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