--- /dev/null
+/*
+ * 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 <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>
+#include <net/caif/cffrml.h>
+
+#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();
+}
Code Review / kvmfornfv.git / blobdiff