--- /dev/null
+/*
+ * 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.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_cmnd.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 <target/target_core_configfs.h>
+#include <target/configfs_macros.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 fc_lport *lport;
+ struct ft_sess *sess;
+
+ if (!cmd)
+ return;
+ sess = cmd->sess;
+ fp = cmd->req_frame;
+ lport = fr_dev(fp);
+ if (fr_seq(fp))
+ lport->tt.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)
+{
+ transport_generic_free_cmd(se_cmd, 0);
+ return 1;
+}
+
+/*
+ * 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 = lport->tt.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 = lport->tt.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;
+ }
+ lport->tt.exch_done(cmd->seq);
+ 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 = lport->tt.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;
+ }
+ }
+ lport->tt.seq_send(lport, cmd->seq, fp);
+ return 0;
+}
+
+u32 ft_get_task_tag(struct se_cmd *se_cmd)
+{
+ struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
+
+ if (cmd->aborted)
+ return ~0;
+ return fc_seq_exch(cmd->seq)->rxid;
+}
+
+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 (unlikely(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) {
+ lport->tt.seq_send(lport, sp, fp);
+ lport->tt.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, 0);
+ 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);
+}
+
+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 = lport->tt.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_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
+ /*
+ * 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, 0))
+ goto err;
+
+ pr_debug("r_ctl %x alloc target_submit_cmd\n", fh->fh_r_ctl);
+ return;
+
+err:
+ ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
+}
Code Review / kvmfornfv.git / blobdiff