[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);
}

int nci_conn_max_data_pkt_payload_size(struct nci_dev *ndev, __u8 conn_id)
{
	struct nci_conn_info *conn_info;

	conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
	if (!conn_info)
		return -EPROTO;

	return conn_info->max_pkt_payload_len;
}
EXPORT_SYMBOL(nci_conn_max_data_pkt_payload_size);

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	}
6a2968aa IE	92
2663589c RD	93	int nci_conn_max_data_pkt_payload_size(struct nci_dev *ndev, __u8 conn_id)
	94	{
	95	struct nci_conn_info *conn_info;
	96
	97	conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
	98	if (!conn_info)
	99	return -EPROTO;
	100
	101	return conn_info->max_pkt_payload_len;
	102	}
	103	EXPORT_SYMBOL(nci_conn_max_data_pkt_payload_size);
	104
6a2968aa	105	static int nci_queue_tx_data_frags(struct nci_dev *ndev,
eb9bc6e9 SO	106	__u8 conn_id,
eb9bc6e9 SO	107	struct sk_buff *skb) {
4aeee687	108	struct nci_conn_info *conn_info;
6a2968aa IE	109	int total_len = skb->len;
	110	unsigned char *data = skb->data;
	111	unsigned long flags;
	112	struct sk_buff_head frags_q;
	113	struct sk_buff *skb_frag;
	114	int frag_len;
	115	int rc = 0;
	116
24bf3304	117	pr_debug("conn_id 0x%x, total_len %d\n", conn_id, total_len);
6a2968aa	118
4aeee687 CR	119	conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
	120	if (!conn_info) {
	121	rc = -EPROTO;
	122	goto free_exit;
	123	}
	124
6a2968aa IE	125	__skb_queue_head_init(&frags_q);
	126
	127	while (total_len) {
e8c0dacd	128	frag_len =
4aeee687	129	min_t(int, total_len, conn_info->max_pkt_payload_len);
6a2968aa IE	130
6a2968aa IE	131	skb_frag = nci_skb_alloc(ndev,
eb9bc6e9 SO	132	(NCI_DATA_HDR_SIZE + frag_len),
eb9bc6e9 SO	133	GFP_KERNEL);
6a2968aa IE	134	if (skb_frag == NULL) {
	135	rc = -ENOMEM;
	136	goto free_exit;
	137	}
	138	skb_reserve(skb_frag, NCI_DATA_HDR_SIZE);
	139
	140	/* first, copy the data */
	141	memcpy(skb_put(skb_frag, frag_len), data, frag_len);
	142
	143	/* second, set the header */
	144	nci_push_data_hdr(ndev, conn_id, skb_frag,
eb9bc6e9 SO	145	((total_len == frag_len) ?
eb9bc6e9 SO	146	(NCI_PBF_LAST) : (NCI_PBF_CONT)));
6a2968aa IE	147
	148	__skb_queue_tail(&frags_q, skb_frag);
	149
	150	data += frag_len;
	151	total_len -= frag_len;
	152
20c239c1 JP	153	pr_debug("frag_len %d, remaining total_len %d\n",
20c239c1 JP	154	frag_len, total_len);
6a2968aa IE	155	}
	156
	157	/* queue all fragments atomically */
	158	spin_lock_irqsave(&ndev->tx_q.lock, flags);
	159
	160	while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
	161	__skb_queue_tail(&ndev->tx_q, skb_frag);
	162
	163	spin_unlock_irqrestore(&ndev->tx_q.lock, flags);
	164
	165	/* free the original skb */
	166	kfree_skb(skb);
	167
	168	goto exit;
	169
	170	free_exit:
	171	while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
	172	kfree_skb(skb_frag);
	173
	174	exit:
	175	return rc;
	176	}
	177
	178	/* Send NCI data */
	179	int nci_send_data(struct nci_dev ndev, __u8 conn_id, struct sk_buff skb)
	180	{
4aeee687	181	struct nci_conn_info *conn_info;
6a2968aa IE	182	int rc = 0;
6a2968aa IE	183
24bf3304	184	pr_debug("conn_id 0x%x, plen %d\n", conn_id, skb->len);
6a2968aa	185
4aeee687 CR	186	conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
	187	if (!conn_info) {
	188	rc = -EPROTO;
	189	goto free_exit;
	190	}
	191
6a2968aa	192	/* check if the packet need to be fragmented */
4aeee687	193	if (skb->len <= conn_info->max_pkt_payload_len) {
6a2968aa IE	194	/* no need to fragment packet */
	195	nci_push_data_hdr(ndev, conn_id, skb, NCI_PBF_LAST);
	196
	197	skb_queue_tail(&ndev->tx_q, skb);
	198	} else {
	199	/* fragment packet and queue the fragments */
	200	rc = nci_queue_tx_data_frags(ndev, conn_id, skb);
	201	if (rc) {
ed1e0ad8	202	pr_err("failed to fragment tx data packet\n");
6a2968aa IE	203	goto free_exit;
	204	}
	205	}
	206
4aeee687	207	ndev->cur_conn_id = conn_id;
6a2968aa IE	208	queue_work(ndev->tx_wq, &ndev->tx_work);
	209
	210	goto exit;
	211
	212	free_exit:
	213	kfree_skb(skb);
	214
	215	exit:
	216	return rc;
	217	}
ea785c09	218	EXPORT_SYMBOL(nci_send_data);
6a2968aa IE	219
	220	/* ----------------- NCI RX Data ----------------- */
	221
	222	static void nci_add_rx_data_frag(struct nci_dev *ndev,
eb9bc6e9	223	struct sk_buff *skb,
4aeee687	224	__u8 pbf, __u8 conn_id, __u8 status)
6a2968aa IE	225	{
	226	int reassembly_len;
	227	int err = 0;
	228
98ff416f CR	229	if (status) {
	230	err = status;
	231	goto exit;
	232	}
	233
6a2968aa IE	234	if (ndev->rx_data_reassembly) {
	235	reassembly_len = ndev->rx_data_reassembly->len;
	236
	237	/* first, make enough room for the already accumulated data */
	238	if (skb_cow_head(skb, reassembly_len)) {
ed1e0ad8	239	pr_err("error adding room for accumulated rx data\n");
6a2968aa IE	240
6a2968aa IE	241	kfree_skb(skb);
040487f3	242	skb = NULL;
6a2968aa IE	243
6a2968aa IE	244	kfree_skb(ndev->rx_data_reassembly);
040487f3	245	ndev->rx_data_reassembly = NULL;
6a2968aa IE	246
	247	err = -ENOMEM;
	248	goto exit;
	249	}
	250
	251	/* second, combine the two fragments */
	252	memcpy(skb_push(skb, reassembly_len),
eb9bc6e9 SO	253	ndev->rx_data_reassembly->data,
eb9bc6e9 SO	254	reassembly_len);
6a2968aa IE	255
	256	/* third, free old reassembly */
	257	kfree_skb(ndev->rx_data_reassembly);
040487f3	258	ndev->rx_data_reassembly = NULL;
6a2968aa IE	259	}
	260
	261	if (pbf == NCI_PBF_CONT) {
	262	/* need to wait for next fragment, store skb and exit */
	263	ndev->rx_data_reassembly = skb;
	264	return;
	265	}
	266
	267	exit:
4aeee687	268	if (ndev->nfc_dev->rf_mode == NFC_RF_TARGET) {
122c1958 JL	269	/* Data received in Target mode, forward to nfc core */
	270	err = nfc_tm_data_received(ndev->nfc_dev, skb);
	271	if (err)
	272	pr_err("unable to handle received data\n");
	273	} else {
4aeee687	274	nci_data_exchange_complete(ndev, skb, conn_id, err);
122c1958	275	}
6a2968aa IE	276	}
	277
	278	/* Rx Data packet */
	279	void nci_rx_data_packet(struct nci_dev ndev, struct sk_buff skb)
	280	{
	281	__u8 pbf = nci_pbf(skb->data);
98ff416f	282	__u8 status = 0;
4aeee687 CR	283	__u8 conn_id = nci_conn_id(skb->data);
4aeee687 CR	284	struct nci_conn_info *conn_info;
6a2968aa	285
24bf3304	286	pr_debug("len %d\n", skb->len);
6a2968aa	287
20c239c1 JP	288	pr_debug("NCI RX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
	289	nci_pbf(skb->data),
	290	nci_conn_id(skb->data),
	291	nci_plen(skb->data));
6a2968aa	292
4aeee687 CR	293	conn_info = nci_get_conn_info_by_conn_id(ndev, nci_conn_id(skb->data));
	294	if (!conn_info)
	295	return;
	296
6a2968aa IE	297	/* strip the nci data header */
	298	skb_pull(skb, NCI_DATA_HDR_SIZE);
	299
83724c33 VC	300	if (ndev->target_active_prot == NFC_PROTO_MIFARE \|\|
	301	ndev->target_active_prot == NFC_PROTO_JEWEL \|\|
	302	ndev->target_active_prot == NFC_PROTO_FELICA \|\|
	303	ndev->target_active_prot == NFC_PROTO_ISO15693) {
6a2968aa	304	/* frame I/F => remove the status byte */
83724c33	305	pr_debug("frame I/F => remove the status byte\n");
98ff416f	306	status = skb->data[skb->len - 1];
6a2968aa IE	307	skb_trim(skb, (skb->len - 1));
	308	}
	309
4aeee687	310	nci_add_rx_data_frag(ndev, skb, pbf, conn_id, nci_to_errno(status));
6a2968aa	311	}