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path: root/drivers/scsi/cxgb3i/cxgb3i_pdu.c
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Diffstat (limited to 'drivers/scsi/cxgb3i/cxgb3i_pdu.c')
-rw-r--r--drivers/scsi/cxgb3i/cxgb3i_pdu.c402
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);
+}
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