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
Only four specific ATA PIO commands transfer several sectors per DRQ block
(interrupt). All other ATA PIO commands transfer one sector or 512 bytes
at one time. Hardcode these exceptions in mvs(4) with ATA_CAM option.
This fixes timeout of READ LOG EXT command used by `smartctl -x /dev/adaX`.
Also it fixes timeout of DOWNLOAD_MICROCODE on `camcontrol fwdownload`.
every architecture's busdma_machdep.c. It is done by unifying the
bus_dmamap_load_buffer() routines so that they may be called from MI
code. The MD busdma is then given a chance to do any final processing
in the complete() callback.
The cam changes unify the bus_dmamap_load* handling in cam drivers.
The arm and mips implementations are updated to track virtual
addresses for sync(). Previously this was done in a type specific
way. Now it is done in a generic way by recording the list of
virtuals in the map.
Submitted by: jeff (sponsored by EMC/Isilon)
Reviewed by: kan (previous version), scottl,
mjacob (isp(4), no objections for target mode changes)
Discussed with: ian (arm changes)
Tested by: marius (sparc64), mips (jmallet), isci(4) on x86 (jharris),
amd64 (Fabian Keil <freebsd-listen@fabiankeil.de>)
then solves because of cache coherency issues. This fixes periodic error
messages on console and command timeouts.
- Patch SATA PHY configuration for 65nm SoCs to improve SNR same as
Linux does.
MFC after: 2 weeks
Return PROTO_ATA protocol in response to XPT_PATH_INQ.
smartmontools uses it to identify ATA devices and I don't know any other
place now where it is important. It could probably use XPT_GDEV_TYPE
instead for more accurate protocol information, but let it live for now.
Reported by: matthew
MFC after: 3 days
until transport will do some probe actions (at least soft reset).
Make ATA/SATA SIMs to not report bogus and confusing PROTO_ATA protocol.
Make ATA/SATA transport to fill that gap by reporting protocol to SIM with
XPT_SET_TRAN_SETTINGS and patching XPT_GET_TRAN_SETTINGS results if needed.
to allow drivers to handle request completion directly without passing
them to the CAM SWI thread removing extra context switch.
Modify all ATA/SATA drivers to use them.
Reviewed by: gibbs, ken
MFC after: 2 weeks
(SEMB) is unable to communicate to Storage Enclosure Processor (SEP), in
response to hard and soft resets it should among other things return value
0x7F in Status register. The weird side is that it means DRQ bit set, which
tells that reset request is not completed. It would be fine if SEMB was the
only device on port. But if SEMB connected to PMP or built into it, it may
block access to other devices sharing same SATA port.
Make some tunings/fixes to soft-reset handling to workaround the issue:
- ahci(4): request CLO on the port after soft reset to ignore DRQ bit;
- siis(4): gracefully reinitialize port after soft reset timeout (hardware
doesn't detect reset request completion in this case);
- mvs(4): if PMP is used, send dummy soft-reset to the PMP port to make it
clear DRQ bit for us.
For now this makes quirks in ata_pmp.c, hiding SEMB ports of SiI3726/SiI4726
PMPs, less important. Further, if hardware permit, I hope to implement real
SEMB support.
Instead of spinning in a tight loop for up to 15 seconds, polling for device
readiness while it spins up, return reset completion just after PHY reports
"connect well" or 100ms connection timeout. If device was found, use callout
for checking device readiness with 100ms period up to full 31 second timeout.
This fixes system freeze for 5-10 seconds on drives hot plug-in.
- make SATA SIMs announce capabilities to handle SDB with Notification bit;
- make PMP driver honor this SIMs capability;
- make SATA XPT to negotiate and enable this feature for ATAPI devices.
This feature allows supporting SATA ATAPI devices to inform system about
some events happened, that may require attention. In my case this allows
LG GH22LS50 SATA DVR-RW drive to report tray open/close events. Events
reported to CAM in form of AC_SCSI_AEN async. Further they could be used
as a hints for checking device status and reporting media change to upper
layers, for example, via spoiling mechanism of GEOM.
of proper value. It caused bunch of "EMPTY CRPB" messages and potentially
may cause premature requests completion, which could cause data corruption.
For most cases it seems enough to just reread register to get proper value.
To protect against worse cases - erase processed queue entries with
impossible values and ignore them if problem still happen.
driver for CAM ATA subsystem. This driver supports same hardware as
atamarvell, ataadaptec and atamvsata drivers from ata(4), but provides
many additional features, such as NCQ, PMP, etc.
