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1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause2/*3 * Copyright(c) 2016 Intel Corporation.4 */5 6#include <linux/slab.h>7#include <linux/sched.h>8#include <linux/rculist.h>9#include <rdma/rdma_vt.h>10#include <rdma/rdmavt_qp.h>11 12#include "mcast.h"13 14/**15 * rvt_driver_mcast_init - init resources for multicast16 * @rdi: rvt dev struct17 *18 * This is per device that registers with rdmavt19 */20void rvt_driver_mcast_init(struct rvt_dev_info *rdi)21{22 /*23 * Anything that needs setup for multicast on a per driver or per rdi24 * basis should be done in here.25 */26 spin_lock_init(&rdi->n_mcast_grps_lock);27}28 29/**30 * rvt_mcast_qp_alloc - alloc a struct to link a QP to mcast GID struct31 * @qp: the QP to link32 */33static struct rvt_mcast_qp *rvt_mcast_qp_alloc(struct rvt_qp *qp)34{35 struct rvt_mcast_qp *mqp;36 37 mqp = kmalloc(sizeof(*mqp), GFP_KERNEL);38 if (!mqp)39 goto bail;40 41 mqp->qp = qp;42 rvt_get_qp(qp);43 44bail:45 return mqp;46}47 48static void rvt_mcast_qp_free(struct rvt_mcast_qp *mqp)49{50 struct rvt_qp *qp = mqp->qp;51 52 /* Notify hfi1_destroy_qp() if it is waiting. */53 rvt_put_qp(qp);54 55 kfree(mqp);56}57 58/**59 * rvt_mcast_alloc - allocate the multicast GID structure60 * @mgid: the multicast GID61 * @lid: the muilticast LID (host order)62 *63 * A list of QPs will be attached to this structure.64 */65static struct rvt_mcast *rvt_mcast_alloc(union ib_gid *mgid, u16 lid)66{67 struct rvt_mcast *mcast;68 69 mcast = kzalloc(sizeof(*mcast), GFP_KERNEL);70 if (!mcast)71 goto bail;72 73 mcast->mcast_addr.mgid = *mgid;74 mcast->mcast_addr.lid = lid;75 76 INIT_LIST_HEAD(&mcast->qp_list);77 init_waitqueue_head(&mcast->wait);78 atomic_set(&mcast->refcount, 0);79 80bail:81 return mcast;82}83 84static void rvt_mcast_free(struct rvt_mcast *mcast)85{86 struct rvt_mcast_qp *p, *tmp;87 88 list_for_each_entry_safe(p, tmp, &mcast->qp_list, list)89 rvt_mcast_qp_free(p);90 91 kfree(mcast);92}93 94/**95 * rvt_mcast_find - search the global table for the given multicast GID/LID96 * NOTE: It is valid to have 1 MLID with multiple MGIDs. It is not valid97 * to have 1 MGID with multiple MLIDs.98 * @ibp: the IB port structure99 * @mgid: the multicast GID to search for100 * @lid: the multicast LID portion of the multicast address (host order)101 *102 * The caller is responsible for decrementing the reference count if found.103 *104 * Return: NULL if not found.105 */106struct rvt_mcast *rvt_mcast_find(struct rvt_ibport *ibp, union ib_gid *mgid,107 u16 lid)108{109 struct rb_node *n;110 unsigned long flags;111 struct rvt_mcast *found = NULL;112 113 spin_lock_irqsave(&ibp->lock, flags);114 n = ibp->mcast_tree.rb_node;115 while (n) {116 int ret;117 struct rvt_mcast *mcast;118 119 mcast = rb_entry(n, struct rvt_mcast, rb_node);120 121 ret = memcmp(mgid->raw, mcast->mcast_addr.mgid.raw,122 sizeof(*mgid));123 if (ret < 0) {124 n = n->rb_left;125 } else if (ret > 0) {126 n = n->rb_right;127 } else {128 /* MGID/MLID must match */129 if (mcast->mcast_addr.lid == lid) {130 atomic_inc(&mcast->refcount);131 found = mcast;132 }133 break;134 }135 }136 spin_unlock_irqrestore(&ibp->lock, flags);137 return found;138}139EXPORT_SYMBOL(rvt_mcast_find);140 141/*142 * rvt_mcast_add - insert mcast GID into table and attach QP struct143 * @mcast: the mcast GID table144 * @mqp: the QP to attach145 *146 * Return: zero if both were added. Return EEXIST if the GID was already in147 * the table but the QP was added. Return ESRCH if the QP was already148 * attached and neither structure was added. Return EINVAL if the MGID was149 * found, but the MLID did NOT match.150 */151static int rvt_mcast_add(struct rvt_dev_info *rdi, struct rvt_ibport *ibp,152 struct rvt_mcast *mcast, struct rvt_mcast_qp *mqp)153{154 struct rb_node **n = &ibp->mcast_tree.rb_node;155 struct rb_node *pn = NULL;156 int ret;157 158 spin_lock_irq(&ibp->lock);159 160 while (*n) {161 struct rvt_mcast *tmcast;162 struct rvt_mcast_qp *p;163 164 pn = *n;165 tmcast = rb_entry(pn, struct rvt_mcast, rb_node);166 167 ret = memcmp(mcast->mcast_addr.mgid.raw,168 tmcast->mcast_addr.mgid.raw,169 sizeof(mcast->mcast_addr.mgid));170 if (ret < 0) {171 n = &pn->rb_left;172 continue;173 }174 if (ret > 0) {175 n = &pn->rb_right;176 continue;177 }178 179 if (tmcast->mcast_addr.lid != mcast->mcast_addr.lid) {180 ret = EINVAL;181 goto bail;182 }183 184 /* Search the QP list to see if this is already there. */185 list_for_each_entry_rcu(p, &tmcast->qp_list, list) {186 if (p->qp == mqp->qp) {187 ret = ESRCH;188 goto bail;189 }190 }191 if (tmcast->n_attached ==192 rdi->dparms.props.max_mcast_qp_attach) {193 ret = ENOMEM;194 goto bail;195 }196 197 tmcast->n_attached++;198 199 list_add_tail_rcu(&mqp->list, &tmcast->qp_list);200 ret = EEXIST;201 goto bail;202 }203 204 spin_lock(&rdi->n_mcast_grps_lock);205 if (rdi->n_mcast_grps_allocated == rdi->dparms.props.max_mcast_grp) {206 spin_unlock(&rdi->n_mcast_grps_lock);207 ret = ENOMEM;208 goto bail;209 }210 211 rdi->n_mcast_grps_allocated++;212 spin_unlock(&rdi->n_mcast_grps_lock);213 214 mcast->n_attached++;215 216 list_add_tail_rcu(&mqp->list, &mcast->qp_list);217 218 atomic_inc(&mcast->refcount);219 rb_link_node(&mcast->rb_node, pn, n);220 rb_insert_color(&mcast->rb_node, &ibp->mcast_tree);221 222 ret = 0;223 224bail:225 spin_unlock_irq(&ibp->lock);226 227 return ret;228}229 230/**231 * rvt_attach_mcast - attach a qp to a multicast group232 * @ibqp: Infiniband qp233 * @gid: multicast guid234 * @lid: multicast lid235 *236 * Return: 0 on success237 */238int rvt_attach_mcast(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)239{240 struct rvt_qp *qp = ibqp_to_rvtqp(ibqp);241 struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);242 struct rvt_ibport *ibp = rdi->ports[qp->port_num - 1];243 struct rvt_mcast *mcast;244 struct rvt_mcast_qp *mqp;245 int ret = -ENOMEM;246 247 if (ibqp->qp_num <= 1 || qp->state == IB_QPS_RESET)248 return -EINVAL;249 250 /*251 * Allocate data structures since its better to do this outside of252 * spin locks and it will most likely be needed.253 */254 mcast = rvt_mcast_alloc(gid, lid);255 if (!mcast)256 return -ENOMEM;257 258 mqp = rvt_mcast_qp_alloc(qp);259 if (!mqp)260 goto bail_mcast;261 262 switch (rvt_mcast_add(rdi, ibp, mcast, mqp)) {263 case ESRCH:264 /* Neither was used: OK to attach the same QP twice. */265 ret = 0;266 goto bail_mqp;267 case EEXIST: /* The mcast wasn't used */268 ret = 0;269 goto bail_mcast;270 case ENOMEM:271 /* Exceeded the maximum number of mcast groups. */272 ret = -ENOMEM;273 goto bail_mqp;274 case EINVAL:275 /* Invalid MGID/MLID pair */276 ret = -EINVAL;277 goto bail_mqp;278 default:279 break;280 }281 282 return 0;283 284bail_mqp:285 rvt_mcast_qp_free(mqp);286 287bail_mcast:288 rvt_mcast_free(mcast);289 290 return ret;291}292 293/**294 * rvt_detach_mcast - remove a qp from a multicast group295 * @ibqp: Infiniband qp296 * @gid: multicast guid297 * @lid: multicast lid298 *299 * Return: 0 on success300 */301int rvt_detach_mcast(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)302{303 struct rvt_qp *qp = ibqp_to_rvtqp(ibqp);304 struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);305 struct rvt_ibport *ibp = rdi->ports[qp->port_num - 1];306 struct rvt_mcast *mcast = NULL;307 struct rvt_mcast_qp *p, *tmp, *delp = NULL;308 struct rb_node *n;309 int last = 0;310 int ret = 0;311 312 if (ibqp->qp_num <= 1)313 return -EINVAL;314 315 spin_lock_irq(&ibp->lock);316 317 /* Find the GID in the mcast table. */318 n = ibp->mcast_tree.rb_node;319 while (1) {320 if (!n) {321 spin_unlock_irq(&ibp->lock);322 return -EINVAL;323 }324 325 mcast = rb_entry(n, struct rvt_mcast, rb_node);326 ret = memcmp(gid->raw, mcast->mcast_addr.mgid.raw,327 sizeof(*gid));328 if (ret < 0) {329 n = n->rb_left;330 } else if (ret > 0) {331 n = n->rb_right;332 } else {333 /* MGID/MLID must match */334 if (mcast->mcast_addr.lid != lid) {335 spin_unlock_irq(&ibp->lock);336 return -EINVAL;337 }338 break;339 }340 }341 342 /* Search the QP list. */343 list_for_each_entry_safe(p, tmp, &mcast->qp_list, list) {344 if (p->qp != qp)345 continue;346 /*347 * We found it, so remove it, but don't poison the forward348 * link until we are sure there are no list walkers.349 */350 list_del_rcu(&p->list);351 mcast->n_attached--;352 delp = p;353 354 /* If this was the last attached QP, remove the GID too. */355 if (list_empty(&mcast->qp_list)) {356 rb_erase(&mcast->rb_node, &ibp->mcast_tree);357 last = 1;358 }359 break;360 }361 362 spin_unlock_irq(&ibp->lock);363 /* QP not attached */364 if (!delp)365 return -EINVAL;366 367 /*368 * Wait for any list walkers to finish before freeing the369 * list element.370 */371 wait_event(mcast->wait, atomic_read(&mcast->refcount) <= 1);372 rvt_mcast_qp_free(delp);373 374 if (last) {375 atomic_dec(&mcast->refcount);376 wait_event(mcast->wait, !atomic_read(&mcast->refcount));377 rvt_mcast_free(mcast);378 spin_lock_irq(&rdi->n_mcast_grps_lock);379 rdi->n_mcast_grps_allocated--;380 spin_unlock_irq(&rdi->n_mcast_grps_lock);381 }382 383 return 0;384}385 386/**387 * rvt_mcast_tree_empty - determine if any qps are attached to any mcast group388 * @rdi: rvt dev struct389 *390 * Return: in use count391 */392int rvt_mcast_tree_empty(struct rvt_dev_info *rdi)393{394 int i;395 int in_use = 0;396 397 for (i = 0; i < rdi->dparms.nports; i++)398 if (rdi->ports[i]->mcast_tree.rb_node)399 in_use++;400 return in_use;401}402