/*
* Copyright (c) 2010 Cisco Systems, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* 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 <linux/percpu_ida.h>
#include <asm/unaligned.h>
#include <scsi/scsi_tcq.h>
#include <scsi/libfc.h>
#include <scsi/fc_encode.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);
percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
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;
}
int ft_write_pending_status(struct se_cmd *se_cmd)
{
struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
return cmd->write_data_len != se_cmd->data_length;
}
/*
* 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;
tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
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->sess = sess;
cmd->seq = fc_seq_assign(lport, fp);
if (!cmd->seq) {
percpu_ida_free(&se_sess->sess_tag_pool, tag);
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: /* Fallthrough */
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_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, fcp->fc_cdb,
&cmd->ft_sense_buffer[0], scsilun_to_int(&fcp->fc_lun),
ntohl(fcp->fc_dl), task_attr, data_dir,
TARGET_SCF_ACK_KREF | TARGET_SCF_USE_CPUID))
goto err;
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);
}
