 ((1 << dev->dd->ipath_lmc) - 1));
222	wc.sl = ah_attr->sl;
223	wc.dlid_path_bits =
224		ah_attr->dlid & ((1 << dev->dd->ipath_lmc) - 1);
225	wc.port_num = 1;
226	/* Signal completion event if the solicited bit is set. */
227	ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
228		       swqe->wr.send_flags & IB_SEND_SOLICITED);
229drop:
230	if (atomic_dec_and_test(&qp->refcount))
231		wake_up(&qp->wait);
232done:;
233}
234
235/**
236 * ipath_make_ud_req - construct a UD request packet
237 * @qp: the QP
238 *
239 * Return 1 if constructed; otherwise, return 0.
240 */
241int ipath_make_ud_req(struct ipath_qp *qp)
242{
243	struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
244	struct ipath_other_headers *ohdr;
245	struct ib_ah_attr *ah_attr;
246	struct ipath_swqe *wqe;
247	unsigned long flags;
248	u32 nwords;
249	u32 extra_bytes;
250	u32 bth0;
251	u16 lrh0;
252	u16 lid;
253	int ret = 0;
254	int next_cur;
255
256	spin_lock_irqsave(&qp->s_lock, flags);
257
258	if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_NEXT_SEND_OK)) {
259		if (!(ib_ipath_state_ops[qp->state] & IPATH_FLUSH_SEND))
260			goto bail;
261		/* We are in the error state, flush the work request. */
262		if (qp->s_last == qp->s_head)
263			goto bail;
264		/* If DMAs are in progress, we can't flush immediately. */
265		if (atomic_read(&qp->s_dma_busy)) {
266			qp->s_flags |= IPATH_S_WAIT_DMA;
267			goto bail;
268		}
269		wqe = get_swqe_ptr(qp, qp->s_last);
270		ipath_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
271		goto done;
272	}
273
274	if (qp->s_cur == qp->s_head)
275		goto bail;
276
277	wqe = get_swqe_ptr(qp, qp->s_cur);
278	next_cur = qp->s_cur + 1;
279	if (next_cur >= qp->s_size)
280		next_cur = 0;
281
282	/* Construct the header. */
283	ah_attr = &to_iah(wqe->wr.wr.ud.ah)->attr;
284	if (ah_attr->dlid >= IPATH_MULTICAST_LID_BASE) {
285		if (ah_attr->dlid != IPATH_PERMISSIVE_LID)
286			dev->n_multicast_xmit++;
287		else
288			dev->n_unicast_xmit++;
289	} else {
290		dev->n_unicast_xmit++;
291		lid = ah_attr->dlid & ~((1 << dev->dd->ipath_lmc) - 1);
292		if (unlikely(lid == dev->dd->ipath_lid)) {
293			/*
294			 * If DMAs are in progress, we can't generate
295			 * a completion for the loopback packet since
296			 * it would be out of order.
297			 * XXX Instead of waiting, we could queue a
298			 * zero length descriptor so we get a callback.
299			 */
300			if (atomic_read(&qp->s_dma_busy)) {
301				qp->s_flags |= IPATH_S_WAIT_DMA;
302				goto bail;
303			}
304			qp->s_cur = next_cur;
305			spin_unlock_irqrestore(&qp->s_lock, flags);
306			ipath_ud_loopback(qp, wqe);
307			spin_lock_irqsave(&qp->s_lock, flags);
308			ipath_send_complete(qp, wqe, IB_WC_SUCCESS);
309			goto done;
310		}
311	}
312
313	qp->s_cur = next_cur;
314	extra_bytes = -wqe->length & 3;
315	nwords = (wqe->length + extra_bytes) >> 2;
316
317	/* header size in 32-bit words LRH+BTH+DETH = (8+12+8)/4. */
318	qp->s_hdrwords = 7;
319	qp->s_cur_size = wqe->length;
320	qp->s_cur_sge = &qp->s_sge;
321	qp->s_dmult = ah_attr->static_rate;
322	qp->s_wqe = wqe;
323	qp->s_sge.sge = wqe->sg_list[0];
324	qp->s_sge.sg_list = wqe->sg_list + 1;
325	qp->s_sge.num_sge = wqe->wr.num_sge;
326
327	if (ah_attr->ah_flags & IB_AH_GRH) {
328		/* Header size in 32-bit words. */
329		qp->s_hdrwords += ipath_make_grh(dev, &qp->s_hdr.u.l.grh,
330						 &ah_attr->grh,
331						 qp->s_hdrwords, nwords);
332		lrh0 = IPATH_LRH_GRH;
333		ohdr = &qp->s_hdr.u.l.oth;
334		/*
335		 * Don't worry about sending to locally attached multicast
336		 * QPs.  It is unspecified by the spec. what happens.
337		 */
338	} else {
339		/* Header size in 32-bit words. */
340		lrh0 = IPATH_LRH_BTH;
341		ohdr = &qp->s_hdr.u.oth;
342	}
343	if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
344		qp->s_hdrwords++;
345		ohdr->u.ud.imm_data = wqe->wr.ex.imm_data;
346		bth0 = IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE << 24;
347	} else
348		bth0 = IB_OPCODE_UD_SEND_ONLY << 24;
349	lrh0 |= ah_attr->sl << 4;
350	if (qp->ibqp.qp_type == IB_QPT_SMI)
351		lrh0 |= 0xF000;	/* Set VL (see ch. 13.5.3.1) */
352	qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
353	qp->s_hdr.lrh[1] = cpu_to_be16(ah_attr->dlid);	/* DEST LID */
354	qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords +
355					   SIZE_OF_CRC);
356	lid = dev->dd->ipath_lid;
357	if (lid) {
358		lid |= ah_attr->src_path_bits &
359			((1 << dev->dd->ipath_lmc) - 1);
360		qp->s_hdr.lrh[3] = cpu_to_be16(lid);
361	} else
362		qp->s_hdr.lrh[3] = IB_LID_PERMISSIVE;
363	if (wqe->wr.send_flags & IB_SEND_SOLICITED)
364		bth0 |= 1 << 23;
365	bth0 |= extra_bytes << 20;
366	bth0 |= qp->ibqp.qp_type == IB_QPT_SMI ? IPATH_DEFAULT_P_KEY :
367		ipath_get_pkey(dev->dd, qp->s_pkey_index);
368	ohdr->bth[0] = cpu_to_be32(bth0);
369	/*
370	 * Use the multicast QP if the destination LID is a multicast LID.
371	 */
372	ohdr->bth[1] = ah_attr->dlid >= IPATH_MULTICAST_LID_BASE &&
373		ah_attr->dlid != IPATH_PERMISSIVE_LID ?
374		cpu_to_be32(IPATH_MULTICAST_QPN) :
375		cpu_to_be32(wqe->wr.wr.ud.remote_qpn);
376	ohdr->bth[2] = cpu_to_be32(qp->s_next_psn++ & IPATH_PSN_MASK);
377	/*
378	 * Qkeys with the high order bit set mean use the
379	 * qkey from the QP context instead of the WR (see 10.2.5).
380	 */
381	ohdr->u.ud.deth[0] = cpu_to_be32((int)wqe->wr.wr.ud.remote_qkey < 0 ?
382					 qp->qkey : wqe->wr.wr.ud.remote_qkey);
383	ohdr->u.ud.deth[1] = cpu_to_be32(qp->ibqp.qp_num);
384
385done:
386	ret = 1;
387	goto unlock;
388
389bail:
390	qp->s_flags &= ~IPATH_S_BUSY;
391unlock:
392	spin_unlock_irqrestore(&qp->s_lock, flags);
393	return ret;
394}
395
396/**
397 * ipath_ud_rcv - receive an incoming UD packet
398 * @dev: the device the packet came in on
399 * @hdr: the packet header
400 * @has_grh: true if the packet has a GRH
401 * @data: the packet data
402 * @tlen: the packet length
403 * @qp: the QP the packet came on
404 *
405 * This is called from ipath_qp_rcv() to process an incoming UD packet
406 * for the given QP.
407 * Called at interrupt level.
408 */
409void ipath_ud_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
410		  int has_grh, void *data, u32 tlen, struct ipath_qp *qp)
411{
412	struct ipath_other_headers *ohdr;
413	int opcode;
414	u32 hdrsize;
415	u32 pad;
416	struct ib_wc wc;
417	u32 qkey;
418	u32 src_qp;
419	u16 dlid;
420	int header_in_data;
421
422	/* Check for GRH */
423	if (!has_grh) {
424		ohdr = &hdr->u.oth;
425		hdrsize = 8 + 12 + 8;	/* LRH + BTH + DETH */
426		qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
427		src_qp = be32_to_cpu(ohdr->u.ud.deth[1]);
428		header_in_data = 0;
429	} else {
430		ohdr = &hdr->u.l.oth;
431		hdrsize = 8 + 40 + 12 + 8; /* LRH + GRH + BTH + DETH */
432		/*
433		 * The header with GRH is 68 bytes and the core driver sets
434		 * the eager header buffer size to 56 bytes so the last 12
435		 * bytes of the IB header is in the data buffer.
436		 */
437		header_in_data = dev->dd->ipath_rcvhdrentsize == 16;
438		if (header_in_data) {
439			qkey = be32_to_cpu(((__be32 *) data)[1]);
440			src_qp = be32_to_cpu(((__be32 *) data)[2]);
441			data += 12;
442		} else {
443			qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
444			src_qp = be32_to_cpu(ohdr->u.ud.deth[1]);
445		}
446	}
447	src_qp &= IPATH_QPN_MASK;
448
449	/*
450	 * Check that the permissive LID is only used on QP0
451	 * and the QKEY matches (see 9.6.1.4.1 and 9.6.1.5.1).
452	 */
453	if (qp->ibqp.qp_num) {
454		if (unlikely(hdr->lrh[1] == IB_LID_PERMISSIVE ||
455			     hdr->lrh[3] == IB_LID_PERMISSIVE)) {
456			dev->n_pkt_drops++;
457			goto bail;
458		}
459		if (unlikely(qkey != qp->qkey)) {
460			/* XXX OK to lose a count once in a while. */
461			dev->qkey_violations++;
462			dev->n_pkt_drops++;
463			goto bail;
464		}
465	} else if (hdr->lrh[1] == IB_LID_PERMISSIVE ||
466		   hdr->lrh[3] == IB_LID_PERMISSIVE) {
467		struct ib_smp *smp = (struct ib_smp *) data;
468
469		if (smp->mgmt_class != IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
470			dev->n_pkt_drops++;
471			goto bail;
472		}
473	}
474
475	/*
476	 * The opcode is in the low byte when its in network order
477	 * (top byte when in host order).
478	 */
479	opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
480	if (qp->ibqp.qp_num > 1 &&
481	    opcode == IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE) {
482		if (header_in_data) {
483			wc.ex.imm_data = *(__be32 *) data;
484			data += sizeof(__be32);
485		} else
486			wc.ex.imm_data = ohdr->u.ud.imm_data;
487		wc.wc_flags = IB_WC_WITH_IMM;
488		hdrsize += sizeof(u32);
489	} else if (opcode == IB_OPCODE_UD_SEND_ONLY) {
490		wc.ex.imm_data = 0;
491		wc.wc_flags = 0;
492	} else {
493		dev->n_pkt_drops++;
494		goto bail;
495	}
496
497	/* Get the number of bytes the message was padded by. */
498	pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
499	if (unlikely(tlen < (hdrsize + pad + 4))) {
500		/* Drop incomplete packets. */
501		dev->n_pkt_drops++;
502		goto bail;
503	}
504	tlen -= hdrsize + pad + 4;
505
506	/* Drop invalid MAD packets (see 13.5.3.1). */
507	if (unlikely((qp->ibqp.qp_num == 0 &&
508		      (tlen != 256 ||
509		       (be16_to_cpu(hdr->lrh[0]) >> 12) != 15)) ||
510		     (qp->ibqp.qp_num == 1 &&
511		      (tlen != 256 ||
512		       (be16_to_cpu(hdr->lrh[0]) >> 12) == 15)))) {
513		dev->n_pkt_drops++;
514		goto bail;
515	}
516
517	/*
518	 * A GRH is expected to precede the data even if not
519	 * present on the wire.
520	 */
521	wc.byte_len = tlen + sizeof(struct ib_grh);
522
523	/*
524	 * Get the next work request entry to find where to put the data.
525	 */
526	if (qp->r_flags & IPATH_R_REUSE_SGE)
527		qp->r_flags &= ~IPATH_R_REUSE_SGE;
528	else if (!ipath_get_rwqe(qp, 0)) {
529		/*
530		 * Count VL15 packets dropped due to no receive buffer.
531		 * Otherwise, count them as buffer overruns since usually,
532		 * the HW will be able to receive packets even if there are
533		 * no QPs with posted receive buffers.
534		 */
535		if (qp->ibqp.qp_num == 0)
536			dev->n_vl15_dropped++;
537		else
538			dev->rcv_errors++;
539		goto bail;
540	}
541	/* Silently drop packets which are too big. */
542	if (wc.byte_len > qp->r_len) {
543		qp->r_flags |= IPATH_R_REUSE_SGE;
544		dev->n_pkt_drops++;
545		goto bail;
546	}
547	if (has_grh) {
548		ipath_copy_sge(&qp->r_sge, &hdr->u.l.grh,
549			       sizeof(struct ib_grh));
550		wc.wc_flags |= IB_WC_GRH;
551	} else
552		ipath_skip_sge(&qp->r_sge, sizeof(struct ib_grh));
553	ipath_copy_sge(&qp->r_sge, data,
554		       wc.byte_len - sizeof(struct ib_grh));
555	if (!test_and_clear_bit(IPATH_R_WRID_VALID, &qp->r_aflags))
556		goto bail;
557	wc.wr_id = qp->r_wr_id;
558	wc.status = IB_WC_SUCCESS;
559	wc.opcode = IB_WC_RECV;
560	wc.vendor_err = 0;
561	wc.qp = &qp->ibqp;
562	wc.src_qp = src_qp;
563	/* XXX do we know which pkey matched? Only needed for GSI. */
564	wc.pkey_index = 0;
565	wc.slid = be16_to_cpu(hdr->lrh[3]);
566	wc.sl = (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF;
567	dlid = be16_to_cpu(hdr->lrh[1]);
568	/*
569	 * Save the LMC lower bits if the destination LID is a unicast LID.
570	 */
571	wc.dlid_path_bits = dlid >= IPATH_MULTICAST_LID_BASE ? 0 :
572		dlid & ((1 << dev->dd->ipath_lmc) - 1);
573	wc.port_num = 1;
574	/* Signal completion event if the solicited bit is set. */
575	ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
576		       (ohdr->bth[0] &
577			cpu_to_be32(1 << 23)) != 0);
578
579bail:;
580}
581