1 /*
2  * Copyright (c) 2006, 2007, 2008, 2009 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/spinlock.h>
35 #include <rdma/ib_smi.h>
36 
37 #include "qib.h"
38 #include "qib_mad.h"
39 
40 /*
41  * Switch to alternate path.
42  * The QP s_lock should be held and interrupts disabled.
43  */
44 void qib_migrate_qp(struct rvt_qp *qp)
45 {
46 	struct ib_event ev;
47 
48 	qp->s_mig_state = IB_MIG_MIGRATED;
49 	qp->remote_ah_attr = qp->alt_ah_attr;
50 	qp->port_num = rdma_ah_get_port_num(&qp->alt_ah_attr);
51 	qp->s_pkey_index = qp->s_alt_pkey_index;
52 
53 	ev.device = qp->ibqp.device;
54 	ev.element.qp = &qp->ibqp;
55 	ev.event = IB_EVENT_PATH_MIG;
56 	qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
57 }
58 
59 static __be64 get_sguid(struct qib_ibport *ibp, unsigned index)
60 {
61 	if (!index) {
62 		struct qib_pportdata *ppd = ppd_from_ibp(ibp);
63 
64 		return ppd->guid;
65 	}
66 	return ibp->guids[index - 1];
67 }
68 
69 static int gid_ok(union ib_gid *gid, __be64 gid_prefix, __be64 id)
70 {
71 	return (gid->global.interface_id == id &&
72 		(gid->global.subnet_prefix == gid_prefix ||
73 		 gid->global.subnet_prefix == IB_DEFAULT_GID_PREFIX));
74 }
75 
76 /*
77  *
78  * This should be called with the QP r_lock held.
79  *
80  * The s_lock will be acquired around the qib_migrate_qp() call.
81  */
82 int qib_ruc_check_hdr(struct qib_ibport *ibp, struct ib_header *hdr,
83 		      int has_grh, struct rvt_qp *qp, u32 bth0)
84 {
85 	__be64 guid;
86 	unsigned long flags;
87 
88 	if (qp->s_mig_state == IB_MIG_ARMED && (bth0 & IB_BTH_MIG_REQ)) {
89 		if (!has_grh) {
90 			if (rdma_ah_get_ah_flags(&qp->alt_ah_attr) &
91 			    IB_AH_GRH)
92 				goto err;
93 		} else {
94 			const struct ib_global_route *grh;
95 
96 			if (!(rdma_ah_get_ah_flags(&qp->alt_ah_attr) &
97 			      IB_AH_GRH))
98 				goto err;
99 			grh = rdma_ah_read_grh(&qp->alt_ah_attr);
100 			guid = get_sguid(ibp, grh->sgid_index);
101 			if (!gid_ok(&hdr->u.l.grh.dgid,
102 				    ibp->rvp.gid_prefix, guid))
103 				goto err;
104 			if (!gid_ok(&hdr->u.l.grh.sgid,
105 			    grh->dgid.global.subnet_prefix,
106 			    grh->dgid.global.interface_id))
107 				goto err;
108 		}
109 		if (!qib_pkey_ok((u16)bth0,
110 				 qib_get_pkey(ibp, qp->s_alt_pkey_index))) {
111 			qib_bad_pkey(ibp,
112 				     (u16)bth0,
113 				     (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF,
114 				     0, qp->ibqp.qp_num,
115 				     hdr->lrh[3], hdr->lrh[1]);
116 			goto err;
117 		}
118 		/* Validate the SLID. See Ch. 9.6.1.5 and 17.2.8 */
119 		if ((be16_to_cpu(hdr->lrh[3]) !=
120 		     rdma_ah_get_dlid(&qp->alt_ah_attr)) ||
121 		    ppd_from_ibp(ibp)->port !=
122 			    rdma_ah_get_port_num(&qp->alt_ah_attr))
123 			goto err;
124 		spin_lock_irqsave(&qp->s_lock, flags);
125 		qib_migrate_qp(qp);
126 		spin_unlock_irqrestore(&qp->s_lock, flags);
127 	} else {
128 		if (!has_grh) {
129 			if (rdma_ah_get_ah_flags(&qp->remote_ah_attr) &
130 			    IB_AH_GRH)
131 				goto err;
132 		} else {
133 			const struct ib_global_route *grh;
134 
135 			if (!(rdma_ah_get_ah_flags(&qp->remote_ah_attr) &
136 			      IB_AH_GRH))
137 				goto err;
138 			grh = rdma_ah_read_grh(&qp->remote_ah_attr);
139 			guid = get_sguid(ibp, grh->sgid_index);
140 			if (!gid_ok(&hdr->u.l.grh.dgid,
141 				    ibp->rvp.gid_prefix, guid))
142 				goto err;
143 			if (!gid_ok(&hdr->u.l.grh.sgid,
144 			    grh->dgid.global.subnet_prefix,
145 			    grh->dgid.global.interface_id))
146 				goto err;
147 		}
148 		if (!qib_pkey_ok((u16)bth0,
149 				 qib_get_pkey(ibp, qp->s_pkey_index))) {
150 			qib_bad_pkey(ibp,
151 				     (u16)bth0,
152 				     (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF,
153 				     0, qp->ibqp.qp_num,
154 				     hdr->lrh[3], hdr->lrh[1]);
155 			goto err;
156 		}
157 		/* Validate the SLID. See Ch. 9.6.1.5 */
158 		if (be16_to_cpu(hdr->lrh[3]) !=
159 		    rdma_ah_get_dlid(&qp->remote_ah_attr) ||
160 		    ppd_from_ibp(ibp)->port != qp->port_num)
161 			goto err;
162 		if (qp->s_mig_state == IB_MIG_REARM &&
163 		    !(bth0 & IB_BTH_MIG_REQ))
164 			qp->s_mig_state = IB_MIG_ARMED;
165 	}
166 
167 	return 0;
168 
169 err:
170 	return 1;
171 }
172 
173 /**
174  * qib_make_grh - construct a GRH header
175  * @ibp: a pointer to the IB port
176  * @hdr: a pointer to the GRH header being constructed
177  * @grh: the global route address to send to
178  * @hwords: the number of 32 bit words of header being sent
179  * @nwords: the number of 32 bit words of data being sent
180  *
181  * Return the size of the header in 32 bit words.
182  */
183 u32 qib_make_grh(struct qib_ibport *ibp, struct ib_grh *hdr,
184 		 const struct ib_global_route *grh, u32 hwords, u32 nwords)
185 {
186 	hdr->version_tclass_flow =
187 		cpu_to_be32((IB_GRH_VERSION << IB_GRH_VERSION_SHIFT) |
188 			    (grh->traffic_class << IB_GRH_TCLASS_SHIFT) |
189 			    (grh->flow_label << IB_GRH_FLOW_SHIFT));
190 	hdr->paylen = cpu_to_be16((hwords - 2 + nwords + SIZE_OF_CRC) << 2);
191 	/* next_hdr is defined by C8-7 in ch. 8.4.1 */
192 	hdr->next_hdr = IB_GRH_NEXT_HDR;
193 	hdr->hop_limit = grh->hop_limit;
194 	/* The SGID is 32-bit aligned. */
195 	hdr->sgid.global.subnet_prefix = ibp->rvp.gid_prefix;
196 	if (!grh->sgid_index)
197 		hdr->sgid.global.interface_id = ppd_from_ibp(ibp)->guid;
198 	else if (grh->sgid_index < QIB_GUIDS_PER_PORT)
199 		hdr->sgid.global.interface_id = ibp->guids[grh->sgid_index - 1];
200 	hdr->dgid = grh->dgid;
201 
202 	/* GRH header size in 32-bit words. */
203 	return sizeof(struct ib_grh) / sizeof(u32);
204 }
205 
206 void qib_make_ruc_header(struct rvt_qp *qp, struct ib_other_headers *ohdr,
207 			 u32 bth0, u32 bth2)
208 {
209 	struct qib_qp_priv *priv = qp->priv;
210 	struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
211 	u16 lrh0;
212 	u32 nwords;
213 	u32 extra_bytes;
214 
215 	/* Construct the header. */
216 	extra_bytes = -qp->s_cur_size & 3;
217 	nwords = (qp->s_cur_size + extra_bytes) >> 2;
218 	lrh0 = QIB_LRH_BTH;
219 	if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)) {
220 		qp->s_hdrwords +=
221 			qib_make_grh(ibp, &priv->s_hdr->u.l.grh,
222 				     rdma_ah_read_grh(&qp->remote_ah_attr),
223 				     qp->s_hdrwords, nwords);
224 		lrh0 = QIB_LRH_GRH;
225 	}
226 	lrh0 |= ibp->sl_to_vl[rdma_ah_get_sl(&qp->remote_ah_attr)] << 12 |
227 		rdma_ah_get_sl(&qp->remote_ah_attr) << 4;
228 	priv->s_hdr->lrh[0] = cpu_to_be16(lrh0);
229 	priv->s_hdr->lrh[1] =
230 			cpu_to_be16(rdma_ah_get_dlid(&qp->remote_ah_attr));
231 	priv->s_hdr->lrh[2] =
232 			cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
233 	priv->s_hdr->lrh[3] =
234 		cpu_to_be16(ppd_from_ibp(ibp)->lid |
235 			    rdma_ah_get_path_bits(&qp->remote_ah_attr));
236 	bth0 |= qib_get_pkey(ibp, qp->s_pkey_index);
237 	bth0 |= extra_bytes << 20;
238 	if (qp->s_mig_state == IB_MIG_MIGRATED)
239 		bth0 |= IB_BTH_MIG_REQ;
240 	ohdr->bth[0] = cpu_to_be32(bth0);
241 	ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
242 	ohdr->bth[2] = cpu_to_be32(bth2);
243 	this_cpu_inc(ibp->pmastats->n_unicast_xmit);
244 }
245 
246 void _qib_do_send(struct work_struct *work)
247 {
248 	struct qib_qp_priv *priv = container_of(work, struct qib_qp_priv,
249 						s_work);
250 	struct rvt_qp *qp = priv->owner;
251 
252 	qib_do_send(qp);
253 }
254 
255 /**
256  * qib_do_send - perform a send on a QP
257  * @qp: pointer to the QP
258  *
259  * Process entries in the send work queue until credit or queue is
260  * exhausted.  Only allow one CPU to send a packet per QP (tasklet).
261  * Otherwise, two threads could send packets out of order.
262  */
263 void qib_do_send(struct rvt_qp *qp)
264 {
265 	struct qib_qp_priv *priv = qp->priv;
266 	struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
267 	struct qib_pportdata *ppd = ppd_from_ibp(ibp);
268 	int (*make_req)(struct rvt_qp *qp, unsigned long *flags);
269 	unsigned long flags;
270 
271 	if ((qp->ibqp.qp_type == IB_QPT_RC ||
272 	     qp->ibqp.qp_type == IB_QPT_UC) &&
273 	    (rdma_ah_get_dlid(&qp->remote_ah_attr) &
274 	     ~((1 << ppd->lmc) - 1)) == ppd->lid) {
275 		rvt_ruc_loopback(qp);
276 		return;
277 	}
278 
279 	if (qp->ibqp.qp_type == IB_QPT_RC)
280 		make_req = qib_make_rc_req;
281 	else if (qp->ibqp.qp_type == IB_QPT_UC)
282 		make_req = qib_make_uc_req;
283 	else
284 		make_req = qib_make_ud_req;
285 
286 	spin_lock_irqsave(&qp->s_lock, flags);
287 
288 	/* Return if we are already busy processing a work request. */
289 	if (!qib_send_ok(qp)) {
290 		spin_unlock_irqrestore(&qp->s_lock, flags);
291 		return;
292 	}
293 
294 	qp->s_flags |= RVT_S_BUSY;
295 
296 	do {
297 		/* Check for a constructed packet to be sent. */
298 		if (qp->s_hdrwords != 0) {
299 			spin_unlock_irqrestore(&qp->s_lock, flags);
300 			/*
301 			 * If the packet cannot be sent now, return and
302 			 * the send tasklet will be woken up later.
303 			 */
304 			if (qib_verbs_send(qp, priv->s_hdr, qp->s_hdrwords,
305 					   qp->s_cur_sge, qp->s_cur_size))
306 				return;
307 			/* Record that s_hdr is empty. */
308 			qp->s_hdrwords = 0;
309 			spin_lock_irqsave(&qp->s_lock, flags);
310 		}
311 	} while (make_req(qp, &flags));
312 
313 	spin_unlock_irqrestore(&qp->s_lock, flags);
314 }
315