drivers/infiniband/hw/qib/qib_keys.c

   1 /*
   2  * Copyright (c) 2006, 2007, 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 "qib.h"
  35
  36 /**
  37  * qib_alloc_lkey - allocate an lkey
  38  * @mr: memory region that this lkey protects
  39  * @dma_region: 0->normal key, 1->restricted DMA key
  40  *
  41  * Returns 0 if successful, otherwise returns -errno.
  42  *
  43  * Increments mr reference count as required.
  44  *
  45  * Sets the lkey field mr for non-dma regions.
  46  *
  47  */
  48
  49 int qib_alloc_lkey(struct qib_mregion *mr, int dma_region)
  50 {
  51         unsigned long flags;
  52         u32 r;
  53         u32 n;
  54         int ret = 0;
  55         struct qib_ibdev *dev = to_idev(mr->pd->device);
  56         struct qib_lkey_table *rkt = &dev->lk_table;
  57
  58         spin_lock_irqsave(&rkt->lock, flags);
  59
  60         /* special case for dma_mr lkey == 0 */
  61         if (dma_region) {
  62                 struct qib_mregion *tmr;
  63
  64                 tmr = rcu_access_pointer(dev->dma_mr);
  65                 if (!tmr) {
  66                         qib_get_mr(mr);
  67                         rcu_assign_pointer(dev->dma_mr, mr);
  68                         mr->lkey_published = 1;
  69                 }
  70                 goto success;
  71         }
  72
  73         /* Find the next available LKEY */
  74         r = rkt->next;
  75         n = r;
  76         for (;;) {
  77                 if (rkt->table[r] == NULL)
  78                         break;
  79                 r = (r + 1) & (rkt->max - 1);
  80                 if (r == n)
  81                         goto bail;
  82         }
  83         rkt->next = (r + 1) & (rkt->max - 1);
  84         /*
  85          * Make sure lkey is never zero which is reserved to indicate an
  86          * unrestricted LKEY.
  87          */
  88         rkt->gen++;
  89         /*
  90          * bits are capped in qib_verbs.c to insure enough bits
  91          * for generation number
  92          */
  93         mr->lkey = (r << (32 - ib_qib_lkey_table_size)) |
  94                 ((((1 << (24 - ib_qib_lkey_table_size)) - 1) & rkt->gen)
  95                  << 8);
  96         if (mr->lkey == 0) {
  97                 mr->lkey |= 1 << 8;
  98                 rkt->gen++;
  99         }
 100         qib_get_mr(mr);
 101         rcu_assign_pointer(rkt->table[r], mr);
 102         mr->lkey_published = 1;
 103 success:
 104         spin_unlock_irqrestore(&rkt->lock, flags);
 105 out:
 106         return ret;
 107 bail:
 108         spin_unlock_irqrestore(&rkt->lock, flags);
 109         ret = -ENOMEM;
 110         goto out;
 111 }
 112
 113 /**
 114  * qib_free_lkey - free an lkey
 115  * @mr: mr to free from tables
 116  */
 117 void qib_free_lkey(struct qib_mregion *mr)
 118 {
 119         unsigned long flags;
 120         u32 lkey = mr->lkey;
 121         u32 r;
 122         struct qib_ibdev *dev = to_idev(mr->pd->device);
 123         struct qib_lkey_table *rkt = &dev->lk_table;
 124
 125         spin_lock_irqsave(&rkt->lock, flags);
 126         if (!mr->lkey_published)
 127                 goto out;
 128         if (lkey == 0)
 129                 RCU_INIT_POINTER(dev->dma_mr, NULL);
 130         else {
 131                 r = lkey >> (32 - ib_qib_lkey_table_size);
 132                 RCU_INIT_POINTER(rkt->table[r], NULL);
 133         }
 134         qib_put_mr(mr);
 135         mr->lkey_published = 0;
 136 out:
 137         spin_unlock_irqrestore(&rkt->lock, flags);
 138 }
 139
 140 /**
 141  * qib_lkey_ok - check IB SGE for validity and initialize
 142  * @rkt: table containing lkey to check SGE against
 143  * @pd: protection domain
 144  * @isge: outgoing internal SGE
 145  * @sge: SGE to check
 146  * @acc: access flags
 147  *
 148  * Return 1 if valid and successful, otherwise returns 0.
 149  *
 150  * increments the reference count upon success
 151  *
 152  * Check the IB SGE for validity and initialize our internal version
 153  * of it.
 154  */
 155 int qib_lkey_ok(struct qib_lkey_table *rkt, struct qib_pd *pd,
 156                 struct qib_sge *isge, struct ib_sge *sge, int acc)
 157 {
 158         struct qib_mregion *mr;
 159         unsigned n, m;
 160         size_t off;
 161
 162         /*
 163          * We use LKEY == zero for kernel virtual addresses
 164          * (see qib_get_dma_mr and qib_dma.c).
 165          */
 166         rcu_read_lock();
 167         if (sge->lkey == 0) {
 168                 struct qib_ibdev *dev = to_idev(pd->ibpd.device);
 169
 170                 if (pd->user)
 171                         goto bail;
 172                 mr = rcu_dereference(dev->dma_mr);
 173                 if (!mr)
 174                         goto bail;
 175                 if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
 176                         goto bail;
 177                 rcu_read_unlock();
 178
 179                 isge->mr = mr;
 180                 isge->vaddr = (void *) sge->addr;
 181                 isge->length = sge->length;
 182                 isge->sge_length = sge->length;
 183                 isge->m = 0;
 184                 isge->n = 0;
 185                 goto ok;
 186         }
 187         mr = rcu_dereference(
 188                 rkt->table[(sge->lkey >> (32 - ib_qib_lkey_table_size))]);
 189         if (unlikely(!mr || mr->lkey != sge->lkey || mr->pd != &pd->ibpd))
 190                 goto bail;
 191
 192         off = sge->addr - mr->user_base;
 193         if (unlikely(sge->addr < mr->user_base ||
 194                      off + sge->length > mr->length ||
 195                      (mr->access_flags & acc) != acc))
 196                 goto bail;
 197         if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
 198                 goto bail;
 199         rcu_read_unlock();
 200
 201         off += mr->offset;
 202         if (mr->page_shift) {
 203                 /*
 204                 page sizes are uniform power of 2 so no loop is necessary
 205                 entries_spanned_by_off is the number of times the loop below
 206                 would have executed.
 207                 */
 208                 size_t entries_spanned_by_off;
 209
 210                 entries_spanned_by_off = off >> mr->page_shift;
 211                 off -= (entries_spanned_by_off << mr->page_shift);
 212                 m = entries_spanned_by_off/QIB_SEGSZ;
 213                 n = entries_spanned_by_off%QIB_SEGSZ;
 214         } else {
 215                 m = 0;
 216                 n = 0;
 217                 while (off >= mr->map[m]->segs[n].length) {
 218                         off -= mr->map[m]->segs[n].length;
 219                         n++;
 220                         if (n >= QIB_SEGSZ) {
 221                                 m++;
 222                                 n = 0;
 223                         }
 224                 }
 225         }
 226         isge->mr = mr;
 227         isge->vaddr = mr->map[m]->segs[n].vaddr + off;
 228         isge->length = mr->map[m]->segs[n].length - off;
 229         isge->sge_length = sge->length;
 230         isge->m = m;
 231         isge->n = n;
 232 ok:
 233         return 1;
 234 bail:
 235         rcu_read_unlock();
 236         return 0;
 237 }
 238
 239 /**
 240  * qib_rkey_ok - check the IB virtual address, length, and RKEY
 241  * @qp: qp for validation
 242  * @sge: SGE state
 243  * @len: length of data
 244  * @vaddr: virtual address to place data
 245  * @rkey: rkey to check
 246  * @acc: access flags
 247  *
 248  * Return 1 if successful, otherwise 0.
 249  *
 250  * increments the reference count upon success
 251  */
 252 int qib_rkey_ok(struct qib_qp *qp, struct qib_sge *sge,
 253                 u32 len, u64 vaddr, u32 rkey, int acc)
 254 {
 255         struct qib_lkey_table *rkt = &to_idev(qp->ibqp.device)->lk_table;
 256         struct qib_mregion *mr;
 257         unsigned n, m;
 258         size_t off;
 259
 260         /*
 261          * We use RKEY == zero for kernel virtual addresses
 262          * (see qib_get_dma_mr and qib_dma.c).
 263          */
 264         rcu_read_lock();
 265         if (rkey == 0) {
 266                 struct qib_pd *pd = to_ipd(qp->ibqp.pd);
 267                 struct qib_ibdev *dev = to_idev(pd->ibpd.device);
 268
 269                 if (pd->user)
 270                         goto bail;
 271                 mr = rcu_dereference(dev->dma_mr);
 272                 if (!mr)
 273                         goto bail;
 274                 if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
 275                         goto bail;
 276                 rcu_read_unlock();
 277
 278                 sge->mr = mr;
 279                 sge->vaddr = (void *) vaddr;
 280                 sge->length = len;
 281                 sge->sge_length = len;
 282                 sge->m = 0;
 283                 sge->n = 0;
 284                 goto ok;
 285         }
 286
 287         mr = rcu_dereference(
 288                 rkt->table[(rkey >> (32 - ib_qib_lkey_table_size))]);
 289         if (unlikely(!mr || mr->lkey != rkey || qp->ibqp.pd != mr->pd))
 290                 goto bail;
 291
 292         off = vaddr - mr->iova;
 293         if (unlikely(vaddr < mr->iova || off + len > mr->length ||
 294                      (mr->access_flags & acc) == 0))
 295                 goto bail;
 296         if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
 297                 goto bail;
 298         rcu_read_unlock();
 299
 300         off += mr->offset;
 301         if (mr->page_shift) {
 302                 /*
 303                 page sizes are uniform power of 2 so no loop is necessary
 304                 entries_spanned_by_off is the number of times the loop below
 305                 would have executed.
 306                 */
 307                 size_t entries_spanned_by_off;
 308
 309                 entries_spanned_by_off = off >> mr->page_shift;
 310                 off -= (entries_spanned_by_off << mr->page_shift);
 311                 m = entries_spanned_by_off/QIB_SEGSZ;
 312                 n = entries_spanned_by_off%QIB_SEGSZ;
 313         } else {
 314                 m = 0;
 315                 n = 0;
 316                 while (off >= mr->map[m]->segs[n].length) {
 317                         off -= mr->map[m]->segs[n].length;
 318                         n++;
 319                         if (n >= QIB_SEGSZ) {
 320                                 m++;
 321                                 n = 0;
 322                         }
 323                 }
 324         }
 325         sge->mr = mr;
 326         sge->vaddr = mr->map[m]->segs[n].vaddr + off;
 327         sge->length = mr->map[m]->segs[n].length - off;
 328         sge->sge_length = len;
 329         sge->m = m;
 330         sge->n = n;
 331 ok:
 332         return 1;
 333 bail:
 334         rcu_read_unlock();
 335         return 0;
 336 }
 337
 338 /*
 339  * Initialize the memory region specified by the work request.
 340  */
 341 int qib_reg_mr(struct qib_qp *qp, struct ib_reg_wr *wr)
 342 {
 343         struct qib_lkey_table *rkt = &to_idev(qp->ibqp.device)->lk_table;
 344         struct qib_pd *pd = to_ipd(qp->ibqp.pd);
 345         struct qib_mr *mr = to_imr(wr->mr);
 346         struct qib_mregion *mrg;
 347         u32 key = wr->key;
 348         unsigned i, n, m;
 349         int ret = -EINVAL;
 350         unsigned long flags;
 351         u64 *page_list;
 352         size_t ps;
 353
 354         spin_lock_irqsave(&rkt->lock, flags);
 355         if (pd->user || key == 0)
 356                 goto bail;
 357
 358         mrg = rcu_dereference_protected(
 359                 rkt->table[(key >> (32 - ib_qib_lkey_table_size))],
 360                 lockdep_is_held(&rkt->lock));
 361         if (unlikely(mrg == NULL || qp->ibqp.pd != mrg->pd))
 362                 goto bail;
 363
 364         if (mr->npages > mrg->max_segs)
 365                 goto bail;
 366
 367         ps = mr->ibmr.page_size;
 368         if (mr->ibmr.length > ps * mr->npages)
 369                 goto bail;
 370
 371         mrg->user_base = mr->ibmr.iova;
 372         mrg->iova = mr->ibmr.iova;
 373         mrg->lkey = key;
 374         mrg->length = mr->ibmr.length;
 375         mrg->access_flags = wr->access;
 376         page_list = mr->pages;
 377         m = 0;
 378         n = 0;
 379         for (i = 0; i < mr->npages; i++) {
 380                 mrg->map[m]->segs[n].vaddr = (void *) page_list[i];
 381                 mrg->map[m]->segs[n].length = ps;
 382                 if (++n == QIB_SEGSZ) {
 383                         m++;
 384                         n = 0;
 385                 }
 386         }
 387
 388         ret = 0;
 389 bail:
 390         spin_unlock_irqrestore(&rkt->lock, flags);
 391         return ret;
 392 }