Commit Graph

46 Commits

Author SHA1 Message Date
Alexander Motin
bae3729be4 Do not retry long ready waits if previous gave nothing.
I have some disks reporting "Logical unit is in process of becoming ready"
for about half an hour before finally reporting failure.  During that time
CAM waits for the readiness during ~2 minutes for each request, that makes
system boot take very long time.

This change reduces wait times for the following requests to ~1 second if
previously long wait for that device has timed out.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
2019-11-22 21:31:59 +00:00
Conrad Meyer
e2e050c8ef Extract eventfilter declarations to sys/_eventfilter.h
This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h"
in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header
pollution substantially.

EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c
files into appropriate headers (e.g., sys/proc.h, powernv/opal.h).

As a side effect of reduced header pollution, many .c files and headers no
longer contain needed definitions.  The remainder of the patch addresses
adding appropriate includes to fix those files.

LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by
sys/mutex.h since r326106 (but silently protected by header pollution prior
to this change).

No functional change (intended).  Of course, any out of tree modules that
relied on header pollution for sys/eventhandler.h, sys/lock.h, or
sys/mutex.h inclusion need to be fixed.  __FreeBSD_version has been bumped.
2019-05-20 00:38:23 +00:00
Alexander Motin
b059686a71 Do not map small IOCTL buffers to KVA, but copy.
CAM IOCTL interfaces traditionally mapped user-space data buffers to KVA.
It was nice originally, but now it takes too much to handle respective
TLB shootdowns, while small kernel memory allocations up to 64KB backed
by UMA and accompanied by copyin()/copyout() can be much cheaper.

For large buffers mapping still may have sense, and unmapped I/O would
be even better, but the last unfortunately is more tricky, since unmapped
I/O API is too specific to struct bio now.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.
2019-03-28 20:41:02 +00:00
Warner Losh
d38677d23c Create a sysctl kern.cam.{,a,n}da.X.invalidate
kern.cam.{,a,n}da.X.invalidate=1 forces *daX to detach by calling
cam_periph_invalidate on the underlying periph. This is for testing
purposes only. Include only with options CAM_TEST_FAILURE and rename
the former [AN]DA_TEST_FAILURE, and fix nda to compile with it set.
We're using it at work to harden geom and the buffer cache to be
resilient in the face of drive failure. Today, it far too often
results in a panic. While much work was done on SIM initiated removal
for the USB thumnb drive removal work, little has been done for periph
initiated removal. This simulates what *daerror() does for some errors
nicely: we get the same panics with it that we do with failing drives.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D14581
2018-03-14 17:53:37 +00:00
Scott Long
99e7a4ad9e Return a C errno for cam_periph_acquire().
There's no compelling reason to return a cam_status type for this
function and doing so only creates confusion with normal C
coding practices. It's technically an API change, but the periph API
isn't widely used. No efffective change to operation.

Reviewed by:	imp, mav, ken
Sponsored by:	Netflix
Differential Revision:	D14063
2018-02-06 06:42:25 +00:00
Scott Long
15747cacb4 Move CAM_PERIPH_PRINT() to cam_periph.h 2018-01-26 23:56:07 +00:00
Scott Long
329e7a8b51 Protect against a possible NULL deference from an accessor
function.

Obtained from:	Netflix
2018-01-09 00:00:55 +00:00
Warner Losh
553484ae07 Remove unused 4th argument to match the standard error routines.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D13386
2017-12-06 00:29:50 +00:00
Pedro F. Giffuni
bec9534d1d sys/cam: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 15:12:43 +00:00
Alexander Motin
94173c3c9b Add mechanism to unload CAM periph drivers.
For now it allows to unload CTL kernel module if there are no target-capable
SIMs in CAM.  As next step full teardown of CAM targets can be implemented.
2017-03-07 17:41:08 +00:00
Mark Johnston
991b5d2630 cam_periph_ccbwait could return while ccb in progress
In cam_periph_runccb, cam_periph_ccbwait was using the value of the ccb
pinfo.index and status fields to determine whether the ccb was done,
but these fields are updated without a contending lock and could glitch
into states that would be erroneously interpreted as done.  Instead,
have cam_periph_ccbwait look for the explicit result of the function
cam_periph_done.

Submitted by:	Ryan Libby <rlibby@gmail.com>
Reviewed by:	mav
MFC after:	3 weeks
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D8020
2016-09-30 21:00:09 +00:00
Alexander Motin
de2393124c Make pass, sg and targ drivers respect HBA's maxio.
Previous limitation of 64K (DFLTPHYS) is quite annoying.
2015-09-30 13:31:37 +00:00
Alexander Motin
c33e40291b Take additional reference on SCSI probe periph to cover its freeze count.
Otherwise periph may be invalidated and freed before single-stepping freeze
is dropped, causing use after free panic.
2014-01-11 13:35:36 +00:00
Alexander Motin
227d67aa54 Merge CAM locking changes from the projects/camlock branch to radically
reduce lock congestion and improve SMP scalability of the SCSI/ATA stack,
preparing the ground for the coming next GEOM direct dispatch support.

Replace big per-SIM locks with bunch of smaller ones:
 - per-LUN locks to protect device and peripheral drivers state;
 - per-target locks to protect list of LUNs on target;
 - per-bus locks to protect reference counting;
 - per-send queue locks to protect queue of CCBs to be sent;
 - per-done queue locks to protect queue of completed CCBs;
 - remaining per-SIM locks now protect only HBA driver internals.

While holding LUN lock it is allowed (while not recommended for performance
reasons) to take SIM lock.  The opposite acquisition order is forbidden.
All the other locks are leaf locks, that can be taken anywhere, but should
not be cascaded.  Many functions, such as: xpt_action(), xpt_done(),
xpt_async(), xpt_create_path(), etc. are no longer require (but allow) SIM
lock to be held.

To keep compatibility and solve cases where SIM lock can't be dropped, all
xpt_async() calls in addition to xpt_done() calls are queued to completion
threads for async processing in clean environment without SIM lock held.

Instead of single CAM SWI thread, used for commands completion processing
before, use multiple (depending on number of CPUs) threads.  Load balanced
between them using "hash" of the device B:T:L address.

HBA drivers that can drop SIM lock during completion processing and have
sufficient number of completion threads to efficiently scale to multiple
CPUs can use new function xpt_done_direct() to avoid extra context switch.
Make ahci(4) driver to use this mechanism depending on hardware setup.

Sponsored by:	iXsystems, Inc.
MFC after:	2 months
2013-10-21 12:00:26 +00:00
Alexander Motin
8d36a71b76 Unify periph invalidation and destruction reporting.
Print message containing device model and serial number on invalidation.

Requested by:   glebius
MFC after:	1 week
2013-10-15 17:59:41 +00:00
Gabor Kovesdan
8fb3bbe770 - Corrrect mispellings of word useful
Submitted by:	Christoph Mallon <christoph.mallon@gmx.de> (via private mail)
2013-04-17 11:45:15 +00:00
Alexander Motin
cccf422080 MFprojects/camlock r248890, r248897, r248898, r248900, r248903, r248905,
r248917, r248918, r248978, r249001, r249014, r249030:

Remove multilevel freezing mechanism, implemented to handle specifics of
the ATA/SATA error recovery, when post-reset recovery commands should be
allocated when queues are already full of payload requests.  Instead of
removing frozen CCBs with specified range of priorities from the queue
to provide free openings, use simple hack, allowing explicit CCBs over-
allocation for requests with priority higher (numerically lower) then
CAM_PRIORITY_OOB threshold.

Simplify CCB allocation logic by removing SIM-level allocation queue.
After that SIM-level queue manages only CCBs execution, while allocation
logic is localized within each single device.

Suggested by:	gibbs
2013-04-14 09:28:14 +00:00
Marius Strobl
03efffd10e Unbreak compilation after r248868. 2013-03-29 11:53:20 +00:00
Alexander Motin
f371c9e260 Implement CAM_PERIPH_FOREACH() macro, safely iterating over the list of
driver's periphs, acquiring and releaseing periph references while doing it.

Use it to iterate over the lists of ada and da periphs when flushing caches
and putting devices to sleep on shutdown and suspend.  Previous code could
panic in theory if some device disappear in the middle of the process.
2013-03-29 07:50:47 +00:00
Alexander Motin
0191d9b367 One more major cam_periph_error() rewrite to improve error handling and
reporting. It includes:
 - removing of error messages controlled by bootverbose, replacing them
with more universal and informative debugging on CAM_DEBUG_INFO level,
that is now built into the kernel by default;
 - more close following to the arguments submitted by caller, such as
SF_PRINT_ALWAYS, SF_QUIET_IR and SF_NO_PRINT; consumer knows better which
errors are usual/expected at this point and which are really informative;
 - adding two new flags SF_NO_RECOVERY and SF_NO_RETRY to allow caller
specify how much assistance it needs at this point; previously consumers
controlled that by not calling cam_periph_error() at all, but that made
behavior inconsistent and debugging complicated;
 - tuning debug messages and taken actions order to make debugging output
more readable and cause-effect relationships visible;
 - making camperiphdone() (common device recovery completion handler) to
also use cam_periph_error() in most cases, instead of own dumb code;
 - removing manual sense fetching code from cam_periph_error(); I was told
by number of people that it is SIM obligation to fetch sense data, so this
code is useless and only significantly complicates recovery logic;
 - making ada, da and pass driver to use cam_periph_error() with new limited
recovery options to handle error recovery and debugging in common way;
as one of results, CAM_REQUEUE_REQ and other retrying statuses are now
working fine with pass driver, that caused many problems before.
 - reverting r186891 by raj@ to avoid burning few seconds in tight DELAY()
loops on device probe, while device simply loads media; I think that problem
may already be fixed in other way, and even if it is not, solution must be
different.

Sponsored by:	iXsystems, Inc.
MFC after:	2 weeks
2012-06-09 13:07:44 +00:00
Kenneth D. Merry
8900f4b872 Fix a race condition in CAM peripheral free handling, locking
in the CAM XPT bus traversal code, and a number of other periph level
issues.

cam_periph.h,
cam_periph.c:	Modify cam_periph_acquire() to test the CAM_PERIPH_INVALID
		flag prior to allowing a reference count to be gained
		on a peripheral.  Callers of this function will receive
		CAM_REQ_CMP_ERR status in the situation of attempting to
		reference an invalidated periph.  This guarantees that
		a peripheral scheduled for a deferred free will not
		be accessed during its wait for destruction.

		Panic during attempts to drop a reference count on
		a peripheral that already has a zero reference count.

		In cam_periph_list(), use a local sbuf with SBUF_FIXEDLEN
		set so that mallocs do not occur while the xpt topology
		lock is held, regardless of the allocation policy of the
		passed in sbuf.

		Add a new routine, cam_periph_release_locked_buses(),
		that can be called when the caller already holds
		the CAM topology lock.

		Add some extra debugging for duplicate peripheral
		allocations in cam_periph_alloc().

		Treat CAM_DEV_NOT_THERE much the same as a selection
		timeout (AC_LOST_DEVICE is emitted), but forgo retries.

cam_xpt.c:      Revamp the way the EDT traversal code does locking
		and reference counting.  This was broken, since it
		assumed that the EDT would not change during
		traversal, but that assumption is no longer valid.

		So, to prevent devices from going away while we
		traverse the EDT, make sure we properly lock
		everything and hold references on devices that
		we are using.

		The two peripheral driver traversal routines should
		be examined.  xptpdperiphtraverse() holds the
		topology lock for the entire time it runs.
		xptperiphtraverse() is now locked properly, but
		only holds the topology lock while it is traversing
		the list, and not while the traversal function is
		running.

		The bus locking code in xptbustraverse() should
		also be revisited at a later time, since it is
		complex and should probably be simplified.

scsi_da.c:	Pay attention to the return value from cam_periph_acquire().

		Return 0 always from daclose() even if the disk is now gone.

		Add some rudimentary error injection support.

scsi_sg.c:	Fix reference counting in the sg(4) driver.

		The sg driver was calling cam_periph_release() on close,
		but never called cam_periph_acquire() (which increments
		the reference count) on open.

		The periph code correctly complained that the sg(4)
		driver was trying to decrement the refcount when it
		was already 0.

Sponsored by:	Spectra Logic
MFC after:	2 weeks
2012-01-12 00:41:48 +00:00
Justin T. Gibbs
3501942bbe Lay groundwork in CAM for recording and reporting physical path and
other device attributes stored in the CAM Existing Device Table (EDT).
This includes some infrastructure requried by the enclosure services
driver to export physical path information.

Make the CAM device advanced info interface accept store requests.

  sys/cam/scsi/scsi_all.c:
  sys/cam/scsi/scsi_all.h:
	- Replace scsi_get_sas_addr() with a scsi_get_devid() which takes
	  a callback that decides whether to accept a particular descriptor.
	  Provide callbacks for NAA IEEE Registered addresses and for SAS
	  addresses, replacing the old function.  This is needed because
	  the old function doesn't work for an enclosure address for a SAS
	  device, which is not flagged as a SAS address, but is NAA IEEE
	  Registered.  It may be worthwhile merging this interface with the
	  devid match interface.
	- Add a few more defines for some device ID fields.

  sbin/camcontrol/camcontrol.c:
	- Update for the CCB_DEV_ADVINFO interface change.

  cam/cam_xpt_internal.h:
	- Add the new fields for the physical path string to the CAM EDT.
  cam/cam_ccb.h:
	- Rename CCB_GDEV_ADVINFO to simply CCB_DEV_ADVINFO, and the ccb
	  structure to ccb_dev_advinfo.
	- Add a flag that changes this CCB's action to store, rather than
	  the default, retrieve.
	- Add a new buffer type, CDAI_TYPE_PHYS_PATH, for the new CAM EDT
	  physpath field.
	- Remove the never-implemented transport & proto flags.
  cam/cam_xpt.c:
  cam/cam_xpt.h:
	- Add xpt_getattr(), which provides a wrapper for fetching a device's
	  attribute using the GEOM strings as key.  This method currently
	  supports "GEOM::ident" and "GEOM::physpath".

Submitted by: will
Reviewed by : gibbs

Extend the XPT_DEV_MATCH api to allow a device search by device ID.
As far as the API is concerned, device ID is a binary blob to be
interpreted by the transport layer.  The SCSI implementation assumes
it is an array of VPD device ID descriptors.

  sys/cam/cam_ccb.h:
	Create a new structure, device_id_match_pattern, and
	update the XPT_DEV_MATCH datastructures and flags so
	that this pattern type can be used.

  sys/cam/cam_xpt.c:
	- A single pattern matching on both inquiry data and device
	  ID is invalid.  Report any violators.
	- Pass device ID match requests through to the new routine
	  scsi_devid_match().  The direct call of a SCSI routine is
	  a layering violation, but no worse than the one a few
	  lines up that checks inquiry data.  Defer cleaning this
	  up until our future, larger, rototilling of CAM.
	- Zero out cam_ed and cam_et nodes on allocation.  Prior to
	  this change, device_id_len and device_id were not inialized,
	  preventing proper detection of the presence of this
	  information.

  sys/cam/scsi/scsi_all.c:
  sys/cam/scsi/scsi_all.h:
	Add the scsi_match_devid() routine.

Add a helper function for extracting peripherial driver names

  sys/cam/cam_periph.c:
  sys/cam/cam_periph.h:
	Add the cam_periph_list() method which fills an sbuf
	with a comma delimited list of the peripheral instances
	associated with a given CAM path.

Add a helper functions for SCSI commands used by the SES driver.

  sys/cam/scsi/scsi_all.c:
  sys/cam/scsi/scsi_all.h:
	Add structure definitions and csio filling functions for
	the receive diagnostic results and send diagnostic commands.

Misc CAM XPT cleanups.

  sys/cam/cam_xpt.c:
	Broadcast AC_FOUND_DEVICE and AC_PATH_REGISTERED
	events at the time async event handlers are attached
	even when registering just for events on a partitular
	SIM.  Previously, you had to register for these
	events on all SIMs in the system in order to get
	the initial broadcast even though subsequent device
	and path arrivals would be delivered.

  sys/cam/cam_xpt.c:
	Remove SIM mutex held asserts from path accessors.
	CAM paths are reference counted and it is this
	reference count, not the sim mutex, that garantees
	they are stable.

Sponsored by: Spectra Logic Corporation
2011-06-14 14:53:17 +00:00
Alexander Motin
83c5d981ac MFp4: Large set of CAM inprovements.
- Unify bus reset/probe sequence. Whenever bus attached at boot or later,
CAM will automatically reset and scan it. It allows to remove duplicate
code from many drivers.
- Any bus, attached before CAM completed it's boot-time initialization,
will equally join to the process, delaying boot if needed.
- New kern.cam.boot_delay loader tunable should help controllers that
are still unable to register their buses in time (such as slow USB/
PCCard/ CardBus devices), by adding one more event to wait on boot.
- To allow synchronization between different CAM levels, concept of
requests priorities was extended. Priorities now split between several
"run levels". Device can be freezed at specified level, allowing higher
priority requests to pass. For example, no payload requests allowed,
until PMP driver enable port. ATA XPT negotiate transfer parameters,
periph driver configure caching and so on.
- Frozen requests are no more counted by request allocation scheduler.
It fixes deadlocks, when frozen low priority payload requests occupying
slots, required by higher levels to manage theit execution.
- Two last changes were holding proper ATA reinitialization and error
recovery implementation. Now it is done: SATA controllers and Port
Multipliers now implement automatic hot-plug and should correctly
recover from timeouts and bus resets.
- Improve SCSI error recovery for devices on buses without automatic sense
reporting, such as ATAPI or USB. For example, it allows CAM to wait, while
CD drive loads disk, instead of immediately return error status.
- Decapitalize diagnostic messages and make them more readable and sensible.
- Teach PMP driver to limit maximum speed on fan-out ports.
- Make boot wait for PMP scan completes, and make rescan more reliable.
- Fix pass driver, to return CCB to user level in case of error.
- Increase number of retries in cd driver, as device may return several UAs.
2010-01-28 08:41:30 +00:00
Alexander Motin
21cc85878c MFp4:
If we panicked with SIM lock held, do not try to flush caches.
Extra lock recursing will not make debugging easier.
2009-12-06 11:48:53 +00:00
Alexander Motin
efa575b6be MFp4:
- Remove CAM_PERIPH_POLLED flag. It is broken by design. Polling can't be
periph flag. May be SIM, may be CCB, but now it works fine just without it.
- Remove check unused for at least five years. If we will ever have non-BIO
devices in CAM, this check is smallest of what we will need.
- If several controllers complete requests same time, call swi_sched()
only once.
2009-11-04 15:40:19 +00:00
Alexander Motin
1e637ba677 MFp4:
- Reduce code duplication in ATA XPT and PMP driver.
- Move PIO size setting from ada driver to ATA XPT. It is XPT business
to negotiate transfer details. ada driver is now stateless.
- Report PIO size to SIM. It is required for correct PATA SIM operation.
- Tune PMP scan timings. It workarounds some problems with SiI.
- If reset hapens during PMP initialization - restart it.
- Introduce early-initialized periph drivers, which are used during initial
scan process. Use it for xpt, probe, aprobe and pmp. It gives pmp chance
to finish scan before mountroot and numerate devices in right order.
2009-10-31 10:43:38 +00:00
Scott Long
571e8e20da Change cam_periph_ioctl() to take 'cmd' and a u_long instead of an
int.  All of its callers pass in cmd as a u_long, so this has
always been a dangerous type demotion.  It was spooted by clang/llvm
trying to do a type promotion and sign extension within
cam_periph_ioctl.

Submitted by:	rdivacky
2009-06-22 14:43:48 +00:00
Edward Tomasz Napierala
24ebf56636 Periph driver fixes, second try.
Reviewed by:	scottl
Approved by:	rwatson (mentor)
Sponsored by:	FreeBSD Foundation
2008-12-19 14:31:40 +00:00
Scott Long
11e4face2d Inline cam_periph_lock|unlock to make debugging easier. Use more
CAM_SIM_LOCK() more uniformly.
2007-04-19 22:46:26 +00:00
Scott Long
2b83592fdc Remove Giant from CAM. Drivers (SIMs) now register a mutex that CAM will
use to synchornize and protect all data objects that are used for that
SIM.  Drivers that are not yet MPSAFE register Giant and operate as
usual.  RIght now, no drivers are MPSAFE, though a few will be changed
in the coming week as this work settles down.

The driver API has changed, so all CAM drivers will need to be recompiled.
The userland API has not changed, so tools like camcontrol do not need to
be recompiled.
2007-04-15 08:49:19 +00:00
Warner Losh
898b0535b7 Start each of the license/copyright comments with /*- 2005-01-05 22:34:37 +00:00
Scott Long
2e8f0ae68c Remove the camnet swi and CAM_PERIPH_NET. It has never been used, and given
that netowrk-over-scsi never really took off, there is little chance that
it will ever be needed.
2004-10-05 04:22:20 +00:00
Poul-Henning Kamp
3e019deaed Do a pass over all modules in the kernel and make them return EOPNOTSUPP
for unknown events.

A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".
2004-07-15 08:26:07 +00:00
Poul-Henning Kamp
60794e0478 Centralize the devstat handling for all GEOM disk device drivers
in geom_disk.c.

As a side effect this makes a lot of #include <sys/devicestat.h>
lines not needed and some biofinish() calls can be reduced to
biodone() again.
2003-03-08 08:01:31 +00:00
Peter Wemm
0b7c27b904 Change the peripheral driver list from a linker set to module driven
driver registration.  This should allow things like da, sa, cd etc to be
in seperate KLD's to the cam core and make them preloadable.
2001-02-07 07:05:59 +00:00
Jake Burkholder
e39756439c Back out the previous change to the queue(3) interface.
It was not discussed and should probably not happen.

Requested by:		msmith and others
2000-05-26 02:09:24 +00:00
Jake Burkholder
740a1973a6 Change the way that the queue(3) structures are declared; don't assume that
the type argument to *_HEAD and *_ENTRY is a struct.

Suggested by:	phk
Reviewed by:	phk
Approved by:	mdodd
2000-05-23 20:41:01 +00:00
Nick Hibma
9a1c8571c7 *sigh* I must have been on something that night. Make xpt_periph an
extern with the original in cam_xpt.c instead of replicating
xpt_periph in all the sources using it (and hence not initialising it)
2000-05-07 18:04:50 +00:00
Nick Hibma
540d9130cc Add a hack to cam that makes the cam_xpt available to the rest of the
kernel. Justin agress that there is no other reasonable alternative to
do automatic rescans on connect.

The problem is that when a new device attaches to a SIM (SCSI host
controller) we need to send a XPT_SCAN_BUS command to the SIM using
xpt_action. This requires however that there is a peripheral available
to take the command (otherwise xpt_done and later bomb). The RESCAN
ioctl uses the same periph.

This enables a USB mass storage drive to do an automatic rescan on
connection of the drive.

The automatic dropping of a CAM entry on disconnection was already
working (asynchronous event).

The next thing to do is find someone to commit a change to vpo to do the
same thing. Just port umass_cam_rescan and friends across to that
driver.

Approved by:   gibbs
2000-04-03 11:11:12 +00:00
Nick Hibma
0cdabce076 Various typo's.
One minor nit. The speed was displayed wrong when below 1Mb/s.
2000-03-15 21:55:48 +00:00
Peter Wemm
c447342094 Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot).  This is consistant with the other
BSD's who made this change quite some time ago.  More commits to come.
1999-12-29 05:07:58 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Justin T. Gibbs
87cfaf0e1f Add the XPT_PATH_STATS and XPT_GDEV_STATS function codes. These ccb
types allow the reporting of error counts and other statistics.  Currently
we provide information on the last BDR or bus reset as well as active
transaction inforamtion, but this will be expanded as more information is
added to aid in error recovery.

Use the 'last reset' information to better handle bus settle delays.
Peripheral drivers now control whether a bus settle delay occurs and
for how long.  This allows target mode peripheral drivers to avoid
having their device queue frozen by the XPT for what shoudl only be
initiator type behavior.

Don't perform a bus reset if the target device is incapable of performing
transfer negotiation (e.g. Fiber Channel).

If we don't perform a bus reset but the controller is capable of transfer
negotiations, force negotiations on the first transaction to go to the
device.  This ensures that we aren't tripped up by a left over negotiation
from the prom, BIOS, loader, etc.

Add a default async handler funstion to cam_periph.c to remove duplicated
code in all initiator type peripheral drivers.

Allow mapping of XPT_CONT_TARGET_IO ccbs from userland.  They are
itentical to XPT_SCSI_IO ccbs as far as data mapping is concerned.
1999-05-22 21:58:47 +00:00
Kenneth D. Merry
ee9c90c75c Fix a problem with the way we handled device invalidation when attaching
to a device failed.

In theory, the same steps that happen when we get an AC_LOST_DEVICE async
notification should have been taken when a driver fails to attach.  In
practice, that wasn't the case.

This only affected the da, cd and ch drivers, but the fix affects all
peripheral drivers.

There were several possible problems:
 - In the da driver, we didn't remove the peripheral's softc from the da
   driver's linked list of softcs.  Once the peripheral and softc got
   removed, we'd get a kernel panic the next time the timeout routine
   called dasendorderedtag().
 - In the da, cd and possibly ch drivers, we didn't remove the
   peripheral's devstat structure from the devstat queue.  Once the
   peripheral and softc were removed, this could cause a panic if anyone
   tried to access device statistics.  (one component of the linked list
   wouldn't exist anymore)
 - In the cd driver, we didn't take the peripheral off the changer run
   queue if it was scheduled to run.  In practice, it's highly unlikely,
   and maybe impossible that the peripheral would have been on the
   changer run queue at that stage of the probe process.

The fix is:
 - Add a new peripheral callback function (the "oninvalidate" function)
   that is called the first time cam_periph_invalidate() is called for a
   peripheral.

 - Create new foooninvalidate() routines for each peripheral driver.  This
   routine is always called at splsoftcam(), and contains all the stuff
   that used to be in the AC_LOST_DEVICE case of the async callback
   handler.

 - Move the devstat cleanup call to the destructor/cleanup routines, since
   some of the drivers do I/O in their close routines.

 - Make sure that when we're flushing the buffer queue, we traverse it at
   splbio().

 - Add a check for the invalid flag in the pt driver's open routine.

Reviewed by:	gibbs
1998-10-22 22:16:56 +00:00
Kenneth D. Merry
60a899a075 Fix a bug in the error recovery code. It was possible to have more than
one error recovery action oustanding for a given peripheral.

This is bad for several reasons.  The first problem is that the error
recovery actions would likely be to fix the same problem.  (e.g., we
queue 5 CCBs to a disk, and the first one comes back with 0x04,0x02.  We
start error recovery, and the second one comes back with the same status.
Then the third one comes back, and so on.  Each one causes the drive to get
nailed with a start unit, when we really only need one.)

The other problem is that we only have space to store one CCB while we're
doing error recovery.  The subsequent error recovery actions that got
started were over-writing the CCBs from previous error recovery actions,
but we still tried to call the done routine N times for N error recovery
actions.  Each call to dadone() was done with the same CCB, though.  So on
the second one, we got a "biodone: buffer not busy" panic, since the buffer
in question had already been through biodone().

In any case, this fixes things so that any any given time, there's only one
error recovery action outstanding for any given peripheral driver.

Reviewed by:	gibbs
Reported by:	Philippe Regnauld <regnauld@deepo.prosa.dk>
[ Philippe wins the "bug finder of the week" award ]
1998-10-13 21:41:32 +00:00
Justin T. Gibbs
8b8a9b1d3e CAM Transport Layer (XPT).
Submitted by:	The CAM Team
1998-09-15 06:33:23 +00:00