LXR linux/drivers/infiniband/sw/rxe/rxe

   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
  12int 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
  40err2:
  41        kfree(ip);
  42err1:
  43        return err;
  44}
  45
  46inline 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
  55struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe, int *num_elem,
  56                        unsigned int elem_size, enum queue_type type)
  57{
  58        struct rxe_queue *q;
  59        size_t buf_size;
  60        unsigned int num_slots;
  61
  62        /* num_elem == 0 is allowed, but uninteresting */
  63        if (*num_elem < 0)
  64                goto err1;
  65
  66        q = kzalloc(sizeof(*q), GFP_KERNEL);
  67        if (!q)
  68                goto err1;
  69
  70        q->rxe = rxe;
  71        q->type = type;
  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
 101err2:
 102        kfree(q);
 103err1:
 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 */
 111static int resize_finish(struct rxe_queue *q, struct rxe_queue *new_q,
 112                         unsigned int num_elem)
 113{
 114        if (!queue_empty(q, q->type) && (num_elem < queue_count(q, q->type)))
 115                return -EINVAL;
 116
 117        while (!queue_empty(q, q->type)) {
 118                memcpy(producer_addr(new_q, new_q->type),
 119                                        consumer_addr(q, q->type),
 120                                        new_q->elem_size);
 121                advance_producer(new_q, new_q->type);
 122                advance_consumer(q, q->type);
 123        }
 124
 125        swap(*q, *new_q);
 126
 127        return 0;
 128}
 129
 130int rxe_queue_resize(struct rxe_queue *q, unsigned int *num_elem_p,
 131                     unsigned int elem_size, struct ib_udata *udata,
 132                     struct mminfo __user *outbuf, spinlock_t *producer_lock,
 133                     spinlock_t *consumer_lock)
 134{
 135        struct rxe_queue *new_q;
 136        unsigned int num_elem = *num_elem_p;
 137        int err;
 138        unsigned long flags = 0, flags1;
 139
 140        new_q = rxe_queue_init(q->rxe, &num_elem, elem_size, q->type);
 141        if (!new_q)
 142                return -ENOMEM;
 143
 144        err = do_mmap_info(new_q->rxe, outbuf, udata, new_q->buf,
 145                           new_q->buf_size, &new_q->ip);
 146        if (err) {
 147                vfree(new_q->buf);
 148                kfree(new_q);
 149                goto err1;
 150        }
 151
 152        spin_lock_irqsave(consumer_lock, flags1);
 153
 154        if (producer_lock) {
 155                spin_lock_irqsave(producer_lock, flags);
 156                err = resize_finish(q, new_q, num_elem);
 157                spin_unlock_irqrestore(producer_lock, flags);
 158        } else {
 159                err = resize_finish(q, new_q, num_elem);
 160        }
 161
 162        spin_unlock_irqrestore(consumer_lock, flags1);
 163
 164        rxe_queue_cleanup(new_q);       /* new/old dep on err */
 165        if (err)
 166                goto err1;
 167
 168        *num_elem_p = num_elem;
 169        return 0;
 170
 171err1:
 172        return err;
 173}
 174
 175void rxe_queue_cleanup(struct rxe_queue *q)
 176{
 177        if (q->ip)
 178                kref_put(&q->ip->ref, rxe_mmap_release);
 179        else
 180                vfree(q->buf);
 181
 182        kfree(q);
 183}
 184