From 1580cbcbfe770b0a7fb76735c1a601483335c1c2 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 12 Apr 2024 07:14:31 -0700 Subject: net: netdevsim: add some fake page pool use Add very basic page pool use so that we can exercise the netlink uAPI in a selftest. Page pool gets created on open, destroyed on close. But we control allocating of a single page thru debugfs. This page may survive past the page pool itself so that we can test orphaned page pools. Link: https://lore.kernel.org/r/20240412141436.828666-2-kuba@kernel.org Signed-off-by: Jakub Kicinski --- drivers/net/netdevsim/netdev.c | 93 +++++++++++++++++++++++++++++++++++++++ drivers/net/netdevsim/netdevsim.h | 4 ++ 2 files changed, 97 insertions(+) diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c index d7ba447db17c..d127856f8f36 100644 --- a/drivers/net/netdevsim/netdev.c +++ b/drivers/net/netdevsim/netdev.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -299,6 +300,29 @@ static int nsim_get_iflink(const struct net_device *dev) return iflink; } +static int nsim_open(struct net_device *dev) +{ + struct netdevsim *ns = netdev_priv(dev); + struct page_pool_params pp = { 0 }; + + pp.pool_size = 128; + pp.dev = &dev->dev; + pp.dma_dir = DMA_BIDIRECTIONAL; + pp.netdev = dev; + + ns->pp = page_pool_create(&pp); + return PTR_ERR_OR_ZERO(ns->pp); +} + +static int nsim_stop(struct net_device *dev) +{ + struct netdevsim *ns = netdev_priv(dev); + + page_pool_destroy(ns->pp); + + return 0; +} + static const struct net_device_ops nsim_netdev_ops = { .ndo_start_xmit = nsim_start_xmit, .ndo_set_rx_mode = nsim_set_rx_mode, @@ -318,6 +342,8 @@ static const struct net_device_ops nsim_netdev_ops = { .ndo_set_features = nsim_set_features, .ndo_get_iflink = nsim_get_iflink, .ndo_bpf = nsim_bpf, + .ndo_open = nsim_open, + .ndo_stop = nsim_stop, }; static const struct net_device_ops nsim_vf_netdev_ops = { @@ -378,6 +404,60 @@ static const struct netdev_stat_ops nsim_stat_ops = { .get_base_stats = nsim_get_base_stats, }; +static ssize_t +nsim_pp_hold_read(struct file *file, char __user *data, + size_t count, loff_t *ppos) +{ + struct netdevsim *ns = file->private_data; + char buf[3] = "n\n"; + + if (ns->page) + buf[0] = 'y'; + + return simple_read_from_buffer(data, count, ppos, buf, 2); +} + +static ssize_t +nsim_pp_hold_write(struct file *file, const char __user *data, + size_t count, loff_t *ppos) +{ + struct netdevsim *ns = file->private_data; + ssize_t ret; + bool val; + + ret = kstrtobool_from_user(data, count, &val); + if (ret) + return ret; + + rtnl_lock(); + ret = count; + if (val == !!ns->page) + goto exit; + + if (!netif_running(ns->netdev) && val) { + ret = -ENETDOWN; + } else if (val) { + ns->page = page_pool_dev_alloc_pages(ns->pp); + if (!ns->page) + ret = -ENOMEM; + } else { + page_pool_put_full_page(ns->page->pp, ns->page, false); + ns->page = NULL; + } + rtnl_unlock(); + +exit: + return count; +} + +static const struct file_operations nsim_pp_hold_fops = { + .open = simple_open, + .read = nsim_pp_hold_read, + .write = nsim_pp_hold_write, + .llseek = generic_file_llseek, + .owner = THIS_MODULE, +}; + static void nsim_setup(struct net_device *dev) { ether_setup(dev); @@ -485,6 +565,10 @@ nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port) err = nsim_init_netdevsim_vf(ns); if (err) goto err_free_netdev; + + ns->pp_dfs = debugfs_create_file("pp_hold", 0600, nsim_dev_port->ddir, + ns, &nsim_pp_hold_fops); + return ns; err_free_netdev: @@ -497,6 +581,8 @@ void nsim_destroy(struct netdevsim *ns) struct net_device *dev = ns->netdev; struct netdevsim *peer; + debugfs_remove(ns->pp_dfs); + rtnl_lock(); peer = rtnl_dereference(ns->peer); if (peer) @@ -511,6 +597,13 @@ void nsim_destroy(struct netdevsim *ns) rtnl_unlock(); if (nsim_dev_port_is_pf(ns->nsim_dev_port)) nsim_exit_netdevsim(ns); + + /* Put this intentionally late to exercise the orphaning path */ + if (ns->page) { + page_pool_put_full_page(ns->page->pp, ns->page, false); + ns->page = NULL; + } + free_netdev(dev); } diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h index 553c4b9b4f63..7664ab823e29 100644 --- a/drivers/net/netdevsim/netdevsim.h +++ b/drivers/net/netdevsim/netdevsim.h @@ -125,6 +125,10 @@ struct netdevsim { struct debugfs_u32_array dfs_ports[2]; } udp_ports; + struct page_pool *pp; + struct page *page; + struct dentry *pp_dfs; + struct nsim_ethtool ethtool; struct netdevsim __rcu *peer; }; -- cgit v1.2.3