drivers/infiniband/sw/rxe/rxe_queue.c

   1 /*
   2  * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
   3  * Copyright (c) 2015 System Fabric Works, 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 retailuce 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/vmalloc.h>
  35 #include "rxe.h"
  36 #include "rxe_loc.h"
  37 #include "rxe_queue.h"
  38
  39 int do_mmap_info(struct rxe_dev *rxe,
  40                  struct ib_udata *udata,
  41                  bool is_req,
  42                  struct ib_ucontext *context,
  43                  struct rxe_queue_buf *buf,
  44                  size_t buf_size,
  45                  struct rxe_mmap_info **ip_p)
  46 {
  47         int err;
  48         u32 len, offset;
  49         struct rxe_mmap_info *ip = NULL;
  50
  51         if (udata) {
  52                 if (is_req) {
  53                         len = udata->outlen - sizeof(struct mminfo);
  54                         offset = sizeof(struct mminfo);
  55                 } else {
  56                         len = udata->outlen;
  57                         offset = 0;
  58                 }
  59
  60                 if (len < sizeof(ip->info))
  61                         goto err1;
  62
  63                 ip = rxe_create_mmap_info(rxe, buf_size, context, buf);
  64                 if (!ip)
  65                         goto err1;
  66
  67                 err = copy_to_user(udata->outbuf + offset, &ip->info,
  68                                    sizeof(ip->info));
  69                 if (err)
  70                         goto err2;
  71
  72                 spin_lock_bh(&rxe->pending_lock);
  73                 list_add(&ip->pending_mmaps, &rxe->pending_mmaps);
  74                 spin_unlock_bh(&rxe->pending_lock);
  75         }
  76
  77         *ip_p = ip;
  78
  79         return 0;
  80
  81 err2:
  82         kfree(ip);
  83 err1:
  84         return -EINVAL;
  85 }
  86
  87 inline void rxe_queue_reset(struct rxe_queue *q)
  88 {
  89         /* queue is comprised from header and the memory
  90          * of the actual queue. See "struct rxe_queue_buf" in rxe_queue.h
  91          * reset only the queue itself and not the management header
  92          */
  93         memset(q->buf->data, 0, q->buf_size - sizeof(struct rxe_queue_buf));
  94 }
  95
  96 struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe,
  97                                  int *num_elem,
  98                                  unsigned int elem_size)
  99 {
 100         struct rxe_queue *q;
 101         size_t buf_size;
 102         unsigned int num_slots;
 103
 104         /* num_elem == 0 is allowed, but uninteresting */
 105         if (*num_elem < 0)
 106                 goto err1;
 107
 108         q = kmalloc(sizeof(*q), GFP_KERNEL);
 109         if (!q)
 110                 goto err1;
 111
 112         q->rxe = rxe;
 113
 114         /* used in resize, only need to copy used part of queue */
 115         q->elem_size = elem_size;
 116
 117         /* pad element up to at least a cacheline and always a power of 2 */
 118         if (elem_size < cache_line_size())
 119                 elem_size = cache_line_size();
 120         elem_size = roundup_pow_of_two(elem_size);
 121
 122         q->log2_elem_size = order_base_2(elem_size);
 123
 124         num_slots = *num_elem + 1;
 125         num_slots = roundup_pow_of_two(num_slots);
 126         q->index_mask = num_slots - 1;
 127
 128         buf_size = sizeof(struct rxe_queue_buf) + num_slots * elem_size;
 129
 130         q->buf = vmalloc_user(buf_size);
 131         if (!q->buf)
 132                 goto err2;
 133
 134         q->buf->log2_elem_size = q->log2_elem_size;
 135         q->buf->index_mask = q->index_mask;
 136
 137         q->buf_size = buf_size;
 138
 139         *num_elem = num_slots - 1;
 140         return q;
 141
 142 err2:
 143         kfree(q);
 144 err1:
 145         return NULL;
 146 }
 147
 148 /* copies elements from original q to new q and then swaps the contents of the
 149  * two q headers. This is so that if anyone is holding a pointer to q it will
 150  * still work
 151  */
 152 static int resize_finish(struct rxe_queue *q, struct rxe_queue *new_q,
 153                          unsigned int num_elem)
 154 {
 155         if (!queue_empty(q) && (num_elem < queue_count(q)))
 156                 return -EINVAL;
 157
 158         while (!queue_empty(q)) {
 159                 memcpy(producer_addr(new_q), consumer_addr(q),
 160                        new_q->elem_size);
 161                 advance_producer(new_q);
 162                 advance_consumer(q);
 163         }
 164
 165         swap(*q, *new_q);
 166
 167         return 0;
 168 }
 169
 170 int rxe_queue_resize(struct rxe_queue *q,
 171                      unsigned int *num_elem_p,
 172                      unsigned int elem_size,
 173                      struct ib_ucontext *context,
 174                      struct ib_udata *udata,
 175                      spinlock_t *producer_lock,
 176                      spinlock_t *consumer_lock)
 177 {
 178         struct rxe_queue *new_q;
 179         unsigned int num_elem = *num_elem_p;
 180         int err;
 181         unsigned long flags = 0, flags1;
 182
 183         new_q = rxe_queue_init(q->rxe, &num_elem, elem_size);
 184         if (!new_q)
 185                 return -ENOMEM;
 186
 187         err = do_mmap_info(new_q->rxe, udata, false, context, new_q->buf,
 188                            new_q->buf_size, &new_q->ip);
 189         if (err) {
 190                 vfree(new_q->buf);
 191                 kfree(new_q);
 192                 goto err1;
 193         }
 194
 195         spin_lock_irqsave(consumer_lock, flags1);
 196
 197         if (producer_lock) {
 198                 spin_lock_irqsave(producer_lock, flags);
 199                 err = resize_finish(q, new_q, num_elem);
 200                 spin_unlock_irqrestore(producer_lock, flags);
 201         } else {
 202                 err = resize_finish(q, new_q, num_elem);
 203         }
 204
 205         spin_unlock_irqrestore(consumer_lock, flags1);
 206
 207         rxe_queue_cleanup(new_q);       /* new/old dep on err */
 208         if (err)
 209                 goto err1;
 210
 211         *num_elem_p = num_elem;
 212         return 0;
 213
 214 err1:
 215         return err;
 216 }
 217
 218 void rxe_queue_cleanup(struct rxe_queue *q)
 219 {
 220         if (q->ip)
 221                 kref_put(&q->ip->ref, rxe_mmap_release);
 222         else
 223                 vfree(q->buf);
 224
 225         kfree(q);
 226 }