1 files changed, 567 insertions, 0 deletions

diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
new file mode 100644
index 000000000..410b723f9
--- /dev/null
+++ b/drivers/target/tcm_fc/tfc_cmd.c
@@ -0,0 +1,567 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2010 Cisco Systems, Inc.
+ */
+
+/* XXX TBD some includes may be extraneous */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/utsname.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/kthread.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/configfs.h>
+#include <linux/ctype.h>
+#include <linux/hash.h>
+#include <asm/unaligned.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/libfc.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_fabric.h>
+
+#include "tcm_fc.h"
+
+/*
+ * Dump cmd state for debugging.
+ */
+static void _ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
+{
+	struct fc_exch *ep;
+	struct fc_seq *sp;
+	struct se_cmd *se_cmd;
+	struct scatterlist *sg;
+	int count;
+
+	se_cmd = &cmd->se_cmd;
+	pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
+		caller, cmd, cmd->sess, cmd->seq, se_cmd);
+
+	pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
+		caller, cmd, se_cmd->t_data_nents,
+	       se_cmd->data_length, se_cmd->se_cmd_flags);
+
+	for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
+		pr_debug("%s: cmd %p sg %p page %p "
+			"len 0x%x off 0x%x\n",
+			caller, cmd, sg,
+			sg_page(sg), sg->length, sg->offset);
+
+	sp = cmd->seq;
+	if (sp) {
+		ep = fc_seq_exch(sp);
+		pr_debug("%s: cmd %p sid %x did %x "
+			"ox_id %x rx_id %x seq_id %x e_stat %x\n",
+			caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
+			sp->id, ep->esb_stat);
+	}
+}
+
+void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
+{
+	if (unlikely(ft_debug_logging))
+		_ft_dump_cmd(cmd, caller);
+}
+
+static void ft_free_cmd(struct ft_cmd *cmd)
+{
+	struct fc_frame *fp;
+	struct ft_sess *sess;
+
+	if (!cmd)
+		return;
+	sess = cmd->sess;
+	fp = cmd->req_frame;
+	if (fr_seq(fp))
+		fc_seq_release(fr_seq(fp));
+	fc_frame_free(fp);
+	target_free_tag(sess->se_sess, &cmd->se_cmd);
+	ft_sess_put(sess);	/* undo get from lookup at recv */
+}
+
+void ft_release_cmd(struct se_cmd *se_cmd)
+{
+	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
+
+	ft_free_cmd(cmd);
+}
+
+int ft_check_stop_free(struct se_cmd *se_cmd)
+{
+	return transport_generic_free_cmd(se_cmd, 0);
+}
+
+/*
+ * Send response.
+ */
+int ft_queue_status(struct se_cmd *se_cmd)
+{
+	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
+	struct fc_frame *fp;
+	struct fcp_resp_with_ext *fcp;
+	struct fc_lport *lport;
+	struct fc_exch *ep;
+	size_t len;
+	int rc;
+
+	if (cmd->aborted)
+		return 0;
+	ft_dump_cmd(cmd, __func__);
+	ep = fc_seq_exch(cmd->seq);
+	lport = ep->lp;
+	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
+	fp = fc_frame_alloc(lport, len);
+	if (!fp) {
+		se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
+		return -ENOMEM;
+	}
+
+	fcp = fc_frame_payload_get(fp, len);
+	memset(fcp, 0, len);
+	fcp->resp.fr_status = se_cmd->scsi_status;
+
+	len = se_cmd->scsi_sense_length;
+	if (len) {
+		fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
+		fcp->ext.fr_sns_len = htonl(len);
+		memcpy((fcp + 1), se_cmd->sense_buffer, len);
+	}
+
+	/*
+	 * Test underflow and overflow with one mask.  Usually both are off.
+	 * Bidirectional commands are not handled yet.
+	 */
+	if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
+		if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
+			fcp->resp.fr_flags |= FCP_RESID_OVER;
+		else
+			fcp->resp.fr_flags |= FCP_RESID_UNDER;
+		fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
+	}
+
+	/*
+	 * Send response.
+	 */
+	cmd->seq = fc_seq_start_next(cmd->seq);
+	fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
+		       FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
+
+	rc = fc_seq_send(lport, cmd->seq, fp);
+	if (rc) {
+		pr_info_ratelimited("%s: Failed to send response frame %p, "
+				    "xid <0x%x>\n", __func__, fp, ep->xid);
+		/*
+		 * Generate a TASK_SET_FULL status to notify the initiator
+		 * to reduce it's queue_depth after the se_cmd response has
+		 * been re-queued by target-core.
+		 */
+		se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
+		return -ENOMEM;
+	}
+	fc_exch_done(cmd->seq);
+	/*
+	 * Drop the extra ACK_KREF reference taken by target_submit_cmd()
+	 * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
+	 * final se_cmd->cmd_kref put.
+	 */
+	target_put_sess_cmd(&cmd->se_cmd);
+	return 0;
+}
+
+/*
+ * Send TX_RDY (transfer ready).
+ */
+int ft_write_pending(struct se_cmd *se_cmd)
+{
+	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
+	struct fc_frame *fp;
+	struct fcp_txrdy *txrdy;
+	struct fc_lport *lport;
+	struct fc_exch *ep;
+	struct fc_frame_header *fh;
+	u32 f_ctl;
+
+	ft_dump_cmd(cmd, __func__);
+
+	if (cmd->aborted)
+		return 0;
+	ep = fc_seq_exch(cmd->seq);
+	lport = ep->lp;
+	fp = fc_frame_alloc(lport, sizeof(*txrdy));
+	if (!fp)
+		return -ENOMEM; /* Signal QUEUE_FULL */
+
+	txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
+	memset(txrdy, 0, sizeof(*txrdy));
+	txrdy->ft_burst_len = htonl(se_cmd->data_length);
+
+	cmd->seq = fc_seq_start_next(cmd->seq);
+	fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
+		       FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
+
+	fh = fc_frame_header_get(fp);
+	f_ctl = ntoh24(fh->fh_f_ctl);
+
+	/* Only if it is 'Exchange Responder' */
+	if (f_ctl & FC_FC_EX_CTX) {
+		/* Target is 'exchange responder' and sending XFER_READY
+		 * to 'exchange initiator (initiator)'
+		 */
+		if ((ep->xid <= lport->lro_xid) &&
+		    (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
+			if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
+			    lport->tt.ddp_target(lport, ep->xid,
+						 se_cmd->t_data_sg,
+						 se_cmd->t_data_nents))
+				cmd->was_ddp_setup = 1;
+		}
+	}
+	fc_seq_send(lport, cmd->seq, fp);
+	return 0;
+}
+
+int ft_get_cmd_state(struct se_cmd *se_cmd)
+{
+	return 0;
+}
+
+/*
+ * FC sequence response handler for follow-on sequences (data) and aborts.
+ */
+static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
+{
+	struct ft_cmd *cmd = arg;
+	struct fc_frame_header *fh;
+
+	if (IS_ERR(fp)) {
+		/* XXX need to find cmd if queued */
+		cmd->seq = NULL;
+		cmd->aborted = true;
+		return;
+	}
+
+	fh = fc_frame_header_get(fp);
+
+	switch (fh->fh_r_ctl) {
+	case FC_RCTL_DD_SOL_DATA:	/* write data */
+		ft_recv_write_data(cmd, fp);
+		break;
+	case FC_RCTL_DD_UNSOL_CTL:	/* command */
+	case FC_RCTL_DD_SOL_CTL:	/* transfer ready */
+	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
+	default:
+		pr_debug("%s: unhandled frame r_ctl %x\n",
+		       __func__, fh->fh_r_ctl);
+		ft_invl_hw_context(cmd);
+		fc_frame_free(fp);
+		transport_generic_free_cmd(&cmd->se_cmd, 0);
+		break;
+	}
+}
+
+/*
+ * Send a FCP response including SCSI status and optional FCP rsp_code.
+ * status is SAM_STAT_GOOD (zero) iff code is valid.
+ * This is used in error cases, such as allocation failures.
+ */
+static void ft_send_resp_status(struct fc_lport *lport,
+				const struct fc_frame *rx_fp,
+				u32 status, enum fcp_resp_rsp_codes code)
+{
+	struct fc_frame *fp;
+	struct fc_seq *sp;
+	const struct fc_frame_header *fh;
+	size_t len;
+	struct fcp_resp_with_ext *fcp;
+	struct fcp_resp_rsp_info *info;
+
+	fh = fc_frame_header_get(rx_fp);
+	pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
+		  ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
+	len = sizeof(*fcp);
+	if (status == SAM_STAT_GOOD)
+		len += sizeof(*info);
+	fp = fc_frame_alloc(lport, len);
+	if (!fp)
+		return;
+	fcp = fc_frame_payload_get(fp, len);
+	memset(fcp, 0, len);
+	fcp->resp.fr_status = status;
+	if (status == SAM_STAT_GOOD) {
+		fcp->ext.fr_rsp_len = htonl(sizeof(*info));
+		fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
+		info = (struct fcp_resp_rsp_info *)(fcp + 1);
+		info->rsp_code = code;
+	}
+
+	fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
+	sp = fr_seq(fp);
+	if (sp) {
+		fc_seq_send(lport, sp, fp);
+		fc_exch_done(sp);
+	} else {
+		lport->tt.frame_send(lport, fp);
+	}
+}
+
+/*
+ * Send error or task management response.
+ */
+static void ft_send_resp_code(struct ft_cmd *cmd,
+			      enum fcp_resp_rsp_codes code)
+{
+	ft_send_resp_status(cmd->sess->tport->lport,
+			    cmd->req_frame, SAM_STAT_GOOD, code);
+}
+
+
+/*
+ * Send error or task management response.
+ * Always frees the cmd and associated state.
+ */
+static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
+				      enum fcp_resp_rsp_codes code)
+{
+	ft_send_resp_code(cmd, code);
+	ft_free_cmd(cmd);
+}
+
+/*
+ * Handle Task Management Request.
+ */
+static void ft_send_tm(struct ft_cmd *cmd)
+{
+	struct fcp_cmnd *fcp;
+	int rc;
+	u8 tm_func;
+
+	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
+
+	switch (fcp->fc_tm_flags) {
+	case FCP_TMF_LUN_RESET:
+		tm_func = TMR_LUN_RESET;
+		break;
+	case FCP_TMF_TGT_RESET:
+		tm_func = TMR_TARGET_WARM_RESET;
+		break;
+	case FCP_TMF_CLR_TASK_SET:
+		tm_func = TMR_CLEAR_TASK_SET;
+		break;
+	case FCP_TMF_ABT_TASK_SET:
+		tm_func = TMR_ABORT_TASK_SET;
+		break;
+	case FCP_TMF_CLR_ACA:
+		tm_func = TMR_CLEAR_ACA;
+		break;
+	default:
+		/*
+		 * FCP4r01 indicates having a combination of
+		 * tm_flags set is invalid.
+		 */
+		pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
+		ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
+		return;
+	}
+
+	/* FIXME: Add referenced task tag for ABORT_TASK */
+	rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
+		&cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
+		cmd, tm_func, GFP_KERNEL, 0, TARGET_SCF_ACK_KREF);
+	if (rc < 0)
+		ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
+}
+
+/*
+ * Send status from completed task management request.
+ */
+void ft_queue_tm_resp(struct se_cmd *se_cmd)
+{
+	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
+	struct se_tmr_req *tmr = se_cmd->se_tmr_req;
+	enum fcp_resp_rsp_codes code;
+
+	if (cmd->aborted)
+		return;
+	switch (tmr->response) {
+	case TMR_FUNCTION_COMPLETE:
+		code = FCP_TMF_CMPL;
+		break;
+	case TMR_LUN_DOES_NOT_EXIST:
+		code = FCP_TMF_INVALID_LUN;
+		break;
+	case TMR_FUNCTION_REJECTED:
+		code = FCP_TMF_REJECTED;
+		break;
+	case TMR_TASK_DOES_NOT_EXIST:
+	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
+	default:
+		code = FCP_TMF_FAILED;
+		break;
+	}
+	pr_debug("tmr fn %d resp %d fcp code %d\n",
+		  tmr->function, tmr->response, code);
+	ft_send_resp_code(cmd, code);
+	/*
+	 * Drop the extra ACK_KREF reference taken by target_submit_tmr()
+	 * ahead of ft_check_stop_free() -> transport_generic_free_cmd()
+	 * final se_cmd->cmd_kref put.
+	 */
+	target_put_sess_cmd(&cmd->se_cmd);
+}
+
+void ft_aborted_task(struct se_cmd *se_cmd)
+{
+	return;
+}
+
+static void ft_send_work(struct work_struct *work);
+
+/*
+ * Handle incoming FCP command.
+ */
+static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
+{
+	struct ft_cmd *cmd;
+	struct fc_lport *lport = sess->tport->lport;
+	struct se_session *se_sess = sess->se_sess;
+	int tag, cpu;
+
+	tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
+	if (tag < 0)
+		goto busy;
+
+	cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag];
+	memset(cmd, 0, sizeof(struct ft_cmd));
+
+	cmd->se_cmd.map_tag = tag;
+	cmd->se_cmd.map_cpu = cpu;
+	cmd->sess = sess;
+	cmd->seq = fc_seq_assign(lport, fp);
+	if (!cmd->seq) {
+		target_free_tag(se_sess, &cmd->se_cmd);
+		goto busy;
+	}
+	cmd->req_frame = fp;		/* hold frame during cmd */
+
+	INIT_WORK(&cmd->work, ft_send_work);
+	queue_work(sess->tport->tpg->workqueue, &cmd->work);
+	return;
+
+busy:
+	pr_debug("cmd or seq allocation failure - sending BUSY\n");
+	ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
+	fc_frame_free(fp);
+	ft_sess_put(sess);		/* undo get from lookup */
+}
+
+
+/*
+ * Handle incoming FCP frame.
+ * Caller has verified that the frame is type FCP.
+ */
+void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
+{
+	struct fc_frame_header *fh = fc_frame_header_get(fp);
+
+	switch (fh->fh_r_ctl) {
+	case FC_RCTL_DD_UNSOL_CMD:	/* command */
+		ft_recv_cmd(sess, fp);
+		break;
+	case FC_RCTL_DD_SOL_DATA:	/* write data */
+	case FC_RCTL_DD_UNSOL_CTL:
+	case FC_RCTL_DD_SOL_CTL:
+	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
+	case FC_RCTL_ELS4_REQ:		/* SRR, perhaps */
+	default:
+		pr_debug("%s: unhandled frame r_ctl %x\n",
+		       __func__, fh->fh_r_ctl);
+		fc_frame_free(fp);
+		ft_sess_put(sess);	/* undo get from lookup */
+		break;
+	}
+}
+
+/*
+ * Send new command to target.
+ */
+static void ft_send_work(struct work_struct *work)
+{
+	struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
+	struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
+	struct fcp_cmnd *fcp;
+	int data_dir = 0;
+	int task_attr;
+
+	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
+	if (!fcp)
+		goto err;
+
+	if (fcp->fc_flags & FCP_CFL_LEN_MASK)
+		goto err;		/* not handling longer CDBs yet */
+
+	/*
+	 * Check for FCP task management flags
+	 */
+	if (fcp->fc_tm_flags) {
+		ft_send_tm(cmd);
+		return;
+	}
+
+	switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
+	case 0:
+		data_dir = DMA_NONE;
+		break;
+	case FCP_CFL_RDDATA:
+		data_dir = DMA_FROM_DEVICE;
+		break;
+	case FCP_CFL_WRDATA:
+		data_dir = DMA_TO_DEVICE;
+		break;
+	case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
+		goto err;	/* TBD not supported by tcm_fc yet */
+	}
+	/*
+	 * Locate the SAM Task Attr from fc_pri_ta
+	 */
+	switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
+	case FCP_PTA_HEADQ:
+		task_attr = TCM_HEAD_TAG;
+		break;
+	case FCP_PTA_ORDERED:
+		task_attr = TCM_ORDERED_TAG;
+		break;
+	case FCP_PTA_ACA:
+		task_attr = TCM_ACA_TAG;
+		break;
+	case FCP_PTA_SIMPLE:
+	default:
+		task_attr = TCM_SIMPLE_TAG;
+	}
+
+	fc_seq_set_resp(cmd->seq, ft_recv_seq, cmd);
+	cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid;
+
+	/*
+	 * Use a single se_cmd->cmd_kref as we expect to release se_cmd
+	 * directly from ft_check_stop_free callback in response path.
+	 */
+	if (target_init_cmd(&cmd->se_cmd, cmd->sess->se_sess,
+			    &cmd->ft_sense_buffer[0],
+			    scsilun_to_int(&fcp->fc_lun), ntohl(fcp->fc_dl),
+			    task_attr, data_dir, TARGET_SCF_ACK_KREF))
+		goto err;
+
+	if (target_submit_prep(&cmd->se_cmd, fcp->fc_cdb, NULL, 0, NULL, 0,
+			       NULL, 0, GFP_KERNEL))
+		return;
+
+	target_submit(&cmd->se_cmd);
+	pr_debug("r_ctl %x target_submit_cmd %p\n", fh->fh_r_ctl, cmd);
+	return;
+
+err:
+	ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
+}