From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- net/can/j1939/bus.c | 333 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 333 insertions(+) create mode 100644 net/can/j1939/bus.c (limited to 'net/can/j1939/bus.c') diff --git a/net/can/j1939/bus.c b/net/can/j1939/bus.c new file mode 100644 index 000000000..486687901 --- /dev/null +++ b/net/can/j1939/bus.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2010-2011 EIA Electronics, +// Kurt Van Dijck +// Copyright (c) 2017-2019 Pengutronix, +// Marc Kleine-Budde +// Copyright (c) 2017-2019 Pengutronix, +// Oleksij Rempel + +/* bus for j1939 remote devices + * Since rtnetlink, no real bus is used. + */ + +#include + +#include "j1939-priv.h" + +static void __j1939_ecu_release(struct kref *kref) +{ + struct j1939_ecu *ecu = container_of(kref, struct j1939_ecu, kref); + struct j1939_priv *priv = ecu->priv; + + list_del(&ecu->list); + kfree(ecu); + j1939_priv_put(priv); +} + +void j1939_ecu_put(struct j1939_ecu *ecu) +{ + kref_put(&ecu->kref, __j1939_ecu_release); +} + +static void j1939_ecu_get(struct j1939_ecu *ecu) +{ + kref_get(&ecu->kref); +} + +static bool j1939_ecu_is_mapped_locked(struct j1939_ecu *ecu) +{ + struct j1939_priv *priv = ecu->priv; + + lockdep_assert_held(&priv->lock); + + return j1939_ecu_find_by_addr_locked(priv, ecu->addr) == ecu; +} + +/* ECU device interface */ +/* map ECU to a bus address space */ +static void j1939_ecu_map_locked(struct j1939_ecu *ecu) +{ + struct j1939_priv *priv = ecu->priv; + struct j1939_addr_ent *ent; + + lockdep_assert_held(&priv->lock); + + if (!j1939_address_is_unicast(ecu->addr)) + return; + + ent = &priv->ents[ecu->addr]; + + if (ent->ecu) { + netdev_warn(priv->ndev, "Trying to map already mapped ECU, addr: 0x%02x, name: 0x%016llx. Skip it.\n", + ecu->addr, ecu->name); + return; + } + + j1939_ecu_get(ecu); + ent->ecu = ecu; + ent->nusers += ecu->nusers; +} + +/* unmap ECU from a bus address space */ +void j1939_ecu_unmap_locked(struct j1939_ecu *ecu) +{ + struct j1939_priv *priv = ecu->priv; + struct j1939_addr_ent *ent; + + lockdep_assert_held(&priv->lock); + + if (!j1939_address_is_unicast(ecu->addr)) + return; + + if (!j1939_ecu_is_mapped_locked(ecu)) + return; + + ent = &priv->ents[ecu->addr]; + ent->ecu = NULL; + ent->nusers -= ecu->nusers; + j1939_ecu_put(ecu); +} + +void j1939_ecu_unmap(struct j1939_ecu *ecu) +{ + write_lock_bh(&ecu->priv->lock); + j1939_ecu_unmap_locked(ecu); + write_unlock_bh(&ecu->priv->lock); +} + +void j1939_ecu_unmap_all(struct j1939_priv *priv) +{ + int i; + + write_lock_bh(&priv->lock); + for (i = 0; i < ARRAY_SIZE(priv->ents); i++) + if (priv->ents[i].ecu) + j1939_ecu_unmap_locked(priv->ents[i].ecu); + write_unlock_bh(&priv->lock); +} + +void j1939_ecu_timer_start(struct j1939_ecu *ecu) +{ + /* The ECU is held here and released in the + * j1939_ecu_timer_handler() or j1939_ecu_timer_cancel(). + */ + j1939_ecu_get(ecu); + + /* Schedule timer in 250 msec to commit address change. */ + hrtimer_start(&ecu->ac_timer, ms_to_ktime(250), + HRTIMER_MODE_REL_SOFT); +} + +void j1939_ecu_timer_cancel(struct j1939_ecu *ecu) +{ + if (hrtimer_cancel(&ecu->ac_timer)) + j1939_ecu_put(ecu); +} + +static enum hrtimer_restart j1939_ecu_timer_handler(struct hrtimer *hrtimer) +{ + struct j1939_ecu *ecu = + container_of(hrtimer, struct j1939_ecu, ac_timer); + struct j1939_priv *priv = ecu->priv; + + write_lock_bh(&priv->lock); + /* TODO: can we test if ecu->addr is unicast before starting + * the timer? + */ + j1939_ecu_map_locked(ecu); + + /* The corresponding j1939_ecu_get() is in + * j1939_ecu_timer_start(). + */ + j1939_ecu_put(ecu); + write_unlock_bh(&priv->lock); + + return HRTIMER_NORESTART; +} + +struct j1939_ecu *j1939_ecu_create_locked(struct j1939_priv *priv, name_t name) +{ + struct j1939_ecu *ecu; + + lockdep_assert_held(&priv->lock); + + ecu = kzalloc(sizeof(*ecu), gfp_any()); + if (!ecu) + return ERR_PTR(-ENOMEM); + kref_init(&ecu->kref); + ecu->addr = J1939_IDLE_ADDR; + ecu->name = name; + + hrtimer_init(&ecu->ac_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT); + ecu->ac_timer.function = j1939_ecu_timer_handler; + INIT_LIST_HEAD(&ecu->list); + + j1939_priv_get(priv); + ecu->priv = priv; + list_add_tail(&ecu->list, &priv->ecus); + + return ecu; +} + +struct j1939_ecu *j1939_ecu_find_by_addr_locked(struct j1939_priv *priv, + u8 addr) +{ + lockdep_assert_held(&priv->lock); + + return priv->ents[addr].ecu; +} + +struct j1939_ecu *j1939_ecu_get_by_addr_locked(struct j1939_priv *priv, u8 addr) +{ + struct j1939_ecu *ecu; + + lockdep_assert_held(&priv->lock); + + if (!j1939_address_is_unicast(addr)) + return NULL; + + ecu = j1939_ecu_find_by_addr_locked(priv, addr); + if (ecu) + j1939_ecu_get(ecu); + + return ecu; +} + +struct j1939_ecu *j1939_ecu_get_by_addr(struct j1939_priv *priv, u8 addr) +{ + struct j1939_ecu *ecu; + + read_lock_bh(&priv->lock); + ecu = j1939_ecu_get_by_addr_locked(priv, addr); + read_unlock_bh(&priv->lock); + + return ecu; +} + +/* get pointer to ecu without increasing ref counter */ +static struct j1939_ecu *j1939_ecu_find_by_name_locked(struct j1939_priv *priv, + name_t name) +{ + struct j1939_ecu *ecu; + + lockdep_assert_held(&priv->lock); + + list_for_each_entry(ecu, &priv->ecus, list) { + if (ecu->name == name) + return ecu; + } + + return NULL; +} + +struct j1939_ecu *j1939_ecu_get_by_name_locked(struct j1939_priv *priv, + name_t name) +{ + struct j1939_ecu *ecu; + + lockdep_assert_held(&priv->lock); + + if (!name) + return NULL; + + ecu = j1939_ecu_find_by_name_locked(priv, name); + if (ecu) + j1939_ecu_get(ecu); + + return ecu; +} + +struct j1939_ecu *j1939_ecu_get_by_name(struct j1939_priv *priv, name_t name) +{ + struct j1939_ecu *ecu; + + read_lock_bh(&priv->lock); + ecu = j1939_ecu_get_by_name_locked(priv, name); + read_unlock_bh(&priv->lock); + + return ecu; +} + +u8 j1939_name_to_addr(struct j1939_priv *priv, name_t name) +{ + struct j1939_ecu *ecu; + int addr = J1939_IDLE_ADDR; + + if (!name) + return J1939_NO_ADDR; + + read_lock_bh(&priv->lock); + ecu = j1939_ecu_find_by_name_locked(priv, name); + if (ecu && j1939_ecu_is_mapped_locked(ecu)) + /* ecu's SA is registered */ + addr = ecu->addr; + + read_unlock_bh(&priv->lock); + + return addr; +} + +/* TX addr/name accounting + * Transport protocol needs to know if a SA is local or not + * These functions originate from userspace manipulating sockets, + * so locking is straigforward + */ + +int j1939_local_ecu_get(struct j1939_priv *priv, name_t name, u8 sa) +{ + struct j1939_ecu *ecu; + int err = 0; + + write_lock_bh(&priv->lock); + + if (j1939_address_is_unicast(sa)) + priv->ents[sa].nusers++; + + if (!name) + goto done; + + ecu = j1939_ecu_get_by_name_locked(priv, name); + if (!ecu) + ecu = j1939_ecu_create_locked(priv, name); + err = PTR_ERR_OR_ZERO(ecu); + if (err) + goto done; + + ecu->nusers++; + /* TODO: do we care if ecu->addr != sa? */ + if (j1939_ecu_is_mapped_locked(ecu)) + /* ecu's sa is active already */ + priv->ents[ecu->addr].nusers++; + + done: + write_unlock_bh(&priv->lock); + + return err; +} + +void j1939_local_ecu_put(struct j1939_priv *priv, name_t name, u8 sa) +{ + struct j1939_ecu *ecu; + + write_lock_bh(&priv->lock); + + if (j1939_address_is_unicast(sa)) + priv->ents[sa].nusers--; + + if (!name) + goto done; + + ecu = j1939_ecu_find_by_name_locked(priv, name); + if (WARN_ON_ONCE(!ecu)) + goto done; + + ecu->nusers--; + /* TODO: do we care if ecu->addr != sa? */ + if (j1939_ecu_is_mapped_locked(ecu)) + /* ecu's sa is active already */ + priv->ents[ecu->addr].nusers--; + j1939_ecu_put(ecu); + + done: + write_unlock_bh(&priv->lock); +} -- cgit v1.2.3