net-caif: add CAIF core protocol stack

CAIF generic protocol implementation. This layer is
somewhat generic in order to be able to use and test it outside
the Linux Kernel.

cfctrl.c     - CAIF control protocol layer
cfdbgl.c     - CAIF debug protocol layer
cfdgml.c     - CAIF datagram protocol layer
cffrml.c     - CAIF framing protocol layer
cfmuxl.c     - CAIF mux protocol layer
cfrfml.c     - CAIF remote file manager protocol layer
cfserl.c     - CAIF serial (fragmentation) protocol layer
cfsrvl.c     - CAIF generic service layer functions
cfutill.c    - CAIF utility protocol layer
cfveil.c     - CAIF AT protocol layer
cfvidl.c     - CAIF video protocol layer

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 246 insertions, 0 deletions

diff --git a/net/caif/cfmuxl.c b/net/caif/cfmuxl.c
new file mode 100644
index 000000000000..6fb9f9e96cf8
--- /dev/null
+++ b/net/caif/cfmuxl.c
@@ -0,0 +1,246 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland/sjur.brandeland@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+#include <linux/stddef.h>
+#include <linux/spinlock.h>
+#include <linux/slab.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 = kmalloc(sizeof(struct cfmuxl), GFP_ATOMIC);
+	if (!this)
+		return NULL;
+	memset(this, 0, sizeof(*this));
+	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_uplayer(struct cflayer *layr, struct cflayer *up, u8 linkid)
+{
+	struct cfmuxl *muxl = container_obj(layr);
+	spin_lock(&muxl->receive_lock);
+	list_add(&up->node, &muxl->srvl_list);
+	spin_unlock(&muxl->receive_lock);
+	return 0;
+}
+
+bool cfmuxl_is_phy_inuse(struct cflayer *layr, u8 phyid)
+{
+	struct list_head *node;
+	struct cflayer *layer;
+	struct cfmuxl *muxl = container_obj(layr);
+	bool match = false;
+	spin_lock(&muxl->receive_lock);
+
+	list_for_each(node, &muxl->srvl_list) {
+		layer = list_entry(node, struct cflayer, node);
+		if (cfsrvl_phyid_match(layer, phyid)) {
+			match = true;
+			break;
+		}
+
+	}
+	spin_unlock(&muxl->receive_lock);
+	return match;
+}
+
+u8 cfmuxl_get_phyid(struct cflayer *layr, u8 channel_id)
+{
+	struct cflayer *up;
+	int phyid;
+	struct cfmuxl *muxl = container_obj(layr);
+	spin_lock(&muxl->receive_lock);
+	up = get_up(muxl, channel_id);
+	if (up != NULL)
+		phyid = cfsrvl_getphyid(up);
+	else
+		phyid = 0;
+	spin_unlock(&muxl->receive_lock);
+	return phyid;
+}
+
+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);
+	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;
+	}
+	return NULL;
+}
+
+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));
+	dn = get_from_id(&muxl->frml_list, phyid);
+	if (dn == NULL) {
+		spin_unlock(&muxl->transmit_lock);
+		return NULL;
+	}
+	list_del(&dn->node);
+	caif_assert(dn != NULL);
+	spin_unlock(&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];
+	if (up == NULL || up->id != id) {
+		up = get_from_id(&muxl->srvl_list, id);
+		muxl->up_cache[idx] = up;
+	}
+	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];
+	if (dn == NULL || dn->id != dev_info->id) {
+		dn = get_from_id(&muxl->frml_list, dev_info->id);
+		muxl->dn_cache[idx] = dn;
+	}
+	return dn;
+}
+
+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);
+	memset(muxl->up_cache, 0, sizeof(muxl->up_cache));
+	list_del(&up->node);
+	spin_unlock(&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("CAIF: %s(): erroneous Caif Packet\n", __func__);
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+
+	spin_lock(&muxl->receive_lock);
+	up = get_up(muxl, id);
+	spin_unlock(&muxl->receive_lock);
+	if (up == NULL) {
+		pr_info("CAIF: %s():Received data on unknown link ID = %d "
+			"(0x%x)	 up == NULL", __func__, id, id);
+		cfpkt_destroy(pkt);
+		/*
+		 * Don't return ERROR, since modem misbehaves and sends out
+		 * flow on before linksetup response.
+		 */
+		return /* CFGLU_EPROT; */ 0;
+	}
+
+	ret = up->receive(up, pkt);
+	return ret;
+}
+
+static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	int ret;
+	struct cfmuxl *muxl = container_obj(layr);
+	u8 linkid;
+	struct cflayer *dn;
+	struct caif_payload_info *info = cfpkt_info(pkt);
+	dn = get_dn(muxl, cfpkt_info(pkt)->dev_info);
+	if (dn == NULL) {
+		pr_warning("CAIF: %s(): Send data on unknown phy "
+			   "ID = %d (0x%x)\n",
+			   __func__, info->dev_info->id, info->dev_info->id);
+		return -ENOTCONN;
+	}
+	info->hdr_len += 1;
+	linkid = info->channel_id;
+	cfpkt_add_head(pkt, &linkid, 1);
+	ret = dn->transmit(dn, pkt);
+	/* Remove MUX protocol header upon error. */
+	if (ret < 0)
+		cfpkt_extr_head(pkt, &linkid, 1);
+	return ret;
+}
+
+static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+				int phyid)
+{
+	struct cfmuxl *muxl = container_obj(layr);
+	struct list_head *node;
+	struct cflayer *layer;
+	list_for_each(node, &muxl->srvl_list) {
+		layer = list_entry(node, struct cflayer, node);
+		if (cfsrvl_phyid_match(layer, phyid))
+			layer->ctrlcmd(layer, ctrl, phyid);
+	}
+}