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_dereference(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         mr->lkey = (r << (32 - ib_qib_lkey_table_size)) |
  90                 ((((1 << (24 - ib_qib_lkey_table_size)) - 1) & rkt->gen)
  91                  << 8);
  92         if (mr->lkey == 0) {
  93                 mr->lkey |= 1 << 8;
  94                 rkt->gen++;
  95         }
  96         qib_get_mr(mr);
  97         rcu_assign_pointer(rkt->table[r], mr);
  98         mr->lkey_published = 1;
  99 success:
 100         spin_unlock_irqrestore(&rkt->lock, flags);
 101 out:
 102         return ret;
 103 bail:
 104         spin_unlock_irqrestore(&rkt->lock, flags);
 105         ret = -ENOMEM;
 106         goto out;
 107 }
 108
 109 /**
 110  * qib_free_lkey - free an lkey
 111  * @mr: mr to free from tables
 112  */
 113 void qib_free_lkey(struct qib_mregion *mr)
 114 {
 115         unsigned long flags;
 116         u32 lkey = mr->lkey;
 117         u32 r;
 118         struct qib_ibdev *dev = to_idev(mr->pd->device);
 119         struct qib_lkey_table *rkt = &dev->lk_table;
 120
 121         spin_lock_irqsave(&rkt->lock, flags);
 122         if (!mr->lkey_published)
 123                 goto out;
 124         if (lkey == 0)
 125                 rcu_assign_pointer(dev->dma_mr, NULL);
 126         else {
 127                 r = lkey >> (32 - ib_qib_lkey_table_size);
 128                 rcu_assign_pointer(rkt->table[r], NULL);
 129         }
 130         qib_put_mr(mr);
 131         mr->lkey_published = 0;
 132 out:
 133         spin_unlock_irqrestore(&rkt->lock, flags);
 134 }
 135
 136 /**
 137  * qib_lkey_ok - check IB SGE for validity and initialize
 138  * @rkt: table containing lkey to check SGE against
 139  * @pd: protection domain
 140  * @isge: outgoing internal SGE
 141  * @sge: SGE to check
 142  * @acc: access flags
 143  *
 144  * Return 1 if valid and successful, otherwise returns 0.
 145  *
 146  * increments the reference count upon success
 147  *
 148  * Check the IB SGE for validity and initialize our internal version
 149  * of it.
 150  */
 151 int qib_lkey_ok(struct qib_lkey_table *rkt, struct qib_pd *pd,
 152                 struct qib_sge *isge, struct ib_sge *sge, int acc)
 153 {
 154         struct qib_mregion *mr;
 155         unsigned n, m;
 156         size_t off;
 157
 158         /*
 159          * We use LKEY == zero for kernel virtual addresses
 160          * (see qib_get_dma_mr and qib_dma.c).
 161          */
 162         rcu_read_lock();
 163         if (sge->lkey == 0) {
 164                 struct qib_ibdev *dev = to_idev(pd->ibpd.device);
 165
 166                 if (pd->user)
 167                         goto bail;
 168                 mr = rcu_dereference(dev->dma_mr);
 169                 if (!mr)
 170                         goto bail;
 171                 if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
 172                         goto bail;
 173                 rcu_read_unlock();
 174
 175                 isge->mr = mr;
 176                 isge->vaddr = (void *) sge->addr;
 177                 isge->length = sge->length;
 178                 isge->sge_length = sge->length;
 179                 isge->m = 0;
 180                 isge->n = 0;
 181                 goto ok;
 182         }
 183         mr = rcu_dereference(
 184                 rkt->table[(sge->lkey >> (32 - ib_qib_lkey_table_size))]);
 185         if (unlikely(!mr || mr->lkey != sge->lkey || mr->pd != &pd->ibpd))
 186                 goto bail;
 187
 188         off = sge->addr - mr->user_base;
 189         if (unlikely(sge->addr < mr->user_base ||
 190                      off + sge->length > mr->length ||
 191                      (mr->access_flags & acc) != acc))
 192                 goto bail;
 193         if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
 194                 goto bail;
 195         rcu_read_unlock();
 196
 197         off += mr->offset;
 198         if (mr->page_shift) {
 199                 /*
 200                 page sizes are uniform power of 2 so no loop is necessary
 201                 entries_spanned_by_off is the number of times the loop below
 202                 would have executed.
 203                 */
 204                 size_t entries_spanned_by_off;
 205
 206                 entries_spanned_by_off = off >> mr->page_shift;
 207                 off -= (entries_spanned_by_off << mr->page_shift);
 208                 m = entries_spanned_by_off/QIB_SEGSZ;
 209                 n = entries_spanned_by_off%QIB_SEGSZ;
 210         } else {
 211                 m = 0;
 212                 n = 0;
 213                 while (off >= mr->map[m]->segs[n].length) {
 214                         off -= mr->map[m]->segs[n].length;
 215                         n++;
 216                         if (n >= QIB_SEGSZ) {
 217                                 m++;
 218                                 n = 0;
 219                         }
 220                 }
 221         }
 222         isge->mr = mr;
 223         isge->vaddr = mr->map[m]->segs[n].vaddr + off;
 224         isge->length = mr->map[m]->segs[n].length - off;
 225         isge->sge_length = sge->length;
 226         isge->m = m;
 227         isge->n = n;
 228 ok:
 229         return 1;
 230 bail:
 231         rcu_read_unlock();
 232         return 0;
 233 }
 234
 235 /**
 236  * qib_rkey_ok - check the IB virtual address, length, and RKEY
 237  * @qp: qp for validation
 238  * @sge: SGE state
 239  * @len: length of data
 240  * @vaddr: virtual address to place data
 241  * @rkey: rkey to check
 242  * @acc: access flags
 243  *
 244  * Return 1 if successful, otherwise 0.
 245  *
 246  * increments the reference count upon success
 247  */
 248 int qib_rkey_ok(struct qib_qp *qp, struct qib_sge *sge,
 249                 u32 len, u64 vaddr, u32 rkey, int acc)
 250 {
 251         struct qib_lkey_table *rkt = &to_idev(qp->ibqp.device)->lk_table;
 252         struct qib_mregion *mr;
 253         unsigned n, m;
 254         size_t off;
 255
 256         /*
 257          * We use RKEY == zero for kernel virtual addresses
 258          * (see qib_get_dma_mr and qib_dma.c).
 259          */
 260         rcu_read_lock();
 261         if (rkey == 0) {
 262                 struct qib_pd *pd = to_ipd(qp->ibqp.pd);
 263                 struct qib_ibdev *dev = to_idev(pd->ibpd.device);
 264
 265                 if (pd->user)
 266                         goto bail;
 267                 mr = rcu_dereference(dev->dma_mr);
 268                 if (!mr)
 269                         goto bail;
 270                 if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
 271                         goto bail;
 272                 rcu_read_unlock();
 273
 274                 sge->mr = mr;
 275                 sge->vaddr = (void *) vaddr;
 276                 sge->length = len;
 277                 sge->sge_length = len;
 278                 sge->m = 0;
 279                 sge->n = 0;
 280                 goto ok;
 281         }
 282
 283         mr = rcu_dereference(
 284                 rkt->table[(rkey >> (32 - ib_qib_lkey_table_size))]);
 285         if (unlikely(!mr || mr->lkey != rkey || qp->ibqp.pd != mr->pd))
 286                 goto bail;
 287
 288         off = vaddr - mr->iova;
 289         if (unlikely(vaddr < mr->iova || off + len > mr->length ||
 290                      (mr->access_flags & acc) == 0))
 291                 goto bail;
 292         if (unlikely(!atomic_inc_not_zero(&mr->refcount)))
 293                 goto bail;
 294         rcu_read_unlock();
 295
 296         off += mr->offset;
 297         if (mr->page_shift) {
 298                 /*
 299                 page sizes are uniform power of 2 so no loop is necessary
 300                 entries_spanned_by_off is the number of times the loop below
 301                 would have executed.
 302                 */
 303                 size_t entries_spanned_by_off;
 304
 305                 entries_spanned_by_off = off >> mr->page_shift;
 306                 off -= (entries_spanned_by_off << mr->page_shift);
 307                 m = entries_spanned_by_off/QIB_SEGSZ;
 308                 n = entries_spanned_by_off%QIB_SEGSZ;
 309         } else {
 310                 m = 0;
 311                 n = 0;
 312                 while (off >= mr->map[m]->segs[n].length) {
 313                         off -= mr->map[m]->segs[n].length;
 314                         n++;
 315                         if (n >= QIB_SEGSZ) {
 316                                 m++;
 317                                 n = 0;
 318                         }
 319                 }
 320         }
 321         sge->mr = mr;
 322         sge->vaddr = mr->map[m]->segs[n].vaddr + off;
 323         sge->length = mr->map[m]->segs[n].length - off;
 324         sge->sge_length = len;
 325         sge->m = m;
 326         sge->n = n;
 327 ok:
 328         return 1;
 329 bail:
 330         rcu_read_unlock();
 331         return 0;
 332 }
 333
 334 /*
 335  * Initialize the memory region specified by the work reqeust.
 336  */
 337 int qib_fast_reg_mr(struct qib_qp *qp, struct ib_send_wr *wr)
 338 {
 339         struct qib_lkey_table *rkt = &to_idev(qp->ibqp.device)->lk_table;
 340         struct qib_pd *pd = to_ipd(qp->ibqp.pd);
 341         struct qib_mregion *mr;
 342         u32 rkey = wr->wr.fast_reg.rkey;
 343         unsigned i, n, m;
 344         int ret = -EINVAL;
 345         unsigned long flags;
 346         u64 *page_list;
 347         size_t ps;
 348
 349         spin_lock_irqsave(&rkt->lock, flags);
 350         if (pd->user || rkey == 0)
 351                 goto bail;
 352
 353         mr = rcu_dereference_protected(
 354                 rkt->table[(rkey >> (32 - ib_qib_lkey_table_size))],
 355                 lockdep_is_held(&rkt->lock));
 356         if (unlikely(mr == NULL || qp->ibqp.pd != mr->pd))
 357                 goto bail;
 358
 359         if (wr->wr.fast_reg.page_list_len > mr->max_segs)
 360                 goto bail;
 361
 362         ps = 1UL << wr->wr.fast_reg.page_shift;
 363         if (wr->wr.fast_reg.length > ps * wr->wr.fast_reg.page_list_len)
 364                 goto bail;
 365
 366         mr->user_base = wr->wr.fast_reg.iova_start;
 367         mr->iova = wr->wr.fast_reg.iova_start;
 368         mr->lkey = rkey;
 369         mr->length = wr->wr.fast_reg.length;
 370         mr->access_flags = wr->wr.fast_reg.access_flags;
 371         page_list = wr->wr.fast_reg.page_list->page_list;
 372         m = 0;
 373         n = 0;
 374         for (i = 0; i < wr->wr.fast_reg.page_list_len; i++) {
 375                 mr->map[m]->segs[n].vaddr = (void *) page_list[i];
 376                 mr->map[m]->segs[n].length = ps;
 377                 if (++n == QIB_SEGSZ) {
 378                         m++;
 379                         n = 0;
 380                 }
 381         }
 382
 383         ret = 0;
 384 bail:
 385         spin_unlock_irqrestore(&rkt->lock, flags);
 386         return ret;
 387 }