net/core/netdev_rx_queue.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2
   3 #include <linux/netdevice.h>
   4 #include <net/netdev_queues.h>
   5 #include <net/netdev_rx_queue.h>
   6
   7 #include "page_pool_priv.h"
   8
   9 int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
  10 {
  11         struct netdev_rx_queue *rxq = __netif_get_rx_queue(dev, rxq_idx);
  12         void *new_mem, *old_mem;
  13         int err;
  14
  15         if (!dev->queue_mgmt_ops || !dev->queue_mgmt_ops->ndo_queue_stop ||
  16             !dev->queue_mgmt_ops->ndo_queue_mem_free ||
  17             !dev->queue_mgmt_ops->ndo_queue_mem_alloc ||
  18             !dev->queue_mgmt_ops->ndo_queue_start)
  19                 return -EOPNOTSUPP;
  20
  21         ASSERT_RTNL();
  22
  23         new_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL);
  24         if (!new_mem)
  25                 return -ENOMEM;
  26
  27         old_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL);
  28         if (!old_mem) {
  29                 err = -ENOMEM;
  30                 goto err_free_new_mem;
  31         }
  32
  33         err = dev->queue_mgmt_ops->ndo_queue_mem_alloc(dev, new_mem, rxq_idx);
  34         if (err)
  35                 goto err_free_old_mem;
  36
  37         err = page_pool_check_memory_provider(dev, rxq);
  38         if (err)
  39                 goto err_free_new_queue_mem;
  40
  41         err = dev->queue_mgmt_ops->ndo_queue_stop(dev, old_mem, rxq_idx);
  42         if (err)
  43                 goto err_free_new_queue_mem;
  44
  45         err = dev->queue_mgmt_ops->ndo_queue_start(dev, new_mem, rxq_idx);
  46         if (err)
  47                 goto err_start_queue;
  48
  49         dev->queue_mgmt_ops->ndo_queue_mem_free(dev, old_mem);
  50
  51         kvfree(old_mem);
  52         kvfree(new_mem);
  53
  54         return 0;
  55
  56 err_start_queue:
  57         /* Restarting the queue with old_mem should be successful as we haven't
  58          * changed any of the queue configuration, and there is not much we can
  59          * do to recover from a failure here.
  60          *
  61          * WARN if we fail to recover the old rx queue, and at least free
  62          * old_mem so we don't also leak that.
  63          */
  64         if (dev->queue_mgmt_ops->ndo_queue_start(dev, old_mem, rxq_idx)) {
  65                 WARN(1,
  66                      "Failed to restart old queue in error path. RX queue %d may be unhealthy.",
  67                      rxq_idx);
  68                 dev->queue_mgmt_ops->ndo_queue_mem_free(dev, old_mem);
  69         }
  70
  71 err_free_new_queue_mem:
  72         dev->queue_mgmt_ops->ndo_queue_mem_free(dev, new_mem);
  73
  74 err_free_old_mem:
  75         kvfree(old_mem);
  76
  77 err_free_new_mem:
  78         kvfree(new_mem);
  79
  80         return err;
  81 }