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Fix Fibre Channel Command Reference Number handling in the isp(4) driver.

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The Command Reference Number is used for precise delivery of
commands, and is part of the FC-Tape functionality set.  (This is
only enabled for devices that support precise delivery of commands.)
It is an 8-bit unsigned number that increments from 1 to 255.  The
commands sent by the initiator must be processed by the target in
CRN order if the CRN is non-zero.

There are certain scenarios where the Command Reference Number
sequence needs to be reset.  When the target is power cycled, for
instance, the initiator needs to reset the CRN to 1.  The initiator
will know this because it will see a LIP (when directly connected)
or get a logout/login event (when connected to a switch).

The isp(4) driver was not resetting the CRN when a target
went away and came back.  When it saw the target again after a
power cycle, it would continue the CRN sequence where it left off.
The target would ignore the command because the CRN sequence is
supposed to be reset to 1 after a power cycle or other similar
event.

The symptom that the user would see is that there would be lots of
aborted INQUIRY commands after a tape library was power cycled, and
the library would fail to probe.  The INQUIRY commands were being
ignored by the tape drive due to the CRN issue mentioned above.

isp_freebsd.c:
	Add a new function, isp_fcp_reset_crn().  This will reset
	all of the CRNs for a given port, or the CRNs for all LUNs
	on a target.

	Reset the CRNs for all targets on a port when we get a LIP,
	loop reset, or loop down event.

	Reset the CRN for a particular target when it arrives, is changed
	or departs.  This is less precise behavior than the
	clearing behavior specified in the FCP-4 spec (which says
	that it should be reset for PRLI, PRLO, PLOGI and LOGO),
	but this is the level of information we have here.  If this
	is insufficient, then we will need to add more precise
	notification from the lower level isp(4) code.

isp_freebsd.h:
	Add a prototype for isp_fcp_reset_crn().

Sponsored by:	Spectra Logic
MFC after:	1 week
This commit is contained in:
Kenneth D. Merry 2015-01-08 17:41:28 +00:00
parent bfffbac603
commit fb4a43562a
2 changed files with 34 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
sys/dev/isp/isp_freebsd.c
View File

@ -5696,6 +5696,8 @@ isp_async(ispsoftc_t *isp, ispasync_t cmd, ...)
}
}
}
isp_fcp_reset_crn(fc, /*tgt*/0, /*tgt_set*/ 0);
isp_prt(isp, ISP_LOGINFO, "Chan %d: %s", bus, msg);
break;
}
@ -5747,6 +5749,7 @@ isp_async(ispsoftc_t *isp, ispasync_t cmd, ...)
if (lp->dev_map_idx) {
tgt = lp->dev_map_idx - 1;
isp_prt(isp, ISP_LOGCONFIG, prom2, bus, lp->portid, lp->handle, buf, "arrived at", tgt, (uint32_t) (lp->port_wwn >> 32), (uint32_t) lp->port_wwn);
isp_fcp_reset_crn(fc, tgt, /*tgt_set*/ 1);
isp_make_here(isp, bus, tgt);
} else {
isp_prt(isp, ISP_LOGCONFIG, prom0, bus, lp->portid, lp->handle, buf, "arrived", (uint32_t) (lp->port_wwn >> 32), (uint32_t) lp->port_wwn);
@ -5783,6 +5786,7 @@ isp_async(ispsoftc_t *isp, ispasync_t cmd, ...)
tgt = lp->dev_map_idx - 1;
isp_prt(isp, ISP_LOGCONFIG, prom2, bus, lp->portid, lp->handle, buf, "changed at", tgt,
(uint32_t) (lp->port_wwn >> 32), (uint32_t) lp->port_wwn);
isp_fcp_reset_crn(fc, tgt, /*tgt_set*/ 1);
} else {
isp_prt(isp, ISP_LOGCONFIG, prom0, bus, lp->portid, lp->handle, buf, "changed", (uint32_t) (lp->port_wwn >> 32), (uint32_t) lp->port_wwn);
}
@ -5795,6 +5799,7 @@ isp_async(ispsoftc_t *isp, ispasync_t cmd, ...)
va_end(ap);
isp_gen_role_str(buf, sizeof (buf), lp->prli_word3);
if (lp->dev_map_idx) {
fc = ISP_FC_PC(isp, bus);
tgt = lp->dev_map_idx - 1;
isp_prt(isp, ISP_LOGCONFIG, prom2, bus, lp->portid, lp->handle, buf, "stayed at", tgt,
(uint32_t) (lp->port_wwn >> 32), (uint32_t) lp->port_wwn);
@ -5829,6 +5834,7 @@ isp_async(ispsoftc_t *isp, ispasync_t cmd, ...)
}
tgt = lp->dev_map_idx - 1;
isp_prt(isp, ISP_LOGCONFIG, prom2, bus, lp->portid, lp->handle, buf, "gone zombie at", tgt, (uint32_t) (lp->port_wwn >> 32), (uint32_t) lp->port_wwn);
isp_fcp_reset_crn(fc, tgt, /*tgt_set*/ 1);
} else if (lp->announced == 0) {
isp_prt(isp, ISP_LOGCONFIG, prom0, bus, lp->portid, lp->handle, buf, "departed", (uint32_t) (lp->port_wwn >> 32), (uint32_t) lp->port_wwn);
}
@ -6377,6 +6383,33 @@ isp_common_dmateardown(ispsoftc_t *isp, struct ccb_scsiio *csio, uint32_t hdl)
bus_dmamap_unload(isp->isp_osinfo.dmat, PISP_PCMD(csio)->dmap);
}
/*
* Reset the command reference number for all LUNs on a specific target
* (needed when a target arrives again) or for all targets on a port
* (needed for events like a LIP).
*/
void
isp_fcp_reset_crn(struct isp_fc *fc, uint32_t tgt, int tgt_set)
{
int i;
struct isp_nexus *nxp;
if (tgt_set == 0)
isp_prt(fc->isp, ISP_LOG_SANCFG, "resetting CRN on all targets");
else
isp_prt(fc->isp, ISP_LOG_SANCFG, "resetting CRN target %u", tgt);
for (i = 0; i < NEXUS_HASH_WIDTH; i++) {
nxp = fc->nexus_hash[i];
while (nxp) {
if ((tgt_set != 0) && (tgt == nxp->tgt))
nxp->crnseed = 0;
nxp = nxp->next;
}
}
}
int
isp_fcp_next_crn(ispsoftc_t *isp, uint8_t *crnp, XS_T *cmd)
{

1
sys/dev/isp/isp_freebsd.h
View File

@ -754,6 +754,7 @@ int isp_fc_scratch_acquire(ispsoftc_t *, int);
int isp_mstohz(int);
void isp_platform_intr(void *);
void isp_common_dmateardown(ispsoftc_t *, struct ccb_scsiio *, uint32_t);
void isp_fcp_reset_crn(struct isp_fc *, uint32_t, int);
int isp_fcp_next_crn(ispsoftc_t *, uint8_t *, XS_T *);
/*