[linux-block.git] / drivers / scsi / cxgb3i / cxgb3i_pdu.c

/*
 * cxgb3i_pdu.c: Chelsio S3xx iSCSI driver.
 *
 * Copyright (c) 2008 Chelsio Communications, Inc.
 * Copyright (c) 2008 Mike Christie
 * Copyright (c) 2008 Red Hat, Inc.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation.
 *
 * Written by: Karen Xie (kxie@chelsio.com)
 */

#include <linux/skbuff.h>
#include <linux/crypto.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>

#include "cxgb3i.h"
#include "cxgb3i_pdu.h"

#ifdef __DEBUG_CXGB3I_RX__
#define cxgb3i_rx_debug		cxgb3i_log_debug
#else
#define cxgb3i_rx_debug(fmt...)
#endif

#ifdef __DEBUG_CXGB3I_TX__
#define cxgb3i_tx_debug		cxgb3i_log_debug
#else
#define cxgb3i_tx_debug(fmt...)
#endif

/* always allocate rooms for AHS */
#define SKB_TX_PDU_HEADER_LEN	\
	(sizeof(struct iscsi_hdr) + ISCSI_MAX_AHS_SIZE)
static unsigned int skb_extra_headroom;
static struct page *pad_page;

/*
 * pdu receive, interact with libiscsi_tcp
 */
static inline int read_pdu_skb(struct iscsi_conn *conn, struct sk_buff *skb,
			       unsigned int offset, int offloaded)
{
	int status = 0;
	int bytes_read;

	bytes_read = iscsi_tcp_recv_skb(conn, skb, offset, offloaded, &status);
	switch (status) {
	case ISCSI_TCP_CONN_ERR:
		return -EIO;
	case ISCSI_TCP_SUSPENDED:
		/* no transfer - just have caller flush queue */
		return bytes_read;
	case ISCSI_TCP_SKB_DONE:
		/*
		 * pdus should always fit in the skb and we should get
		 * segment done notifcation.
		 */
		iscsi_conn_printk(KERN_ERR, conn, "Invalid pdu or skb.");
		return -EFAULT;
	case ISCSI_TCP_SEGMENT_DONE:
		return bytes_read;
	default:
		iscsi_conn_printk(KERN_ERR, conn, "Invalid iscsi_tcp_recv_skb "
				  "status %d\n", status);
		return -EINVAL;
	}
}

static int cxgb3i_conn_read_pdu_skb(struct iscsi_conn *conn,
				    struct sk_buff *skb)
{
	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	bool offloaded = 0;
	unsigned int offset;
	int rc;

	cxgb3i_rx_debug("conn 0x%p, skb 0x%p, len %u, flag 0x%x.\n",
			conn, skb, skb->len, skb_ulp_mode(skb));

	if (!iscsi_tcp_recv_segment_is_hdr(tcp_conn)) {
		iscsi_conn_failure(conn, ISCSI_ERR_PROTO);
		return -EIO;
	}

	if (conn->hdrdgst_en && (skb_ulp_mode(skb) & ULP2_FLAG_HCRC_ERROR)) {
		iscsi_conn_failure(conn, ISCSI_ERR_HDR_DGST);
		return -EIO;
	}

	if (conn->datadgst_en && (skb_ulp_mode(skb) & ULP2_FLAG_DCRC_ERROR)) {
		iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
		return -EIO;
	}

	/* iscsi hdr */
	rc = read_pdu_skb(conn, skb, 0, 0);
	if (rc <= 0)
		return rc;

	if (iscsi_tcp_recv_segment_is_hdr(tcp_conn))
		return 0;

	offset = rc;
	if (conn->hdrdgst_en)
		offset += ISCSI_DIGEST_SIZE;

	/* iscsi data */
	if (skb_ulp_mode(skb) & ULP2_FLAG_DATA_DDPED) {
		cxgb3i_rx_debug("skb 0x%p, opcode 0x%x, data %u, ddp'ed, "
				"itt 0x%x.\n",
				skb,
				tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK,
				tcp_conn->in.datalen,
				ntohl(tcp_conn->in.hdr->itt));
		offloaded = 1;
	} else {
		cxgb3i_rx_debug("skb 0x%p, opcode 0x%x, data %u, NOT ddp'ed, "
				"itt 0x%x.\n",
				skb,
				tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK,
				tcp_conn->in.datalen,
				ntohl(tcp_conn->in.hdr->itt));
		offset += sizeof(struct cpl_iscsi_hdr_norss);
	}

	rc = read_pdu_skb(conn, skb, offset, offloaded);
	if (rc < 0)
		return rc;
	else
		return 0;
}

/*
 * pdu transmit, interact with libiscsi_tcp
 */
static inline void tx_skb_setmode(struct sk_buff *skb, int hcrc, int dcrc)
{
	u8 submode = 0;

	if (hcrc)
		submode |= 1;
	if (dcrc)
		submode |= 2;
	skb_ulp_mode(skb) = (ULP_MODE_ISCSI << 4) | submode;
}

void cxgb3i_conn_cleanup_task(struct iscsi_task *task)
{
	struct cxgb3i_task_data *tdata = task->dd_data +
					sizeof(struct iscsi_tcp_task);

	/* never reached the xmit task callout */
	if (tdata->skb)
		__kfree_skb(tdata->skb);
	memset(tdata, 0, sizeof(struct cxgb3i_task_data));

	/* MNC - Do we need a check in case this is called but
	 * cxgb3i_conn_alloc_pdu has never been called on the task */
	cxgb3i_release_itt(task, task->hdr_itt);
	iscsi_tcp_cleanup_task(task);
}

static int sgl_seek_offset(struct scatterlist *sgl, unsigned int sgcnt,
				unsigned int offset, unsigned int *off,
				struct scatterlist **sgp)
{
	int i;
	struct scatterlist *sg;

	for_each_sg(sgl, sg, sgcnt, i) {
		if (offset < sg->length) {
			*off = offset;
			*sgp = sg;
			return 0;
		}
		offset -= sg->length;
	}
	return -EFAULT;
}

static int sgl_read_to_frags(struct scatterlist *sg, unsigned int sgoffset,
				unsigned int dlen, skb_frag_t *frags,
				int frag_max)
{
	unsigned int datalen = dlen;
	unsigned int sglen = sg->length - sgoffset;
	struct page *page = sg_page(sg);
	int i;

	i = 0;
	do {
		unsigned int copy;

		if (!sglen) {
			sg = sg_next(sg);
			if (!sg) {
				cxgb3i_log_error("%s, sg NULL, len %u/%u.\n",
						 __func__, datalen, dlen);
				return -EINVAL;
			}
			sgoffset = 0;
			sglen = sg->length;
			page = sg_page(sg);

		}
		copy = min(datalen, sglen);
		if (i && page == frags[i - 1].page &&
		    sgoffset + sg->offset ==
			frags[i - 1].page_offset + frags[i - 1].size) {
			frags[i - 1].size += copy;
		} else {
			if (i >= frag_max) {
				cxgb3i_log_error("%s, too many pages %u, "
						 "dlen %u.\n", __func__,
						 frag_max, dlen);
				return -EINVAL;
			}

			frags[i].page = page;
			frags[i].page_offset = sg->offset + sgoffset;
			frags[i].size = copy;
			i++;
		}
		datalen -= copy;
		sgoffset += copy;
		sglen -= copy;
	} while (datalen);

	return i;
}

int cxgb3i_conn_alloc_pdu(struct iscsi_task *task, u8 opcode)
{
	struct iscsi_conn *conn = task->conn;
	struct iscsi_tcp_task *tcp_task = task->dd_data;
	struct cxgb3i_task_data *tdata = task->dd_data + sizeof(*tcp_task);
	struct scsi_cmnd *sc = task->sc;
	int headroom = SKB_TX_PDU_HEADER_LEN;

	tcp_task->dd_data = tdata;
	task->hdr = NULL;

	/* write command, need to send data pdus */
	if (skb_extra_headroom && (opcode == ISCSI_OP_SCSI_DATA_OUT ||
	    (opcode == ISCSI_OP_SCSI_CMD &&
	    (scsi_bidi_cmnd(sc) || sc->sc_data_direction == DMA_TO_DEVICE))))
		headroom += min(skb_extra_headroom, conn->max_xmit_dlength);

	tdata->skb = alloc_skb(TX_HEADER_LEN + headroom, GFP_ATOMIC);
	if (!tdata->skb)
		return -ENOMEM;
	skb_reserve(tdata->skb, TX_HEADER_LEN);

	cxgb3i_tx_debug("task 0x%p, opcode 0x%x, skb 0x%p.\n",
			task, opcode, tdata->skb);

	task->hdr = (struct iscsi_hdr *)tdata->skb->data;
	task->hdr_max = SKB_TX_PDU_HEADER_LEN;

	/* data_out uses scsi_cmd's itt */
	if (opcode != ISCSI_OP_SCSI_DATA_OUT)
		cxgb3i_reserve_itt(task, &task->hdr->itt);

	return 0;
}

int cxgb3i_conn_init_pdu(struct iscsi_task *task, unsigned int offset,
			      unsigned int count)
{
	struct iscsi_conn *conn = task->conn;
	struct iscsi_tcp_task *tcp_task = task->dd_data;
	struct cxgb3i_task_data *tdata = tcp_task->dd_data;
	struct sk_buff *skb = tdata->skb;
	unsigned int datalen = count;
	int i, padlen = iscsi_padding(count);
	struct page *pg;

	cxgb3i_tx_debug("task 0x%p,0x%p, offset %u, count %u, skb 0x%p.\n",
			task, task->sc, offset, count, skb);

	skb_put(skb, task->hdr_len);
	tx_skb_setmode(skb, conn->hdrdgst_en, datalen ? conn->datadgst_en : 0);
	if (!count)
		return 0;

	if (task->sc) {
		struct scsi_data_buffer *sdb = scsi_out(task->sc);
		struct scatterlist *sg = NULL;
		int err;

		tdata->offset = offset;
		tdata->count = count;
		err = sgl_seek_offset(sdb->table.sgl, sdb->table.nents,
					tdata->offset, &tdata->sgoffset, &sg);
		if (err < 0) {
			cxgb3i_log_warn("tpdu, sgl %u, bad offset %u/%u.\n",
					sdb->table.nents, tdata->offset,
					sdb->length);
			return err;
		}
		err = sgl_read_to_frags(sg, tdata->sgoffset, tdata->count,
					tdata->frags, MAX_PDU_FRAGS);
		if (err < 0) {
			cxgb3i_log_warn("tpdu, sgl %u, bad offset %u + %u.\n",
					sdb->table.nents, tdata->offset,
					tdata->count);
			return err;
		}
		tdata->nr_frags = err;

		if (tdata->nr_frags > MAX_SKB_FRAGS ||
		    (padlen && tdata->nr_frags == MAX_SKB_FRAGS)) {
			char *dst = skb->data + task->hdr_len;
			skb_frag_t *frag = tdata->frags;

			/* data fits in the skb's headroom */
			for (i = 0; i < tdata->nr_frags; i++, frag++) {
				char *src = kmap_atomic(frag->page,
							KM_SOFTIRQ0);

				memcpy(dst, src+frag->page_offset, frag->size);
				dst += frag->size;
				kunmap_atomic(src, KM_SOFTIRQ0);
			}
			if (padlen) {
				memset(dst, 0, padlen);
				padlen = 0;
			}
			skb_put(skb, count + padlen);
		} else {
			/* data fit into frag_list */
			for (i = 0; i < tdata->nr_frags; i++)
				get_page(tdata->frags[i].page);

			memcpy(skb_shinfo(skb)->frags, tdata->frags,
				sizeof(skb_frag_t) * tdata->nr_frags);
			skb_shinfo(skb)->nr_frags = tdata->nr_frags;
			skb->len += count;
			skb->data_len += count;
			skb->truesize += count;
		}

	} else {
		pg = virt_to_page(task->data);

		get_page(pg);
		skb_fill_page_desc(skb, 0, pg, offset_in_page(task->data),
					count);
		skb->len += count;
		skb->data_len += count;
		skb->truesize += count;
	}

	if (padlen) {
		i = skb_shinfo(skb)->nr_frags;
		get_page(pad_page);
		skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, pad_page, 0,
				 padlen);

		skb->data_len += padlen;
		skb->truesize += padlen;
		skb->len += padlen;
	}

	return 0;
}

int cxgb3i_conn_xmit_pdu(struct iscsi_task *task)
{
	struct iscsi_tcp_conn *tcp_conn = task->conn->dd_data;
	struct cxgb3i_conn *cconn = tcp_conn->dd_data;
	struct iscsi_tcp_task *tcp_task = task->dd_data;
	struct cxgb3i_task_data *tdata = tcp_task->dd_data;
	struct sk_buff *skb = tdata->skb;
	unsigned int datalen;
	int err;

	if (!skb)
		return 0;

	datalen = skb->data_len;
	tdata->skb = NULL;
	err = cxgb3i_c3cn_send_pdus(cconn->cep->c3cn, skb);
	if (err > 0) {
		int pdulen = err;

	cxgb3i_tx_debug("task 0x%p, skb 0x%p, len %u/%u, rv %d.\n",
			task, skb, skb->len, skb->data_len, err);

		if (task->conn->hdrdgst_en)
			pdulen += ISCSI_DIGEST_SIZE;
		if (datalen && task->conn->datadgst_en)
			pdulen += ISCSI_DIGEST_SIZE;

		task->conn->txdata_octets += pdulen;
		return 0;
	}

	if (err < 0 && err != -EAGAIN) {
		kfree_skb(skb);
		cxgb3i_tx_debug("itt 0x%x, skb 0x%p, len %u/%u, xmit err %d.\n",
				task->itt, skb, skb->len, skb->data_len, err);
		iscsi_conn_printk(KERN_ERR, task->conn, "xmit err %d.\n", err);
		iscsi_conn_failure(task->conn, ISCSI_ERR_XMIT_FAILED);
		return err;
	}
	/* reset skb to send when we are called again */
	tdata->skb = skb;
	return -EAGAIN;
}

int cxgb3i_pdu_init(void)
{
	if (SKB_TX_HEADROOM > (512 * MAX_SKB_FRAGS))
		skb_extra_headroom = SKB_TX_HEADROOM;
	pad_page = alloc_page(GFP_KERNEL);
	if (!pad_page)
		return -ENOMEM;
	memset(page_address(pad_page), 0, PAGE_SIZE);
	return 0;
}

void cxgb3i_pdu_cleanup(void)
{
	if (pad_page) {
		__free_page(pad_page);
		pad_page = NULL;
	}
}

void cxgb3i_conn_pdu_ready(struct s3_conn *c3cn)
{
	struct sk_buff *skb;
	unsigned int read = 0;
	struct iscsi_conn *conn = c3cn->user_data;
	int err = 0;

	cxgb3i_rx_debug("cn 0x%p.\n", c3cn);

	read_lock(&c3cn->callback_lock);
	if (unlikely(!conn || conn->suspend_rx)) {
		cxgb3i_rx_debug("conn 0x%p, id %d, suspend_rx %lu!\n",
				conn, conn ? conn->id : 0xFF,
				conn ? conn->suspend_rx : 0xFF);
		read_unlock(&c3cn->callback_lock);
		return;
	}
	skb = skb_peek(&c3cn->receive_queue);
	while (!err && skb) {
		__skb_unlink(skb, &c3cn->receive_queue);
		read += skb_rx_pdulen(skb);
		cxgb3i_rx_debug("conn 0x%p, cn 0x%p, rx skb 0x%p, pdulen %u.\n",
				conn, c3cn, skb, skb_rx_pdulen(skb));
		err = cxgb3i_conn_read_pdu_skb(conn, skb);
		__kfree_skb(skb);
		skb = skb_peek(&c3cn->receive_queue);
	}
	read_unlock(&c3cn->callback_lock);
	if (c3cn) {
		c3cn->copied_seq += read;
		cxgb3i_c3cn_rx_credits(c3cn, read);
	}
	conn->rxdata_octets += read;

	if (err) {
		cxgb3i_log_info("conn 0x%p rx failed err %d.\n", conn, err);
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
	}
}

void cxgb3i_conn_tx_open(struct s3_conn *c3cn)
{
	struct iscsi_conn *conn = c3cn->user_data;

	cxgb3i_tx_debug("cn 0x%p.\n", c3cn);
	if (conn) {
		cxgb3i_tx_debug("cn 0x%p, cid %d.\n", c3cn, conn->id);
		scsi_queue_work(conn->session->host, &conn->xmitwork);
	}
}

void cxgb3i_conn_closing(struct s3_conn *c3cn)
{
	struct iscsi_conn *conn;

	read_lock(&c3cn->callback_lock);
	conn = c3cn->user_data;
	if (conn && c3cn->state != C3CN_STATE_ESTABLISHED)
		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
	read_unlock(&c3cn->callback_lock);
}
Commit	Line	Data
c3673464 KX	1	/*
	2	* cxgb3i_pdu.c: Chelsio S3xx iSCSI driver.
	3	*
	4	* Copyright (c) 2008 Chelsio Communications, Inc.
	5	* Copyright (c) 2008 Mike Christie
	6	* Copyright (c) 2008 Red Hat, Inc. All rights reserved.
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation.
	11	*
	12	* Written by: Karen Xie (kxie@chelsio.com)
	13	*/
	14
	15	#include <linux/skbuff.h>
	16	#include <linux/crypto.h>
	17	#include <scsi/scsi_cmnd.h>
	18	#include <scsi/scsi_host.h>
	19
	20	#include "cxgb3i.h"
	21	#include "cxgb3i_pdu.h"
	22
	23	#ifdef __DEBUG_CXGB3I_RX__
	24	#define cxgb3i_rx_debug cxgb3i_log_debug
	25	#else
	26	#define cxgb3i_rx_debug(fmt...)
	27	#endif
	28
	29	#ifdef __DEBUG_CXGB3I_TX__
	30	#define cxgb3i_tx_debug cxgb3i_log_debug
	31	#else
	32	#define cxgb3i_tx_debug(fmt...)
	33	#endif
	34
f62d0896 KX	35	/* always allocate rooms for AHS */
	36	#define SKB_TX_PDU_HEADER_LEN \
	37	(sizeof(struct iscsi_hdr) + ISCSI_MAX_AHS_SIZE)
	38	static unsigned int skb_extra_headroom;
c3673464 KX	39	static struct page *pad_page;
	40
	41	/*
	42	* pdu receive, interact with libiscsi_tcp
	43	*/
	44	static inline int read_pdu_skb(struct iscsi_conn conn, struct sk_buff skb,
	45	unsigned int offset, int offloaded)
	46	{
	47	int status = 0;
	48	int bytes_read;
	49
	50	bytes_read = iscsi_tcp_recv_skb(conn, skb, offset, offloaded, &status);
	51	switch (status) {
	52	case ISCSI_TCP_CONN_ERR:
	53	return -EIO;
	54	case ISCSI_TCP_SUSPENDED:
	55	/* no transfer - just have caller flush queue */
	56	return bytes_read;
	57	case ISCSI_TCP_SKB_DONE:
	58	/*
	59	* pdus should always fit in the skb and we should get
	60	* segment done notifcation.
	61	*/
	62	iscsi_conn_printk(KERN_ERR, conn, "Invalid pdu or skb.");
	63	return -EFAULT;
	64	case ISCSI_TCP_SEGMENT_DONE:
	65	return bytes_read;
	66	default:
	67	iscsi_conn_printk(KERN_ERR, conn, "Invalid iscsi_tcp_recv_skb "
	68	"status %d\n", status);
	69	return -EINVAL;
	70	}
	71	}
	72
	73	static int cxgb3i_conn_read_pdu_skb(struct iscsi_conn *conn,
	74	struct sk_buff *skb)
	75	{
	76	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
	77	bool offloaded = 0;
	78	unsigned int offset;
	79	int rc;
	80
	81	cxgb3i_rx_debug("conn 0x%p, skb 0x%p, len %u, flag 0x%x.\n",
	82	conn, skb, skb->len, skb_ulp_mode(skb));
	83
	84	if (!iscsi_tcp_recv_segment_is_hdr(tcp_conn)) {
	85	iscsi_conn_failure(conn, ISCSI_ERR_PROTO);
	86	return -EIO;
	87	}
	88
	89	if (conn->hdrdgst_en && (skb_ulp_mode(skb) & ULP2_FLAG_HCRC_ERROR)) {
	90	iscsi_conn_failure(conn, ISCSI_ERR_HDR_DGST);
	91	return -EIO;
	92	}
	93
	94	if (conn->datadgst_en && (skb_ulp_mode(skb) & ULP2_FLAG_DCRC_ERROR)) {
	95	iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
	96	return -EIO;
	97	}
	98
	99	/* iscsi hdr */
	100	rc = read_pdu_skb(conn, skb, 0, 0);
	101	if (rc <= 0)
	102	return rc;
103
104	if (iscsi_tcp_recv_segment_is_hdr(tcp_conn))
105	return 0;
106
107	offset = rc;
108	if (conn->hdrdgst_en)
109	offset += ISCSI_DIGEST_SIZE;
110
111	/* iscsi data */
112	if (skb_ulp_mode(skb) & ULP2_FLAG_DATA_DDPED) {
113	cxgb3i_rx_debug("skb 0x%p, opcode 0x%x, data %u, ddp'ed, "
114	"itt 0x%x.\n",
115	skb,
116	tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK,
117	tcp_conn->in.datalen,
118	ntohl(tcp_conn->in.hdr->itt));
119	offloaded = 1;
120	} else {
121	cxgb3i_rx_debug("skb 0x%p, opcode 0x%x, data %u, NOT ddp'ed, "
122	"itt 0x%x.\n",
123	skb,
124	tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK,
125	tcp_conn->in.datalen,
126	ntohl(tcp_conn->in.hdr->itt));
127	offset += sizeof(struct cpl_iscsi_hdr_norss);
128	}
129
130	rc = read_pdu_skb(conn, skb, offset, offloaded);
131	if (rc < 0)
132	return rc;
133	else
134	return 0;
135	}
136
137	/*
138	* pdu transmit, interact with libiscsi_tcp
139	*/
140	static inline void tx_skb_setmode(struct sk_buff *skb, int hcrc, int dcrc)
141	{
142	u8 submode = 0;
143
144	if (hcrc)
145	submode \|= 1;
146	if (dcrc)
147	submode \|= 2;
148	skb_ulp_mode(skb) = (ULP_MODE_ISCSI << 4) \| submode;
149	}
150
151	void cxgb3i_conn_cleanup_task(struct iscsi_task *task)
152	{
f62d0896 KX	153	struct cxgb3i_task_data *tdata = task->dd_data +
f62d0896 KX	154	sizeof(struct iscsi_tcp_task);
c3673464 KX	155
c3673464 KX	156	/* never reached the xmit task callout */
f62d0896 KX	157	if (tdata->skb)
	158	__kfree_skb(tdata->skb);
	159	memset(tdata, 0, sizeof(struct cxgb3i_task_data));
c3673464 KX	160
	161	/* MNC - Do we need a check in case this is called but
	162	* cxgb3i_conn_alloc_pdu has never been called on the task */
	163	cxgb3i_release_itt(task, task->hdr_itt);
	164	iscsi_tcp_cleanup_task(task);
	165	}
	166
f62d0896 KX	167	static int sgl_seek_offset(struct scatterlist *sgl, unsigned int sgcnt,
	168	unsigned int offset, unsigned int *off,
	169	struct scatterlist **sgp)
	170	{
	171	int i;
	172	struct scatterlist *sg;
	173
	174	for_each_sg(sgl, sg, sgcnt, i) {
	175	if (offset < sg->length) {
	176	*off = offset;
	177	*sgp = sg;
	178	return 0;
	179	}
	180	offset -= sg->length;
	181	}
	182	return -EFAULT;
	183	}
	184
	185	static int sgl_read_to_frags(struct scatterlist *sg, unsigned int sgoffset,
	186	unsigned int dlen, skb_frag_t *frags,
	187	int frag_max)
	188	{
	189	unsigned int datalen = dlen;
	190	unsigned int sglen = sg->length - sgoffset;
	191	struct page *page = sg_page(sg);
	192	int i;
	193
	194	i = 0;
	195	do {
	196	unsigned int copy;
	197
	198	if (!sglen) {
	199	sg = sg_next(sg);
	200	if (!sg) {
	201	cxgb3i_log_error("%s, sg NULL, len %u/%u.\n",
	202	__func__, datalen, dlen);
	203	return -EINVAL;
	204	}
	205	sgoffset = 0;
	206	sglen = sg->length;
	207	page = sg_page(sg);
	208
	209	}
	210	copy = min(datalen, sglen);
	211	if (i && page == frags[i - 1].page &&
	212	sgoffset + sg->offset ==
	213	frags[i - 1].page_offset + frags[i - 1].size) {
	214	frags[i - 1].size += copy;
	215	} else {
	216	if (i >= frag_max) {
	217	cxgb3i_log_error("%s, too many pages %u, "
	218	"dlen %u.\n", __func__,
	219	frag_max, dlen);
	220	return -EINVAL;
	221	}
	222
	223	frags[i].page = page;
	224	frags[i].page_offset = sg->offset + sgoffset;
	225	frags[i].size = copy;
	226	i++;
	227	}
	228	datalen -= copy;
	229	sgoffset += copy;
	230	sglen -= copy;
231	} while (datalen);
232
233	return i;
234	}
235
c3673464 KX	236	int cxgb3i_conn_alloc_pdu(struct iscsi_task *task, u8 opcode)
c3673464 KX	237	{
f62d0896	238	struct iscsi_conn *conn = task->conn;
c3673464	239	struct iscsi_tcp_task *tcp_task = task->dd_data;
f62d0896 KX	240	struct cxgb3i_task_data tdata = task->dd_data + sizeof(tcp_task);
	241	struct scsi_cmnd *sc = task->sc;
	242	int headroom = SKB_TX_PDU_HEADER_LEN;
c3673464	243
f62d0896	244	tcp_task->dd_data = tdata;
c3673464	245	task->hdr = NULL;
f62d0896 KX	246
	247	/* write command, need to send data pdus */
	248	if (skb_extra_headroom && (opcode == ISCSI_OP_SCSI_DATA_OUT \|\|
	249	(opcode == ISCSI_OP_SCSI_CMD &&
	250	(scsi_bidi_cmnd(sc) \|\| sc->sc_data_direction == DMA_TO_DEVICE))))
	251	headroom += min(skb_extra_headroom, conn->max_xmit_dlength);
	252
	253	tdata->skb = alloc_skb(TX_HEADER_LEN + headroom, GFP_ATOMIC);
	254	if (!tdata->skb)
c3673464	255	return -ENOMEM;
f62d0896	256	skb_reserve(tdata->skb, TX_HEADER_LEN);
c3673464 KX	257
c3673464 KX	258	cxgb3i_tx_debug("task 0x%p, opcode 0x%x, skb 0x%p.\n",
f62d0896	259	task, opcode, tdata->skb);
c3673464	260
f62d0896 KX	261	task->hdr = (struct iscsi_hdr *)tdata->skb->data;
f62d0896 KX	262	task->hdr_max = SKB_TX_PDU_HEADER_LEN;
c3673464 KX	263
	264	/* data_out uses scsi_cmd's itt */
	265	if (opcode != ISCSI_OP_SCSI_DATA_OUT)
	266	cxgb3i_reserve_itt(task, &task->hdr->itt);
	267
	268	return 0;
	269	}
	270
	271	int cxgb3i_conn_init_pdu(struct iscsi_task *task, unsigned int offset,
	272	unsigned int count)
	273	{
c3673464	274	struct iscsi_conn *conn = task->conn;
f62d0896 KX	275	struct iscsi_tcp_task *tcp_task = task->dd_data;
	276	struct cxgb3i_task_data *tdata = tcp_task->dd_data;
	277	struct sk_buff *skb = tdata->skb;
c3673464 KX	278	unsigned int datalen = count;
c3673464 KX	279	int i, padlen = iscsi_padding(count);
f62d0896	280	struct page *pg;
c3673464 KX	281
	282	cxgb3i_tx_debug("task 0x%p,0x%p, offset %u, count %u, skb 0x%p.\n",
	283	task, task->sc, offset, count, skb);
	284
	285	skb_put(skb, task->hdr_len);
	286	tx_skb_setmode(skb, conn->hdrdgst_en, datalen ? conn->datadgst_en : 0);
	287	if (!count)
	288	return 0;
	289
	290	if (task->sc) {
f62d0896 KX	291	struct scsi_data_buffer *sdb = scsi_out(task->sc);
	292	struct scatterlist *sg = NULL;
	293	int err;
	294
	295	tdata->offset = offset;
	296	tdata->count = count;
	297	err = sgl_seek_offset(sdb->table.sgl, sdb->table.nents,
	298	tdata->offset, &tdata->sgoffset, &sg);
	299	if (err < 0) {
	300	cxgb3i_log_warn("tpdu, sgl %u, bad offset %u/%u.\n",
	301	sdb->table.nents, tdata->offset,
	302	sdb->length);
	303	return err;
c3673464	304	}
f62d0896 KX	305	err = sgl_read_to_frags(sg, tdata->sgoffset, tdata->count,
	306	tdata->frags, MAX_PDU_FRAGS);
	307	if (err < 0) {
	308	cxgb3i_log_warn("tpdu, sgl %u, bad offset %u + %u.\n",
	309	sdb->table.nents, tdata->offset,
	310	tdata->count);
	311	return err;
	312	}
	313	tdata->nr_frags = err;
	314
	315	if (tdata->nr_frags > MAX_SKB_FRAGS \|\|
	316	(padlen && tdata->nr_frags == MAX_SKB_FRAGS)) {
	317	char *dst = skb->data + task->hdr_len;
	318	skb_frag_t *frag = tdata->frags;
	319
	320	/* data fits in the skb's headroom */
	321	for (i = 0; i < tdata->nr_frags; i++, frag++) {
	322	char *src = kmap_atomic(frag->page,
	323	KM_SOFTIRQ0);
	324
	325	memcpy(dst, src+frag->page_offset, frag->size);
	326	dst += frag->size;
	327	kunmap_atomic(src, KM_SOFTIRQ0);
c3673464	328	}
f62d0896 KX	329	if (padlen) {
	330	memset(dst, 0, padlen);
	331	padlen = 0;
c3673464	332	}
f62d0896 KX	333	skb_put(skb, count + padlen);
	334	} else {
	335	/* data fit into frag_list */
	336	for (i = 0; i < tdata->nr_frags; i++)
	337	get_page(tdata->frags[i].page);
	338
	339	memcpy(skb_shinfo(skb)->frags, tdata->frags,
	340	sizeof(skb_frag_t) * tdata->nr_frags);
	341	skb_shinfo(skb)->nr_frags = tdata->nr_frags;
	342	skb->len += count;
	343	skb->data_len += count;
	344	skb->truesize += count;
	345	}
	346
c3673464 KX	347	} else {
	348	pg = virt_to_page(task->data);
	349
f62d0896 KX	350	get_page(pg);
	351	skb_fill_page_desc(skb, 0, pg, offset_in_page(task->data),
	352	count);
	353	skb->len += count;
	354	skb->data_len += count;
	355	skb->truesize += count;
c3673464 KX	356	}
	357
	358	if (padlen) {
	359	i = skb_shinfo(skb)->nr_frags;
f62d0896 KX	360	get_page(pad_page);
	361	skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, pad_page, 0,
	362	padlen);
	363
	364	skb->data_len += padlen;
	365	skb->truesize += padlen;
	366	skb->len += padlen;
c3673464 KX	367	}
c3673464 KX	368
c3673464 KX	369	return 0;
	370	}
	371
	372	int cxgb3i_conn_xmit_pdu(struct iscsi_task *task)
	373	{
c3673464 KX	374	struct iscsi_tcp_conn *tcp_conn = task->conn->dd_data;
c3673464 KX	375	struct cxgb3i_conn *cconn = tcp_conn->dd_data;
f62d0896 KX	376	struct iscsi_tcp_task *tcp_task = task->dd_data;
	377	struct cxgb3i_task_data *tdata = tcp_task->dd_data;
	378	struct sk_buff *skb = tdata->skb;
c3673464 KX	379	unsigned int datalen;
	380	int err;
	381
	382	if (!skb)
	383	return 0;
	384
	385	datalen = skb->data_len;
f62d0896	386	tdata->skb = NULL;
c3673464	387	err = cxgb3i_c3cn_send_pdus(cconn->cep->c3cn, skb);
c3673464 KX	388	if (err > 0) {
	389	int pdulen = err;
	390
f62d0896 KX	391	cxgb3i_tx_debug("task 0x%p, skb 0x%p, len %u/%u, rv %d.\n",
	392	task, skb, skb->len, skb->data_len, err);
	393
c3673464 KX	394	if (task->conn->hdrdgst_en)
	395	pdulen += ISCSI_DIGEST_SIZE;
	396	if (datalen && task->conn->datadgst_en)
	397	pdulen += ISCSI_DIGEST_SIZE;
	398
	399	task->conn->txdata_octets += pdulen;
	400	return 0;
	401	}
	402
	403	if (err < 0 && err != -EAGAIN) {
	404	kfree_skb(skb);
	405	cxgb3i_tx_debug("itt 0x%x, skb 0x%p, len %u/%u, xmit err %d.\n",
	406	task->itt, skb, skb->len, skb->data_len, err);
	407	iscsi_conn_printk(KERN_ERR, task->conn, "xmit err %d.\n", err);
	408	iscsi_conn_failure(task->conn, ISCSI_ERR_XMIT_FAILED);
	409	return err;
	410	}
	411	/* reset skb to send when we are called again */
f62d0896	412	tdata->skb = skb;
c3673464 KX	413	return -EAGAIN;
	414	}
	415
	416	int cxgb3i_pdu_init(void)
	417	{
f62d0896 KX	418	if (SKB_TX_HEADROOM > (512 * MAX_SKB_FRAGS))
f62d0896 KX	419	skb_extra_headroom = SKB_TX_HEADROOM;
c3673464 KX	420	pad_page = alloc_page(GFP_KERNEL);
	421	if (!pad_page)
	422	return -ENOMEM;
	423	memset(page_address(pad_page), 0, PAGE_SIZE);
	424	return 0;
	425	}
	426
	427	void cxgb3i_pdu_cleanup(void)
	428	{
	429	if (pad_page) {
	430	__free_page(pad_page);
	431	pad_page = NULL;
	432	}
	433	}
	434
	435	void cxgb3i_conn_pdu_ready(struct s3_conn *c3cn)
	436	{
	437	struct sk_buff *skb;
	438	unsigned int read = 0;
	439	struct iscsi_conn *conn = c3cn->user_data;
	440	int err = 0;
	441
	442	cxgb3i_rx_debug("cn 0x%p.\n", c3cn);
	443
	444	read_lock(&c3cn->callback_lock);
	445	if (unlikely(!conn \|\| conn->suspend_rx)) {
	446	cxgb3i_rx_debug("conn 0x%p, id %d, suspend_rx %lu!\n",
	447	conn, conn ? conn->id : 0xFF,
	448	conn ? conn->suspend_rx : 0xFF);
	449	read_unlock(&c3cn->callback_lock);
	450	return;
	451	}
	452	skb = skb_peek(&c3cn->receive_queue);
	453	while (!err && skb) {
	454	__skb_unlink(skb, &c3cn->receive_queue);
f62d0896 KX	455	read += skb_rx_pdulen(skb);
	456	cxgb3i_rx_debug("conn 0x%p, cn 0x%p, rx skb 0x%p, pdulen %u.\n",
	457	conn, c3cn, skb, skb_rx_pdulen(skb));
c3673464 KX	458	err = cxgb3i_conn_read_pdu_skb(conn, skb);
	459	__kfree_skb(skb);
	460	skb = skb_peek(&c3cn->receive_queue);
	461	}
	462	read_unlock(&c3cn->callback_lock);
	463	if (c3cn) {
	464	c3cn->copied_seq += read;
	465	cxgb3i_c3cn_rx_credits(c3cn, read);
	466	}
	467	conn->rxdata_octets += read;
f62d0896 KX	468
	469	if (err) {
	470	cxgb3i_log_info("conn 0x%p rx failed err %d.\n", conn, err);
	471	iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
	472	}
c3673464 KX	473	}
	474
	475	void cxgb3i_conn_tx_open(struct s3_conn *c3cn)
	476	{
	477	struct iscsi_conn *conn = c3cn->user_data;
	478
	479	cxgb3i_tx_debug("cn 0x%p.\n", c3cn);
	480	if (conn) {
	481	cxgb3i_tx_debug("cn 0x%p, cid %d.\n", c3cn, conn->id);
	482	scsi_queue_work(conn->session->host, &conn->xmitwork);
	483	}
	484	}
	485
	486	void cxgb3i_conn_closing(struct s3_conn *c3cn)
	487	{
	488	struct iscsi_conn *conn;
	489
	490	read_lock(&c3cn->callback_lock);
	491	conn = c3cn->user_data;
	492	if (conn && c3cn->state != C3CN_STATE_ESTABLISHED)
	493	iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
	494	read_unlock(&c3cn->callback_lock);
	495	}