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,
  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
 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) && (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
 129int 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
 170err1:
 171        return err;
 172}
 173
 174void 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}
 183