/*
 * zfcp device driver
 *
 * Debug traces for zfcp.
 *
 * Copyright IBM Corp. 2002, 2013
 */

#define KMSG_COMPONENT "zfcp"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/slab.h>
#include <asm/debug.h>
#include "zfcp_dbf.h"
#include "zfcp_ext.h"
#include "zfcp_fc.h"

static u32 dbfsize = 4;

module_param(dbfsize, uint, 0400);
MODULE_PARM_DESC(dbfsize,
                 "number of pages for each debug feature area (default 4)");

static u32 dbflevel = 3;

module_param(dbflevel, uint, 0400);
MODULE_PARM_DESC(dbflevel,
                 "log level for each debug feature area "
                 "(default 3, range 0..6)");

static inline unsigned int zfcp_dbf_plen(unsigned int offset)
{
        return sizeof(struct zfcp_dbf_pay) + offset - ZFCP_DBF_PAY_MAX_REC;
}

static inline
void zfcp_dbf_pl_write(struct zfcp_dbf *dbf, void *data, u16 length, char *area,
                       u64 req_id)
{
        struct zfcp_dbf_pay *pl = &dbf->pay_buf;
        u16 offset = 0, rec_length;

        spin_lock(&dbf->pay_lock);
        memset(pl, 0, sizeof(*pl));
        pl->fsf_req_id = req_id;
        memcpy(pl->area, area, ZFCP_DBF_TAG_LEN);

        while (offset < length) {
                rec_length = min((u16) ZFCP_DBF_PAY_MAX_REC,
                                 (u16) (length - offset));
                memcpy(pl->data, data + offset, rec_length);
                debug_event(dbf->pay, 1, pl, zfcp_dbf_plen(rec_length));

                offset += rec_length;
                pl->counter++;
        }

        spin_unlock(&dbf->pay_lock);
}

/**
 * zfcp_dbf_hba_fsf_res - trace event for fsf responses
 * @tag: tag indicating which kind of unsolicited status has been received
 * @req: request for which a response was received
 */
void zfcp_dbf_hba_fsf_res(char *tag, struct zfcp_fsf_req *req)
{
        struct zfcp_dbf *dbf = req->adapter->dbf;
        struct fsf_qtcb_prefix *q_pref = &req->qtcb->prefix;
        struct fsf_qtcb_header *q_head = &req->qtcb->header;
        struct zfcp_dbf_hba *rec = &dbf->hba_buf;
        unsigned long flags;

        spin_lock_irqsave(&dbf->hba_lock, flags);
        memset(rec, 0, sizeof(*rec));

        memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
        rec->id = ZFCP_DBF_HBA_RES;
        rec->fsf_req_id = req->req_id;
        rec->fsf_req_status = req->status;
        rec->fsf_cmd = req->fsf_command;
        rec->fsf_seq_no = req->seq_no;
        rec->u.res.req_issued = req->issued;
        rec->u.res.prot_status = q_pref->prot_status;
        rec->u.res.fsf_status = q_head->fsf_status;

        memcpy(rec->u.res.prot_status_qual, &q_pref->prot_status_qual,
               FSF_PROT_STATUS_QUAL_SIZE);
        memcpy(rec->u.res.fsf_status_qual, &q_head->fsf_status_qual,
               FSF_STATUS_QUALIFIER_SIZE);

        if (req->fsf_command != FSF_QTCB_FCP_CMND) {
                rec->pl_len = q_head->log_length;
                zfcp_dbf_pl_write(dbf, (char *)q_pref + q_head->log_start,
                                  rec->pl_len, "fsf_res", req->req_id);
        }

        debug_event(dbf->hba, 1, rec, sizeof(*rec));
        spin_unlock_irqrestore(&dbf->hba_lock, flags);
}

/**
 * zfcp_dbf_hba_fsf_uss - trace event for an unsolicited status buffer
 * @tag: tag indicating which kind of unsolicited status has been received
 * @req: request providing the unsolicited status
 */
void zfcp_dbf_hba_fsf_uss(char *tag, struct zfcp_fsf_req *req)
{
        struct zfcp_dbf *dbf = req->adapter->dbf;
        struct fsf_status_read_buffer *srb = req->data;
        struct zfcp_dbf_hba *rec = &dbf->hba_buf;
        unsigned long flags;

        spin_lock_irqsave(&dbf->hba_lock, flags);
        memset(rec, 0, sizeof(*rec));

        memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
        rec->id = ZFCP_DBF_HBA_USS;
        rec->fsf_req_id = req->req_id;
        rec->fsf_req_status = req->status;
        rec->fsf_cmd = req->fsf_command;

        if (!srb)
                goto log;

        rec->u.uss.status_type = srb->status_type;
        rec->u.uss.status_subtype = srb->status_subtype;
        rec->u.uss.d_id = ntoh24(srb->d_id);
        rec->u.uss.lun = srb->fcp_lun;
        memcpy(&rec->u.uss.queue_designator, &srb->queue_designator,
               sizeof(rec->u.uss.queue_designator));

        /* status read buffer payload length */
        rec->pl_len = (!srb->length) ? 0 : srb->length -
                        offsetof(struct fsf_status_read_buffer, payload);

        if (rec->pl_len)
                zfcp_dbf_pl_write(dbf, srb->payload.data, rec->pl_len,
                                  "fsf_uss", req->req_id);
log:
        debug_event(dbf->hba, 2, rec, sizeof(*rec));
        spin_unlock_irqrestore(&dbf->hba_lock, flags);
}

/**
 * zfcp_dbf_hba_bit_err - trace event for bit error conditions
 * @tag: tag indicating which kind of unsolicited status has been received
 * @req: request which caused the bit_error condition
 */
void zfcp_dbf_hba_bit_err(char *tag, struct zfcp_fsf_req *req)
{
        struct zfcp_dbf *dbf = req->adapter->dbf;
        struct zfcp_dbf_hba *rec = &dbf->hba_buf;
        struct fsf_status_read_buffer *sr_buf = req->data;
        unsigned long flags;

        spin_lock_irqsave(&dbf->hba_lock, flags);
        memset(rec, 0, sizeof(*rec));

        memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
        rec->id = ZFCP_DBF_HBA_BIT;
        rec->fsf_req_id = req->req_id;
        rec->fsf_req_status = req->status;
        rec->fsf_cmd = req->fsf_command;
        memcpy(&rec->u.be, &sr_buf->payload.bit_error,
               sizeof(struct fsf_bit_error_payload));

        debug_event(dbf->hba, 1, rec, sizeof(*rec));
        spin_unlock_irqrestore(&dbf->hba_lock, flags);
}

/**
 * zfcp_dbf_hba_def_err - trace event for deferred error messages
 * @adapter: pointer to struct zfcp_adapter
 * @req_id: request id which caused the deferred error message
 * @scount: number of sbals incl. the signaling sbal
 * @pl: array of all involved sbals
 */
void zfcp_dbf_hba_def_err(struct zfcp_adapter *adapter, u64 req_id, u16 scount,
                          void **pl)
{
        struct zfcp_dbf *dbf = adapter->dbf;
        struct zfcp_dbf_pay *payload = &dbf->pay_buf;
        unsigned long flags;
        u16 length;

        if (!pl)
                return;

        spin_lock_irqsave(&dbf->pay_lock, flags);
        memset(payload, 0, sizeof(*payload));

        memcpy(payload->area, "def_err", 7);
        payload->fsf_req_id = req_id;
        payload->counter = 0;
        length = min((u16)sizeof(struct qdio_buffer),
                     (u16)ZFCP_DBF_PAY_MAX_REC);

        while (payload->counter < scount && (char *)pl[payload->counter]) {
                memcpy(payload->data, (char *)pl[payload->counter], length);
                debug_event(dbf->pay, 1, payload, zfcp_dbf_plen(length));
                payload->counter++;
        }

        spin_unlock_irqrestore(&dbf->pay_lock, flags);
}

/**
 * zfcp_dbf_hba_basic - trace event for basic adapter events
 * @adapter: pointer to struct zfcp_adapter
 */
void zfcp_dbf_hba_basic(char *tag, struct zfcp_adapter *adapter)
{
        struct zfcp_dbf *dbf = adapter->dbf;
        struct zfcp_dbf_hba *rec = &dbf->hba_buf;
        unsigned long flags;

        spin_lock_irqsave(&dbf->hba_lock, flags);
        memset(rec, 0, sizeof(*rec));

        memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
        rec->id = ZFCP_DBF_HBA_BASIC;

        debug_event(dbf->hba, 1, rec, sizeof(*rec));
        spin_unlock_irqrestore(&dbf->hba_lock, flags);
}

static void zfcp_dbf_set_common(struct zfcp_dbf_rec *rec,
                                struct zfcp_adapter *adapter,
                                struct zfcp_port *port,
                                struct scsi_device *sdev)
{
        rec->adapter_status = atomic_read(&adapter->status);
        if (port) {
                rec->port_status = atomic_read(&port->status);
                rec->wwpn = port->wwpn;
                rec->d_id = port->d_id;
        }
        if (sdev) {
                rec->lun_status = atomic_read(&sdev_to_zfcp(sdev)->status);
                rec->lun = zfcp_scsi_dev_lun(sdev);
        }
}

/**
 * zfcp_dbf_rec_trig - trace event related to triggered recovery
 * @tag: identifier for event
 * @adapter: adapter on which the erp_action should run
 * @port: remote port involved in the erp_action
 * @sdev: scsi device involved in the erp_action
 * @want: wanted erp_action
 * @need: required erp_action
 *
 * The adapter->erp_lock has to be held.
 */
void zfcp_dbf_rec_trig(char *tag, struct zfcp_adapter *adapter,
                       struct zfcp_port *port, struct scsi_device *sdev,
                       u8 want, u8 need)
{
        struct zfcp_dbf *dbf = adapter->dbf;
        struct zfcp_dbf_rec *rec = &dbf->rec_buf;
        struct list_head *entry;
        unsigned long flags;

        spin_lock_irqsave(&dbf->rec_lock, flags);
        memset(rec, 0, sizeof(*rec));

        rec->id = ZFCP_DBF_REC_TRIG;
        memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
        zfcp_dbf_set_common(rec, adapter, port, sdev);

        list_for_each(entry, &adapter->erp_ready_head)
                rec->u.trig.ready++;

        list_for_each(entry, &adapter->erp_running_head)
                rec->u.trig.running++;

        rec->u.trig.want = want;
        rec->u.trig.need = need;

        debug_event(dbf->rec, 1, rec, sizeof(*rec));
        spin_unlock_irqrestore(&dbf->rec_lock, flags);
}


/**
 * zfcp_dbf_rec_run - trace event related to running recovery
 * @tag: identifier for event
 * @erp: erp_action running
 */
void zfcp_dbf_rec_run(char *tag, struct zfcp_erp_action *erp)
{
        struct zfcp_dbf *dbf = erp->adapter->dbf;
        struct zfcp_dbf_rec *rec = &dbf->rec_buf;
        unsigned long flags;

        spin_lock_irqsave(&dbf->rec_lock, flags);
        memset(rec, 0, sizeof(*rec));

        rec->id = ZFCP_DBF_REC_RUN;
        memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
        zfcp_dbf_set_common(rec, erp->adapter, erp->port, erp->sdev);

        rec->u.run.fsf_req_id = erp->fsf_req_id;
        rec->u.run.rec_status = erp->status;
        rec->u.run.rec_step = erp->step;
        rec->u.run.rec_action = erp->action;

        if (erp->sdev)
                rec->u.run.rec_count =
                        atomic_read(&sdev_to_zfcp(erp->sdev)->erp_counter);
        else if (erp->port)
                rec->u.run.rec_count = atomic_read(&erp->port->erp_counter);
        else
                rec->u.run.rec_count = atomic_read(&erp->adapter->erp_counter);

        debug_event(dbf->rec, 1, rec, sizeof(*rec));
        spin_unlock_irqrestore(&dbf->rec_lock, flags);
}

static inline
void zfcp_dbf_san(char *tag, struct zfcp_dbf *dbf, void *data, u8 id, u16 len,
                  u64 req_id, u32 d_id)
{
        struct zfcp_dbf_san *rec = &dbf->san_buf;
        u16 rec_len;
        unsigned long flags;

        spin_lock_irqsave(&dbf->san_lock, flags);
        memset(rec, 0, sizeof(*rec));

        rec->id = id;
        rec->fsf_req_id = req_id;
        rec->d_id = d_id;
        rec_len = min(len, (u16)ZFCP_DBF_SAN_MAX_PAYLOAD);
        memcpy(rec->payload, data, rec_len);
        memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);

        debug_event(dbf->san, 1, rec, sizeof(*rec));
        spin_unlock_irqrestore(&dbf->san_lock, flags);
}

/**
 * zfcp_dbf_san_req - trace event for issued SAN request
 * @tag: identifier for event
 * @fsf_req: request containing issued CT data
 * d_id: destination ID
 */
void zfcp_dbf_san_req(char *tag, struct zfcp_fsf_req *fsf, u32 d_id)
{
        struct zfcp_dbf *dbf = fsf->adapter->dbf;
        struct zfcp_fsf_ct_els *ct_els = fsf->data;
        u16 length;

        length = (u16)(ct_els->req->length + FC_CT_HDR_LEN);
        zfcp_dbf_san(tag, dbf, sg_virt(ct_els->req), ZFCP_DBF_SAN_REQ, length,
                     fsf->req_id, d_id);
}

/**
 * zfcp_dbf_san_res - trace event for received SAN request
 * @tag: identifier for event
 * @fsf_req: request containing issued CT data
 */
void zfcp_dbf_san_res(char *tag, struct zfcp_fsf_req *fsf)
{
        struct zfcp_dbf *dbf = fsf->adapter->dbf;
        struct zfcp_fsf_ct_els *ct_els = fsf->data;
        u16 length;

        length = (u16)(ct_els->resp->length + FC_CT_HDR_LEN);
        zfcp_dbf_san(tag, dbf, sg_virt(ct_els->resp), ZFCP_DBF_SAN_RES, length,
                     fsf->req_id, 0);
}

/**
 * zfcp_dbf_san_in_els - trace event for incoming ELS
 * @tag: identifier for event
 * @fsf_req: request containing issued CT data
 */
void zfcp_dbf_san_in_els(char *tag, struct zfcp_fsf_req *fsf)
{
        struct zfcp_dbf *dbf = fsf->adapter->dbf;
        struct fsf_status_read_buffer *srb =
                (struct fsf_status_read_buffer *) fsf->data;
        u16 length;

        length = (u16)(srb->length -
                        offsetof(struct fsf_status_read_buffer, payload));
        zfcp_dbf_san(tag, dbf, srb->payload.data, ZFCP_DBF_SAN_ELS, length,
                     fsf->req_id, ntoh24(srb->d_id));
}

/**
 * zfcp_dbf_scsi - trace event for scsi commands
 * @tag: identifier for event
 * @sc: pointer to struct scsi_cmnd
 * @fsf: pointer to struct zfcp_fsf_req
 */
void zfcp_dbf_scsi(char *tag, struct scsi_cmnd *sc, struct zfcp_fsf_req *fsf)
{
        struct zfcp_adapter *adapter =
                (struct zfcp_adapter *) sc->device->host->hostdata[0];
        struct zfcp_dbf *dbf = adapter->dbf;
        struct zfcp_dbf_scsi *rec = &dbf->scsi_buf;
        struct fcp_resp_with_ext *fcp_rsp;
        struct fcp_resp_rsp_info *fcp_rsp_info;
        unsigned long flags;

        spin_lock_irqsave(&dbf->scsi_lock, flags);
        memset(rec, 0, sizeof(*rec));

        memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
        rec->id = ZFCP_DBF_SCSI_CMND;
        rec->scsi_result = sc->result;
        rec->scsi_retries = sc->retries;
        rec->scsi_allowed = sc->allowed;
        rec->scsi_id = sc->device->id;
        /* struct zfcp_dbf_scsi needs to be updated to handle 64bit LUNs */
        rec->scsi_lun = (u32)sc->device->lun;
        rec->host_scribble = (unsigned long)sc->host_scribble;

        memcpy(rec->scsi_opcode, sc->cmnd,
               min((int)sc->cmd_len, ZFCP_DBF_SCSI_OPCODE));

        if (fsf) {
                rec->fsf_req_id = fsf->req_id;
                fcp_rsp = (struct fcp_resp_with_ext *)
                                &(fsf->qtcb->bottom.io.fcp_rsp);
                memcpy(&rec->fcp_rsp, fcp_rsp, FCP_RESP_WITH_EXT);
                if (fcp_rsp->resp.fr_flags & FCP_RSP_LEN_VAL) {
                        fcp_rsp_info = (struct fcp_resp_rsp_info *) &fcp_rsp[1];
                        rec->fcp_rsp_info = fcp_rsp_info->rsp_code;
                }
                if (fcp_rsp->resp.fr_flags & FCP_SNS_LEN_VAL) {
                        rec->pl_len = min((u16)SCSI_SENSE_BUFFERSIZE,
                                          (u16)ZFCP_DBF_PAY_MAX_REC);
                        zfcp_dbf_pl_write(dbf, sc->sense_buffer, rec->pl_len,
                                          "fcp_sns", fsf->req_id);
                }
        }

        debug_event(dbf->scsi, 1, rec, sizeof(*rec));
        spin_unlock_irqrestore(&dbf->scsi_lock, flags);
}

static debug_info_t *zfcp_dbf_reg(const char *name, int size, int rec_size)
{
        struct debug_info *d;

        d = debug_register(name, size, 1, rec_size);
        if (!d)
                return NULL;

        debug_register_view(d, &debug_hex_ascii_view);
        debug_set_level(d, dbflevel);

        return d;
}

static void zfcp_dbf_unregister(struct zfcp_dbf *dbf)
{
        if (!dbf)
                return;

        debug_unregister(dbf->scsi);
        debug_unregister(dbf->san);
        debug_unregister(dbf->hba);
        debug_unregister(dbf->pay);
        debug_unregister(dbf->rec);
        kfree(dbf);
}

/**
 * zfcp_adapter_debug_register - registers debug feature for an adapter
 * @adapter: pointer to adapter for which debug features should be registered
 * return: -ENOMEM on error, 0 otherwise
 */
int zfcp_dbf_adapter_register(struct zfcp_adapter *adapter)
{
        char name[DEBUG_MAX_NAME_LEN];
        struct zfcp_dbf *dbf;

        dbf = kzalloc(sizeof(struct zfcp_dbf), GFP_KERNEL);
        if (!dbf)
                return -ENOMEM;

        spin_lock_init(&dbf->pay_lock);
        spin_lock_init(&dbf->hba_lock);
        spin_lock_init(&dbf->san_lock);
        spin_lock_init(&dbf->scsi_lock);
        spin_lock_init(&dbf->rec_lock);

        /* debug feature area which records recovery activity */
        sprintf(name, "zfcp_%s_rec", dev_name(&adapter->ccw_device->dev));
        dbf->rec = zfcp_dbf_reg(name, dbfsize, sizeof(struct zfcp_dbf_rec));
        if (!dbf->rec)
                goto err_out;

        /* debug feature area which records HBA (FSF and QDIO) conditions */
        sprintf(name, "zfcp_%s_hba", dev_name(&adapter->ccw_device->dev));
        dbf->hba = zfcp_dbf_reg(name, dbfsize, sizeof(struct zfcp_dbf_hba));
        if (!dbf->hba)
                goto err_out;

        /* debug feature area which records payload info */
        sprintf(name, "zfcp_%s_pay", dev_name(&adapter->ccw_device->dev));
        dbf->pay = zfcp_dbf_reg(name, dbfsize * 2, sizeof(struct zfcp_dbf_pay));
        if (!dbf->pay)
                goto err_out;

        /* debug feature area which records SAN command failures and recovery */
        sprintf(name, "zfcp_%s_san", dev_name(&adapter->ccw_device->dev));
        dbf->san = zfcp_dbf_reg(name, dbfsize, sizeof(struct zfcp_dbf_san));
        if (!dbf->san)
                goto err_out;

        /* debug feature area which records SCSI command failures and recovery */
        sprintf(name, "zfcp_%s_scsi", dev_name(&adapter->ccw_device->dev));
        dbf->scsi = zfcp_dbf_reg(name, dbfsize, sizeof(struct zfcp_dbf_scsi));
        if (!dbf->scsi)
                goto err_out;

        adapter->dbf = dbf;

        return 0;
err_out:
        zfcp_dbf_unregister(dbf);
        return -ENOMEM;
}

/**
 * zfcp_adapter_debug_unregister - unregisters debug feature for an adapter
 * @adapter: pointer to adapter for which debug features should be unregistered
 */
void zfcp_dbf_adapter_unregister(struct zfcp_adapter *adapter)
{
        struct zfcp_dbf *dbf = adapter->dbf;

        adapter->dbf = NULL;
        zfcp_dbf_unregister(dbf);
}