diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/caif/cffrml.c | 8 | ||||
| -rw-r--r-- | net/caif/cfmuxl.c | 119 |
2 files changed, 83 insertions, 44 deletions
diff --git a/net/caif/cffrml.c b/net/caif/cffrml.c index 2423fed..f4b8892 100644 --- a/net/caif/cffrml.c +++ b/net/caif/cffrml.c @@ -145,3 +145,11 @@ static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl, if (layr->up->ctrlcmd) layr->up->ctrlcmd(layr->up, ctrl, layr->id); } + +void cffrml_put(struct cflayer *layr) +{ +} + +void cffrml_hold(struct cflayer *layr) +{ +} diff --git a/net/caif/cfmuxl.c b/net/caif/cfmuxl.c index fc24974..2a56df7 100644 --- a/net/caif/cfmuxl.c +++ b/net/caif/cfmuxl.c @@ -9,6 +9,7 @@ #include <linux/stddef.h> #include <linux/spinlock.h> #include <linux/slab.h> +#include <linux/rculist.h> #include <net/caif/cfpkt.h> #include <net/caif/cfmuxl.h> #include <net/caif/cfsrvl.h> @@ -64,31 +65,31 @@ struct cflayer *cfmuxl_create(void) int cfmuxl_set_uplayer(struct cflayer *layr, struct cflayer *up, u8 linkid) { struct cfmuxl *muxl = container_obj(layr); - spin_lock(&muxl->receive_lock); - cfsrvl_get(up); - list_add(&up->node, &muxl->srvl_list); - spin_unlock(&muxl->receive_lock); + + spin_lock_bh(&muxl->receive_lock); + list_add_rcu(&up->node, &muxl->srvl_list); + spin_unlock_bh(&muxl->receive_lock); return 0; } int cfmuxl_set_dnlayer(struct cflayer *layr, struct cflayer *dn, u8 phyid) { struct cfmuxl *muxl = (struct cfmuxl *) layr; - spin_lock(&muxl->transmit_lock); - list_add(&dn->node, &muxl->frml_list); - spin_unlock(&muxl->transmit_lock); + + 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 list_head *node; - struct cflayer *layer; - list_for_each(node, list) { - layer = list_entry(node, struct cflayer, node); - if (layer->id == id) - return layer; + struct cflayer *lyr; + list_for_each_entry_rcu(lyr, list, node) { + if (lyr->id == id) + return lyr; } + return NULL; } @@ -96,41 +97,45 @@ struct cflayer *cfmuxl_remove_dnlayer(struct cflayer *layr, u8 phyid) { struct cfmuxl *muxl = container_obj(layr); struct cflayer *dn; - spin_lock(&muxl->transmit_lock); - memset(muxl->dn_cache, 0, sizeof(muxl->dn_cache)); + int idx = phyid % DN_CACHE_SIZE; + + spin_lock_bh(&muxl->transmit_lock); + rcu_assign_pointer(muxl->dn_cache[idx], NULL); dn = get_from_id(&muxl->frml_list, phyid); - if (dn == NULL) { - spin_unlock(&muxl->transmit_lock); - return NULL; - } - list_del(&dn->node); + if (dn == NULL) + goto out; + + list_del_rcu(&dn->node); caif_assert(dn != NULL); - spin_unlock(&muxl->transmit_lock); +out: + spin_unlock_bh(&muxl->transmit_lock); return dn; } -/* Invariant: lock is taken */ static struct cflayer *get_up(struct cfmuxl *muxl, u16 id) { struct cflayer *up; int idx = id % UP_CACHE_SIZE; - up = muxl->up_cache[idx]; + 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); - muxl->up_cache[idx] = up; + rcu_assign_pointer(muxl->up_cache[idx], up); + spin_unlock_bh(&muxl->receive_lock); } return up; } -/* Invariant: lock is taken */ 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 = muxl->dn_cache[idx]; + 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); - muxl->dn_cache[idx] = dn; + rcu_assign_pointer(muxl->dn_cache[idx], dn); + spin_unlock_bh(&muxl->transmit_lock); } return dn; } @@ -139,15 +144,17 @@ struct cflayer *cfmuxl_remove_uplayer(struct cflayer *layr, u8 id) { struct cflayer *up; struct cfmuxl *muxl = container_obj(layr); - spin_lock(&muxl->receive_lock); - up = get_up(muxl, id); + int idx = id % UP_CACHE_SIZE; + + spin_lock_bh(&muxl->receive_lock); + up = get_from_id(&muxl->srvl_list, id); if (up == NULL) goto out; - memset(muxl->up_cache, 0, sizeof(muxl->up_cache)); - list_del(&up->node); - cfsrvl_put(up); + + rcu_assign_pointer(muxl->up_cache[idx], NULL); + list_del_rcu(&up->node); out: - spin_unlock(&muxl->receive_lock); + spin_unlock_bh(&muxl->receive_lock); return up; } @@ -162,22 +169,28 @@ static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt) cfpkt_destroy(pkt); return -EPROTO; } - - spin_lock(&muxl->receive_lock); + rcu_read_lock(); up = get_up(muxl, id); - spin_unlock(&muxl->receive_lock); + if (up == NULL) { - pr_info("Received data on unknown link ID = %d (0x%x) up == NULL", - id, id); + 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; } @@ -185,31 +198,49 @@ static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt) 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_warn("Send data on unknown phy ID = %d (0x%x)\n", + 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); - return dn->transmit(dn, pkt); + + /* 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 list_head *node, *next; struct cflayer *layer; - list_for_each_safe(node, next, &muxl->srvl_list) { - layer = list_entry(node, struct cflayer, node); - if (cfsrvl_phyid_match(layer, phyid)) + + rcu_read_lock(); + list_for_each_entry_rcu(layer, &muxl->srvl_list, node) { + if (cfsrvl_phyid_match(layer, phyid) && layer->ctrlcmd) + /* NOTE: ctrlcmd is not allowed to block */ layer->ctrlcmd(layer, ctrl, phyid); } + rcu_read_unlock(); } |
