drivers/infiniband/sw/rxe/rxe_queue.c

   1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
   2 /*
   3  * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
   4  * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
   5  */
   6
   7 #include <linux/vmalloc.h>
   8 #include "rxe.h"
   9 #include "rxe_loc.h"
  10 #include "rxe_queue.h"
  11
  12 int do_mmap_info(struct rxe_dev *rxe, struct mminfo __user *outbuf,
  13                  struct ib_udata *udata, struct rxe_queue_buf *buf,
  14                  size_t buf_size, struct rxe_mmap_info **ip_p)
  15 {
  16         int err;
  17         struct rxe_mmap_info *ip = NULL;
  18
  19         if (outbuf) {
  20                 ip = rxe_create_mmap_info(rxe, buf_size, udata, buf);
  21                 if (IS_ERR(ip)) {
  22                         err = PTR_ERR(ip);
  23                         goto err1;
  24                 }
  25
  26                 if (copy_to_user(outbuf, &ip->info, sizeof(ip->info))) {
  27                         err = -EFAULT;
  28                         goto err2;
  29                 }
  30
  31                 spin_lock_bh(&rxe->pending_lock);
  32                 list_add(&ip->pending_mmaps, &rxe->pending_mmaps);
  33                 spin_unlock_bh(&rxe->pending_lock);
  34         }
  35
  36         *ip_p = ip;
  37
  38         return 0;
  39
  40 err2:
  41         kfree(ip);
  42 err1:
  43         return err;
  44 }
  45
  46 inline void rxe_queue_reset(struct rxe_queue *q)
  47 {
  48         /* queue is comprised from header and the memory
  49          * of the actual queue. See "struct rxe_queue_buf" in rxe_queue.h
  50          * reset only the queue itself and not the management header
  51          */
  52         memset(q->buf->data, 0, q->buf_size - sizeof(struct rxe_queue_buf));
  53 }
  54
  55 struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe,
  56                                  int *num_elem,
  57                                  unsigned int elem_size)
  58 {
  59         struct rxe_queue *q;
  60         size_t buf_size;
  61         unsigned int num_slots;
  62
  63         /* num_elem == 0 is allowed, but uninteresting */
  64         if (*num_elem < 0)
  65                 goto err1;
  66
  67         q = kmalloc(sizeof(*q), GFP_KERNEL);
  68         if (!q)
  69                 goto err1;
  70
  71         q->rxe = rxe;
  72
  73         /* used in resize, only need to copy used part of queue */
  74         q->elem_size = elem_size;
  75
  76         /* pad element up to at least a cacheline and always a power of 2 */
  77         if (elem_size < cache_line_size())
  78                 elem_size = cache_line_size();
  79         elem_size = roundup_pow_of_two(elem_size);
  80
  81         q->log2_elem_size = order_base_2(elem_size);
  82
  83         num_slots = *num_elem + 1;
  84         num_slots = roundup_pow_of_two(num_slots);
  85         q->index_mask = num_slots - 1;
  86
  87         buf_size = sizeof(struct rxe_queue_buf) + num_slots * elem_size;
  88
  89         q->buf = vmalloc_user(buf_size);
  90         if (!q->buf)
  91                 goto err2;
  92
  93         q->buf->log2_elem_size = q->log2_elem_size;
  94         q->buf->index_mask = q->index_mask;
  95
  96         q->buf_size = buf_size;
  97
  98         *num_elem = num_slots - 1;
  99         return q;
 100
 101 err2:
 102         kfree(q);
 103 err1:
 104         return NULL;
 105 }
 106
 107 /* copies elements from original q to new q and then swaps the contents of the
 108  * two q headers. This is so that if anyone is holding a pointer to q it will
 109  * still work
 110  */
 111 static int resize_finish(struct rxe_queue *q, struct rxe_queue *new_q,
 112                          unsigned int num_elem)
 113 {
 114         if (!queue_empty(q) && (num_elem < queue_count(q)))
 115                 return -EINVAL;
 116
 117         while (!queue_empty(q)) {
 118                 memcpy(producer_addr(new_q), consumer_addr(q),
 119                        new_q->elem_size);
 120                 advance_producer(new_q);
 121                 advance_consumer(q);
 122         }
 123
 124         swap(*q, *new_q);
 125
 126         return 0;
 127 }
 128
 129 int rxe_queue_resize(struct rxe_queue *q, unsigned int *num_elem_p,
 130                      unsigned int elem_size, struct ib_udata *udata,
 131                      struct mminfo __user *outbuf, spinlock_t *producer_lock,
 132                      spinlock_t *consumer_lock)
 133 {
 134         struct rxe_queue *new_q;
 135         unsigned int num_elem = *num_elem_p;
 136         int err;
 137         unsigned long flags = 0, flags1;
 138
 139         new_q = rxe_queue_init(q->rxe, &num_elem, elem_size);
 140         if (!new_q)
 141                 return -ENOMEM;
 142
 143         err = do_mmap_info(new_q->rxe, outbuf, udata, new_q->buf,
 144                            new_q->buf_size, &new_q->ip);
 145         if (err) {
 146                 vfree(new_q->buf);
 147                 kfree(new_q);
 148                 goto err1;
 149         }
 150
 151         spin_lock_irqsave(consumer_lock, flags1);
 152
 153         if (producer_lock) {
 154                 spin_lock_irqsave(producer_lock, flags);
 155                 err = resize_finish(q, new_q, num_elem);
 156                 spin_unlock_irqrestore(producer_lock, flags);
 157         } else {
 158                 err = resize_finish(q, new_q, num_elem);
 159         }
 160
 161         spin_unlock_irqrestore(consumer_lock, flags1);
 162
 163         rxe_queue_cleanup(new_q);       /* new/old dep on err */
 164         if (err)
 165                 goto err1;
 166
 167         *num_elem_p = num_elem;
 168         return 0;
 169
 170 err1:
 171         return err;
 172 }
 173
 174 void rxe_queue_cleanup(struct rxe_queue *q)
 175 {
 176         if (q->ip)
 177                 kref_put(&q->ip->ref, rxe_mmap_release);
 178         else
 179                 vfree(q->buf);
 180
 181         kfree(q);
 182 }