[deliverable/linux.git] / net / nfc / nci / data.c

/*
 *  The NFC Controller Interface is the communication protocol between an
 *  NFC Controller (NFCC) and a Device Host (DH).
 *
 *  Copyright (C) 2011 Texas Instruments, Inc.
 *  Copyright (C) 2014 Marvell International Ltd.
 *
 *  Written by Ilan Elias <ilane@ti.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__

#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <linux/skbuff.h>

#include "../nfc.h"
#include <net/nfc/nci.h>
#include <net/nfc/nci_core.h>
#include <linux/nfc.h>

/* Complete data exchange transaction and forward skb to nfc core */
void nci_data_exchange_complete(struct nci_dev *ndev, struct sk_buff *skb,
				__u8 conn_id, int err)
{
	struct nci_conn_info    *conn_info;
	data_exchange_cb_t cb;
	void *cb_context;

	conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
	if (!conn_info) {
		kfree_skb(skb);
		goto exit;
	}

	cb = conn_info->data_exchange_cb;
	cb_context = conn_info->data_exchange_cb_context;

	pr_debug("len %d, err %d\n", skb ? skb->len : 0, err);

	/* data exchange is complete, stop the data timer */
	del_timer_sync(&ndev->data_timer);
	clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);

	if (cb) {
		/* forward skb to nfc core */
		cb(cb_context, skb, err);
	} else if (skb) {
		pr_err("no rx callback, dropping rx data...\n");

		/* no waiting callback, free skb */
		kfree_skb(skb);
	}

exit:
	clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
}

/* ----------------- NCI TX Data ----------------- */

static inline void nci_push_data_hdr(struct nci_dev *ndev,
				     __u8 conn_id,
				     struct sk_buff *skb,
				     __u8 pbf)
{
	struct nci_data_hdr *hdr;
	int plen = skb->len;

	hdr = (struct nci_data_hdr *) skb_push(skb, NCI_DATA_HDR_SIZE);
	hdr->conn_id = conn_id;
	hdr->rfu = 0;
	hdr->plen = plen;

	nci_mt_set((__u8 *)hdr, NCI_MT_DATA_PKT);
	nci_pbf_set((__u8 *)hdr, pbf);
}

static int nci_queue_tx_data_frags(struct nci_dev *ndev,
				   __u8 conn_id,
				   struct sk_buff *skb) {
	struct nci_conn_info    *conn_info;
	int total_len = skb->len;
	unsigned char *data = skb->data;
	unsigned long flags;
	struct sk_buff_head frags_q;
	struct sk_buff *skb_frag;
	int frag_len;
	int rc = 0;

	pr_debug("conn_id 0x%x, total_len %d\n", conn_id, total_len);

	conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
	if (!conn_info) {
		rc = -EPROTO;
		goto free_exit;
	}

	__skb_queue_head_init(&frags_q);

	while (total_len) {
		frag_len =
			min_t(int, total_len, conn_info->max_pkt_payload_len);

		skb_frag = nci_skb_alloc(ndev,
					 (NCI_DATA_HDR_SIZE + frag_len),
					 GFP_KERNEL);
		if (skb_frag == NULL) {
			rc = -ENOMEM;
			goto free_exit;
		}
		skb_reserve(skb_frag, NCI_DATA_HDR_SIZE);

		/* first, copy the data */
		memcpy(skb_put(skb_frag, frag_len), data, frag_len);

		/* second, set the header */
		nci_push_data_hdr(ndev, conn_id, skb_frag,
				  ((total_len == frag_len) ?
				   (NCI_PBF_LAST) : (NCI_PBF_CONT)));

		__skb_queue_tail(&frags_q, skb_frag);

		data += frag_len;
		total_len -= frag_len;

		pr_debug("frag_len %d, remaining total_len %d\n",
			 frag_len, total_len);
	}

	/* queue all fragments atomically */
	spin_lock_irqsave(&ndev->tx_q.lock, flags);

	while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
		__skb_queue_tail(&ndev->tx_q, skb_frag);

	spin_unlock_irqrestore(&ndev->tx_q.lock, flags);

	/* free the original skb */
	kfree_skb(skb);

	goto exit;

free_exit:
	while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
		kfree_skb(skb_frag);

exit:
	return rc;
}

/* Send NCI data */
int nci_send_data(struct nci_dev *ndev, __u8 conn_id, struct sk_buff *skb)
{
	struct nci_conn_info    *conn_info;
	int rc = 0;

	pr_debug("conn_id 0x%x, plen %d\n", conn_id, skb->len);

	conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
	if (!conn_info) {
		rc = -EPROTO;
		goto free_exit;
	}

	/* check if the packet need to be fragmented */
	if (skb->len <= conn_info->max_pkt_payload_len) {
		/* no need to fragment packet */
		nci_push_data_hdr(ndev, conn_id, skb, NCI_PBF_LAST);

		skb_queue_tail(&ndev->tx_q, skb);
	} else {
		/* fragment packet and queue the fragments */
		rc = nci_queue_tx_data_frags(ndev, conn_id, skb);
		if (rc) {
			pr_err("failed to fragment tx data packet\n");
			goto free_exit;
		}
	}

	ndev->cur_conn_id = conn_id;
	queue_work(ndev->tx_wq, &ndev->tx_work);

	goto exit;

free_exit:
	kfree_skb(skb);

exit:
	return rc;
}
EXPORT_SYMBOL(nci_send_data);

/* ----------------- NCI RX Data ----------------- */

static void nci_add_rx_data_frag(struct nci_dev *ndev,
				 struct sk_buff *skb,
				 __u8 pbf, __u8 conn_id, __u8 status)
{
	int reassembly_len;
	int err = 0;

	if (status) {
		err = status;
		goto exit;
	}

	if (ndev->rx_data_reassembly) {
		reassembly_len = ndev->rx_data_reassembly->len;

		/* first, make enough room for the already accumulated data */
		if (skb_cow_head(skb, reassembly_len)) {
			pr_err("error adding room for accumulated rx data\n");

			kfree_skb(skb);
			skb = NULL;

			kfree_skb(ndev->rx_data_reassembly);
			ndev->rx_data_reassembly = NULL;

			err = -ENOMEM;
			goto exit;
		}

		/* second, combine the two fragments */
		memcpy(skb_push(skb, reassembly_len),
		       ndev->rx_data_reassembly->data,
		       reassembly_len);

		/* third, free old reassembly */
		kfree_skb(ndev->rx_data_reassembly);
		ndev->rx_data_reassembly = NULL;
	}

	if (pbf == NCI_PBF_CONT) {
		/* need to wait for next fragment, store skb and exit */
		ndev->rx_data_reassembly = skb;
		return;
	}

exit:
	if (ndev->nfc_dev->rf_mode == NFC_RF_TARGET) {
		/* Data received in Target mode, forward to nfc core */
		err = nfc_tm_data_received(ndev->nfc_dev, skb);
		if (err)
			pr_err("unable to handle received data\n");
	} else {
		nci_data_exchange_complete(ndev, skb, conn_id, err);
	}
}

/* Rx Data packet */
void nci_rx_data_packet(struct nci_dev *ndev, struct sk_buff *skb)
{
	__u8 pbf = nci_pbf(skb->data);
	__u8 status = 0;
	__u8 conn_id = nci_conn_id(skb->data);
	struct nci_conn_info    *conn_info;

	pr_debug("len %d\n", skb->len);

	pr_debug("NCI RX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
		 nci_pbf(skb->data),
		 nci_conn_id(skb->data),
		 nci_plen(skb->data));

	conn_info = nci_get_conn_info_by_conn_id(ndev, nci_conn_id(skb->data));
	if (!conn_info)
		return;

	/* strip the nci data header */
	skb_pull(skb, NCI_DATA_HDR_SIZE);

	if (ndev->target_active_prot == NFC_PROTO_MIFARE ||
	    ndev->target_active_prot == NFC_PROTO_JEWEL ||
	    ndev->target_active_prot == NFC_PROTO_FELICA ||
	    ndev->target_active_prot == NFC_PROTO_ISO15693) {
		/* frame I/F => remove the status byte */
		pr_debug("frame I/F => remove the status byte\n");
		status = skb->data[skb->len - 1];
		skb_trim(skb, (skb->len - 1));
	}

	nci_add_rx_data_frag(ndev, skb, pbf, conn_id, nci_to_errno(status));
}
Commit	Line	Data
6a2968aa IE	1	/*
	2	* The NFC Controller Interface is the communication protocol between an
	3	* NFC Controller (NFCC) and a Device Host (DH).
	4	*
	5	* Copyright (C) 2011 Texas Instruments, Inc.
122c1958	6	* Copyright (C) 2014 Marvell International Ltd.
6a2968aa IE	7	*
	8	* Written by Ilan Elias <ilane@ti.com>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2
	12	* as published by the Free Software Foundation
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
98b32dec	20	* along with this program; if not, see <http://www.gnu.org/licenses/>.
6a2968aa IE	21	*
	22	*/
	23
52858b51	24	#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
ed1e0ad8	25
6a2968aa IE	26	#include <linux/types.h>
	27	#include <linux/interrupt.h>
	28	#include <linux/wait.h>
	29	#include <linux/bitops.h>
	30	#include <linux/skbuff.h>
	31
	32	#include "../nfc.h"
	33	#include <net/nfc/nci.h>
	34	#include <net/nfc/nci_core.h>
	35	#include <linux/nfc.h>
	36
	37	/* Complete data exchange transaction and forward skb to nfc core */
eb9bc6e9	38	void nci_data_exchange_complete(struct nci_dev ndev, struct sk_buff skb,
4aeee687	39	__u8 conn_id, int err)
6a2968aa	40	{
4aeee687 CR	41	struct nci_conn_info *conn_info;
	42	data_exchange_cb_t cb;
	43	void *cb_context;
	44
	45	conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
	46	if (!conn_info) {
	47	kfree_skb(skb);
	48	goto exit;
	49	}
	50
	51	cb = conn_info->data_exchange_cb;
	52	cb_context = conn_info->data_exchange_cb_context;
6a2968aa	53
24bf3304	54	pr_debug("len %d, err %d\n", skb ? skb->len : 0, err);
6a2968aa	55
c4bf98b2 IE	56	/* data exchange is complete, stop the data timer */
	57	del_timer_sync(&ndev->data_timer);
	58	clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
	59
6a2968aa	60	if (cb) {
6a2968aa IE	61	/* forward skb to nfc core */
	62	cb(cb_context, skb, err);
	63	} else if (skb) {
ed1e0ad8	64	pr_err("no rx callback, dropping rx data...\n");
6a2968aa IE	65
	66	/* no waiting callback, free skb */
	67	kfree_skb(skb);
	68	}
38f04c6b	69
4aeee687	70	exit:
38f04c6b	71	clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
6a2968aa IE	72	}
	73
	74	/* ----------------- NCI TX Data ----------------- */
	75
	76	static inline void nci_push_data_hdr(struct nci_dev *ndev,
eb9bc6e9 SO	77	__u8 conn_id,
	78	struct sk_buff *skb,
	79	__u8 pbf)
6a2968aa IE	80	{
	81	struct nci_data_hdr *hdr;
	82	int plen = skb->len;
	83
	84	hdr = (struct nci_data_hdr *) skb_push(skb, NCI_DATA_HDR_SIZE);
	85	hdr->conn_id = conn_id;
	86	hdr->rfu = 0;
	87	hdr->plen = plen;
	88
	89	nci_mt_set((__u8 *)hdr, NCI_MT_DATA_PKT);
	90	nci_pbf_set((__u8 *)hdr, pbf);
6a2968aa IE	91	}
	92
	93	static int nci_queue_tx_data_frags(struct nci_dev *ndev,
eb9bc6e9 SO	94	__u8 conn_id,
eb9bc6e9 SO	95	struct sk_buff *skb) {
4aeee687	96	struct nci_conn_info *conn_info;
6a2968aa IE	97	int total_len = skb->len;
	98	unsigned char *data = skb->data;
	99	unsigned long flags;
	100	struct sk_buff_head frags_q;
	101	struct sk_buff *skb_frag;
	102	int frag_len;
	103	int rc = 0;
	104
24bf3304	105	pr_debug("conn_id 0x%x, total_len %d\n", conn_id, total_len);
6a2968aa	106
4aeee687 CR	107	conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
	108	if (!conn_info) {
	109	rc = -EPROTO;
	110	goto free_exit;
	111	}
	112
6a2968aa IE	113	__skb_queue_head_init(&frags_q);
	114
	115	while (total_len) {
e8c0dacd	116	frag_len =
4aeee687	117	min_t(int, total_len, conn_info->max_pkt_payload_len);
6a2968aa IE	118
6a2968aa IE	119	skb_frag = nci_skb_alloc(ndev,
eb9bc6e9 SO	120	(NCI_DATA_HDR_SIZE + frag_len),
eb9bc6e9 SO	121	GFP_KERNEL);
6a2968aa IE	122	if (skb_frag == NULL) {
	123	rc = -ENOMEM;
	124	goto free_exit;
	125	}
	126	skb_reserve(skb_frag, NCI_DATA_HDR_SIZE);
	127
	128	/* first, copy the data */
	129	memcpy(skb_put(skb_frag, frag_len), data, frag_len);
	130
	131	/* second, set the header */
	132	nci_push_data_hdr(ndev, conn_id, skb_frag,
eb9bc6e9 SO	133	((total_len == frag_len) ?
eb9bc6e9 SO	134	(NCI_PBF_LAST) : (NCI_PBF_CONT)));
6a2968aa IE	135
	136	__skb_queue_tail(&frags_q, skb_frag);
	137
	138	data += frag_len;
	139	total_len -= frag_len;
	140
20c239c1 JP	141	pr_debug("frag_len %d, remaining total_len %d\n",
20c239c1 JP	142	frag_len, total_len);
6a2968aa IE	143	}
	144
	145	/* queue all fragments atomically */
	146	spin_lock_irqsave(&ndev->tx_q.lock, flags);
	147
	148	while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
	149	__skb_queue_tail(&ndev->tx_q, skb_frag);
	150
	151	spin_unlock_irqrestore(&ndev->tx_q.lock, flags);
	152
	153	/* free the original skb */
	154	kfree_skb(skb);
	155
	156	goto exit;
	157
	158	free_exit:
	159	while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
	160	kfree_skb(skb_frag);
	161
	162	exit:
	163	return rc;
	164	}
	165
	166	/* Send NCI data */
	167	int nci_send_data(struct nci_dev ndev, __u8 conn_id, struct sk_buff skb)
	168	{
4aeee687	169	struct nci_conn_info *conn_info;
6a2968aa IE	170	int rc = 0;
6a2968aa IE	171
24bf3304	172	pr_debug("conn_id 0x%x, plen %d\n", conn_id, skb->len);
6a2968aa	173
4aeee687 CR	174	conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
	175	if (!conn_info) {
	176	rc = -EPROTO;
	177	goto free_exit;
	178	}
	179
6a2968aa	180	/* check if the packet need to be fragmented */
4aeee687	181	if (skb->len <= conn_info->max_pkt_payload_len) {
6a2968aa IE	182	/* no need to fragment packet */
	183	nci_push_data_hdr(ndev, conn_id, skb, NCI_PBF_LAST);
	184
	185	skb_queue_tail(&ndev->tx_q, skb);
	186	} else {
	187	/* fragment packet and queue the fragments */
	188	rc = nci_queue_tx_data_frags(ndev, conn_id, skb);
	189	if (rc) {
ed1e0ad8	190	pr_err("failed to fragment tx data packet\n");
6a2968aa IE	191	goto free_exit;
	192	}
	193	}
	194
4aeee687	195	ndev->cur_conn_id = conn_id;
6a2968aa IE	196	queue_work(ndev->tx_wq, &ndev->tx_work);
	197
	198	goto exit;
	199
	200	free_exit:
	201	kfree_skb(skb);
	202
	203	exit:
	204	return rc;
	205	}
ea785c09	206	EXPORT_SYMBOL(nci_send_data);
6a2968aa IE	207
	208	/* ----------------- NCI RX Data ----------------- */
	209
	210	static void nci_add_rx_data_frag(struct nci_dev *ndev,
eb9bc6e9	211	struct sk_buff *skb,
4aeee687	212	__u8 pbf, __u8 conn_id, __u8 status)
6a2968aa IE	213	{
	214	int reassembly_len;
	215	int err = 0;
	216
98ff416f CR	217	if (status) {
	218	err = status;
	219	goto exit;
	220	}
	221
6a2968aa IE	222	if (ndev->rx_data_reassembly) {
	223	reassembly_len = ndev->rx_data_reassembly->len;
	224
	225	/* first, make enough room for the already accumulated data */
	226	if (skb_cow_head(skb, reassembly_len)) {
ed1e0ad8	227	pr_err("error adding room for accumulated rx data\n");
6a2968aa IE	228
6a2968aa IE	229	kfree_skb(skb);
040487f3	230	skb = NULL;
6a2968aa IE	231
6a2968aa IE	232	kfree_skb(ndev->rx_data_reassembly);
040487f3	233	ndev->rx_data_reassembly = NULL;
6a2968aa IE	234
	235	err = -ENOMEM;
	236	goto exit;
	237	}
	238
	239	/* second, combine the two fragments */
	240	memcpy(skb_push(skb, reassembly_len),
eb9bc6e9 SO	241	ndev->rx_data_reassembly->data,
eb9bc6e9 SO	242	reassembly_len);
6a2968aa IE	243
	244	/* third, free old reassembly */
	245	kfree_skb(ndev->rx_data_reassembly);
040487f3	246	ndev->rx_data_reassembly = NULL;
6a2968aa IE	247	}
	248
	249	if (pbf == NCI_PBF_CONT) {
	250	/* need to wait for next fragment, store skb and exit */
	251	ndev->rx_data_reassembly = skb;
	252	return;
	253	}
	254
	255	exit:
4aeee687	256	if (ndev->nfc_dev->rf_mode == NFC_RF_TARGET) {
122c1958 JL	257	/* Data received in Target mode, forward to nfc core */
	258	err = nfc_tm_data_received(ndev->nfc_dev, skb);
	259	if (err)
	260	pr_err("unable to handle received data\n");
	261	} else {
4aeee687	262	nci_data_exchange_complete(ndev, skb, conn_id, err);
122c1958	263	}
6a2968aa IE	264	}
	265
	266	/* Rx Data packet */
	267	void nci_rx_data_packet(struct nci_dev ndev, struct sk_buff skb)
	268	{
	269	__u8 pbf = nci_pbf(skb->data);
98ff416f	270	__u8 status = 0;
4aeee687 CR	271	__u8 conn_id = nci_conn_id(skb->data);
4aeee687 CR	272	struct nci_conn_info *conn_info;
6a2968aa	273
24bf3304	274	pr_debug("len %d\n", skb->len);
6a2968aa	275
20c239c1 JP	276	pr_debug("NCI RX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
	277	nci_pbf(skb->data),
	278	nci_conn_id(skb->data),
	279	nci_plen(skb->data));
6a2968aa	280
4aeee687 CR	281	conn_info = nci_get_conn_info_by_conn_id(ndev, nci_conn_id(skb->data));
	282	if (!conn_info)
	283	return;
	284
6a2968aa IE	285	/* strip the nci data header */
	286	skb_pull(skb, NCI_DATA_HDR_SIZE);
	287
83724c33 VC	288	if (ndev->target_active_prot == NFC_PROTO_MIFARE \|\|
	289	ndev->target_active_prot == NFC_PROTO_JEWEL \|\|
	290	ndev->target_active_prot == NFC_PROTO_FELICA \|\|
	291	ndev->target_active_prot == NFC_PROTO_ISO15693) {
6a2968aa	292	/* frame I/F => remove the status byte */
83724c33	293	pr_debug("frame I/F => remove the status byte\n");
98ff416f	294	status = skb->data[skb->len - 1];
6a2968aa IE	295	skb_trim(skb, (skb->len - 1));
	296	}
	297
4aeee687	298	nci_add_rx_data_frag(ndev, skb, pbf, conn_id, nci_to_errno(status));
6a2968aa	299	}