Previously such LUNs were silently ignored. But while they indeed unable
to process most of SCSI commands, some, like RTPG, they still can.
MFC after: 1 month
referenced. I think that there does exist an unlikely edge case for a
memory leak, but only if a driver is incorrectly written and specifies no
valid range of targets to scan. That can be fixed in a follow-up commit.
Obtained from: Netflix, Inc.
This VPD page is effectively an extension of the standard Inquiry
data page, and includes lots of additional bits.
This commit includes support for probing the page in the SCSI probe code,
and an additional request type for the XPT_DEV_ADVINFO CCB. CTL already
supports the Extended Inquiry page.
Support for querying this page in the sa(4) driver will come later.
sys/cam/scsi/scsi_xpt.c:
Probe the Extended Inquiry page, if the device supports it, and
return it in response to a XPT_DEV_ADVINFO CCB if it is requested.
sys/cam/scsi/cam_ccb.h:
Define a new advanced information CCB data type, CDAI_TYPE_EXT_INQ.
sys/cam/cam_xpt.c:
Free the extended inquiry data in a device when the device goes
away.
sys/cam/cam_xpt_internal.h:
Add an extended inquiry data pointer and length to struct cam_ed.
sys/sys/param.h
Bump __FreeBSD_version for the addition of the new
CDAI_TYPE_EXT_INQ advanced information type.
Sponsored by: Spectra Logic
MFC after: 1 week
data to go undetected.
The probe code does an MD5 checksum of the inquiry data (and page
0x80 serial number if available) before doing a reprobe of an
existing device, and then compares a checksum after the probe to
see whether the device has changed.
This check was broken in January, 2000 by change 56146 when the extended
inquiry probe code was added.
In the extended inquiry probe case, it was calculating the checksum
a second time. The second time it included the updated inquiry
data from the short inquiry probe (first 36 bytes). So it wouldn't
catch cases where the vendor, product, revision, etc. changed.
This change will have the effect that when a device's inquiry data is
updated and a rescan is issued, it will disappear and then reappear.
This is the appropriate action, because if the inquiry data or serial
number changes, it is either a different device or the device
configuration may have changed significantly. (e.g. with updated
firmware.)
scsi_xpt.c: Don't calculate the initial MD5 checksum on
standard inquiry data and the page 0x80 serial
number if we have already calculated it.
MFC after: 1 week
Sponsored by: Spectra Logic
SPC-2 tells REPORT LUNS shall be supported by devices supporting LUNs other
then LUN 0. If we see LUN 0 disconnected, guess there may be others, and
so REPORT LUNS shall be supported.
MFC after: 1 month
Previous logic was not differentiating disconnected LUNs and absent targets.
That made it to stop scan if LUN 0 was not found for any reason. That made
problematic, for example, using iSCSI targets declaring SPC-2 compliance and
having no LUN 0 configured.
The new logic continues sequential LUN scan if:
-- we have more configured LUNs that need recheck;
-- this LUN is connected and its SCSI version allows more LUNs;
-- this LUN is disconnected, its SCSI version allows more LUNs and we
guess they may be connected (we haven't scanned first 8 LUNs yet or
kern.cam.cam_srch_hi sysctl is set to scan more).
Reported by: trasz
MFC after: 1 month
These changes prevent sysctl(8) from returning proper output,
such as:
1) no output from sysctl(8)
2) erroneously returning ENOMEM with tools like truss(1)
or uname(1)
truss: can not get etype: Cannot allocate memory
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.
Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.
MFC after: 2 weeks
Sponsored by: Mellanox Technologies
support all valid SAM-5 LUN IDs. CAM_VERSION is bumped, as the CAM ABI
(though not API) is changed. No behavior is changed relative to r257345
except that LUNs with non-zero high 32 bits will no longer be ignored
during device enumeration for SIMs that have set PIM_EXTLUNS.
Reviewed by: scottl
the upper 32-bits of the LUN, if possible, into the target_lun field as
passed directly from the REPORT LUNs response. This allows extended LUN
support to work for all LUNs with zeros in the lower 32-bits, which covers
most addressing modes without breaking KBI. Behavior for drivers not
setting PIM_EXTLUNS is unchanged. No user-facing interfaces are modified.
Extended LUNs are stored with swizzled 16-bit word order so that, for
devices implementing LUN addressing (like SCSI-2), the numerical
representation of the LUN is identical with and without PIM_EXTLUNS. Thus
setting PIM_EXTLUNS keeps most behavior, and user-facing LUN IDs, unchanged.
This follows the strategy used in Solaris. A macro (CAM_EXTLUN_BYTE_SWIZZLE)
is provided to transform a lun_id_t into a uint64_t ordered for the wire.
This is the second part of work for full 64-bit extended LUN support and is
designed to a bridge for stable/10 to the final 64-bit LUN code. The
third and final part will involve widening lun_id_t to 64 bits and will
not be MFCed. This third part will break the KBI but will keep the KPI
unchanged so that all drivers that will care about this can be updated now
and not require code changes between HEAD and stable/10.
Reviewed by: scottl
MFC after: 2 weeks
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
so its available for use in generic scsi code.
This is a pre-requirement for using VPD queries to determine available SCSI
delete methods within scsi_da.
Reviewed by: mav
Approved by: pjd (mentor)
MFC after: 2 weeks
Stop abusing xpt_periph in random plases that really have no periph related
to CCB, for example, bus scanning. NULL value is fine in such cases and it
is correctly logged in debug messages as "noperiph". If at some point we
need some real XPT periphs (alike to pmpX now), quite likely they will be
per-bus, and not a single global instance as xpt_periph now.
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
r249017:
Some cosmetic things:
- Unify device to target insertion inside xpt_alloc_device() instead of
duplicating it three times.
- Remove extra checks for empty lists of devices and targets on release
since zero refcount check also implies it.
- Reformat code to reduce indentation.
r249103:
- Add lock assertions to every point where reference counters are modified.
- When reference counters are reaching zero, add assertions that there are
no children items left.
- Add a bit more locking to the xptpdperiphtraverse().
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
data changes.
cam_ccb.h: Add a new advanced information type, CDAI_TYPE_RCAPLONG,
for long read capacity data.
cam_xpt_internal.h:
Add a read capacity data pointer and length to struct cam_ed.
cam_xpt.c: Free the read capacity buffer when a device goes away.
While we're here, make sure we don't leak memory for other
malloced fields in struct cam_ed.
scsi_all.c: Update the scsi_read_capacity_16() to take a uint8_t * and
a length instead of just a pointer to the parameter data
structure. This will hopefully make this function somewhat
immune to future changes in the parameter data.
scsi_all.h: Add some extra bit definitions to struct
scsi_read_capacity_data_long, and bump up the structure
size to the full size specified by SBC-3.
Change the prototype for scsi_read_capacity_16().
scsi_da.c: Register changes in read capacity data with the transport
layer. This allows the transport layer to send out an
async notification to interested parties. Update the
dasetgeom() API.
Use scsi_extract_sense_len() instead of
scsi_extract_sense().
scsi_xpt.c: Add support for the new CDAI_TYPE_RCAPLONG advanced
information type.
Make sure we set the physpath pointer to NULL after freeing
it. This allows blindly freeing it in the struct cam_ed
destructor.
sys/param.h: Bump __FreeBSD_version from 1000005 to 1000006 to make it
easier for third party drivers to determine that the read
capacity data async notification is available.
camcontrol.c,
mptutil/mpt_cam.c:
Update these for the new scsi_read_capacity_16() argument
structure.
Sponsored by: Spectra Logic
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
This includes support in the kernel, camcontrol(8), libcam and the mps(4)
driver for SMP passthrough.
The CAM SCSI probe code has been modified to fetch Inquiry VPD page 0x00
to determine supported pages, and will now fetch page 0x83 in addition to
page 0x80 if supported.
Add two new CAM CCBs, XPT_SMP_IO, and XPT_GDEV_ADVINFO. The SMP CCB is
intended for SMP requests and responses. The ADVINFO is currently used to
fetch cached VPD page 0x83 data from the transport layer, but is intended
to be extensible to fetch other types of device-specific data.
SMP-only devices are not currently represented in the CAM topology, and so
the current semantics are that the SIM will route SMP CCBs to either the
addressed device, if it contains an SMP target, or its parent, if it
contains an SMP target. (This is noted in cam_ccb.h, since it will change
later once we have the ability to have SMP-only devices in CAM's topology.)
smp_all.c,
smp_all.h: New helper routines for SMP. This includes
SMP request building routines, response parsing
routines, error decoding routines, and structure
definitions for a number of SMP commands.
libcam/Makefile: Add smp_all.c to libcam, so that SMP functionality
is available to userland applications.
camcontrol.8,
camcontrol.c: Add smp passthrough support to camcontrol. Several
new subcommands are now available:
'smpcmd' functions much like 'cmd', except that it
allows the user to send generic SMP commands.
'smprg' sends the SMP report general command, and
displays the decoded output. It will automatically
fetch extended output if it is available.
'smppc' sends the SMP phy control command, with any
number of potential options. Among other things,
this allows the user to reset a phy on a SAS
expander, or disable a phy on an expander.
'smpmaninfo' sends the SMP report manufacturer
information and displays the decoded output.
'smpphylist' displays a list of phys on an
expander, and the CAM devices attached to those
phys, if any.
cam.h,
cam.c: Add a status value for SMP errors
(CAM_SMP_STATUS_ERROR).
Add a missing description for CAM_SCSI_IT_NEXUS_LOST.
Add support for SMP commands to cam_error_string().
cam_ccb.h: Rename the CAM_DIR_RESV flag to CAM_DIR_BOTH. SMP
commands are by nature bi-directional, and we may
need to support bi-directional SCSI commands later.
Add the XPT_SMP_IO CCB. Since SMP commands are
bi-directional, there are pointers for both the
request and response.
Add a fill routine for SMP CCBs.
Add the XPT_GDEV_ADVINFO CCB. This is currently
used to fetch cached page 0x83 data from the
transport later, but is extensible to fetch many
other types of data.
cam_periph.c: Add support in cam_periph_mapmem() for XPT_SMP_IO
and XPT_GDEV_ADVINFO CCBs.
cam_xpt.c: Add support for executing XPT_SMP_IO CCBs.
cam_xpt_internal.h: Add fields for VPD pages 0x00 and 0x83 in struct
cam_ed.
scsi_all.c: Add scsi_get_sas_addr(), a function that parses
VPD page 0x83 data and pulls out a SAS address.
scsi_all.h: Add VPD page 0x00 and 0x83 structures, and a
prototype for scsi_get_sas_addr().
scsi_pass.c: Add support for mapping buffers in XPT_SMP_IO and
XPT_GDEV_ADVINFO CCBs.
scsi_xpt.c: In the SCSI probe code, first ask the device for
VPD page 0x00. If any VPD pages are supported,
that page is required to be implemented. Based on
the response, we may probe for the serial number
(page 0x80) or device id (page 0x83).
Add support for the XPT_GDEV_ADVINFO CCB.
sys/conf/files: Add smp_all.c.
mps.c: Add support for passing in a uio in mps_map_command(),
so we can map a S/G list at once.
Add support for SMP passthrough commands in
mps_data_cb(). SMP is a special case, because the
first buffer in the S/G list is outbound and the
second buffer is inbound.
Add support for warning the user if the busdma code
comes back with more buffers than will work for the
command. This will, for example, help the user
determine why an SMP command failed if busdma comes
back with three buffers.
mps_pci.c: Add sys/uio.h.
mps_sas.c: Add the SAS address and the parent handle to the
list of fields we pull from device page 0 and cache
in struct mpssas_target. These are needed for SMP
passthrough.
Add support for the XPT_SMP_IO CCB. For now, this
CCB is routed to the addressed device if it supports
SMP, or to its parent if it does not and the parent
does. This is necessary because CAM does not
currently support SMP-only nodes in the topology.
Make SMP passthrough support conditional on
__FreeBSD_version >= 900026. This will make it
easier to MFC this change to the driver without
MFCing the CAM changes as well.
mps_user.c: Un-staticize mpi_init_sge() so we can use it for
the SMP passthrough code.
mpsvar.h: Add a uio and iovecs into struct mps_command for
SMP passthrough commands.
Add a cm_max_segs field to struct mps_command so
that we can warn the user if busdma comes back with
too many segments.
Clear the cm_reply when a command gets freed. If
it is not cleared, reply frames will eventually get
freed into the pool multiple times and corrupt the
pool. (This fix is from scottl.)
Add a prototype for mpi_init_sge().
sys/param.h: Bump __FreeBSD_version to 900026 for the for the
inclusion of the XPT_GDEV_ADVINFO and XPT_SMP_IO
CAM CCBs.
better devices. This can be disabled on a per-device basis using quirks as
well.
This also handles the case where there is actually no connected LUN 0
(which can definitely be the case for storage arrays).
Reviewed by: scsi@
MFC after: 1 month
whole bus (XPT_SCAN_BUS) and a single lun on that bus (XPT_SCAN_LUN).
It's less resource comsumptive than scanning a whole bus when the
caller knows only one target has changes.
Reviewed by: scsi@
Sponsored by: Panasas
MFC after: 1 month
- 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.
- Move tagged queueing control from ADA to ATA XPT. It allows to control
device command queue length correctly. First step to support < 32 tags.
- Limit queue for non-tagged devices by 2 slots for ahci(4) and siis(4).
- Implement quirk matching for ATA devices.
- Move xpt_schedule_dev_sendq() from header to source file.
- Move delayed queue shrinking to the more expected place - element freeing.
- Remove some SCSIsms in ATA.
Fix reference counting bug, when device unreferenced before then
invalidated. To do it, do not handle validity flag as another
reference, but explicitly modify reference count each time flag is
modified.
Discovered by: thompsa
- 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.
page_list using the matching malloc type for the allocation.
Approved by: re
Reviewed by: scottl [1]
MFC after: 1 week
[1] Original patch was against xpt_cam.c, prior to the cam refactoring.
modularize it so that new transports can be created.
Add a transport for SATA
Add a periph+protocol layer for ATA
Add a driver for AHCI-compliant hardware.
Add a maxio field to CAM so that drivers can advertise their max
I/O capability. Modify various drivers so that they are insulated
from the value of MAXPHYS.
The new ATA/SATA code supports AHCI-compliant hardware, and will override
the classic ATA driver if it is loaded as a module at boot time or compiled
into the kernel. The stack now support NCQ (tagged queueing) for increased
performance on modern SATA drives. It also supports port multipliers.
ATA drives are accessed via 'ada' device nodes. ATAPI drives are
accessed via 'cd' device nodes. They can all be enumerated and manipulated
via camcontrol, just like SCSI drives. SCSI commands are not translated to
their ATA equivalents; ATA native commands are used throughout the entire
stack, including camcontrol. See the camcontrol manpage for further
details. Testing this code may require that you update your fstab, and
possibly modify your BIOS to enable AHCI functionality, if available.
This code is very experimental at the moment. The userland ABI/API has
changed, so applications will need to be recompiled. It may change
further in the near future. The 'ada' device name may also change as
more infrastructure is completed in this project. The goal is to
eventually put all CAM busses and devices until newbus, allowing for
interesting topology and management options.
Few functional changes will be seen with existing SCSI/SAS/FC drivers,
though the userland ABI has still changed. In the future, transports
specific modules for SAS and FC may appear in order to better support
the topologies and capabilities of these technologies.
The modularization of CAM and the addition of the ATA/SATA modules is
meant to break CAM out of the mold of being specific to SCSI, letting it
grow to be a framework for arbitrary transports and protocols. It also
allows drivers to be written to support discrete hardware without
jeopardizing the stability of non-related hardware. While only an AHCI
driver is provided now, a Silicon Image driver is also in the works.
Drivers for ICH1-4, ICH5-6, PIIX, classic IDE, and any other hardware
is possible and encouraged. Help with new transports is also encouraged.
Submitted by: scottl, mav
Approved by: re
