/* * Copyright (C) ST-Ericsson AB 2010 * Author: Sjur Brendeland * License terms: GNU General Public License (GPL) version 2 */ #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ #include #include #include #include #include #include #include #include #define container_obj(layr) container_of(layr, struct cfmuxl, layer) #define CAIF_CTRL_CHANNEL 0 #define UP_CACHE_SIZE 8 #define DN_CACHE_SIZE 8 struct cfmuxl { struct cflayer layer; struct list_head srvl_list; struct list_head frml_list; struct cflayer *up_cache[UP_CACHE_SIZE]; struct cflayer *dn_cache[DN_CACHE_SIZE]; /* * Set when inserting or removing downwards layers. */ spinlock_t transmit_lock; /* * Set when inserting or removing upwards layers. */ spinlock_t receive_lock; }; static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt); static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt); static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl, int phyid); static struct cflayer *get_up(struct cfmuxl *muxl, u16 id); struct cflayer *cfmuxl_create(void) { struct cfmuxl *this = kzalloc(sizeof(struct cfmuxl), GFP_ATOMIC); if (!this) return NULL; this->layer.receive = cfmuxl_receive; this->layer.transmit = cfmuxl_transmit; this->layer.ctrlcmd = cfmuxl_ctrlcmd; INIT_LIST_HEAD(&this->srvl_list); INIT_LIST_HEAD(&this->frml_list); spin_lock_init(&this->transmit_lock); spin_lock_init(&this->receive_lock); snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "mux"); return &this->layer; } int cfmuxl_set_dnlayer(struct cflayer *layr, struct cflayer *dn, u8 phyid) { struct cfmuxl *muxl = (struct cfmuxl *) layr; spin_lock_bh(&muxl->transmit_lock); list_add_rcu(&dn->node, &muxl->frml_list); spin_unlock_bh(&muxl->transmit_lock); return 0; } static struct cflayer *get_from_id(struct list_head *list, u16 id) { struct cflayer *lyr; list_for_each_entry_rcu(lyr, list, node) { if (lyr->id == id) return lyr; } return NULL; } int cfmuxl_set_uplayer(struct cflayer *layr, struct cflayer *up, u8 linkid) { struct cfmuxl *muxl = container_obj(layr); struct cflayer *old; spin_lock_bh(&muxl->receive_lock); /* Two entries with same id is wrong, so remove old layer from mux */ old = get_from_id(&muxl->srvl_list, linkid); if (old != NULL) list_del_rcu(&old->node); list_add_rcu(&up->node, &muxl->srvl_list); spin_unlock_bh(&muxl->receive_lock); return 0; } struct cflayer *cfmuxl_remove_dnlayer(struct cflayer *layr, u8 phyid) { struct cfmuxl *muxl = container_obj(layr); struct cflayer *dn; int idx = phyid % DN_CACHE_SIZE; spin_lock_bh(&muxl->transmit_lock); RCU_INIT_POINTER(muxl->dn_cache[idx], NULL); dn = get_from_id(&muxl->frml_list, phyid); if (dn == NULL) goto out; list_del_rcu(&dn->node); caif_assert(dn != NULL); out: spin_unlock_bh(&muxl->transmit_lock); return dn; } static struct cflayer *get_up(struct cfmuxl *muxl, u16 id) { struct cflayer *up; int idx = id % UP_CACHE_SIZE; up = rcu_dereference(muxl->up_cache[idx]); if (up == NULL || up->id != id) { spin_lock_bh(&muxl->receive_lock); up = get_from_id(&muxl->srvl_list, id); rcu_assign_pointer(muxl->up_cache[idx], up); spin_unlock_bh(&muxl->receive_lock); } return up; } static struct cflayer *get_dn(struct cfmuxl *muxl, struct dev_info *dev_info) { struct cflayer *dn; int idx = dev_info->id % DN_CACHE_SIZE; dn = rcu_dereference(muxl->dn_cache[idx]); if (dn == NULL || dn->id != dev_info->id) { spin_lock_bh(&muxl->transmit_lock); dn = get_from_id(&muxl->frml_list, dev_info->id); rcu_assign_pointer(muxl->dn_cache[idx], dn); spin_unlock_bh(&muxl->transmit_lock); } return dn; } struct cflayer *cfmuxl_remove_uplayer(struct cflayer *layr, u8 id) { struct cflayer *up; struct cfmuxl *muxl = container_obj(layr); int idx = id % UP_CACHE_SIZE; if (id == 0) { pr_warn("Trying to remove control layer\n"); return NULL; } spin_lock_bh(&muxl->receive_lock); up = get_from_id(&muxl->srvl_list, id); if (up == NULL) goto out; RCU_INIT_POINTER(muxl->up_cache[idx], NULL); list_del_rcu(&up->node); out: spin_unlock_bh(&muxl->receive_lock); return up; } static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt) { int ret; struct cfmuxl *muxl = container_obj(layr); u8 id; struct cflayer *up; if (cfpkt_extr_head(pkt, &id, 1) < 0) { pr_err("erroneous Caif Packet\n"); cfpkt_destroy(pkt); return -EPROTO; } rcu_read_lock(); up = get_up(muxl, id); if (up == NULL) { pr_debug("Received data on unknown link ID = %d (0x%x)" " up == NULL", id, id); cfpkt_destroy(pkt); /* * Don't return ERROR, since modem misbehaves and sends out * flow on before linksetup response. */ rcu_read_unlock(); return /* CFGLU_EPROT; */ 0; } /* We can't hold rcu_lock during receive, so take a ref count instead */ cfsrvl_get(up); rcu_read_unlock(); ret = up->receive(up, pkt); cfsrvl_put(up); return ret; } static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt) { struct cfmuxl *muxl = container_obj(layr); int err; u8 linkid; struct cflayer *dn; struct caif_payload_info *info = cfpkt_info(pkt); BUG_ON(!info); rcu_read_lock(); dn = get_dn(muxl, info->dev_info); if (dn == NULL) { pr_debug("Send data on unknown phy ID = %d (0x%x)\n", info->dev_info->id, info->dev_info->id); rcu_read_unlock(); cfpkt_destroy(pkt); return -ENOTCONN; } info->hdr_len += 1; linkid = info->channel_id; cfpkt_add_head(pkt, &linkid, 1); /* We can't hold rcu_lock during receive, so take a ref count instead */ cffrml_hold(dn); rcu_read_unlock(); err = dn->transmit(dn, pkt); cffrml_put(dn); return err; } static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl, int phyid) { struct cfmuxl *muxl = container_obj(layr); struct cflayer *layer; rcu_read_lock(); list_for_each_entry_rcu(layer, &muxl->srvl_list, node) { if (cfsrvl_phyid_match(layer, phyid) && layer->ctrlcmd) { if ((ctrl == _CAIF_CTRLCMD_PHYIF_DOWN_IND || ctrl == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND) && layer->id != 0) cfmuxl_remove_uplayer(layr, layer->id); /* NOTE: ctrlcmd is not allowed to block */ layer->ctrlcmd(layer, ctrl, phyid); } } rcu_read_unlock(); } add_timer_on() is pretty pointless in this code because the timer is strictlty per CPU, initialized as pinned and all operations which arm the timer happen on the CPU to which the timer belongs. Simplify the whole machinery by using mod_timer() instead of add_timer_on() which avoids the problem because mod_timer() can handle already queued timers. Use __start_timer() everywhere so the earliest armed expiry time is preserved. Reported-by: Erik Veijola <erik.veijola@intel.com> Tested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701310936080.3457@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'net/key')