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 struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe,
  88                                  int *num_elem,
  89                                  unsigned int elem_size)
  90 {
  91         struct rxe_queue *q;
  92         size_t buf_size;
  93         unsigned int num_slots;
  94
  95         /* num_elem == 0 is allowed, but uninteresting */
  96         if (*num_elem < 0)
  97                 goto err1;
  98
  99         q = kmalloc(sizeof(*q), GFP_KERNEL);
 100         if (!q)
 101                 goto err1;
 102
 103         q->rxe = rxe;
 104
 105         /* used in resize, only need to copy used part of queue */
 106         q->elem_size = elem_size;
 107
 108         /* pad element up to at least a cacheline and always a power of 2 */
 109         if (elem_size < cache_line_size())
 110                 elem_size = cache_line_size();
 111         elem_size = roundup_pow_of_two(elem_size);
 112
 113         q->log2_elem_size = order_base_2(elem_size);
 114
 115         num_slots = *num_elem + 1;
 116         num_slots = roundup_pow_of_two(num_slots);
 117         q->index_mask = num_slots - 1;
 118
 119         buf_size = sizeof(struct rxe_queue_buf) + num_slots * elem_size;
 120
 121         q->buf = vmalloc_user(buf_size);
 122         if (!q->buf)
 123                 goto err2;
 124
 125         q->buf->log2_elem_size = q->log2_elem_size;
 126         q->buf->index_mask = q->index_mask;
 127
 128         q->buf_size = buf_size;
 129
 130         *num_elem = num_slots - 1;
 131         return q;
 132
 133 err2:
 134         kfree(q);
 135 err1:
 136         return NULL;
 137 }
 138
 139 /* copies elements from original q to new q and then swaps the contents of the
 140  * two q headers. This is so that if anyone is holding a pointer to q it will
 141  * still work
 142  */
 143 static int resize_finish(struct rxe_queue *q, struct rxe_queue *new_q,
 144                          unsigned int num_elem)
 145 {
 146         if (!queue_empty(q) && (num_elem < queue_count(q)))
 147                 return -EINVAL;
 148
 149         while (!queue_empty(q)) {
 150                 memcpy(producer_addr(new_q), consumer_addr(q),
 151                        new_q->elem_size);
 152                 advance_producer(new_q);
 153                 advance_consumer(q);
 154         }
 155
 156         swap(*q, *new_q);
 157
 158         return 0;
 159 }
 160
 161 int rxe_queue_resize(struct rxe_queue *q,
 162                      unsigned int *num_elem_p,
 163                      unsigned int elem_size,
 164                      struct ib_ucontext *context,
 165                      struct ib_udata *udata,
 166                      spinlock_t *producer_lock,
 167                      spinlock_t *consumer_lock)
 168 {
 169         struct rxe_queue *new_q;
 170         unsigned int num_elem = *num_elem_p;
 171         int err;
 172         unsigned long flags = 0, flags1;
 173
 174         new_q = rxe_queue_init(q->rxe, &num_elem, elem_size);
 175         if (!new_q)
 176                 return -ENOMEM;
 177
 178         err = do_mmap_info(new_q->rxe, udata, false, context, new_q->buf,
 179                            new_q->buf_size, &new_q->ip);
 180         if (err) {
 181                 vfree(new_q->buf);
 182                 kfree(new_q);
 183                 goto err1;
 184         }
 185
 186         spin_lock_irqsave(consumer_lock, flags1);
 187
 188         if (producer_lock) {
 189                 spin_lock_irqsave(producer_lock, flags);
 190                 err = resize_finish(q, new_q, num_elem);
 191                 spin_unlock_irqrestore(producer_lock, flags);
 192         } else {
 193                 err = resize_finish(q, new_q, num_elem);
 194         }
 195
 196         spin_unlock_irqrestore(consumer_lock, flags1);
 197
 198         rxe_queue_cleanup(new_q);       /* new/old dep on err */
 199         if (err)
 200                 goto err1;
 201
 202         *num_elem_p = num_elem;
 203         return 0;
 204
 205 err1:
 206         return err;
 207 }
 208
 209 void rxe_queue_cleanup(struct rxe_queue *q)
 210 {
 211         if (q->ip)
 212                 kref_put(&q->ip->ref, rxe_mmap_release);
 213         else
 214                 vfree(q->buf);
 215
 216         kfree(q);
 217 }