[SCSI] libfc, fcoe: Add FC passthrough support

This is the Open-FCoE implementation of the FC
passthrough support via bsg interface.

Passthrough support is added to both N_Ports and
VN_Ports.

Signed-off-by: Steve Ma <steve.ma@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

2 files changed, 271 insertions, 0 deletions

diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index f1c126b798af..8f078d306a0a 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -134,6 +134,8 @@ struct fc_function_template fcoe_transport_function = {
         .vport_delete = fcoe_vport_destroy,
         .vport_disable = fcoe_vport_disable,
         .set_vport_symbolic_name = fcoe_set_vport_symbolic_name,
+
+        .bsg_request = fc_lport_bsg_request,
 };
 
 struct fc_function_template fcoe_vport_transport_function = {
@@ -167,6 +169,8 @@ struct fc_function_template fcoe_vport_transport_function = {
         .issue_fc_host_lip = fcoe_reset,
 
         .terminate_rport_io = fc_rport_terminate_io,
+
+        .bsg_request = fc_lport_bsg_request,
 };
 
 static struct scsi_host_template fcoe_shost_template = {
diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
index dfea6c572dfb..2162e6b0f43e 100644
--- a/drivers/scsi/libfc/fc_lport.c
+++ b/drivers/scsi/libfc/fc_lport.c
@@ -94,6 +94,7 @@
 
 #include <scsi/libfc.h>
 #include <scsi/fc_encode.h>
+#include <linux/scatterlist.h>
 
 #include "fc_libfc.h"
 
@@ -127,6 +128,24 @@ static const char *fc_lport_state_names[] = {
         [LPORT_ST_RESET] =    "reset",
 };
 
+/**
+ * struct fc_bsg_info - FC Passthrough managemet structure
+ * @job:      The passthrough job
+ * @lport:    The local port to pass through a command
+ * @rsp_code: The expected response code
+ * @sg:       job->reply_payload.sg_list
+ * @nents:    job->reply_payload.sg_cnt
+ * @offset:   The offset into the response data
+ */
+struct fc_bsg_info {
+        struct fc_bsg_job *job;
+        struct fc_lport *lport;
+        u16 rsp_code;
+        struct scatterlist *sg;
+        u32 nents;
+        size_t offset;
+};
+
 static int fc_frame_drop(struct fc_lport *lport, struct fc_frame *fp)
 {
         fc_frame_free(fp);
@@ -1512,3 +1531,251 @@ int fc_lport_init(struct fc_lport *lport)
         return 0;
 }
 EXPORT_SYMBOL(fc_lport_init);
+
+/**
+ * fc_lport_bsg_resp() - The common response handler for fc pass-thru requests
+ * @sp: current sequence in the fc pass-thru request exchange
+ * @fp: received response frame
+ * @info_arg: pointer to struct fc_bsg_info
+ */
+static void fc_lport_bsg_resp(struct fc_seq *sp, struct fc_frame *fp,
+                              void *info_arg)
+{
+        struct fc_bsg_info *info = info_arg;
+        struct fc_bsg_job *job = info->job;
+        struct fc_lport *lport = info->lport;
+        struct fc_frame_header *fh;
+        size_t len;
+        void *buf;
+
+        if (IS_ERR(fp)) {
+                job->reply->result = (PTR_ERR(fp) == -FC_EX_CLOSED) ?
+                        -ECONNABORTED : -ETIMEDOUT;
+                job->reply_len = sizeof(uint32_t);
+                job->state_flags |= FC_RQST_STATE_DONE;
+                job->job_done(job);
+                kfree(info);
+                return;
+        }
+
+        mutex_lock(&lport->lp_mutex);
+        fh = fc_frame_header_get(fp);
+        len = fr_len(fp) - sizeof(*fh);
+        buf = fc_frame_payload_get(fp, 0);
+
+        if (fr_sof(fp) == FC_SOF_I3 && !ntohs(fh->fh_seq_cnt)) {
+                /* Get the response code from the first frame payload */
+                unsigned short cmd = (info->rsp_code == FC_FS_ACC) ?
+                        ntohs(((struct fc_ct_hdr *)buf)->ct_cmd) :
+                        (unsigned short)fc_frame_payload_op(fp);
+
+                /* Save the reply status of the job */
+                job->reply->reply_data.ctels_reply.status =
+                        (cmd == info->rsp_code) ?
+                        FC_CTELS_STATUS_OK : FC_CTELS_STATUS_REJECT;
+        }
+
+        job->reply->reply_payload_rcv_len +=
+                fc_copy_buffer_to_sglist(buf, len, info->sg, &info->nents,
+                                         &info->offset, KM_BIO_SRC_IRQ, NULL);
+
+        if (fr_eof(fp) == FC_EOF_T &&
+            (ntoh24(fh->fh_f_ctl) & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
+            (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
+                if (job->reply->reply_payload_rcv_len >
+                    job->reply_payload.payload_len)
+                        job->reply->reply_payload_rcv_len =
+                                job->reply_payload.payload_len;
+                job->reply->result = 0;
+                job->state_flags |= FC_RQST_STATE_DONE;
+                job->job_done(job);
+                kfree(info);
+        }
+        fc_frame_free(fp);
+        mutex_unlock(&lport->lp_mutex);
+}
+
+/**
+ * fc_lport_els_request() - Send ELS pass-thru request
+ * @job: The bsg fc pass-thru job structure
+ * @lport: The local port sending the request
+ * @did: The destination port id.
+ *
+ * Locking Note: The lport lock is expected to be held before calling
+ * this routine.
+ */
+static int fc_lport_els_request(struct fc_bsg_job *job,
+                                struct fc_lport *lport,
+                                u32 did, u32 tov)
+{
+        struct fc_bsg_info *info;
+        struct fc_frame *fp;
+        struct fc_frame_header *fh;
+        char *pp;
+        int len;
+
+        fp = fc_frame_alloc(lport, sizeof(struct fc_frame_header) +
+                            job->request_payload.payload_len);
+        if (!fp)
+                return -ENOMEM;
+
+        len = job->request_payload.payload_len;
+        pp = fc_frame_payload_get(fp, len);
+
+        sg_copy_to_buffer(job->request_payload.sg_list,
+                          job->request_payload.sg_cnt,
+                          pp, len);
+
+        fh = fc_frame_header_get(fp);
+        fh->fh_r_ctl = FC_RCTL_ELS_REQ;
+        hton24(fh->fh_d_id, did);
+        hton24(fh->fh_s_id, fc_host_port_id(lport->host));
+        fh->fh_type = FC_TYPE_ELS;
+        hton24(fh->fh_f_ctl, FC_FC_FIRST_SEQ |
+               FC_FC_END_SEQ | FC_FC_SEQ_INIT);
+        fh->fh_cs_ctl = 0;
+        fh->fh_df_ctl = 0;
+        fh->fh_parm_offset = 0;
+
+        info = kzalloc(sizeof(struct fc_bsg_info), GFP_KERNEL);
+        if (!info) {
+                fc_frame_free(fp);
+                return -ENOMEM;
+        }
+
+        info->job = job;
+        info->lport = lport;
+        info->rsp_code = ELS_LS_ACC;
+        info->nents = job->reply_payload.sg_cnt;
+        info->sg = job->reply_payload.sg_list;
+
+        if (!lport->tt.exch_seq_send(lport, fp, fc_lport_bsg_resp,
+                                     NULL, info, tov))
+                return -ECOMM;
+        return 0;
+}
+
+/**
+ * fc_lport_ct_request() - Send CT pass-thru request
+ * @job:   The bsg fc pass-thru job structure
+ * @lport: The local port sending the request
+ * @did:   The destination FC-ID
+ * @tov:   The time to wait for a response
+ *
+ * Locking Note: The lport lock is expected to be held before calling
+ * this routine.
+ */
+static int fc_lport_ct_request(struct fc_bsg_job *job,
+                               struct fc_lport *lport, u32 did, u32 tov)
+{
+        struct fc_bsg_info *info;
+        struct fc_frame *fp;
+        struct fc_frame_header *fh;
+        struct fc_ct_req *ct;
+        size_t len;
+
+        fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
+                            job->request_payload.payload_len);
+        if (!fp)
+                return -ENOMEM;
+
+        len = job->request_payload.payload_len;
+        ct = fc_frame_payload_get(fp, len);
+
+        sg_copy_to_buffer(job->request_payload.sg_list,
+                          job->request_payload.sg_cnt,
+                          ct, len);
+
+        fh = fc_frame_header_get(fp);
+        fh->fh_r_ctl = FC_RCTL_DD_UNSOL_CTL;
+        hton24(fh->fh_d_id, did);
+        hton24(fh->fh_s_id, fc_host_port_id(lport->host));
+        fh->fh_type = FC_TYPE_CT;
+        hton24(fh->fh_f_ctl, FC_FC_FIRST_SEQ |
+               FC_FC_END_SEQ | FC_FC_SEQ_INIT);
+        fh->fh_cs_ctl = 0;
+        fh->fh_df_ctl = 0;
+        fh->fh_parm_offset = 0;
+
+        info = kzalloc(sizeof(struct fc_bsg_info), GFP_KERNEL);
+        if (!info) {
+                fc_frame_free(fp);
+                return -ENOMEM;
+        }
+
+        info->job = job;
+        info->lport = lport;
+        info->rsp_code = FC_FS_ACC;
+        info->nents = job->reply_payload.sg_cnt;
+        info->sg = job->reply_payload.sg_list;
+
+        if (!lport->tt.exch_seq_send(lport, fp, fc_lport_bsg_resp,
+                                     NULL, info, tov))
+                return -ECOMM;
+        return 0;
+}
+
+/**
+ * fc_lport_bsg_request() - The common entry point for sending
+ *                          fc pass-thru requests
+ * @job: The fc pass-thru job structure
+ */
+int fc_lport_bsg_request(struct fc_bsg_job *job)
+{
+        struct request *rsp = job->req->next_rq;
+        struct Scsi_Host *shost = job->shost;
+        struct fc_lport *lport = shost_priv(shost);
+        struct fc_rport *rport;
+        struct fc_rport_priv *rdata;
+        int rc = -EINVAL;
+        u32 did;
+
+        job->reply->reply_payload_rcv_len = 0;
+        rsp->resid_len = job->reply_payload.payload_len;
+
+        mutex_lock(&lport->lp_mutex);
+
+        switch (job->request->msgcode) {
+        case FC_BSG_RPT_ELS:
+                rport = job->rport;
+                if (!rport)
+                        break;
+
+                rdata = rport->dd_data;
+                rc = fc_lport_els_request(job, lport, rport->port_id,
+                                          rdata->e_d_tov);
+                break;
+
+        case FC_BSG_RPT_CT:
+                rport = job->rport;
+                if (!rport)
+                        break;
+
+                rdata = rport->dd_data;
+                rc = fc_lport_ct_request(job, lport, rport->port_id,
+                                         rdata->e_d_tov);
+                break;
+
+        case FC_BSG_HST_CT:
+                did = ntoh24(job->request->rqst_data.h_ct.port_id);
+                if (did == FC_FID_DIR_SERV)
+                        rdata = lport->dns_rp;
+                else
+                        rdata = lport->tt.rport_lookup(lport, did);
+
+                if (!rdata)
+                        break;
+
+                rc = fc_lport_ct_request(job, lport, did, rdata->e_d_tov);
+                break;
+
+        case FC_BSG_HST_ELS_NOLOGIN:
+                did = ntoh24(job->request->rqst_data.h_els.port_id);
+                rc = fc_lport_els_request(job, lport, did, lport->e_d_tov);
+                break;
+        }
+
+        mutex_unlock(&lport->lp_mutex);
+        return rc;
+}
+EXPORT_SYMBOL(fc_lport_bsg_request);