[net-next-2.6.git] / net / caif / cffrml.c

/*
 * CAIF Framing Layer.
 *
 * Copyright (C) ST-Ericsson AB 2010
 * Author:	Sjur Brendeland/sjur.brandeland@stericsson.com
 * 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/crc-ccitt.h>
#include <net/caif/caif_layer.h>
#include <net/caif/cfpkt.h>
#include <net/caif/cffrml.h>

#define container_obj(layr) container_of(layr, struct cffrml, layer)

struct cffrml {
	struct cflayer layer;
	bool dofcs;		/* !< FCS active */
};

static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt);
static int cffrml_transmit(struct cflayer *layr, struct cfpkt *pkt);
static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
				int phyid);

static u32 cffrml_rcv_error;
static u32 cffrml_rcv_checsum_error;
struct cflayer *cffrml_create(u16 phyid, bool use_fcs)
{
	struct cffrml *this = kmalloc(sizeof(struct cffrml), GFP_ATOMIC);
	if (!this) {
		pr_warn("Out of memory\n");
		return NULL;
	}
	caif_assert(offsetof(struct cffrml, layer) == 0);

	memset(this, 0, sizeof(struct cflayer));
	this->layer.receive = cffrml_receive;
	this->layer.transmit = cffrml_transmit;
	this->layer.ctrlcmd = cffrml_ctrlcmd;
	snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "frm%d", phyid);
	this->dofcs = use_fcs;
	this->layer.id = phyid;
	return (struct cflayer *) this;
}

void cffrml_set_uplayer(struct cflayer *this, struct cflayer *up)
{
	this->up = up;
}

void cffrml_set_dnlayer(struct cflayer *this, struct cflayer *dn)
{
	this->dn = dn;
}

static u16 cffrml_checksum(u16 chks, void *buf, u16 len)
{
	/* FIXME: FCS should be moved to glue in order to use OS-Specific
	 * solutions
	 */
	return crc_ccitt(chks, buf, len);
}

static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt)
{
	u16 tmp;
	u16 len;
	u16 hdrchks;
	u16 pktchks;
	struct cffrml *this;
	this = container_obj(layr);

	cfpkt_extr_head(pkt, &tmp, 2);
	len = le16_to_cpu(tmp);

	/* Subtract for FCS on length if FCS is not used. */
	if (!this->dofcs)
		len -= 2;

	if (cfpkt_setlen(pkt, len) < 0) {
		++cffrml_rcv_error;
		pr_err("Framing length error (%d)\n", len);
		cfpkt_destroy(pkt);
		return -EPROTO;
	}
	/*
	 * Don't do extract if FCS is false, rather do setlen - then we don't
	 * get a cache-miss.
	 */
	if (this->dofcs) {
		cfpkt_extr_trail(pkt, &tmp, 2);
		hdrchks = le16_to_cpu(tmp);
		pktchks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff);
		if (pktchks != hdrchks) {
			cfpkt_add_trail(pkt, &tmp, 2);
			++cffrml_rcv_error;
			++cffrml_rcv_checsum_error;
			pr_info("Frame checksum error (0x%x != 0x%x)\n",
				hdrchks, pktchks);
			return -EILSEQ;
		}
	}
	if (cfpkt_erroneous(pkt)) {
		++cffrml_rcv_error;
		pr_err("Packet is erroneous!\n");
		cfpkt_destroy(pkt);
		return -EPROTO;
	}
	return layr->up->receive(layr->up, pkt);
}

static int cffrml_transmit(struct cflayer *layr, struct cfpkt *pkt)
{
	int tmp;
	u16 chks;
	u16 len;
	int ret;
	struct cffrml *this = container_obj(layr);
	if (this->dofcs) {
		chks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff);
		tmp = cpu_to_le16(chks);
		cfpkt_add_trail(pkt, &tmp, 2);
	} else {
		cfpkt_pad_trail(pkt, 2);
	}
	len = cfpkt_getlen(pkt);
	tmp = cpu_to_le16(len);
	cfpkt_add_head(pkt, &tmp, 2);
	cfpkt_info(pkt)->hdr_len += 2;
	if (cfpkt_erroneous(pkt)) {
		pr_err("Packet is erroneous!\n");
		return -EPROTO;
	}
	ret = layr->dn->transmit(layr->dn, pkt);
	if (ret < 0) {
		/* Remove header on faulty packet. */
		cfpkt_extr_head(pkt, &tmp, 2);
	}
	return ret;
}

static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
					int phyid)
{
	if (layr->up->ctrlcmd)
		layr->up->ctrlcmd(layr->up, ctrl, layr->id);
}
Commit	Line	Data
b482cd20 SB	1	/*
	2	* CAIF Framing Layer.
	3	*
	4	* Copyright (C) ST-Ericsson AB 2010
	5	* Author: Sjur Brendeland/sjur.brandeland@stericsson.com
	6	* License terms: GNU General Public License (GPL) version 2
	7	*/
	8
b31fa5ba JP	9	#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
b31fa5ba JP	10
b482cd20 SB	11	#include <linux/stddef.h>
	12	#include <linux/spinlock.h>
	13	#include <linux/slab.h>
	14	#include <linux/crc-ccitt.h>
	15	#include <net/caif/caif_layer.h>
	16	#include <net/caif/cfpkt.h>
	17	#include <net/caif/cffrml.h>
	18
	19	#define container_obj(layr) container_of(layr, struct cffrml, layer)
	20
	21	struct cffrml {
	22	struct cflayer layer;
	23	bool dofcs; /* !< FCS active */
	24	};
	25
	26	static int cffrml_receive(struct cflayer layr, struct cfpkt pkt);
	27	static int cffrml_transmit(struct cflayer layr, struct cfpkt pkt);
	28	static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
	29	int phyid);
	30
	31	static u32 cffrml_rcv_error;
	32	static u32 cffrml_rcv_checsum_error;
	33	struct cflayer *cffrml_create(u16 phyid, bool use_fcs)
	34	{
	35	struct cffrml *this = kmalloc(sizeof(struct cffrml), GFP_ATOMIC);
	36	if (!this) {
b31fa5ba	37	pr_warn("Out of memory\n");
b482cd20 SB	38	return NULL;
	39	}
	40	caif_assert(offsetof(struct cffrml, layer) == 0);
	41
	42	memset(this, 0, sizeof(struct cflayer));
	43	this->layer.receive = cffrml_receive;
	44	this->layer.transmit = cffrml_transmit;
	45	this->layer.ctrlcmd = cffrml_ctrlcmd;
	46	snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "frm%d", phyid);
	47	this->dofcs = use_fcs;
	48	this->layer.id = phyid;
	49	return (struct cflayer *) this;
	50	}
	51
	52	void cffrml_set_uplayer(struct cflayer this, struct cflayer up)
	53	{
	54	this->up = up;
	55	}
	56
	57	void cffrml_set_dnlayer(struct cflayer this, struct cflayer dn)
	58	{
	59	this->dn = dn;
	60	}
	61
	62	static u16 cffrml_checksum(u16 chks, void *buf, u16 len)
	63	{
	64	/* FIXME: FCS should be moved to glue in order to use OS-Specific
	65	* solutions
	66	*/
	67	return crc_ccitt(chks, buf, len);
	68	}
	69
	70	static int cffrml_receive(struct cflayer layr, struct cfpkt pkt)
	71	{
	72	u16 tmp;
	73	u16 len;
	74	u16 hdrchks;
	75	u16 pktchks;
	76	struct cffrml *this;
	77	this = container_obj(layr);
	78
	79	cfpkt_extr_head(pkt, &tmp, 2);
	80	len = le16_to_cpu(tmp);
	81
	82	/* Subtract for FCS on length if FCS is not used. */
	83	if (!this->dofcs)
	84	len -= 2;
	85
	86	if (cfpkt_setlen(pkt, len) < 0) {
	87	++cffrml_rcv_error;
b31fa5ba	88	pr_err("Framing length error (%d)\n", len);
b482cd20 SB	89	cfpkt_destroy(pkt);
	90	return -EPROTO;
	91	}
	92	/*
	93	* Don't do extract if FCS is false, rather do setlen - then we don't
	94	* get a cache-miss.
	95	*/
	96	if (this->dofcs) {
	97	cfpkt_extr_trail(pkt, &tmp, 2);
	98	hdrchks = le16_to_cpu(tmp);
	99	pktchks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff);
	100	if (pktchks != hdrchks) {
	101	cfpkt_add_trail(pkt, &tmp, 2);
	102	++cffrml_rcv_error;
	103	++cffrml_rcv_checsum_error;
b31fa5ba JP	104	pr_info("Frame checksum error (0x%x != 0x%x)\n",
b31fa5ba JP	105	hdrchks, pktchks);
b482cd20 SB	106	return -EILSEQ;
	107	}
	108	}
	109	if (cfpkt_erroneous(pkt)) {
	110	++cffrml_rcv_error;
b31fa5ba	111	pr_err("Packet is erroneous!\n");
b482cd20 SB	112	cfpkt_destroy(pkt);
	113	return -EPROTO;
	114	}
	115	return layr->up->receive(layr->up, pkt);
	116	}
	117
	118	static int cffrml_transmit(struct cflayer layr, struct cfpkt pkt)
	119	{
	120	int tmp;
	121	u16 chks;
	122	u16 len;
	123	int ret;
	124	struct cffrml *this = container_obj(layr);
	125	if (this->dofcs) {
	126	chks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff);
	127	tmp = cpu_to_le16(chks);
	128	cfpkt_add_trail(pkt, &tmp, 2);
	129	} else {
	130	cfpkt_pad_trail(pkt, 2);
	131	}
	132	len = cfpkt_getlen(pkt);
	133	tmp = cpu_to_le16(len);
	134	cfpkt_add_head(pkt, &tmp, 2);
	135	cfpkt_info(pkt)->hdr_len += 2;
	136	if (cfpkt_erroneous(pkt)) {
b31fa5ba	137	pr_err("Packet is erroneous!\n");
b482cd20 SB	138	return -EPROTO;
	139	}
	140	ret = layr->dn->transmit(layr->dn, pkt);
	141	if (ret < 0) {
	142	/* Remove header on faulty packet. */
	143	cfpkt_extr_head(pkt, &tmp, 2);
	144	}
	145	return ret;
	146	}
	147
	148	static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
	149	int phyid)
	150	{
	151	if (layr->up->ctrlcmd)
	152	layr->up->ctrlcmd(layr->up, ctrl, layr->id);
	153	}