From e2c9bb0297a32eedab83294e350896053900e20a Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Thu, 28 Jul 2022 09:02:48 +0200 Subject: can: slcan: use KBUILD_MODNAME and define pr_fmt to replace hardcoded names The driver uses the string "slcan" to populate tty_ldisc_ops::name. KBUILD_MODNAME also evaluates to "slcan". Use KBUILD_MODNAME to get rid on the hardcoded string names. Similarly, the pr_info() and pr_err() hardcoded the "slcan" prefix. Define pr_fmt so that the "slcan" prefix gets automatically added. CC: Dario Binacchi Signed-off-by: Vincent Mailhol Signed-off-by: Dario Binacchi Link: https://lore.kernel.org/all/20220728070254.267974-2-dario.binacchi@amarulasolutions.com Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan/slcan-core.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c index 6162e6132ea4..3b1f39d69e6e 100644 --- a/drivers/net/can/slcan/slcan-core.c +++ b/drivers/net/can/slcan/slcan-core.c @@ -35,6 +35,8 @@ * */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include #include @@ -864,7 +866,7 @@ static struct slcan *slc_alloc(void) if (!dev) return NULL; - snprintf(dev->name, sizeof(dev->name), "slcan%d", i); + snprintf(dev->name, sizeof(dev->name), KBUILD_MODNAME "%d", i); dev->netdev_ops = &slc_netdev_ops; dev->ethtool_ops = &slcan_ethtool_ops; dev->base_addr = i; @@ -937,7 +939,7 @@ static int slcan_open(struct tty_struct *tty) rtnl_unlock(); err = register_candev(sl->dev); if (err) { - pr_err("slcan: can't register candev\n"); + pr_err("can't register candev\n"); goto err_free_chan; } } else { @@ -1028,7 +1030,7 @@ static int slcan_ioctl(struct tty_struct *tty, unsigned int cmd, static struct tty_ldisc_ops slc_ldisc = { .owner = THIS_MODULE, .num = N_SLCAN, - .name = "slcan", + .name = KBUILD_MODNAME, .open = slcan_open, .close = slcan_close, .hangup = slcan_hangup, @@ -1044,8 +1046,8 @@ static int __init slcan_init(void) if (maxdev < 4) maxdev = 4; /* Sanity */ - pr_info("slcan: serial line CAN interface driver\n"); - pr_info("slcan: %d dynamic interface channels.\n", maxdev); + pr_info("serial line CAN interface driver\n"); + pr_info("%d dynamic interface channels.\n", maxdev); slcan_devs = kcalloc(maxdev, sizeof(struct net_device *), GFP_KERNEL); if (!slcan_devs) @@ -1054,7 +1056,7 @@ static int __init slcan_init(void) /* Fill in our line protocol discipline, and register it */ status = tty_register_ldisc(&slc_ldisc); if (status) { - pr_err("slcan: can't register line discipline\n"); + pr_err("can't register line discipline\n"); kfree(slcan_devs); } return status; -- cgit v1.2.3 From 7a1fc3eea76f0d85ddfaede0885fca765d17cf6a Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Thu, 28 Jul 2022 09:02:49 +0200 Subject: can: slcan: remove useless header inclusions Include only the necessary headers. Signed-off-by: Dario Binacchi Link: https://lore.kernel.org/all/20220728070254.267974-3-dario.binacchi@amarulasolutions.com Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan/slcan-core.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c index 3b1f39d69e6e..509053ea1742 100644 --- a/drivers/net/can/slcan/slcan-core.c +++ b/drivers/net/can/slcan/slcan-core.c @@ -48,9 +48,6 @@ #include #include #include -#include -#include -#include #include #include #include -- cgit v1.2.3 From cfcb4465e9923bb9ac168abcea84e880633f9cef Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Thu, 28 Jul 2022 09:02:50 +0200 Subject: can: slcan: remove legacy infrastructure Taking inspiration from the drivers/net/can/can327.c driver and at the suggestion of its author Max Staudt, I removed legacy stuff like `SLCAN_MAGIC' and `slcan_devs' resulting in simplification of the code and its maintainability. The use of slcan_devs is derived from a very old kernel, since slip.c is about 30 years old, so today's kernel allows us to remove it. The .hangup() ldisc function, which only called the ldisc .close(), has been removed since the ldisc layer calls .close() in a good place anyway. The old slcanX name has been dropped in order to use the standard canX interface naming. The ioctl SIOCGIFNAME can be used to query the name of the created interface. Furthermore, there are several ways to get stable interfaces names in user space, e.g. udev or systemd-networkd. The `maxdev' module parameter has also been removed. CC: Max Staudt Signed-off-by: Dario Binacchi Reviewed-by: Max Staudt Link: https://lore.kernel.org/all/20220728070254.267974-4-dario.binacchi@amarulasolutions.com Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan/slcan-core.c | 318 ++++++++----------------------------- 1 file changed, 63 insertions(+), 255 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c index 509053ea1742..133a9e045760 100644 --- a/drivers/net/can/slcan/slcan-core.c +++ b/drivers/net/can/slcan/slcan-core.c @@ -1,11 +1,14 @@ /* * slcan.c - serial line CAN interface driver (using tty line discipline) * - * This file is derived from linux/drivers/net/slip/slip.c + * This file is derived from linux/drivers/net/slip/slip.c and got + * inspiration from linux/drivers/net/can/can327.c for the rework made + * on the line discipline code. * * slip.c Authors : Laurence Culhane * Fred N. van Kempen * slcan.c Author : Oliver Hartkopp + * can327.c Author : Max Staudt * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the @@ -38,7 +41,6 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include -#include #include #include @@ -48,7 +50,6 @@ #include #include #include -#include #include #include #include @@ -63,15 +64,6 @@ MODULE_DESCRIPTION("serial line CAN interface"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Oliver Hartkopp "); -#define SLCAN_MAGIC 0x53CA - -static int maxdev = 10; /* MAX number of SLCAN channels; - * This can be overridden with - * insmod slcan.ko maxdev=nnn - */ -module_param(maxdev, int, 0); -MODULE_PARM_DESC(maxdev, "Maximum number of slcan interfaces"); - /* maximum rx buffer len: extended CAN frame with timestamp */ #define SLC_MTU (sizeof("T1111222281122334455667788EA5F\r") + 1) @@ -85,7 +77,6 @@ MODULE_PARM_DESC(maxdev, "Maximum number of slcan interfaces"); SLC_STATE_BE_TXCNT_LEN) struct slcan { struct can_priv can; - int magic; /* Various fields. */ struct tty_struct *tty; /* ptr to TTY structure */ @@ -101,17 +92,14 @@ struct slcan { int xleft; /* bytes left in XMIT queue */ unsigned long flags; /* Flag values/ mode etc */ -#define SLF_INUSE 0 /* Channel in use */ -#define SLF_ERROR 1 /* Parity, etc. error */ -#define SLF_XCMD 2 /* Command transmission */ +#define SLF_ERROR 0 /* Parity, etc. error */ +#define SLF_XCMD 1 /* Command transmission */ unsigned long cmd_flags; /* Command flags */ #define CF_ERR_RST 0 /* Reset errors on open */ wait_queue_head_t xcmd_wait; /* Wait queue for commands */ /* transmission */ }; -static struct net_device **slcan_devs; - static const u32 slcan_bitrate_const[] = { 10000, 20000, 50000, 100000, 125000, 250000, 500000, 800000, 1000000 @@ -556,9 +544,8 @@ static void slcan_transmit(struct work_struct *work) spin_lock_bh(&sl->lock); /* First make sure we're connected. */ - if (!sl->tty || sl->magic != SLCAN_MAGIC || - (unlikely(!netif_running(sl->dev)) && - likely(!test_bit(SLF_XCMD, &sl->flags)))) { + if (unlikely(!netif_running(sl->dev)) && + likely(!test_bit(SLF_XCMD, &sl->flags))) { spin_unlock_bh(&sl->lock); return; } @@ -593,13 +580,9 @@ static void slcan_transmit(struct work_struct *work) */ static void slcan_write_wakeup(struct tty_struct *tty) { - struct slcan *sl; + struct slcan *sl = (struct slcan *)tty->disc_data; - rcu_read_lock(); - sl = rcu_dereference(tty->disc_data); - if (sl) - schedule_work(&sl->tx_work); - rcu_read_unlock(); + schedule_work(&sl->tx_work); } /* Send a can_frame to a TTY queue. */ @@ -670,25 +653,21 @@ static int slc_close(struct net_device *dev) struct slcan *sl = netdev_priv(dev); int err; - spin_lock_bh(&sl->lock); - if (sl->tty) { - if (sl->can.bittiming.bitrate && - sl->can.bittiming.bitrate != CAN_BITRATE_UNKNOWN) { - spin_unlock_bh(&sl->lock); - err = slcan_transmit_cmd(sl, "C\r"); - spin_lock_bh(&sl->lock); - if (err) - netdev_warn(dev, - "failed to send close command 'C\\r'\n"); - } - - /* TTY discipline is running. */ - clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); + if (sl->can.bittiming.bitrate && + sl->can.bittiming.bitrate != CAN_BITRATE_UNKNOWN) { + err = slcan_transmit_cmd(sl, "C\r"); + if (err) + netdev_warn(dev, + "failed to send close command 'C\\r'\n"); } + + /* TTY discipline is running. */ + clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags); + flush_work(&sl->tx_work); + netif_stop_queue(dev); sl->rcount = 0; sl->xleft = 0; - spin_unlock_bh(&sl->lock); close_candev(dev); sl->can.state = CAN_STATE_STOPPED; if (sl->can.bittiming.bitrate == CAN_BITRATE_UNKNOWN) @@ -704,9 +683,6 @@ static int slc_open(struct net_device *dev) unsigned char cmd[SLC_MTU]; int err, s; - if (!sl->tty) - return -ENODEV; - /* The baud rate is not set with the command * `ip link set type can bitrate ' and therefore * can.bittiming.bitrate is CAN_BITRATE_UNSET (0), causing @@ -721,8 +697,6 @@ static int slc_open(struct net_device *dev) return err; } - sl->flags &= BIT(SLF_INUSE); - if (sl->can.bittiming.bitrate != CAN_BITRATE_UNKNOWN) { for (s = 0; s < ARRAY_SIZE(slcan_bitrate_const); s++) { if (sl->can.bittiming.bitrate == slcan_bitrate_const[s]) @@ -766,14 +740,6 @@ cmd_transmit_failed: return err; } -static void slc_dealloc(struct slcan *sl) -{ - int i = sl->dev->base_addr; - - free_candev(sl->dev); - slcan_devs[i] = NULL; -} - static int slcan_change_mtu(struct net_device *dev, int new_mtu) { return -EINVAL; @@ -803,7 +769,7 @@ static void slcan_receive_buf(struct tty_struct *tty, { struct slcan *sl = (struct slcan *)tty->disc_data; - if (!sl || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev)) + if (!netif_running(sl->dev)) return; /* Read the characters out of the buffer */ @@ -818,80 +784,15 @@ static void slcan_receive_buf(struct tty_struct *tty, } } -/************************************ - * slcan_open helper routines. - ************************************/ - -/* Collect hanged up channels */ -static void slc_sync(void) -{ - int i; - struct net_device *dev; - struct slcan *sl; - - for (i = 0; i < maxdev; i++) { - dev = slcan_devs[i]; - if (!dev) - break; - - sl = netdev_priv(dev); - if (sl->tty) - continue; - if (dev->flags & IFF_UP) - dev_close(dev); - } -} - -/* Find a free SLCAN channel, and link in this `tty' line. */ -static struct slcan *slc_alloc(void) -{ - int i; - struct net_device *dev = NULL; - struct slcan *sl; - - for (i = 0; i < maxdev; i++) { - dev = slcan_devs[i]; - if (!dev) - break; - } - - /* Sorry, too many, all slots in use */ - if (i >= maxdev) - return NULL; - - dev = alloc_candev(sizeof(*sl), 1); - if (!dev) - return NULL; - - snprintf(dev->name, sizeof(dev->name), KBUILD_MODNAME "%d", i); - dev->netdev_ops = &slc_netdev_ops; - dev->ethtool_ops = &slcan_ethtool_ops; - dev->base_addr = i; - sl = netdev_priv(dev); - - /* Initialize channel control data */ - sl->magic = SLCAN_MAGIC; - sl->dev = dev; - sl->can.bitrate_const = slcan_bitrate_const; - sl->can.bitrate_const_cnt = ARRAY_SIZE(slcan_bitrate_const); - spin_lock_init(&sl->lock); - INIT_WORK(&sl->tx_work, slcan_transmit); - init_waitqueue_head(&sl->xcmd_wait); - slcan_devs[i] = dev; - - return sl; -} - /* Open the high-level part of the SLCAN channel. * This function is called by the TTY module when the - * SLCAN line discipline is called for. Because we are - * sure the tty line exists, we only have to link it to - * a free SLCAN channel... + * SLCAN line discipline is called for. * * Called in process context serialized from other ldisc calls. */ static int slcan_open(struct tty_struct *tty) { + struct net_device *dev; struct slcan *sl; int err; @@ -901,72 +802,49 @@ static int slcan_open(struct tty_struct *tty) if (!tty->ops->write) return -EOPNOTSUPP; - /* RTnetlink lock is misused here to serialize concurrent - * opens of slcan channels. There are better ways, but it is - * the simplest one. - */ - rtnl_lock(); + dev = alloc_candev(sizeof(*sl), 1); + if (!dev) + return -ENFILE; - /* Collect hanged up channels. */ - slc_sync(); + sl = netdev_priv(dev); - sl = tty->disc_data; + /* Configure TTY interface */ + tty->receive_room = 65536; /* We don't flow control */ + sl->rcount = 0; + sl->xleft = 0; + spin_lock_init(&sl->lock); + INIT_WORK(&sl->tx_work, slcan_transmit); + init_waitqueue_head(&sl->xcmd_wait); - err = -EEXIST; - /* First make sure we're not already connected. */ - if (sl && sl->magic == SLCAN_MAGIC) - goto err_exit; + /* Configure CAN metadata */ + sl->can.bitrate_const = slcan_bitrate_const; + sl->can.bitrate_const_cnt = ARRAY_SIZE(slcan_bitrate_const); - /* OK. Find a free SLCAN channel to use. */ - err = -ENFILE; - sl = slc_alloc(); - if (!sl) - goto err_exit; + /* Configure netdev interface */ + sl->dev = dev; + dev->netdev_ops = &slc_netdev_ops; + dev->ethtool_ops = &slcan_ethtool_ops; + /* Mark ldisc channel as alive */ sl->tty = tty; tty->disc_data = sl; - if (!test_bit(SLF_INUSE, &sl->flags)) { - /* Perform the low-level SLCAN initialization. */ - sl->rcount = 0; - sl->xleft = 0; - - set_bit(SLF_INUSE, &sl->flags); - - rtnl_unlock(); - err = register_candev(sl->dev); - if (err) { - pr_err("can't register candev\n"); - goto err_free_chan; - } - } else { - rtnl_unlock(); + err = register_candev(dev); + if (err) { + free_candev(dev); + pr_err("can't register candev\n"); + return err; } - tty->receive_room = 65536; /* We don't flow control */ - + netdev_info(dev, "slcan on %s.\n", tty->name); /* TTY layer expects 0 on success */ return 0; - -err_free_chan: - rtnl_lock(); - sl->tty = NULL; - tty->disc_data = NULL; - clear_bit(SLF_INUSE, &sl->flags); - slc_dealloc(sl); - rtnl_unlock(); - return err; - -err_exit: - rtnl_unlock(); - - /* Count references from TTY module */ - return err; } /* Close down a SLCAN channel. * This means flushing out any pending queues, and then returning. This * call is serialized against other ldisc functions. + * Once this is called, no other ldisc function of ours is entered. * * We also use this method for a hangup event. */ @@ -974,28 +852,20 @@ static void slcan_close(struct tty_struct *tty) { struct slcan *sl = (struct slcan *)tty->disc_data; - /* First make sure we're connected. */ - if (!sl || sl->magic != SLCAN_MAGIC || sl->tty != tty) - return; + /* unregister_netdev() calls .ndo_stop() so we don't have to. + * Our .ndo_stop() also flushes the TTY write wakeup handler, + * so we can safely set sl->tty = NULL after this. + */ + unregister_candev(sl->dev); + /* Mark channel as dead */ spin_lock_bh(&sl->lock); - rcu_assign_pointer(tty->disc_data, NULL); + tty->disc_data = NULL; sl->tty = NULL; spin_unlock_bh(&sl->lock); - synchronize_rcu(); - flush_work(&sl->tx_work); - - slc_close(sl->dev); - unregister_candev(sl->dev); - rtnl_lock(); - slc_dealloc(sl); - rtnl_unlock(); -} - -static void slcan_hangup(struct tty_struct *tty) -{ - slcan_close(tty); + netdev_info(sl->dev, "slcan off %s.\n", tty->name); + free_candev(sl->dev); } /* Perform I/O control on an active SLCAN channel. */ @@ -1005,10 +875,6 @@ static int slcan_ioctl(struct tty_struct *tty, unsigned int cmd, struct slcan *sl = (struct slcan *)tty->disc_data; unsigned int tmp; - /* First make sure we're connected. */ - if (!sl || sl->magic != SLCAN_MAGIC) - return -EINVAL; - switch (cmd) { case SIOCGIFNAME: tmp = strlen(sl->dev->name) + 1; @@ -1030,7 +896,6 @@ static struct tty_ldisc_ops slc_ldisc = { .name = KBUILD_MODNAME, .open = slcan_open, .close = slcan_close, - .hangup = slcan_hangup, .ioctl = slcan_ioctl, .receive_buf = slcan_receive_buf, .write_wakeup = slcan_write_wakeup, @@ -1040,78 +905,21 @@ static int __init slcan_init(void) { int status; - if (maxdev < 4) - maxdev = 4; /* Sanity */ - pr_info("serial line CAN interface driver\n"); - pr_info("%d dynamic interface channels.\n", maxdev); - - slcan_devs = kcalloc(maxdev, sizeof(struct net_device *), GFP_KERNEL); - if (!slcan_devs) - return -ENOMEM; /* Fill in our line protocol discipline, and register it */ status = tty_register_ldisc(&slc_ldisc); - if (status) { + if (status) pr_err("can't register line discipline\n"); - kfree(slcan_devs); - } + return status; } static void __exit slcan_exit(void) { - int i; - struct net_device *dev; - struct slcan *sl; - unsigned long timeout = jiffies + HZ; - int busy = 0; - - if (!slcan_devs) - return; - - /* First of all: check for active disciplines and hangup them. - */ - do { - if (busy) - msleep_interruptible(100); - - busy = 0; - for (i = 0; i < maxdev; i++) { - dev = slcan_devs[i]; - if (!dev) - continue; - sl = netdev_priv(dev); - spin_lock_bh(&sl->lock); - if (sl->tty) { - busy++; - tty_hangup(sl->tty); - } - spin_unlock_bh(&sl->lock); - } - } while (busy && time_before(jiffies, timeout)); - - /* FIXME: hangup is async so we should wait when doing this second - * phase + /* This will only be called when all channels have been closed by + * userspace - tty_ldisc.c takes care of the module's refcount. */ - - for (i = 0; i < maxdev; i++) { - dev = slcan_devs[i]; - if (!dev) - continue; - - sl = netdev_priv(dev); - if (sl->tty) - netdev_err(dev, "tty discipline still running\n"); - - slc_close(dev); - unregister_candev(dev); - slc_dealloc(sl); - } - - kfree(slcan_devs); - slcan_devs = NULL; - tty_unregister_ldisc(&slc_ldisc); } -- cgit v1.2.3 From 0cef03b109ca671252cf00481eabc3032acb9d80 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Thu, 28 Jul 2022 09:02:51 +0200 Subject: can: slcan: change every `slc' occurrence in `slcan' In the driver there are parts of code where the prefix `slc' is used and others where the prefix `slcan' is used instead. The patch replaces every occurrence of `slc' with `slcan', except for the netdev functions where, to avoid compilation conflicts, it was necessary to replace `slc' with `slcan_netdev'. The patch does not make any functional changes. Signed-off-by: Dario Binacchi Link: https://lore.kernel.org/all/20220728070254.267974-5-dario.binacchi@amarulasolutions.com Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan/slcan-core.c | 109 +++++++++++++++++++------------------ 1 file changed, 56 insertions(+), 53 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c index 133a9e045760..3a4701d8e081 100644 --- a/drivers/net/can/slcan/slcan-core.c +++ b/drivers/net/can/slcan/slcan-core.c @@ -65,16 +65,17 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Oliver Hartkopp "); /* maximum rx buffer len: extended CAN frame with timestamp */ -#define SLC_MTU (sizeof("T1111222281122334455667788EA5F\r") + 1) - -#define SLC_CMD_LEN 1 -#define SLC_SFF_ID_LEN 3 -#define SLC_EFF_ID_LEN 8 -#define SLC_STATE_LEN 1 -#define SLC_STATE_BE_RXCNT_LEN 3 -#define SLC_STATE_BE_TXCNT_LEN 3 -#define SLC_STATE_FRAME_LEN (1 + SLC_CMD_LEN + SLC_STATE_BE_RXCNT_LEN + \ - SLC_STATE_BE_TXCNT_LEN) +#define SLCAN_MTU (sizeof("T1111222281122334455667788EA5F\r") + 1) + +#define SLCAN_CMD_LEN 1 +#define SLCAN_SFF_ID_LEN 3 +#define SLCAN_EFF_ID_LEN 8 +#define SLCAN_STATE_LEN 1 +#define SLCAN_STATE_BE_RXCNT_LEN 3 +#define SLCAN_STATE_BE_TXCNT_LEN 3 +#define SLCAN_STATE_FRAME_LEN (1 + SLCAN_CMD_LEN + \ + SLCAN_STATE_BE_RXCNT_LEN + \ + SLCAN_STATE_BE_TXCNT_LEN) struct slcan { struct can_priv can; @@ -85,9 +86,9 @@ struct slcan { struct work_struct tx_work; /* Flushes transmit buffer */ /* These are pointers to the malloc()ed frame buffers. */ - unsigned char rbuff[SLC_MTU]; /* receiver buffer */ + unsigned char rbuff[SLCAN_MTU]; /* receiver buffer */ int rcount; /* received chars counter */ - unsigned char xbuff[SLC_MTU]; /* transmitter buffer */ + unsigned char xbuff[SLCAN_MTU]; /* transmitter buffer*/ unsigned char *xhead; /* pointer to next XMIT byte */ int xleft; /* bytes left in XMIT queue */ @@ -166,7 +167,7 @@ int slcan_enable_err_rst_on_open(struct net_device *ndev, bool on) *************************************************************************/ /* Send one completely decapsulated can_frame to the network layer */ -static void slc_bump_frame(struct slcan *sl) +static void slcan_bump_frame(struct slcan *sl) { struct sk_buff *skb; struct can_frame *cf; @@ -186,10 +187,10 @@ static void slc_bump_frame(struct slcan *sl) fallthrough; case 't': /* store dlc ASCII value and terminate SFF CAN ID string */ - cf->len = sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN]; - sl->rbuff[SLC_CMD_LEN + SLC_SFF_ID_LEN] = 0; + cf->len = sl->rbuff[SLCAN_CMD_LEN + SLCAN_SFF_ID_LEN]; + sl->rbuff[SLCAN_CMD_LEN + SLCAN_SFF_ID_LEN] = 0; /* point to payload data behind the dlc */ - cmd += SLC_CMD_LEN + SLC_SFF_ID_LEN + 1; + cmd += SLCAN_CMD_LEN + SLCAN_SFF_ID_LEN + 1; break; case 'R': cf->can_id = CAN_RTR_FLAG; @@ -197,16 +198,16 @@ static void slc_bump_frame(struct slcan *sl) case 'T': cf->can_id |= CAN_EFF_FLAG; /* store dlc ASCII value and terminate EFF CAN ID string */ - cf->len = sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN]; - sl->rbuff[SLC_CMD_LEN + SLC_EFF_ID_LEN] = 0; + cf->len = sl->rbuff[SLCAN_CMD_LEN + SLCAN_EFF_ID_LEN]; + sl->rbuff[SLCAN_CMD_LEN + SLCAN_EFF_ID_LEN] = 0; /* point to payload data behind the dlc */ - cmd += SLC_CMD_LEN + SLC_EFF_ID_LEN + 1; + cmd += SLCAN_CMD_LEN + SLCAN_EFF_ID_LEN + 1; break; default: goto decode_failed; } - if (kstrtou32(sl->rbuff + SLC_CMD_LEN, 16, &tmpid)) + if (kstrtou32(sl->rbuff + SLCAN_CMD_LEN, 16, &tmpid)) goto decode_failed; cf->can_id |= tmpid; @@ -253,7 +254,7 @@ decode_failed: * sb256256 : state bus-off: rx counter 256, tx counter 256 * sa057033 : state active, rx counter 57, tx counter 33 */ -static void slc_bump_state(struct slcan *sl) +static void slcan_bump_state(struct slcan *sl) { struct net_device *dev = sl->dev; struct sk_buff *skb; @@ -279,16 +280,16 @@ static void slc_bump_state(struct slcan *sl) return; } - if (state == sl->can.state || sl->rcount < SLC_STATE_FRAME_LEN) + if (state == sl->can.state || sl->rcount < SLCAN_STATE_FRAME_LEN) return; - cmd += SLC_STATE_BE_RXCNT_LEN + SLC_CMD_LEN + 1; - cmd[SLC_STATE_BE_TXCNT_LEN] = 0; + cmd += SLCAN_STATE_BE_RXCNT_LEN + SLCAN_CMD_LEN + 1; + cmd[SLCAN_STATE_BE_TXCNT_LEN] = 0; if (kstrtou32(cmd, 10, &txerr)) return; *cmd = 0; - cmd -= SLC_STATE_BE_RXCNT_LEN; + cmd -= SLCAN_STATE_BE_RXCNT_LEN; if (kstrtou32(cmd, 10, &rxerr)) return; @@ -317,7 +318,7 @@ static void slc_bump_state(struct slcan *sl) * e1a : len 1, errors: ACK error * e3bcO: len 3, errors: Bit0 error, CRC error, Tx overrun error */ -static void slc_bump_err(struct slcan *sl) +static void slcan_bump_err(struct slcan *sl) { struct net_device *dev = sl->dev; struct sk_buff *skb; @@ -333,7 +334,7 @@ static void slc_bump_err(struct slcan *sl) else return; - if ((len + SLC_CMD_LEN + 1) > sl->rcount) + if ((len + SLCAN_CMD_LEN + 1) > sl->rcount) return; skb = alloc_can_err_skb(dev, &cf); @@ -341,7 +342,7 @@ static void slc_bump_err(struct slcan *sl) if (skb) cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; - cmd += SLC_CMD_LEN + 1; + cmd += SLCAN_CMD_LEN + 1; for (i = 0; i < len; i++, cmd++) { switch (*cmd) { case 'a': @@ -430,7 +431,7 @@ static void slc_bump_err(struct slcan *sl) netif_rx(skb); } -static void slc_bump(struct slcan *sl) +static void slcan_bump(struct slcan *sl) { switch (sl->rbuff[0]) { case 'r': @@ -440,11 +441,11 @@ static void slc_bump(struct slcan *sl) case 'R': fallthrough; case 'T': - return slc_bump_frame(sl); + return slcan_bump_frame(sl); case 'e': - return slc_bump_err(sl); + return slcan_bump_err(sl); case 's': - return slc_bump_state(sl); + return slcan_bump_state(sl); default: return; } @@ -456,12 +457,12 @@ static void slcan_unesc(struct slcan *sl, unsigned char s) if ((s == '\r') || (s == '\a')) { /* CR or BEL ends the pdu */ if (!test_and_clear_bit(SLF_ERROR, &sl->flags) && sl->rcount > 4) - slc_bump(sl); + slcan_bump(sl); sl->rcount = 0; } else { if (!test_bit(SLF_ERROR, &sl->flags)) { - if (sl->rcount < SLC_MTU) { + if (sl->rcount < SLCAN_MTU) { sl->rbuff[sl->rcount++] = s; return; } @@ -477,7 +478,7 @@ static void slcan_unesc(struct slcan *sl, unsigned char s) *************************************************************************/ /* Encapsulate one can_frame and stuff into a TTY queue. */ -static void slc_encaps(struct slcan *sl, struct can_frame *cf) +static void slcan_encaps(struct slcan *sl, struct can_frame *cf) { int actual, i; unsigned char *pos; @@ -494,11 +495,11 @@ static void slc_encaps(struct slcan *sl, struct can_frame *cf) /* determine number of chars for the CAN-identifier */ if (cf->can_id & CAN_EFF_FLAG) { id &= CAN_EFF_MASK; - endpos = pos + SLC_EFF_ID_LEN; + endpos = pos + SLCAN_EFF_ID_LEN; } else { *pos |= 0x20; /* convert R/T to lower case for SFF */ id &= CAN_SFF_MASK; - endpos = pos + SLC_SFF_ID_LEN; + endpos = pos + SLCAN_SFF_ID_LEN; } /* build 3 (SFF) or 8 (EFF) digit CAN identifier */ @@ -508,7 +509,8 @@ static void slc_encaps(struct slcan *sl, struct can_frame *cf) id >>= 4; } - pos += (cf->can_id & CAN_EFF_FLAG) ? SLC_EFF_ID_LEN : SLC_SFF_ID_LEN; + pos += (cf->can_id & CAN_EFF_FLAG) ? + SLCAN_EFF_ID_LEN : SLCAN_SFF_ID_LEN; *pos++ = cf->len + '0'; @@ -586,7 +588,8 @@ static void slcan_write_wakeup(struct tty_struct *tty) } /* Send a can_frame to a TTY queue. */ -static netdev_tx_t slc_xmit(struct sk_buff *skb, struct net_device *dev) +static netdev_tx_t slcan_netdev_xmit(struct sk_buff *skb, + struct net_device *dev) { struct slcan *sl = netdev_priv(dev); @@ -605,7 +608,7 @@ static netdev_tx_t slc_xmit(struct sk_buff *skb, struct net_device *dev) } netif_stop_queue(sl->dev); - slc_encaps(sl, (struct can_frame *)skb->data); /* encaps & send */ + slcan_encaps(sl, (struct can_frame *)skb->data); /* encaps & send */ spin_unlock(&sl->lock); out: @@ -648,7 +651,7 @@ static int slcan_transmit_cmd(struct slcan *sl, const unsigned char *cmd) } /* Netdevice UP -> DOWN routine */ -static int slc_close(struct net_device *dev) +static int slcan_netdev_close(struct net_device *dev) { struct slcan *sl = netdev_priv(dev); int err; @@ -677,10 +680,10 @@ static int slc_close(struct net_device *dev) } /* Netdevice DOWN -> UP routine */ -static int slc_open(struct net_device *dev) +static int slcan_netdev_open(struct net_device *dev) { struct slcan *sl = netdev_priv(dev); - unsigned char cmd[SLC_MTU]; + unsigned char cmd[SLCAN_MTU]; int err, s; /* The baud rate is not set with the command @@ -740,16 +743,16 @@ cmd_transmit_failed: return err; } -static int slcan_change_mtu(struct net_device *dev, int new_mtu) +static int slcan_netdev_change_mtu(struct net_device *dev, int new_mtu) { return -EINVAL; } -static const struct net_device_ops slc_netdev_ops = { - .ndo_open = slc_open, - .ndo_stop = slc_close, - .ndo_start_xmit = slc_xmit, - .ndo_change_mtu = slcan_change_mtu, +static const struct net_device_ops slcan_netdev_ops = { + .ndo_open = slcan_netdev_open, + .ndo_stop = slcan_netdev_close, + .ndo_start_xmit = slcan_netdev_xmit, + .ndo_change_mtu = slcan_netdev_change_mtu, }; /****************************************** @@ -822,7 +825,7 @@ static int slcan_open(struct tty_struct *tty) /* Configure netdev interface */ sl->dev = dev; - dev->netdev_ops = &slc_netdev_ops; + dev->netdev_ops = &slcan_netdev_ops; dev->ethtool_ops = &slcan_ethtool_ops; /* Mark ldisc channel as alive */ @@ -890,7 +893,7 @@ static int slcan_ioctl(struct tty_struct *tty, unsigned int cmd, } } -static struct tty_ldisc_ops slc_ldisc = { +static struct tty_ldisc_ops slcan_ldisc = { .owner = THIS_MODULE, .num = N_SLCAN, .name = KBUILD_MODNAME, @@ -908,7 +911,7 @@ static int __init slcan_init(void) pr_info("serial line CAN interface driver\n"); /* Fill in our line protocol discipline, and register it */ - status = tty_register_ldisc(&slc_ldisc); + status = tty_register_ldisc(&slcan_ldisc); if (status) pr_err("can't register line discipline\n"); @@ -920,7 +923,7 @@ static void __exit slcan_exit(void) /* This will only be called when all channels have been closed by * userspace - tty_ldisc.c takes care of the module's refcount. */ - tty_unregister_ldisc(&slc_ldisc); + tty_unregister_ldisc(&slcan_ldisc); } module_init(slcan_init); -- cgit v1.2.3 From 341c5724d7a1c71899752201dab88f87343c0c2b Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Thu, 28 Jul 2022 09:02:52 +0200 Subject: can: slcan: use the generic can_change_mtu() It is useless to define a custom function that does nothing but always return the same error code. Better to use the generic can_change_mtu() function. Signed-off-by: Dario Binacchi Link: https://lore.kernel.org/all/20220728070254.267974-6-dario.binacchi@amarulasolutions.com Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan/slcan-core.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c index 3a4701d8e081..740d82d68ca4 100644 --- a/drivers/net/can/slcan/slcan-core.c +++ b/drivers/net/can/slcan/slcan-core.c @@ -743,16 +743,11 @@ cmd_transmit_failed: return err; } -static int slcan_netdev_change_mtu(struct net_device *dev, int new_mtu) -{ - return -EINVAL; -} - static const struct net_device_ops slcan_netdev_ops = { .ndo_open = slcan_netdev_open, .ndo_stop = slcan_netdev_close, .ndo_start_xmit = slcan_netdev_xmit, - .ndo_change_mtu = slcan_netdev_change_mtu, + .ndo_change_mtu = can_change_mtu, }; /****************************************** -- cgit v1.2.3 From 3e720131960bb724e2ae365aa9e240c1c11f45c1 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Thu, 28 Jul 2022 09:02:53 +0200 Subject: can: slcan: add support for listen-only mode For non-legacy, i.e. ip based configuration, add support for listen-only mode. If listen-only is requested send a listen-only ("L\r") command instead of an open ("O\r") command to the adapter. Signed-off-by: Dario Binacchi Link: https://lore.kernel.org/all/20220728070254.267974-7-dario.binacchi@amarulasolutions.com Signed-off-by: Marc Kleine-Budde --- drivers/net/can/slcan/slcan-core.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c index 740d82d68ca4..5c7dffc1ada2 100644 --- a/drivers/net/can/slcan/slcan-core.c +++ b/drivers/net/can/slcan/slcan-core.c @@ -727,10 +727,20 @@ static int slcan_netdev_open(struct net_device *dev) } } - err = slcan_transmit_cmd(sl, "O\r"); - if (err) { - netdev_err(dev, "failed to send open command 'O\\r'\n"); - goto cmd_transmit_failed; + if (sl->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) { + err = slcan_transmit_cmd(sl, "L\r"); + if (err) { + netdev_err(dev, + "failed to send listen-only command 'L\\r'\n"); + goto cmd_transmit_failed; + } + } else { + err = slcan_transmit_cmd(sl, "O\r"); + if (err) { + netdev_err(dev, + "failed to send open command 'O\\r'\n"); + goto cmd_transmit_failed; + } } } @@ -817,6 +827,7 @@ static int slcan_open(struct tty_struct *tty) /* Configure CAN metadata */ sl->can.bitrate_const = slcan_bitrate_const; sl->can.bitrate_const_cnt = ARRAY_SIZE(slcan_bitrate_const); + sl->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY; /* Configure netdev interface */ sl->dev = dev; -- cgit v1.2.3 From 4aeccfd84d2808574ef32b19877f022462c81d79 Mon Sep 17 00:00:00 2001 From: Dario Binacchi Date: Thu, 28 Jul 2022 09:02:54 +0200 Subject: MAINTAINERS: Add maintainer for the slcan driver At the suggestion of its author Oliver Hartkopp ([1]), I take over the maintainer-ship and add myself to the authors of the driver. [1] https://lore.kernel.org/all/507b5973-d673-4755-3b64-b41cb9a13b6f@hartkopp.net Suggested-by: Oliver Hartkopp Signed-off-by: Dario Binacchi Link: https://lore.kernel.org/all/20220728070254.267974-8-dario.binacchi@amarulasolutions.com Signed-off-by: Marc Kleine-Budde --- MAINTAINERS | 6 ++++++ drivers/net/can/slcan/slcan-core.c | 1 + 2 files changed, 7 insertions(+) (limited to 'drivers/net') diff --git a/MAINTAINERS b/MAINTAINERS index 46b345ddc67c..24da5570e20c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -18470,6 +18470,12 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab.git F: include/linux/sl?b*.h F: mm/sl?b* +SLCAN CAN NETWORK DRIVER +M: Dario Binacchi +L: linux-can@vger.kernel.org +S: Maintained +F: drivers/net/can/slcan/ + SLEEPABLE READ-COPY UPDATE (SRCU) M: Lai Jiangshan M: "Paul E. McKenney" diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c index 5c7dffc1ada2..93e9b08f5653 100644 --- a/drivers/net/can/slcan/slcan-core.c +++ b/drivers/net/can/slcan/slcan-core.c @@ -63,6 +63,7 @@ MODULE_ALIAS_LDISC(N_SLCAN); MODULE_DESCRIPTION("serial line CAN interface"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Oliver Hartkopp "); +MODULE_AUTHOR("Dario Binacchi "); /* maximum rx buffer len: extended CAN frame with timestamp */ #define SLCAN_MTU (sizeof("T1111222281122334455667788EA5F\r") + 1) -- cgit v1.2.3