Abort and Reset Management

The following sections discuss the abort and reset entry points for SCSI HBA.

tran_abort() Entry Point

The tran_abort(9E) entry point for a SCSI HBA driver is called to abort any commands that are currently in transport for a particular target. This entry point is called when a target driver calls scsi_abort(9F).

The tran_abort() entry point should attempt to abort the command denoted by the pkt parameter. If the pkt parameter is NULL, tran_abort() should attempt to abort all outstanding commands in the transport layer for the particular target or logical unit.

Each command successfully aborted must be marked with pkt_reason CMD_ABORTED and pkt_statistics OR'd with STAT_ABORTED.

tran_reset() Entry Point

The tran_reset(9E) entry point for a SCSI HBA driver is called to reset either the SCSI bus or a particular SCSI target device. This entry point is called when a target driver calls scsi_reset(9F).

The tran_reset() entry point must reset the SCSI bus if level is RESET_ALL. If level is RESET_TARGET, just the particular target or logical unit must be reset.

Active commands affected by the reset must be marked with pkt_reason CMD_RESET. The type of reset determines whether STAT_BUS_RESET or STAT_DEV_RESET should be used to OR pkt_statistics.

Commands in the transport layer, but not yet active on the target, must be marked with pkt_reason CMD_RESET, and pkt_statistics OR'd with STAT_ABORTED.

tran_bus_reset() Entry Point

tran_bus_reset(9E) must reset the SCSI bus without resetting targets.

#include <sys/scsi/scsi.h>

int tran_bus_reset(dev_info_t *hba-dip, int level);

where:

*hba-dip

Pointer associated with the SCSI HBA

level

Must be set to RESET_BUS so that only the SCSI bus is reset, not the targets

The tran_bus_reset() vector in the scsi_hba_tran(9S) structure should be initialized during the HBA driver's attach(9E). The vector should point to an HBA entry point that is to be called when a user initiates a bus reset.

Implementation is hardware specific. If the HBA driver cannot reset the SCSI bus without affecting the targets, the driver should fail RESET_BUS or not initialize this vector.

tran_reset_notify() Entry Point

Use the tran_reset_notify(9E) entry point when a SCSI bus reset occurs. This function requests the SCSI HBA driver to notify the target driver by callback.

Example 18–12 HBA Driver tran_reset_notify(9E) Entry Point

isp_scsi_reset_notify(
    struct scsi_address    *ap,
    int                    flag,
    void                   (*callback)(caddr_t),
    caddr_t                arg)
{
    struct isp                       *isp;
    struct isp_reset_notify_entry    *p, *beforep;
    int                              rval = DDI_FAILURE;

    isp = (struct isp *)ap->a_hba_tran->tran_hba_private;
    mutex_enter(ISP_REQ_MUTEX(isp));
    /*
     * Try to find an existing entry for this target
     */
    p = isp->isp_reset_notify_listf;
    beforep = NULL;

    while (p) {
        if (p->ap == ap)
            break;
        beforep = p;
        p = p->next;
    }

    if ((flag & SCSI_RESET_CANCEL) && (p != NULL)) {
        if (beforep == NULL) {
            isp->isp_reset_notify_listf = p->next;
        } else {
            beforep->next = p->next;
        }
        kmem_free((caddr_t)p, sizeof (struct isp_reset_notify_entry));
        rval = DDI_SUCCESS;
    } else if ((flag & SCSI_RESET_NOTIFY) && (p == NULL)) {
        p = kmem_zalloc(sizeof (struct isp_reset_notify_entry),
          KM_SLEEP);
        p->ap = ap;
        p->callback = callback;
        p->arg = arg;
        p->next = isp->isp_reset_notify_listf;
        isp->isp_reset_notify_listf = p;
        rval = DDI_SUCCESS;
    }
    mutex_exit(ISP_REQ_MUTEX(isp));
    return (rval);
}