Date:   Fri, 23 Dec 2016 11:17:07 -0800
From:   "Dupuis, Chad" <chad.dupuis@...ium.com>
To:     <martin.petersen@...cle.com>
CC:     <linux-scsi@...r.kernel.org>, <fcoe-devel@...n-fcoe.org>,
        <netdev@...r.kernel.org>, <yuval.mintz@...ium.com>,
        <QLogic-Storage-Upstream@...ium.com>
Subject: [PATCH RFC 4/5] qedf: Add offload ELS request handling.

From: "Dupuis, Chad" <chad.dupuis@...ium.com>

This patch adds support for ELS requests that are handled by the firmware for
offloaded sessions.

Signed-off-by: Nilesh Javali <nilesh.javali@...ium.com>
Signed-off-by: Manish Rangankar <manish.rangankar@...ium.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@...ium.com>
Signed-off-by: Chad Dupuis <chad.dupuis@...ium.com>
---
 drivers/scsi/qedf/qedf_els.c | 984 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 984 insertions(+)
 create mode 100644 drivers/scsi/qedf/qedf_els.c

diff --git a/drivers/scsi/qedf/qedf_els.c b/drivers/scsi/qedf/qedf_els.c
new file mode 100644
index 0000000..98a80b3
--- /dev/null
+++ b/drivers/scsi/qedf/qedf_els.c
@@ -0,0 +1,984 @@
+/*
+ *  QLogic FCoE Offload Driver
+ *  Copyright (c) 2016 Cavium Inc.
+ *
+ *  This software is available under the terms of the GNU General Public License
+ *  (GPL) Version 2, available from the file COPYING in the main directory of
+ *  this source tree.
+ */
+#include "qedf.h"
+
+/* It's assumed that the lock is held when calling this function. */
+static int qedf_initiate_els(struct qedf_rport *fcport, unsigned int op,
+	void *data, uint32_t data_len,
+	void (*cb_func)(struct qedf_els_cb_arg *cb_arg),
+	struct qedf_els_cb_arg *cb_arg, uint32_t timer_msec)
+{
+	struct qedf_ctx *qedf = fcport->qedf;
+	struct fc_lport *lport = qedf->lport;
+	struct qedf_ioreq *els_req;
+	struct qedf_mp_req *mp_req;
+	struct fc_frame_header *fc_hdr;
+	struct fcoe_task_context *task;
+	int rc = 0;
+	uint32_t did, sid;
+	uint16_t xid;
+	uint32_t start_time = jiffies / HZ;
+	uint32_t current_time;
+
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Sending ELS\n");
+
+	rc = fc_remote_port_chkready(fcport->rport);
+	if (rc) {
+		QEDF_ERR(&(qedf->dbg_ctx), "els 0x%x: rport not ready\n", op);
+		rc = -EAGAIN;
+		goto els_err;
+	}
+	if (lport->state != LPORT_ST_READY || !(lport->link_up)) {
+		QEDF_ERR(&(qedf->dbg_ctx), "els 0x%x: link is not ready\n",
+			  op);
+		rc = -EAGAIN;
+		goto els_err;
+	}
+
+	if (!(test_bit(QEDF_RPORT_SESSION_READY, &fcport->flags))) {
+		QEDF_ERR(&(qedf->dbg_ctx), "els 0x%x: fcport not ready\n", op);
+		rc = -EINVAL;
+		goto els_err;
+	}
+
+retry_els:
+	els_req = qedf_alloc_cmd(fcport, QEDF_ELS);
+	if (!els_req) {
+		current_time = jiffies / HZ;
+		if ((current_time - start_time) > 10) {
+			QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+				   "els: Failed els 0x%x\n", op);
+			rc = -ENOMEM;
+			goto els_err;
+		}
+		mdelay(20 * USEC_PER_MSEC);
+		goto retry_els;
+	}
+
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "initiate_els els_req = "
+		   "0x%p cb_arg = %p xid = %x\n", els_req, cb_arg,
+		   els_req->xid);
+	els_req->sc_cmd = NULL;
+	els_req->cmd_type = QEDF_ELS;
+	els_req->fcport = fcport;
+	els_req->cb_func = cb_func;
+	cb_arg->io_req = els_req;
+	cb_arg->op = op;
+	els_req->cb_arg = cb_arg;
+	els_req->data_xfer_len = data_len;
+
+	/* Record which cpu this request is associated with */
+	els_req->cpu = smp_processor_id();
+	qedf_inc_percpu_requests(els_req->cpu);
+
+	mp_req = (struct qedf_mp_req *)&(els_req->mp_req);
+	rc = qedf_init_mp_req(els_req);
+	if (rc) {
+		QEDF_ERR(&(qedf->dbg_ctx), "ELS MP request init failed\n");
+		kref_put(&els_req->refcount, qedf_release_cmd);
+		goto els_err;
+	} else {
+		rc = 0;
+	}
+
+	/* Fill ELS Payload */
+	if ((op >= ELS_LS_RJT) && (op <= ELS_AUTH_ELS)) {
+		memcpy(mp_req->req_buf, data, data_len);
+	} else {
+		QEDF_ERR(&(qedf->dbg_ctx), "Invalid ELS op 0x%x\n", op);
+		els_req->cb_func = NULL;
+		els_req->cb_arg = NULL;
+		kref_put(&els_req->refcount, qedf_release_cmd);
+		rc = -EINVAL;
+	}
+
+	if (rc)
+		goto els_err;
+
+	/* Fill FC header */
+	fc_hdr = &(mp_req->req_fc_hdr);
+
+	did = fcport->rdata->ids.port_id;
+	sid = fcport->sid;
+
+	__fc_fill_fc_hdr(fc_hdr, FC_RCTL_ELS_REQ, sid, did,
+			   FC_TYPE_ELS, FC_FC_FIRST_SEQ | FC_FC_END_SEQ |
+			   FC_FC_SEQ_INIT, 0);
+
+	/* Obtain exchange id */
+	xid = els_req->xid;
+
+	/* Initialize task context for this IO request */
+	task = qedf_get_task_mem(&qedf->tasks, xid);
+	qedf_init_mp_task(els_req, task);
+
+	/* Put timer on original I/O request */
+	if (timer_msec)
+		qedf_cmd_timer_set(qedf, els_req, timer_msec);
+
+	qedf_add_to_sq(fcport, xid, 0, FCOE_TASK_TYPE_MIDPATH, 0);
+
+	/* Ring doorbell */
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Ringing doorbell for ELS "
+		   "req\n");
+	qedf_ring_doorbell(fcport);
+els_err:
+	return rc;
+}
+
+void qedf_process_els_compl(struct qedf_ctx *qedf, struct fcoe_cqe *cqe,
+	struct qedf_ioreq *els_req)
+{
+	struct fcoe_task_context *task_ctx;
+	struct scsi_cmnd *sc_cmd;
+	uint16_t xid;
+	struct fcoe_cqe_midpath_info *mp_info;
+
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Entered with xid = 0x%x"
+		   " cmd_type = %d.\n", els_req->xid, els_req->cmd_type);
+
+	/* Kill the ELS timer */
+	cancel_delayed_work(&els_req->timeout_work);
+
+	xid = els_req->xid;
+	task_ctx = qedf_get_task_mem(&qedf->tasks, xid);
+	sc_cmd = els_req->sc_cmd;
+
+	/* Get ELS response length from CQE */
+	mp_info = &cqe->cqe_info.midpath_info;
+	els_req->mp_req.resp_len = mp_info->data_placement_size;
+
+	/* Parse ELS response */
+	if ((els_req->cb_func) && (els_req->cb_arg)) {
+		els_req->cb_func(els_req->cb_arg);
+		els_req->cb_arg = NULL;
+	}
+
+	kref_put(&els_req->refcount, qedf_release_cmd);
+}
+
+static void qedf_rrq_compl(struct qedf_els_cb_arg *cb_arg)
+{
+	struct qedf_ioreq *orig_io_req;
+	struct qedf_ioreq *rrq_req;
+	struct qedf_ctx *qedf;
+	int refcount;
+
+	rrq_req = cb_arg->io_req;
+	qedf = rrq_req->fcport->qedf;
+
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Entered.\n");
+
+	orig_io_req = cb_arg->aborted_io_req;
+
+	if (!orig_io_req)
+		goto out_free;
+
+	if (rrq_req->event != QEDF_IOREQ_EV_ELS_TMO &&
+	    rrq_req->event != QEDF_IOREQ_EV_ELS_ERR_DETECT)
+		cancel_delayed_work_sync(&orig_io_req->timeout_work);
+
+	refcount = atomic_read(&orig_io_req->refcount.refcount);
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "rrq_compl: orig io = %p,"
+		   " orig xid = 0x%x, rrq_xid = 0x%x, refcount=%d\n",
+		   orig_io_req, orig_io_req->xid, rrq_req->xid, refcount);
+
+	/* This should return the aborted io_req to the command pool */
+	if (orig_io_req)
+		kref_put(&orig_io_req->refcount, qedf_release_cmd);
+
+out_free:
+	kfree(cb_arg);
+}
+
+/* Assumes kref is already held by caller */
+int qedf_send_rrq(struct qedf_ioreq *aborted_io_req)
+{
+
+	struct fc_els_rrq rrq;
+	struct qedf_rport *fcport;
+	struct fc_lport *lport;
+	struct qedf_els_cb_arg *cb_arg = NULL;
+	struct qedf_ctx *qedf;
+	uint32_t sid;
+	uint32_t r_a_tov;
+	int rc;
+
+	if (!aborted_io_req) {
+		QEDF_ERR(NULL, "abort_io_req is NULL.\n");
+		return -EINVAL;
+	}
+
+	fcport = aborted_io_req->fcport;
+
+	/* Check that fcport is still offloaded */
+	if (fcport->conn_id == -1) {
+		QEDF_ERR(NULL, "fcport is no longer offloaded.\n");
+		return -EINVAL;
+	}
+
+	if (!fcport->qedf) {
+		QEDF_ERR(NULL, "fcport->qedf is NULL.\n");
+		return -EINVAL;
+	}
+
+	qedf = fcport->qedf;
+	lport = qedf->lport;
+	sid = fcport->sid;
+	r_a_tov = lport->r_a_tov;
+
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Sending RRQ orig "
+		   "io = %p, orig_xid = 0x%x\n", aborted_io_req,
+		   aborted_io_req->xid);
+	memset(&rrq, 0, sizeof(rrq));
+
+	cb_arg = kzalloc(sizeof(struct qedf_els_cb_arg), GFP_NOIO);
+	if (!cb_arg) {
+		QEDF_ERR(&(qedf->dbg_ctx), "Unable to allocate cb_arg for "
+			  "RRQ\n");
+		rc = -ENOMEM;
+		goto rrq_err;
+	}
+
+	cb_arg->aborted_io_req = aborted_io_req;
+
+	rrq.rrq_cmd = ELS_RRQ;
+	hton24(rrq.rrq_s_id, sid);
+	rrq.rrq_ox_id = htons(aborted_io_req->xid);
+	rrq.rrq_rx_id =
+	    htons(aborted_io_req->task->tstorm_st_context.read_write.rx_id);
+
+	rc = qedf_initiate_els(fcport, ELS_RRQ, &rrq, sizeof(rrq),
+	    qedf_rrq_compl, cb_arg, r_a_tov);
+
+rrq_err:
+	if (rc) {
+		QEDF_ERR(&(qedf->dbg_ctx), "RRQ failed - release orig io "
+			  "req 0x%x\n", aborted_io_req->xid);
+		kfree(cb_arg);
+		kref_put(&aborted_io_req->refcount, qedf_release_cmd);
+	}
+	return rc;
+}
+
+static void qedf_process_l2_frame_compl(struct qedf_rport *fcport,
+					unsigned char *buf,
+					u32 frame_len, u16 l2_oxid)
+{
+	struct fc_lport *lport = fcport->qedf->lport;
+	struct fc_frame_header *fh;
+	struct fc_frame *fp;
+	u32 payload_len;
+	u32 crc;
+
+	payload_len = frame_len - sizeof(struct fc_frame_header);
+
+	fp = fc_frame_alloc(lport, payload_len);
+	if (!fp) {
+		QEDF_ERR(&(fcport->qedf->dbg_ctx),
+		    "fc_frame_alloc failure.\n");
+		return;
+	}
+
+	/* Copy FC Frame header and payload into the frame */
+	fh = (struct fc_frame_header *)fc_frame_header_get(fp);
+	memcpy(fh, buf, frame_len);
+
+	/* Set the OXID we return to what libfc used */
+	if (l2_oxid != FC_XID_UNKNOWN)
+		fh->fh_ox_id = htons(l2_oxid);
+
+	/* Setup header fields */
+	fh->fh_r_ctl = FC_RCTL_ELS_REP;
+	fh->fh_type = FC_TYPE_ELS;
+	/* Last sequence, end sequence */
+	fh->fh_f_ctl[0] = 0x98;
+	hton24(fh->fh_d_id, lport->port_id);
+	hton24(fh->fh_s_id, fcport->rdata->ids.port_id);
+	fh->fh_rx_id = 0xffff;
+
+	/* Set frame attributes */
+	crc = fcoe_fc_crc(fp);
+	fc_frame_init(fp);
+	fr_dev(fp) = lport;
+	fr_sof(fp) = FC_SOF_I3;
+	fr_eof(fp) = FC_EOF_T;
+	fr_crc(fp) = cpu_to_le32(~crc);
+
+	/* Send completed request to libfc */
+	fc_exch_recv(lport, fp);
+}
+
+/*
+ * In instances where an ELS command times out we may need to restart the
+ * rport by logging out and then logging back in.
+ */
+void qedf_restart_rport(struct qedf_rport *fcport)
+{
+	struct fc_lport *lport;
+	struct fc_rport_priv *rdata;
+	u32 port_id;
+
+	if (!fcport)
+		return;
+
+	rdata = fcport->rdata;
+	if (rdata) {
+		lport = fcport->qedf->lport;
+		port_id = rdata->ids.port_id;
+		QEDF_ERR(&(fcport->qedf->dbg_ctx),
+		    "LOGO port_id=%x.\n", port_id);
+		mutex_lock(&lport->disc.disc_mutex);
+		fc_rport_logoff(rdata);
+		/* Recreate the rport and log back in */
+		rdata = fc_rport_create(lport, port_id);
+		if (rdata)
+			fc_rport_login(rdata);
+		mutex_unlock(&lport->disc.disc_mutex);
+	}
+}
+
+static void qedf_l2_els_compl(struct qedf_els_cb_arg *cb_arg)
+{
+	struct qedf_ioreq *els_req;
+	struct qedf_rport *fcport;
+	struct qedf_mp_req *mp_req;
+	struct fc_frame_header *fc_hdr;
+	unsigned char *buf;
+	void *resp_buf;
+	u32 resp_len, hdr_len;
+	u16 l2_oxid;
+	int frame_len;
+
+	l2_oxid = cb_arg->l2_oxid;
+	els_req = cb_arg->io_req;
+
+	if (!els_req) {
+		QEDF_ERR(NULL, "els_req is NULL.\n");
+		goto free_arg;
+	}
+
+	/*
+	 * If we are flushing the command just free the cb_arg as none of the
+	 * response data will be valid.
+	 */
+	if (els_req->event == QEDF_IOREQ_EV_ELS_FLUSH)
+		goto free_arg;
+
+	fcport = els_req->fcport;
+	mp_req = &(els_req->mp_req);
+	fc_hdr = &(mp_req->resp_fc_hdr);
+	resp_len = mp_req->resp_len;
+	resp_buf = mp_req->resp_buf;
+
+	/*
+	 * If a middle path ELS command times out, don't try to return
+	 * the command but rather do any internal cleanup and then libfc
+	 * timeout the command and clean up its internal resources.
+	 */
+	if (els_req->event == QEDF_IOREQ_EV_ELS_TMO) {
+		/*
+		 * If ADISC times out, libfc will timeout the exchange and then
+		 * try to send a PLOGI which will timeout since the session is
+		 * still offloaded.  Force libfc to logout the session which
+		 * will offload the connection and allow the PLOGI response to
+		 * flow over the LL2 path.
+		 */
+		if (cb_arg->op == ELS_ADISC)
+			qedf_restart_rport(fcport);
+		return;
+	}
+
+	buf = kzalloc(QEDF_PAGE_SIZE, GFP_ATOMIC);
+	if (!buf) {
+		QEDF_ERR(&(fcport->qedf->dbg_ctx),
+		    "Unable to alloc mp buf.\n");
+		goto free_arg;
+	}
+	hdr_len = sizeof(*fc_hdr);
+	if (hdr_len + resp_len > QEDF_PAGE_SIZE) {
+		QEDF_ERR(&(fcport->qedf->dbg_ctx), "resp_len is "
+		   "beyond page size.\n");
+		goto free_buf;
+	}
+	memcpy(buf, fc_hdr, hdr_len);
+	memcpy(buf + hdr_len, resp_buf, resp_len);
+	frame_len = hdr_len + resp_len;
+
+	QEDF_INFO(&(fcport->qedf->dbg_ctx), QEDF_LOG_ELS,
+	    "Completing OX_ID 0x%x back to libfc.\n", l2_oxid);
+	qedf_process_l2_frame_compl(fcport, buf, frame_len, l2_oxid);
+
+free_buf:
+	kfree(buf);
+free_arg:
+	kfree(cb_arg);
+}
+
+int qedf_send_adisc(struct qedf_rport *fcport, struct fc_frame *fp)
+{
+	struct fc_els_adisc *adisc;
+	struct fc_frame_header *fh;
+	struct fc_lport *lport = fcport->qedf->lport;
+	struct qedf_els_cb_arg *cb_arg = NULL;
+	struct qedf_ctx *qedf;
+	uint32_t r_a_tov = lport->r_a_tov;
+	int rc;
+
+	qedf = fcport->qedf;
+	fh = fc_frame_header_get(fp);
+
+	cb_arg = kzalloc(sizeof(struct qedf_els_cb_arg), GFP_NOIO);
+	if (!cb_arg) {
+		QEDF_ERR(&(qedf->dbg_ctx), "Unable to allocate cb_arg for "
+			  "ADISC\n");
+		rc = -ENOMEM;
+		goto adisc_err;
+	}
+	cb_arg->l2_oxid = ntohs(fh->fh_ox_id);
+
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+	    "Sending ADISC ox_id=0x%x.\n", cb_arg->l2_oxid);
+
+	adisc = fc_frame_payload_get(fp, sizeof(*adisc));
+
+	rc = qedf_initiate_els(fcport, ELS_ADISC, adisc, sizeof(*adisc),
+	    qedf_l2_els_compl, cb_arg, r_a_tov);
+
+adisc_err:
+	if (rc) {
+		QEDF_ERR(&(qedf->dbg_ctx), "ADISC failed.\n");
+		kfree(cb_arg);
+	}
+	return rc;
+}
+
+static void qedf_srr_compl(struct qedf_els_cb_arg *cb_arg)
+{
+	struct qedf_ioreq *orig_io_req;
+	struct qedf_ioreq *srr_req;
+	struct qedf_mp_req *mp_req;
+	struct fc_frame_header *fc_hdr, *fh;
+	struct fc_frame *fp;
+	unsigned char *buf;
+	void *resp_buf;
+	u32 resp_len, hdr_len;
+	struct fc_lport *lport;
+	struct qedf_ctx *qedf;
+	int refcount;
+	u8 opcode;
+
+	srr_req = cb_arg->io_req;
+	qedf = srr_req->fcport->qedf;
+	lport = qedf->lport;
+
+	orig_io_req = cb_arg->aborted_io_req;
+
+	if (!orig_io_req)
+		goto out_free;
+
+	clear_bit(QEDF_CMD_SRR_SENT, &orig_io_req->flags);
+
+	if (srr_req->event != QEDF_IOREQ_EV_ELS_TMO &&
+	    srr_req->event != QEDF_IOREQ_EV_ELS_ERR_DETECT)
+		cancel_delayed_work_sync(&orig_io_req->timeout_work);
+
+	refcount = atomic_read(&orig_io_req->refcount.refcount);
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Entered: orig_io=%p,"
+		   " orig_io_xid=0x%x, rec_xid=0x%x, refcount=%d\n",
+		   orig_io_req, orig_io_req->xid, srr_req->xid, refcount);
+
+	/* If a SRR times out, simply free resources */
+	if (srr_req->event == QEDF_IOREQ_EV_ELS_TMO)
+		goto out_free;
+
+	/* Normalize response data into struct fc_frame */
+	mp_req = &(srr_req->mp_req);
+	fc_hdr = &(mp_req->resp_fc_hdr);
+	resp_len = mp_req->resp_len;
+	resp_buf = mp_req->resp_buf;
+	hdr_len = sizeof(*fc_hdr);
+
+	buf = kzalloc(QEDF_PAGE_SIZE, GFP_ATOMIC);
+	if (!buf) {
+		QEDF_ERR(&(qedf->dbg_ctx),
+		    "Unable to alloc mp buf.\n");
+		goto out_free;
+	}
+
+	memcpy(buf, fc_hdr, hdr_len);
+	memcpy(buf + hdr_len, resp_buf, resp_len);
+
+	fp = fc_frame_alloc(lport, resp_len);
+	if (!fp) {
+		QEDF_ERR(&(qedf->dbg_ctx),
+		    "fc_frame_alloc failure.\n");
+		goto out_buf;
+	}
+
+	/* Copy FC Frame header and payload into the frame */
+	fh = (struct fc_frame_header *)fc_frame_header_get(fp);
+	memcpy(fh, buf, hdr_len + resp_len);
+
+	opcode = fc_frame_payload_op(fp);
+	switch (opcode) {
+	case ELS_LS_ACC:
+		QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+		    "SRR success.\n");
+		break;
+	case ELS_LS_RJT:
+		QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_ELS,
+		    "SRR rejected.\n");
+		qedf_initiate_abts(orig_io_req, true);
+		break;
+	}
+
+	fc_frame_free(fp);
+out_buf:
+	kfree(buf);
+out_free:
+	/* Put reference for original command since SRR completed */
+	kref_put(&orig_io_req->refcount, qedf_release_cmd);
+	kfree(cb_arg);
+}
+
+static int qedf_send_srr(struct qedf_ioreq *orig_io_req, u32 offset, u8 r_ctl)
+{
+	struct fcp_srr srr;
+	struct qedf_ctx *qedf;
+	struct qedf_rport *fcport;
+	struct fc_lport *lport;
+	struct qedf_els_cb_arg *cb_arg = NULL;
+	u32 sid, r_a_tov;
+	int rc;
+
+	if (!orig_io_req) {
+		QEDF_ERR(NULL, "orig_io_req is NULL.\n");
+		return -EINVAL;
+	}
+
+	fcport = orig_io_req->fcport;
+
+	/* Check that fcport is still offloaded */
+	if (fcport->conn_id == -1) {
+		QEDF_ERR(NULL, "fcport is no longer offloaded.\n");
+		return -EINVAL;
+	}
+
+	if (!fcport->qedf) {
+		QEDF_ERR(NULL, "fcport->qedf is NULL.\n");
+		return -EINVAL;
+	}
+
+	/* Take reference until SRR command completion */
+	kref_get(&orig_io_req->refcount);
+
+	qedf = fcport->qedf;
+	lport = qedf->lport;
+	sid = fcport->sid;
+	r_a_tov = lport->r_a_tov;
+
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Sending SRR orig_io=%p, "
+		   "orig_xid=0x%x\n", orig_io_req, orig_io_req->xid);
+	memset(&srr, 0, sizeof(srr));
+
+	cb_arg = kzalloc(sizeof(struct qedf_els_cb_arg), GFP_NOIO);
+	if (!cb_arg) {
+		QEDF_ERR(&(qedf->dbg_ctx), "Unable to allocate cb_arg for "
+			  "SRR\n");
+		rc = -ENOMEM;
+		goto srr_err;
+	}
+
+	cb_arg->aborted_io_req = orig_io_req;
+
+	srr.srr_op = ELS_SRR;
+	srr.srr_ox_id = htons(orig_io_req->xid);
+	srr.srr_rx_id = htons(orig_io_req->rx_id);
+	srr.srr_rel_off = htonl(offset);
+	srr.srr_r_ctl = r_ctl;
+
+	rc = qedf_initiate_els(fcport, ELS_SRR, &srr, sizeof(srr),
+	    qedf_srr_compl, cb_arg, r_a_tov);
+
+srr_err:
+	if (rc) {
+		QEDF_ERR(&(qedf->dbg_ctx), "SRR failed - release orig_io_req"
+			  "=0x%x\n", orig_io_req->xid);
+		kfree(cb_arg);
+		/* If we fail to queue SRR, send ABTS to orig_io */
+		qedf_initiate_abts(orig_io_req, true);
+		kref_put(&orig_io_req->refcount, qedf_release_cmd);
+	} else
+		/* Tell other threads that SRR is in progress */
+		set_bit(QEDF_CMD_SRR_SENT, &orig_io_req->flags);
+
+	return rc;
+}
+
+static void qedf_initiate_seq_cleanup(struct qedf_ioreq *orig_io_req,
+	u32 offset, u8 r_ctl)
+{
+	struct qedf_rport *fcport;
+	unsigned long flags;
+	struct qedf_els_cb_arg *cb_arg;
+
+	fcport = orig_io_req->fcport;
+
+	QEDF_INFO(&(fcport->qedf->dbg_ctx), QEDF_LOG_ELS,
+	    "Doing sequence cleanup for xid=0x%x offset=%u.\n",
+	    orig_io_req->xid, offset);
+
+	cb_arg = kzalloc(sizeof(struct qedf_els_cb_arg), GFP_NOIO);
+	if (!cb_arg) {
+		QEDF_ERR(&(fcport->qedf->dbg_ctx), "Unable to allocate cb_arg "
+			  "for sequence cleanup\n");
+		return;
+	}
+
+	/* Get reference for cleanup request */
+	kref_get(&orig_io_req->refcount);
+
+	orig_io_req->cmd_type = QEDF_SEQ_CLEANUP;
+	cb_arg->offset = offset;
+	cb_arg->r_ctl = r_ctl;
+	orig_io_req->cb_arg = cb_arg;
+
+	qedf_cmd_timer_set(fcport->qedf, orig_io_req,
+	    QEDF_CLEANUP_TIMEOUT * HZ);
+
+	spin_lock_irqsave(&fcport->rport_lock, flags);
+
+	qedf_add_to_sq(fcport, orig_io_req->xid, 0,
+	    FCOE_TASK_TYPE_SEQUENCE_CLEANUP, offset);
+	qedf_ring_doorbell(fcport);
+
+	spin_unlock_irqrestore(&fcport->rport_lock, flags);
+}
+
+void qedf_process_seq_cleanup_compl(struct qedf_ctx *qedf,
+	struct fcoe_cqe *cqe, struct qedf_ioreq *io_req)
+{
+	int rc;
+	struct qedf_els_cb_arg *cb_arg;
+
+	cb_arg = io_req->cb_arg;
+
+	/* If we timed out just free resources */
+	if (io_req->event == QEDF_IOREQ_EV_ELS_TMO || !cqe)
+		goto free;
+
+	/* Kill the timer we put on the request */
+	cancel_delayed_work_sync(&io_req->timeout_work);
+
+	rc = qedf_send_srr(io_req, cb_arg->offset, cb_arg->r_ctl);
+	if (rc)
+		QEDF_ERR(&(qedf->dbg_ctx), "Unable to send SRR, I/O will "
+		    "abort, xid=0x%x.\n", io_req->xid);
+free:
+	kfree(cb_arg);
+	kref_put(&io_req->refcount, qedf_release_cmd);
+}
+
+static bool qedf_requeue_io_req(struct qedf_ioreq *orig_io_req)
+{
+	struct qedf_rport *fcport;
+	struct qedf_ioreq *new_io_req;
+	unsigned long flags;
+	bool rc = false;
+
+	fcport = orig_io_req->fcport;
+	if (!fcport) {
+		QEDF_ERR(NULL, "fcport is NULL.\n");
+		goto out;
+	}
+
+	if (!orig_io_req->sc_cmd) {
+		QEDF_ERR(&(fcport->qedf->dbg_ctx), "sc_cmd is NULL for "
+		    "xid=0x%x.\n", orig_io_req->xid);
+		goto out;
+	}
+
+	new_io_req = qedf_alloc_cmd(fcport, QEDF_SCSI_CMD);
+	if (!new_io_req) {
+		QEDF_ERR(&(fcport->qedf->dbg_ctx), "Could not allocate new "
+		    "io_req.\n");
+		goto out;
+	}
+
+	new_io_req->sc_cmd = orig_io_req->sc_cmd;
+
+	/*
+	 * This keeps the sc_cmd struct from being returned to the tape
+	 * driver and being requeued twice. We do need to put a reference
+	 * for the original I/O request since we will not do a SCSI completion
+	 * for it.
+	 */
+	orig_io_req->sc_cmd = NULL;
+	kref_put(&orig_io_req->refcount, qedf_release_cmd);
+
+	spin_lock_irqsave(&fcport->rport_lock, flags);
+
+	/* kref for new command released in qedf_post_io_req on error */
+	if (qedf_post_io_req(fcport, new_io_req)) {
+		QEDF_ERR(&(fcport->qedf->dbg_ctx), "Unable to post io_req\n");
+		/* Return SQE to pool */
+		atomic_inc(&fcport->free_sqes);
+	} else {
+		QEDF_INFO(&(fcport->qedf->dbg_ctx), QEDF_LOG_ELS,
+		    "Reissued SCSI command from  orig_xid=0x%x on "
+		    "new_xid=0x%x.\n", orig_io_req->xid, new_io_req->xid);
+		/*
+		 * Abort the original I/O but do not return SCSI command as
+		 * it has been reissued on another OX_ID.
+		 */
+		spin_unlock_irqrestore(&fcport->rport_lock, flags);
+		qedf_initiate_abts(orig_io_req, false);
+		goto out;
+	}
+
+	spin_unlock_irqrestore(&fcport->rport_lock, flags);
+out:
+	return rc;
+}
+
+
+static void qedf_rec_compl(struct qedf_els_cb_arg *cb_arg)
+{
+	struct qedf_ioreq *orig_io_req;
+	struct qedf_ioreq *rec_req;
+	struct qedf_mp_req *mp_req;
+	struct fc_frame_header *fc_hdr, *fh;
+	struct fc_frame *fp;
+	unsigned char *buf;
+	void *resp_buf;
+	u32 resp_len, hdr_len;
+	struct fc_lport *lport;
+	struct qedf_ctx *qedf;
+	int refcount;
+	enum fc_rctl r_ctl;
+	struct fc_els_ls_rjt *rjt;
+	struct fc_els_rec_acc *acc;
+	u8 opcode;
+	u32 offset, e_stat;
+	struct scsi_cmnd *sc_cmd;
+	bool srr_needed = false;
+
+	rec_req = cb_arg->io_req;
+	qedf = rec_req->fcport->qedf;
+	lport = qedf->lport;
+
+	orig_io_req = cb_arg->aborted_io_req;
+
+	if (!orig_io_req)
+		goto out_free;
+
+	if (rec_req->event != QEDF_IOREQ_EV_ELS_TMO &&
+	    rec_req->event != QEDF_IOREQ_EV_ELS_ERR_DETECT)
+		cancel_delayed_work_sync(&orig_io_req->timeout_work);
+
+	refcount = atomic_read(&orig_io_req->refcount.refcount);
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Entered: orig_io=%p,"
+		   " orig_io_xid=0x%x, rec_xid=0x%x, refcount=%d\n",
+		   orig_io_req, orig_io_req->xid, rec_req->xid, refcount);
+
+	/* If a REC times out, free resources */
+	if (rec_req->event == QEDF_IOREQ_EV_ELS_TMO)
+		goto out_free;
+
+	/* Normalize response data into struct fc_frame */
+	mp_req = &(rec_req->mp_req);
+	fc_hdr = &(mp_req->resp_fc_hdr);
+	resp_len = mp_req->resp_len;
+	acc = resp_buf = mp_req->resp_buf;
+	hdr_len = sizeof(*fc_hdr);
+
+	buf = kzalloc(QEDF_PAGE_SIZE, GFP_ATOMIC);
+	if (!buf) {
+		QEDF_ERR(&(qedf->dbg_ctx),
+		    "Unable to alloc mp buf.\n");
+		goto out_free;
+	}
+
+	memcpy(buf, fc_hdr, hdr_len);
+	memcpy(buf + hdr_len, resp_buf, resp_len);
+
+	fp = fc_frame_alloc(lport, resp_len);
+	if (!fp) {
+		QEDF_ERR(&(qedf->dbg_ctx),
+		    "fc_frame_alloc failure.\n");
+		goto out_buf;
+	}
+
+	/* Copy FC Frame header and payload into the frame */
+	fh = (struct fc_frame_header *)fc_frame_header_get(fp);
+	memcpy(fh, buf, hdr_len + resp_len);
+
+	opcode = fc_frame_payload_op(fp);
+
+	if (opcode == ELS_LS_RJT) {
+		rjt = fc_frame_payload_get(fp, sizeof(*rjt));
+		QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+		    "Received LS_RJT for REC: er_reason=0x%x, "
+		    "er_explan=0x%x.\n", rjt->er_reason, rjt->er_explan);
+		/*
+		 * The following response(s) mean that we need to reissue the
+		 * request on another exchange.  We need to do this without
+		 * informing the upper layers lest it cause an application
+		 * error.
+		 */
+		if ((rjt->er_reason == ELS_RJT_LOGIC ||
+		    rjt->er_reason == ELS_RJT_UNAB) &&
+		    rjt->er_explan == ELS_EXPL_OXID_RXID) {
+			QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+			    "Handle CMD LOST case.\n");
+			qedf_requeue_io_req(orig_io_req);
+		}
+	} else if (opcode == ELS_LS_ACC) {
+		offset = ntohl(acc->reca_fc4value);
+		e_stat = ntohl(acc->reca_e_stat);
+		QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+		    "Received LS_ACC for REC: offset=0x%x, e_stat=0x%x.\n",
+		    offset, e_stat);
+		if (e_stat & ESB_ST_SEQ_INIT)  {
+			QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+			    "Target has the seq init\n");
+			goto out_free_frame;
+		}
+		sc_cmd = orig_io_req->sc_cmd;
+		if (!sc_cmd) {
+			QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+			    "sc_cmd is NULL for xid=0x%x.\n",
+			    orig_io_req->xid);
+			goto out_free_frame;
+		}
+		/* SCSI write case */
+		if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
+			if (offset == orig_io_req->data_xfer_len) {
+				QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+				    "WRITE - response lost.\n");
+				r_ctl = FC_RCTL_DD_CMD_STATUS;
+				srr_needed = true;
+				offset = 0;
+			} else {
+				QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+				    "WRITE - XFER_RDY/DATA lost.\n");
+				r_ctl = FC_RCTL_DD_DATA_DESC;
+				/* Use data from warning CQE instead of REC */
+				offset = orig_io_req->tx_buf_off;
+			}
+		/* SCSI read case */
+		} else {
+			if (orig_io_req->rx_buf_off ==
+			    orig_io_req->data_xfer_len) {
+				QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+				    "READ - response lost.\n");
+				srr_needed = true;
+				r_ctl = FC_RCTL_DD_CMD_STATUS;
+				offset = 0;
+			} else {
+				QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS,
+				    "READ - DATA lost.\n");
+				/*
+				 * For read case we always set the offset to 0
+				 * for sequence recovery task.
+				 */
+				offset = 0;
+				r_ctl = FC_RCTL_DD_SOL_DATA;
+			}
+		}
+
+		if (srr_needed)
+			qedf_send_srr(orig_io_req, offset, r_ctl);
+		else
+			qedf_initiate_seq_cleanup(orig_io_req, offset, r_ctl);
+	}
+
+out_free_frame:
+	fc_frame_free(fp);
+out_buf:
+	kfree(buf);
+out_free:
+	/* Put reference for original command since REC completed */
+	kref_put(&orig_io_req->refcount, qedf_release_cmd);
+	kfree(cb_arg);
+}
+
+/* Assumes kref is already held by caller */
+int qedf_send_rec(struct qedf_ioreq *orig_io_req)
+{
+
+	struct fc_els_rec rec;
+	struct qedf_rport *fcport;
+	struct fc_lport *lport;
+	struct qedf_els_cb_arg *cb_arg = NULL;
+	struct qedf_ctx *qedf;
+	uint32_t sid;
+	uint32_t r_a_tov;
+	int rc;
+
+	if (!orig_io_req) {
+		QEDF_ERR(NULL, "orig_io_req is NULL.\n");
+		return -EINVAL;
+	}
+
+	fcport = orig_io_req->fcport;
+
+	/* Check that fcport is still offloaded */
+	if (fcport->conn_id == -1) {
+		QEDF_ERR(NULL, "fcport is no longer offloaded.\n");
+		return -EINVAL;
+	}
+
+	if (!fcport->qedf) {
+		QEDF_ERR(NULL, "fcport->qedf is NULL.\n");
+		return -EINVAL;
+	}
+
+	/* Take reference until REC command completion */
+	kref_get(&orig_io_req->refcount);
+
+	qedf = fcport->qedf;
+	lport = qedf->lport;
+	sid = fcport->sid;
+	r_a_tov = lport->r_a_tov;
+
+	memset(&rec, 0, sizeof(rec));
+
+	cb_arg = kzalloc(sizeof(struct qedf_els_cb_arg), GFP_NOIO);
+	if (!cb_arg) {
+		QEDF_ERR(&(qedf->dbg_ctx), "Unable to allocate cb_arg for "
+			  "REC\n");
+		rc = -ENOMEM;
+		goto rec_err;
+	}
+
+	cb_arg->aborted_io_req = orig_io_req;
+
+	rec.rec_cmd = ELS_REC;
+	hton24(rec.rec_s_id, sid);
+	rec.rec_ox_id = htons(orig_io_req->xid);
+	rec.rec_rx_id =
+	    htons(orig_io_req->task->tstorm_st_context.read_write.rx_id);
+
+	QEDF_INFO(&(qedf->dbg_ctx), QEDF_LOG_ELS, "Sending REC orig_io=%p, "
+	   "orig_xid=0x%x rx_id=0x%x\n", orig_io_req,
+	   orig_io_req->xid, rec.rec_rx_id);
+	rc = qedf_initiate_els(fcport, ELS_REC, &rec, sizeof(rec),
+	    qedf_rec_compl, cb_arg, r_a_tov);
+
+rec_err:
+	if (rc) {
+		QEDF_ERR(&(qedf->dbg_ctx), "REC failed - release orig_io_req"
+			  "=0x%x\n", orig_io_req->xid);
+		kfree(cb_arg);
+		kref_put(&orig_io_req->refcount, qedf_release_cmd);
+	}
+	return rc;
+}
-- 
1.8.5.6

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