[linux-2.6-block.git] / drivers / target / tcm_fc / tfc_cmd.c

// 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;
}

/*
 * 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);
}
Commit	Line	Data
a61127c2	1	// SPDX-License-Identifier: GPL-2.0-only
3699d92a KP	2	/*
3699d92a KP	3	* Copyright (c) 2010 Cisco Systems, Inc.
3699d92a KP	4	*/
	5
	6	/* XXX TBD some includes may be extraneous */
	7
	8	#include <linux/module.h>
	9	#include <linux/moduleparam.h>
3699d92a KP	10	#include <linux/utsname.h>
	11	#include <linux/init.h>
	12	#include <linux/slab.h>
	13	#include <linux/kthread.h>
	14	#include <linux/types.h>
	15	#include <linux/string.h>
	16	#include <linux/configfs.h>
	17	#include <linux/ctype.h>
	18	#include <linux/hash.h>
	19	#include <asm/unaligned.h>
61db1802	20	#include <scsi/scsi_tcq.h>
3699d92a	21	#include <scsi/libfc.h>
3699d92a KP	22
3699d92a KP	23	#include <target/target_core_base.h>
c4795fb2	24	#include <target/target_core_fabric.h>
3699d92a KP	25
	26	#include "tcm_fc.h"
	27
	28	/*
	29	* Dump cmd state for debugging.
	30	*/
1fa8f450	31	static void _ft_dump_cmd(struct ft_cmd cmd, const char caller)
3699d92a KP	32	{
	33	struct fc_exch *ep;
	34	struct fc_seq *sp;
	35	struct se_cmd *se_cmd;
ec98f782 AG	36	struct scatterlist *sg;
ec98f782 AG	37	int count;
3699d92a	38
3699d92a	39	se_cmd = &cmd->se_cmd;
58fc73d1 CH	40	pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
58fc73d1 CH	41	caller, cmd, cmd->sess, cmd->seq, se_cmd);
3699d92a	42
6708bb27	43	pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
ec98f782	44	caller, cmd, se_cmd->t_data_nents,
05d1c7c0	45	se_cmd->data_length, se_cmd->se_cmd_flags);
5951146d	46
ec98f782	47	for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
6708bb27	48	pr_debug("%s: cmd %p sg %p page %p "
ec98f782 AG	49	"len 0x%x off 0x%x\n",
	50	caller, cmd, sg,
	51	sg_page(sg), sg->length, sg->offset);
	52
3699d92a KP	53	sp = cmd->seq;
	54	if (sp) {
	55	ep = fc_seq_exch(sp);
6708bb27	56	pr_debug("%s: cmd %p sid %x did %x "
3699d92a KP	57	"ox_id %x rx_id %x seq_id %x e_stat %x\n",
	58	caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
	59	sp->id, ep->esb_stat);
	60	}
3699d92a KP	61	}
3699d92a KP	62
1fa8f450 MR	63	void ft_dump_cmd(struct ft_cmd cmd, const char caller)
	64	{
	65	if (unlikely(ft_debug_logging))
	66	_ft_dump_cmd(cmd, caller);
	67	}
	68
3699d92a KP	69	static void ft_free_cmd(struct ft_cmd *cmd)
	70	{
	71	struct fc_frame *fp;
ed8ec8f7	72	struct ft_sess *sess;
3699d92a KP	73
	74	if (!cmd)
	75	return;
ed8ec8f7	76	sess = cmd->sess;
3699d92a	77	fp = cmd->req_frame;
3699d92a	78	if (fr_seq(fp))
9625cc48	79	fc_seq_release(fr_seq(fp));
3699d92a	80	fc_frame_free(fp);
83c2b54b	81	target_free_tag(sess->se_sess, &cmd->se_cmd);
ed8ec8f7	82	ft_sess_put(sess); /* undo get from lookup at recv */
3699d92a KP	83	}
	84
	85	void ft_release_cmd(struct se_cmd *se_cmd)
	86	{
	87	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
	88
	89	ft_free_cmd(cmd);
	90	}
	91
88dd9e26	92	int ft_check_stop_free(struct se_cmd *se_cmd)
3699d92a	93	{
91973cd6	94	return transport_generic_free_cmd(se_cmd, 0);
3699d92a KP	95	}
	96
	97	/*
	98	* Send response.
	99	*/
	100	int ft_queue_status(struct se_cmd *se_cmd)
	101	{
	102	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
	103	struct fc_frame *fp;
	104	struct fcp_resp_with_ext *fcp;
	105	struct fc_lport *lport;
	106	struct fc_exch *ep;
	107	size_t len;
6dbe7f4e	108	int rc;
3699d92a	109
e1c40382 MR	110	if (cmd->aborted)
e1c40382 MR	111	return 0;
3699d92a KP	112	ft_dump_cmd(cmd, __func__);
	113	ep = fc_seq_exch(cmd->seq);
	114	lport = ep->lp;
	115	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
	116	fp = fc_frame_alloc(lport, len);
	117	if (!fp) {
6dbe7f4e NB	118	se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
6dbe7f4e NB	119	return -ENOMEM;
3699d92a	120	}
6dbe7f4e	121
3699d92a KP	122	fcp = fc_frame_payload_get(fp, len);
	123	memset(fcp, 0, len);
	124	fcp->resp.fr_status = se_cmd->scsi_status;
	125
	126	len = se_cmd->scsi_sense_length;
	127	if (len) {
	128	fcp->resp.fr_flags \|= FCP_SNS_LEN_VAL;
	129	fcp->ext.fr_sns_len = htonl(len);
	130	memcpy((fcp + 1), se_cmd->sense_buffer, len);
	131	}
	132
	133	/*
	134	* Test underflow and overflow with one mask. Usually both are off.
	135	* Bidirectional commands are not handled yet.
	136	*/
	137	if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT \| SCF_UNDERFLOW_BIT)) {
	138	if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
	139	fcp->resp.fr_flags \|= FCP_RESID_OVER;
	140	else
	141	fcp->resp.fr_flags \|= FCP_RESID_UNDER;
	142	fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
	143	}
	144
	145	/*
	146	* Send response.
	147	*/
c6865b30	148	cmd->seq = fc_seq_start_next(cmd->seq);
3699d92a KP	149	fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
	150	FC_FC_EX_CTX \| FC_FC_LAST_SEQ \| FC_FC_END_SEQ, 0);
	151
0cac937d	152	rc = fc_seq_send(lport, cmd->seq, fp);
6dbe7f4e NB	153	if (rc) {
	154	pr_info_ratelimited("%s: Failed to send response frame %p, "
	155	"xid <0x%x>\n", __func__, fp, ep->xid);
	156	/*
	157	* Generate a TASK_SET_FULL status to notify the initiator
	158	* to reduce it's queue_depth after the se_cmd response has
	159	* been re-queued by target-core.
	160	*/
	161	se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
	162	return -ENOMEM;
	163	}
768c72cc	164	fc_exch_done(cmd->seq);
91973cd6 NB	165	/*
	166	* Drop the extra ACK_KREF reference taken by target_submit_cmd()
	167	* ahead of ft_check_stop_free() -> transport_generic_free_cmd()
	168	* final se_cmd->cmd_kref put.
	169	*/
	170	target_put_sess_cmd(&cmd->se_cmd);
3699d92a KP	171	return 0;
	172	}
	173
3699d92a KP	174	/*
	175	* Send TX_RDY (transfer ready).
	176	*/
	177	int ft_write_pending(struct se_cmd *se_cmd)
	178	{
	179	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
	180	struct fc_frame *fp;
	181	struct fcp_txrdy *txrdy;
	182	struct fc_lport *lport;
	183	struct fc_exch *ep;
	184	struct fc_frame_header *fh;
	185	u32 f_ctl;
	186
	187	ft_dump_cmd(cmd, __func__);
	188
e1c40382 MR	189	if (cmd->aborted)
e1c40382 MR	190	return 0;
3699d92a KP	191	ep = fc_seq_exch(cmd->seq);
	192	lport = ep->lp;
	193	fp = fc_frame_alloc(lport, sizeof(*txrdy));
	194	if (!fp)
03e98c9e	195	return -ENOMEM; /* Signal QUEUE_FULL */
3699d92a KP	196
	197	txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
	198	memset(txrdy, 0, sizeof(*txrdy));
	199	txrdy->ft_burst_len = htonl(se_cmd->data_length);
	200
c6865b30	201	cmd->seq = fc_seq_start_next(cmd->seq);
3699d92a KP	202	fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
	203	FC_FC_EX_CTX \| FC_FC_END_SEQ \| FC_FC_SEQ_INIT, 0);
	204
	205	fh = fc_frame_header_get(fp);
	206	f_ctl = ntoh24(fh->fh_f_ctl);
	207
	208	/* Only if it is 'Exchange Responder' */
	209	if (f_ctl & FC_FC_EX_CTX) {
	210	/* Target is 'exchange responder' and sending XFER_READY
	211	* to 'exchange initiator (initiator)'
	212	*/
	213	if ((ep->xid <= lport->lro_xid) &&
	214	(fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
64f1db38	215	if ((se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
e182d682 RD	216	lport->tt.ddp_target(lport, ep->xid,
	217	se_cmd->t_data_sg,
	218	se_cmd->t_data_nents))
3699d92a KP	219	cmd->was_ddp_setup = 1;
	220	}
	221	}
0cac937d	222	fc_seq_send(lport, cmd->seq, fp);
3699d92a KP	223	return 0;
	224	}
	225
3699d92a KP	226	/*
	227	* FC sequence response handler for follow-on sequences (data) and aborts.
	228	*/
	229	static void ft_recv_seq(struct fc_seq sp, struct fc_frame fp, void *arg)
	230	{
	231	struct ft_cmd *cmd = arg;
	232	struct fc_frame_header *fh;
	233
9d8c94e4	234	if (IS_ERR(fp)) {
3699d92a	235	/* XXX need to find cmd if queued */
3699d92a	236	cmd->seq = NULL;
e1c40382	237	cmd->aborted = true;
3699d92a KP	238	return;
	239	}
	240
	241	fh = fc_frame_header_get(fp);
	242
	243	switch (fh->fh_r_ctl) {
	244	case FC_RCTL_DD_SOL_DATA: /* write data */
	245	ft_recv_write_data(cmd, fp);
	246	break;
	247	case FC_RCTL_DD_UNSOL_CTL: /* command */
	248	case FC_RCTL_DD_SOL_CTL: /* transfer ready */
	249	case FC_RCTL_DD_DATA_DESC: /* transfer ready */
	250	default:
6708bb27	251	pr_debug("%s: unhandled frame r_ctl %x\n",
3699d92a	252	__func__, fh->fh_r_ctl);
dcd998cc	253	ft_invl_hw_context(cmd);
3699d92a	254	fc_frame_free(fp);
82f1c8a4	255	transport_generic_free_cmd(&cmd->se_cmd, 0);
3699d92a KP	256	break;
	257	}
	258	}
	259
	260	/*
	261	* Send a FCP response including SCSI status and optional FCP rsp_code.
	262	* status is SAM_STAT_GOOD (zero) iff code is valid.
	263	* This is used in error cases, such as allocation failures.
	264	*/
	265	static void ft_send_resp_status(struct fc_lport *lport,
	266	const struct fc_frame *rx_fp,
	267	u32 status, enum fcp_resp_rsp_codes code)
	268	{
	269	struct fc_frame *fp;
	270	struct fc_seq *sp;
	271	const struct fc_frame_header *fh;
	272	size_t len;
	273	struct fcp_resp_with_ext *fcp;
	274	struct fcp_resp_rsp_info *info;
	275
	276	fh = fc_frame_header_get(rx_fp);
6708bb27	277	pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
3699d92a KP	278	ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
	279	len = sizeof(*fcp);
	280	if (status == SAM_STAT_GOOD)
	281	len += sizeof(*info);
	282	fp = fc_frame_alloc(lport, len);
	283	if (!fp)
	284	return;
	285	fcp = fc_frame_payload_get(fp, len);
	286	memset(fcp, 0, len);
	287	fcp->resp.fr_status = status;
	288	if (status == SAM_STAT_GOOD) {
	289	fcp->ext.fr_rsp_len = htonl(sizeof(*info));
	290	fcp->resp.fr_flags \|= FCP_RSP_LEN_VAL;
	291	info = (struct fcp_resp_rsp_info *)(fcp + 1);
	292	info->rsp_code = code;
	293	}
	294
	295	fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
	296	sp = fr_seq(fp);
031ed4d5	297	if (sp) {
0cac937d	298	fc_seq_send(lport, sp, fp);
768c72cc	299	fc_exch_done(sp);
031ed4d5	300	} else {
3699d92a	301	lport->tt.frame_send(lport, fp);
031ed4d5	302	}
3699d92a KP	303	}
	304
	305	/*
	306	* Send error or task management response.
3699d92a	307	*/
f2f7b09c KP	308	static void ft_send_resp_code(struct ft_cmd *cmd,
f2f7b09c KP	309	enum fcp_resp_rsp_codes code)
3699d92a KP	310	{
	311	ft_send_resp_status(cmd->sess->tport->lport,
	312	cmd->req_frame, SAM_STAT_GOOD, code);
f2f7b09c KP	313	}
	314
	315
	316	/*
	317	* Send error or task management response.
	318	* Always frees the cmd and associated state.
	319	*/
	320	static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
	321	enum fcp_resp_rsp_codes code)
	322	{
	323	ft_send_resp_code(cmd, code);
3699d92a KP	324	ft_free_cmd(cmd);
	325	}
	326
	327	/*
	328	* Handle Task Management Request.
	329	*/
	330	static void ft_send_tm(struct ft_cmd *cmd)
	331	{
3699d92a	332	struct fcp_cmnd *fcp;
00ad4c4e	333	int rc;
3699d92a KP	334	u8 tm_func;
	335
	336	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
	337
	338	switch (fcp->fc_tm_flags) {
	339	case FCP_TMF_LUN_RESET:
	340	tm_func = TMR_LUN_RESET;
3699d92a KP	341	break;
	342	case FCP_TMF_TGT_RESET:
	343	tm_func = TMR_TARGET_WARM_RESET;
	344	break;
	345	case FCP_TMF_CLR_TASK_SET:
	346	tm_func = TMR_CLEAR_TASK_SET;
	347	break;
	348	case FCP_TMF_ABT_TASK_SET:
	349	tm_func = TMR_ABORT_TASK_SET;
	350	break;
	351	case FCP_TMF_CLR_ACA:
	352	tm_func = TMR_CLEAR_ACA;
	353	break;
	354	default:
	355	/*
	356	* FCP4r01 indicates having a combination of
	357	* tm_flags set is invalid.
	358	*/
6708bb27	359	pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
f2f7b09c	360	ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
3699d92a KP	361	return;
	362	}
	363
c0974f89	364	/* FIXME: Add referenced task tag for ABORT_TASK */
00ad4c4e	365	rc = target_submit_tmr(&cmd->se_cmd, cmd->sess->se_sess,
59dcb5ec	366	&cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
91973cd6	367	cmd, tm_func, GFP_KERNEL, 0, TARGET_SCF_ACK_KREF);
00ad4c4e NB	368	if (rc < 0)
00ad4c4e NB	369	ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
3699d92a KP	370	}
	371
	372	/*
	373	* Send status from completed task management request.
	374	*/
b79fafac	375	void ft_queue_tm_resp(struct se_cmd *se_cmd)
3699d92a KP	376	{
	377	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
	378	struct se_tmr_req *tmr = se_cmd->se_tmr_req;
	379	enum fcp_resp_rsp_codes code;
	380
e1c40382	381	if (cmd->aborted)
b79fafac	382	return;
3699d92a KP	383	switch (tmr->response) {
	384	case TMR_FUNCTION_COMPLETE:
	385	code = FCP_TMF_CMPL;
	386	break;
	387	case TMR_LUN_DOES_NOT_EXIST:
	388	code = FCP_TMF_INVALID_LUN;
	389	break;
	390	case TMR_FUNCTION_REJECTED:
	391	code = FCP_TMF_REJECTED;
	392	break;
	393	case TMR_TASK_DOES_NOT_EXIST:
3699d92a	394	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
3699d92a KP	395	default:
	396	code = FCP_TMF_FAILED;
	397	break;
	398	}
6708bb27	399	pr_debug("tmr fn %d resp %d fcp code %d\n",
3699d92a KP	400	tmr->function, tmr->response, code);
3699d92a KP	401	ft_send_resp_code(cmd, code);
91973cd6 NB	402	/*
	403	* Drop the extra ACK_KREF reference taken by target_submit_tmr()
	404	* ahead of ft_check_stop_free() -> transport_generic_free_cmd()
	405	* final se_cmd->cmd_kref put.
	406	*/
	407	target_put_sess_cmd(&cmd->se_cmd);
3699d92a KP	408	}
3699d92a KP	409
131e6abc NB	410	void ft_aborted_task(struct se_cmd *se_cmd)
	411	{
	412	return;
	413	}
	414
58fc73d1 CH	415	static void ft_send_work(struct work_struct *work);
58fc73d1 CH	416
3699d92a KP	417	/*
	418	* Handle incoming FCP command.
	419	*/
	420	static void ft_recv_cmd(struct ft_sess sess, struct fc_frame fp)
	421	{
	422	struct ft_cmd *cmd;
	423	struct fc_lport *lport = sess->tport->lport;
5f544cfa	424	struct se_session *se_sess = sess->se_sess;
10e9cbb6	425	int tag, cpu;
3699d92a	426
10e9cbb6	427	tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
5f544cfa	428	if (tag < 0)
3699d92a	429	goto busy;
5f544cfa NB	430
	431	cmd = &((struct ft_cmd *)se_sess->sess_cmd_map)[tag];
	432	memset(cmd, 0, sizeof(struct ft_cmd));
	433
	434	cmd->se_cmd.map_tag = tag;
10e9cbb6	435	cmd->se_cmd.map_cpu = cpu;
3699d92a	436	cmd->sess = sess;
96d564e2	437	cmd->seq = fc_seq_assign(lport, fp);
3699d92a	438	if (!cmd->seq) {
83c2b54b	439	target_free_tag(se_sess, &cmd->se_cmd);
3699d92a KP	440	goto busy;
	441	}
	442	cmd->req_frame = fp; /* hold frame during cmd */
58fc73d1 CH	443
	444	INIT_WORK(&cmd->work, ft_send_work);
	445	queue_work(sess->tport->tpg->workqueue, &cmd->work);
3699d92a KP	446	return;
	447
	448	busy:
6708bb27	449	pr_debug("cmd or seq allocation failure - sending BUSY\n");
3699d92a KP	450	ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
	451	fc_frame_free(fp);
	452	ft_sess_put(sess); /* undo get from lookup */
	453	}
	454
	455
	456	/*
	457	* Handle incoming FCP frame.
	458	* Caller has verified that the frame is type FCP.
	459	*/
	460	void ft_recv_req(struct ft_sess sess, struct fc_frame fp)
	461	{
	462	struct fc_frame_header *fh = fc_frame_header_get(fp);
	463
	464	switch (fh->fh_r_ctl) {
	465	case FC_RCTL_DD_UNSOL_CMD: /* command */
	466	ft_recv_cmd(sess, fp);
	467	break;
	468	case FC_RCTL_DD_SOL_DATA: /* write data */
	469	case FC_RCTL_DD_UNSOL_CTL:
	470	case FC_RCTL_DD_SOL_CTL:
	471	case FC_RCTL_DD_DATA_DESC: /* transfer ready */
	472	case FC_RCTL_ELS4_REQ: /* SRR, perhaps */
	473	default:
6708bb27	474	pr_debug("%s: unhandled frame r_ctl %x\n",
3699d92a KP	475	__func__, fh->fh_r_ctl);
	476	fc_frame_free(fp);
	477	ft_sess_put(sess); /* undo get from lookup */
	478	break;
	479	}
	480	}
	481
	482	/*
	483	* Send new command to target.
	484	*/
58fc73d1	485	static void ft_send_work(struct work_struct *work)
3699d92a	486	{
58fc73d1	487	struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
3699d92a	488	struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
3699d92a	489	struct fcp_cmnd *fcp;
58fc73d1	490	int data_dir = 0;
3699d92a	491	int task_attr;
3699d92a KP	492
	493	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
	494	if (!fcp)
	495	goto err;
	496
	497	if (fcp->fc_flags & FCP_CFL_LEN_MASK)
	498	goto err; /* not handling longer CDBs yet */
	499
3699d92a KP	500	/*
	501	* Check for FCP task management flags
	502	*/
	503	if (fcp->fc_tm_flags) {
	504	ft_send_tm(cmd);
	505	return;
	506	}
0dccb69d AG	507
	508	switch (fcp->fc_flags & (FCP_CFL_RDDATA \| FCP_CFL_WRDATA)) {
	509	case 0:
	510	data_dir = DMA_NONE;
	511	break;
	512	case FCP_CFL_RDDATA:
	513	data_dir = DMA_FROM_DEVICE;
	514	break;
	515	case FCP_CFL_WRDATA:
	516	data_dir = DMA_TO_DEVICE;
	517	break;
	518	case FCP_CFL_WRDATA \| FCP_CFL_RDDATA:
	519	goto err; /* TBD not supported by tcm_fc yet */
	520	}
	521	/*
	522	* Locate the SAM Task Attr from fc_pri_ta
	523	*/
	524	switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
	525	case FCP_PTA_HEADQ:
68d81f40	526	task_attr = TCM_HEAD_TAG;
0dccb69d AG	527	break;
0dccb69d AG	528	case FCP_PTA_ORDERED:
68d81f40	529	task_attr = TCM_ORDERED_TAG;
0dccb69d AG	530	break;
0dccb69d AG	531	case FCP_PTA_ACA:
68d81f40	532	task_attr = TCM_ACA_TAG;
0dccb69d	533	break;
df561f66	534	case FCP_PTA_SIMPLE:
0dccb69d	535	default:
68d81f40	536	task_attr = TCM_SIMPLE_TAG;
0dccb69d AG	537	}
0dccb69d AG	538
f1d61e6e	539	fc_seq_set_resp(cmd->seq, ft_recv_seq, cmd);
649ee054	540	cmd->se_cmd.tag = fc_seq_exch(cmd->seq)->rxid;
47edc84f	541
4355a911 NB	542	/*
	543	* Use a single se_cmd->cmd_kref as we expect to release se_cmd
	544	* directly from ft_check_stop_free callback in response path.
	545	*/
47edc84f MC	546	if (target_init_cmd(&cmd->se_cmd, cmd->sess->se_sess,
	547	&cmd->ft_sense_buffer[0],
	548	scsilun_to_int(&fcp->fc_lun), ntohl(fcp->fc_dl),
	549	task_attr, data_dir, TARGET_SCF_ACK_KREF))
d6dfc868 RD	550	goto err;
d6dfc868 RD	551
47edc84f	552	if (target_submit_prep(&cmd->se_cmd, fcp->fc_cdb, NULL, 0, NULL, 0,
08694199	553	NULL, 0, GFP_KERNEL))
47edc84f MC	554	return;
	555
	556	target_submit(&cmd->se_cmd);
b04bf583	557	pr_debug("r_ctl %x target_submit_cmd %p\n", fh->fh_r_ctl, cmd);
3699d92a KP	558	return;
	559
	560	err:
f2f7b09c	561	ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
3699d92a	562	}