Bryan O'Sullivan | 6522108 | 2006-03-29 15:23:38 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved. |
| 3 | * |
| 4 | * This software is available to you under a choice of one of two |
| 5 | * licenses. You may choose to be licensed under the terms of the GNU |
| 6 | * General Public License (GPL) Version 2, available from the file |
| 7 | * COPYING in the main directory of this source tree, or the |
| 8 | * OpenIB.org BSD license below: |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or |
| 11 | * without modification, are permitted provided that the following |
| 12 | * conditions are met: |
| 13 | * |
| 14 | * - Redistributions of source code must retain the above |
| 15 | * copyright notice, this list of conditions and the following |
| 16 | * disclaimer. |
| 17 | * |
| 18 | * - Redistributions in binary form must reproduce the above |
| 19 | * copyright notice, this list of conditions and the following |
| 20 | * disclaimer in the documentation and/or other materials |
| 21 | * provided with the distribution. |
| 22 | * |
| 23 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 24 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 25 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| 26 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS |
| 27 | * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
| 28 | * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
| 29 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 30 | * SOFTWARE. |
| 31 | */ |
| 32 | |
| 33 | #include <linux/list.h> |
| 34 | #include <linux/rcupdate.h> |
| 35 | |
| 36 | #include "ipath_verbs.h" |
| 37 | |
| 38 | /* |
| 39 | * Global table of GID to attached QPs. |
| 40 | * The table is global to all ipath devices since a send from one QP/device |
| 41 | * needs to be locally routed to any locally attached QPs on the same |
| 42 | * or different device. |
| 43 | */ |
| 44 | static struct rb_root mcast_tree; |
| 45 | static DEFINE_SPINLOCK(mcast_lock); |
| 46 | |
| 47 | /** |
| 48 | * ipath_mcast_qp_alloc - alloc a struct to link a QP to mcast GID struct |
| 49 | * @qp: the QP to link |
| 50 | */ |
| 51 | static struct ipath_mcast_qp *ipath_mcast_qp_alloc(struct ipath_qp *qp) |
| 52 | { |
| 53 | struct ipath_mcast_qp *mqp; |
| 54 | |
| 55 | mqp = kmalloc(sizeof *mqp, GFP_KERNEL); |
| 56 | if (!mqp) |
| 57 | goto bail; |
| 58 | |
| 59 | mqp->qp = qp; |
| 60 | atomic_inc(&qp->refcount); |
| 61 | |
| 62 | bail: |
| 63 | return mqp; |
| 64 | } |
| 65 | |
| 66 | static void ipath_mcast_qp_free(struct ipath_mcast_qp *mqp) |
| 67 | { |
| 68 | struct ipath_qp *qp = mqp->qp; |
| 69 | |
| 70 | /* Notify ipath_destroy_qp() if it is waiting. */ |
| 71 | if (atomic_dec_and_test(&qp->refcount)) |
| 72 | wake_up(&qp->wait); |
| 73 | |
| 74 | kfree(mqp); |
| 75 | } |
| 76 | |
| 77 | /** |
| 78 | * ipath_mcast_alloc - allocate the multicast GID structure |
| 79 | * @mgid: the multicast GID |
| 80 | * |
| 81 | * A list of QPs will be attached to this structure. |
| 82 | */ |
| 83 | static struct ipath_mcast *ipath_mcast_alloc(union ib_gid *mgid) |
| 84 | { |
| 85 | struct ipath_mcast *mcast; |
| 86 | |
| 87 | mcast = kmalloc(sizeof *mcast, GFP_KERNEL); |
| 88 | if (!mcast) |
| 89 | goto bail; |
| 90 | |
| 91 | mcast->mgid = *mgid; |
| 92 | INIT_LIST_HEAD(&mcast->qp_list); |
| 93 | init_waitqueue_head(&mcast->wait); |
| 94 | atomic_set(&mcast->refcount, 0); |
| 95 | |
| 96 | bail: |
| 97 | return mcast; |
| 98 | } |
| 99 | |
| 100 | static void ipath_mcast_free(struct ipath_mcast *mcast) |
| 101 | { |
| 102 | struct ipath_mcast_qp *p, *tmp; |
| 103 | |
| 104 | list_for_each_entry_safe(p, tmp, &mcast->qp_list, list) |
| 105 | ipath_mcast_qp_free(p); |
| 106 | |
| 107 | kfree(mcast); |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * ipath_mcast_find - search the global table for the given multicast GID |
| 112 | * @mgid: the multicast GID to search for |
| 113 | * |
| 114 | * Returns NULL if not found. |
| 115 | * |
| 116 | * The caller is responsible for decrementing the reference count if found. |
| 117 | */ |
| 118 | struct ipath_mcast *ipath_mcast_find(union ib_gid *mgid) |
| 119 | { |
| 120 | struct rb_node *n; |
| 121 | unsigned long flags; |
| 122 | struct ipath_mcast *mcast; |
| 123 | |
| 124 | spin_lock_irqsave(&mcast_lock, flags); |
| 125 | n = mcast_tree.rb_node; |
| 126 | while (n) { |
| 127 | int ret; |
| 128 | |
| 129 | mcast = rb_entry(n, struct ipath_mcast, rb_node); |
| 130 | |
| 131 | ret = memcmp(mgid->raw, mcast->mgid.raw, |
| 132 | sizeof(union ib_gid)); |
| 133 | if (ret < 0) |
| 134 | n = n->rb_left; |
| 135 | else if (ret > 0) |
| 136 | n = n->rb_right; |
| 137 | else { |
| 138 | atomic_inc(&mcast->refcount); |
| 139 | spin_unlock_irqrestore(&mcast_lock, flags); |
| 140 | goto bail; |
| 141 | } |
| 142 | } |
| 143 | spin_unlock_irqrestore(&mcast_lock, flags); |
| 144 | |
| 145 | mcast = NULL; |
| 146 | |
| 147 | bail: |
| 148 | return mcast; |
| 149 | } |
| 150 | |
| 151 | /** |
| 152 | * ipath_mcast_add - insert mcast GID into table and attach QP struct |
| 153 | * @mcast: the mcast GID table |
| 154 | * @mqp: the QP to attach |
| 155 | * |
| 156 | * Return zero if both were added. Return EEXIST if the GID was already in |
| 157 | * the table but the QP was added. Return ESRCH if the QP was already |
| 158 | * attached and neither structure was added. |
| 159 | */ |
| 160 | static int ipath_mcast_add(struct ipath_mcast *mcast, |
| 161 | struct ipath_mcast_qp *mqp) |
| 162 | { |
| 163 | struct rb_node **n = &mcast_tree.rb_node; |
| 164 | struct rb_node *pn = NULL; |
| 165 | unsigned long flags; |
| 166 | int ret; |
| 167 | |
| 168 | spin_lock_irqsave(&mcast_lock, flags); |
| 169 | |
| 170 | while (*n) { |
| 171 | struct ipath_mcast *tmcast; |
| 172 | struct ipath_mcast_qp *p; |
| 173 | |
| 174 | pn = *n; |
| 175 | tmcast = rb_entry(pn, struct ipath_mcast, rb_node); |
| 176 | |
| 177 | ret = memcmp(mcast->mgid.raw, tmcast->mgid.raw, |
| 178 | sizeof(union ib_gid)); |
| 179 | if (ret < 0) { |
| 180 | n = &pn->rb_left; |
| 181 | continue; |
| 182 | } |
| 183 | if (ret > 0) { |
| 184 | n = &pn->rb_right; |
| 185 | continue; |
| 186 | } |
| 187 | |
| 188 | /* Search the QP list to see if this is already there. */ |
| 189 | list_for_each_entry_rcu(p, &tmcast->qp_list, list) { |
| 190 | if (p->qp == mqp->qp) { |
| 191 | spin_unlock_irqrestore(&mcast_lock, flags); |
| 192 | ret = ESRCH; |
| 193 | goto bail; |
| 194 | } |
| 195 | } |
| 196 | list_add_tail_rcu(&mqp->list, &tmcast->qp_list); |
| 197 | spin_unlock_irqrestore(&mcast_lock, flags); |
| 198 | ret = EEXIST; |
| 199 | goto bail; |
| 200 | } |
| 201 | |
| 202 | list_add_tail_rcu(&mqp->list, &mcast->qp_list); |
| 203 | |
| 204 | atomic_inc(&mcast->refcount); |
| 205 | rb_link_node(&mcast->rb_node, pn, n); |
| 206 | rb_insert_color(&mcast->rb_node, &mcast_tree); |
| 207 | |
| 208 | spin_unlock_irqrestore(&mcast_lock, flags); |
| 209 | |
| 210 | ret = 0; |
| 211 | |
| 212 | bail: |
| 213 | return ret; |
| 214 | } |
| 215 | |
| 216 | int ipath_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid) |
| 217 | { |
| 218 | struct ipath_qp *qp = to_iqp(ibqp); |
| 219 | struct ipath_mcast *mcast; |
| 220 | struct ipath_mcast_qp *mqp; |
| 221 | int ret; |
| 222 | |
| 223 | /* |
| 224 | * Allocate data structures since its better to do this outside of |
| 225 | * spin locks and it will most likely be needed. |
| 226 | */ |
| 227 | mcast = ipath_mcast_alloc(gid); |
| 228 | if (mcast == NULL) { |
| 229 | ret = -ENOMEM; |
| 230 | goto bail; |
| 231 | } |
| 232 | mqp = ipath_mcast_qp_alloc(qp); |
| 233 | if (mqp == NULL) { |
| 234 | ipath_mcast_free(mcast); |
| 235 | ret = -ENOMEM; |
| 236 | goto bail; |
| 237 | } |
| 238 | switch (ipath_mcast_add(mcast, mqp)) { |
| 239 | case ESRCH: |
| 240 | /* Neither was used: can't attach the same QP twice. */ |
| 241 | ipath_mcast_qp_free(mqp); |
| 242 | ipath_mcast_free(mcast); |
| 243 | ret = -EINVAL; |
| 244 | goto bail; |
| 245 | case EEXIST: /* The mcast wasn't used */ |
| 246 | ipath_mcast_free(mcast); |
| 247 | break; |
| 248 | default: |
| 249 | break; |
| 250 | } |
| 251 | |
| 252 | ret = 0; |
| 253 | |
| 254 | bail: |
| 255 | return ret; |
| 256 | } |
| 257 | |
| 258 | int ipath_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid) |
| 259 | { |
| 260 | struct ipath_qp *qp = to_iqp(ibqp); |
| 261 | struct ipath_mcast *mcast = NULL; |
| 262 | struct ipath_mcast_qp *p, *tmp; |
| 263 | struct rb_node *n; |
| 264 | unsigned long flags; |
| 265 | int last = 0; |
| 266 | int ret; |
| 267 | |
| 268 | spin_lock_irqsave(&mcast_lock, flags); |
| 269 | |
| 270 | /* Find the GID in the mcast table. */ |
| 271 | n = mcast_tree.rb_node; |
| 272 | while (1) { |
| 273 | if (n == NULL) { |
| 274 | spin_unlock_irqrestore(&mcast_lock, flags); |
| 275 | ret = 0; |
| 276 | goto bail; |
| 277 | } |
| 278 | |
| 279 | mcast = rb_entry(n, struct ipath_mcast, rb_node); |
| 280 | ret = memcmp(gid->raw, mcast->mgid.raw, |
| 281 | sizeof(union ib_gid)); |
| 282 | if (ret < 0) |
| 283 | n = n->rb_left; |
| 284 | else if (ret > 0) |
| 285 | n = n->rb_right; |
| 286 | else |
| 287 | break; |
| 288 | } |
| 289 | |
| 290 | /* Search the QP list. */ |
| 291 | list_for_each_entry_safe(p, tmp, &mcast->qp_list, list) { |
| 292 | if (p->qp != qp) |
| 293 | continue; |
| 294 | /* |
| 295 | * We found it, so remove it, but don't poison the forward |
| 296 | * link until we are sure there are no list walkers. |
| 297 | */ |
| 298 | list_del_rcu(&p->list); |
| 299 | |
| 300 | /* If this was the last attached QP, remove the GID too. */ |
| 301 | if (list_empty(&mcast->qp_list)) { |
| 302 | rb_erase(&mcast->rb_node, &mcast_tree); |
| 303 | last = 1; |
| 304 | } |
| 305 | break; |
| 306 | } |
| 307 | |
| 308 | spin_unlock_irqrestore(&mcast_lock, flags); |
| 309 | |
| 310 | if (p) { |
| 311 | /* |
| 312 | * Wait for any list walkers to finish before freeing the |
| 313 | * list element. |
| 314 | */ |
| 315 | wait_event(mcast->wait, atomic_read(&mcast->refcount) <= 1); |
| 316 | ipath_mcast_qp_free(p); |
| 317 | } |
| 318 | if (last) { |
| 319 | atomic_dec(&mcast->refcount); |
| 320 | wait_event(mcast->wait, !atomic_read(&mcast->refcount)); |
| 321 | ipath_mcast_free(mcast); |
| 322 | } |
| 323 | |
| 324 | ret = 0; |
| 325 | |
| 326 | bail: |
| 327 | return ret; |
| 328 | } |
| 329 | |
| 330 | int ipath_mcast_tree_empty(void) |
| 331 | { |
| 332 | return mcast_tree.rb_node == NULL; |
| 333 | } |