1 files changed, 402 insertions, 0 deletions

diff --git a/drivers/scsi/cxgb3i/cxgb3i_pdu.c b/drivers/scsi/cxgb3i/cxgb3i_pdu.c
new file mode 100644
index 0000000..ce7ce8c
--- /dev/null
+++ b/drivers/scsi/cxgb3i/cxgb3i_pdu.c
@@ -0,0 +1,402 @@
+/*
+ * 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
+
+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 iscsi_tcp_task *tcp_task = task->dd_data;
+
+	/* never reached the xmit task callout */
+	if (tcp_task->dd_data)
+		kfree_skb(tcp_task->dd_data);
+	tcp_task->dd_data = NULL;
+
+	/* 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);
+}
+
+/*
+ * We do not support ahs yet
+ */
+int cxgb3i_conn_alloc_pdu(struct iscsi_task *task, u8 opcode)
+{
+	struct iscsi_tcp_task *tcp_task = task->dd_data;
+	struct sk_buff *skb;
+
+	task->hdr = NULL;
+	/* always allocate rooms for AHS */
+	skb = alloc_skb(sizeof(struct iscsi_hdr) + ISCSI_MAX_AHS_SIZE +
+			TX_HEADER_LEN,  GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
+
+	cxgb3i_tx_debug("task 0x%p, opcode 0x%x, skb 0x%p.\n",
+			task, opcode, skb);
+
+	tcp_task->dd_data = skb;
+	skb_reserve(skb, TX_HEADER_LEN);
+	task->hdr = (struct iscsi_hdr *)skb->data;
+	task->hdr_max = sizeof(struct iscsi_hdr);
+
+	/* 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_tcp_task *tcp_task = task->dd_data;
+	struct sk_buff *skb = tcp_task->dd_data;
+	struct iscsi_conn *conn = task->conn;
+	struct page *pg;
+	unsigned int datalen = count;
+	int i, padlen = iscsi_padding(count);
+	skb_frag_t *frag;
+
+	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 scatterlist *sg;
+		struct scsi_data_buffer *sdb;
+		unsigned int sgoffset = offset;
+		struct page *sgpg;
+		unsigned int sglen;
+
+		sdb = scsi_out(task->sc);
+		sg = sdb->table.sgl;
+
+		for_each_sg(sdb->table.sgl, sg, sdb->table.nents, i) {
+			cxgb3i_tx_debug("sg %d, page 0x%p, len %u offset %u\n",
+					i, sg_page(sg), sg->length, sg->offset);
+
+			if (sgoffset < sg->length)
+				break;
+			sgoffset -= sg->length;
+		}
+		sgpg = sg_page(sg);
+		sglen = sg->length - sgoffset;
+
+		do {
+			int j = skb_shinfo(skb)->nr_frags;
+			unsigned int copy;
+
+			if (!sglen) {
+				sg = sg_next(sg);
+				sgpg = sg_page(sg);
+				sgoffset = 0;
+				sglen = sg->length;
+				++i;
+			}
+			copy = min(sglen, datalen);
+			if (j && skb_can_coalesce(skb, j, sgpg,
+						  sg->offset + sgoffset)) {
+				skb_shinfo(skb)->frags[j - 1].size += copy;
+			} else {
+				get_page(sgpg);
+				skb_fill_page_desc(skb, j, sgpg,
+						   sg->offset + sgoffset, copy);
+			}
+			sgoffset += copy;
+			sglen -= copy;
+			datalen -= copy;
+		} while (datalen);
+	} else {
+		pg = virt_to_page(task->data);
+
+		while (datalen) {
+			i = skb_shinfo(skb)->nr_frags;
+			frag = &skb_shinfo(skb)->frags[i];
+
+			get_page(pg);
+			frag->page = pg;
+			frag->page_offset = 0;
+			frag->size = min((unsigned int)PAGE_SIZE, datalen);
+
+			skb_shinfo(skb)->nr_frags++;
+			datalen -= frag->size;
+			pg++;
+		}
+	}
+
+	if (padlen) {
+		i = skb_shinfo(skb)->nr_frags;
+		frag = &skb_shinfo(skb)->frags[i];
+		frag->page = pad_page;
+		frag->page_offset = 0;
+		frag->size = padlen;
+		skb_shinfo(skb)->nr_frags++;
+	}
+
+	datalen = count + padlen;
+	skb->data_len += datalen;
+	skb->truesize += datalen;
+	skb->len += datalen;
+	return 0;
+}
+
+int cxgb3i_conn_xmit_pdu(struct iscsi_task *task)
+{
+	struct iscsi_tcp_task *tcp_task = task->dd_data;
+	struct sk_buff *skb = tcp_task->dd_data;
+	struct iscsi_tcp_conn *tcp_conn = task->conn->dd_data;
+	struct cxgb3i_conn *cconn = tcp_conn->dd_data;
+	unsigned int datalen;
+	int err;
+
+	if (!skb)
+		return 0;
+
+	datalen = skb->data_len;
+	tcp_task->dd_data = NULL;
+	err = cxgb3i_c3cn_send_pdus(cconn->cep->c3cn, skb);
+	cxgb3i_tx_debug("task 0x%p, skb 0x%p, len %u/%u, rv %d.\n",
+			task, skb, skb->len, skb->data_len, err);
+	if (err > 0) {
+		int pdulen = 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 */
+	tcp_task->dd_data = skb;
+	return -EAGAIN;
+}
+
+int cxgb3i_pdu_init(void)
+{
+	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_ulp_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;
+}
+
+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);
+}