Create a wrapper for newbus to take giant and for busses to take it too.
bus_topo_lock() should be called before interacting with newbus routines
and unlocked with bus_topo_unlock(). If you need the topology lock for
some reason, bus_topo_mtx() will provide that.
Sponsored by: Netflix
Reviewed by: mav
Differential Revision: https://reviews.freebsd.org/D31831
Replace MAXPHYS by runtime variable maxphys. It is initialized from
MAXPHYS by default, but can be also adjusted with the tunable kern.maxphys.
Make b_pages[] array in struct buf flexible. Size b_pages[] for buffer
cache buffers exactly to atop(maxbcachebuf) (currently it is sized to
atop(MAXPHYS)), and b_pages[] for pbufs is sized to atop(maxphys) + 1.
The +1 for pbufs allow several pbuf consumers, among them vmapbuf(),
to use unaligned buffers still sized to maxphys, esp. when such
buffers come from userspace (*). Overall, we save significant amount
of otherwise wasted memory in b_pages[] for buffer cache buffers,
while bumping MAXPHYS to desired high value.
Eliminate all direct uses of the MAXPHYS constant in kernel and driver
sources, except a place which initialize maxphys. Some random (and
arguably weird) uses of MAXPHYS, e.g. in linuxolator, are converted
straight. Some drivers, which use MAXPHYS to size embeded structures,
get private MAXPHYS-like constant; their convertion is out of scope
for this work.
Changes to cam/, dev/ahci, dev/ata, dev/mpr, dev/mpt, dev/mvs,
dev/siis, where either submitted by, or based on changes by mav.
Suggested by: mav (*)
Reviewed by: imp, mav, imp, mckusick, scottl (intermediate versions)
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D27225
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718
BIO_READ and BIO_WRITE, we've handled this expanded syntax poorly in
drivers when the driver doesn't support a particular command. Do a
sweep and fix that.
Reported by: imp
opt_compat.h is mentioned in nearly 180 files. In-progress network
driver compabibility improvements may add over 100 more so this is
closer to "just about everywhere" than "only some files" per the
guidance in sys/conf/options.
Keep COMPAT_LINUX32 in opt_compat.h as it is confined to a subset of
sys/compat/linux/*.c. A fake _COMPAT_LINUX option ensure opt_compat.h
is created on all architectures.
Move COMPAT_LINUXKPI to opt_dontuse.h as it is only used to control the
set of compiled files.
Reviewed by: kib, cem, jhb, jtl
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D14941
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.
--Remove special-case handling of sparc64 bus_dmamap* functions.
Replace with a more generic mechanism that allows MD busdma
implementations to generate inline mapping functions by
defining WANT_INLINE_DMAMAP in <machine/bus_dma.h>. This
is currently useful for sparc64, x86, and arm64, which all
implement non-load dmamap operations as simple wrappers
around map objects which may be bus- or device-specific.
--Remove NULL-checked bus_dmamap macros. Implement the
equivalent NULL checks in the inlined x86 implementation.
For non-x86 platforms, these checks are a minor pessimization
as those platforms do not currently allow NULL maps. NULL
maps were originally allowed on arm64, which appears to have
been the motivation behind adding arm[64]-specific barriers
to bus_dma.h, but that support was removed in r299463.
--Simplify the internal interface used by the bus_dmamap_load*
variants and move it to bus_dma_internal.h
--Fix some drivers that directly include sys/bus_dma.h
despite the recommendations of bus_dma(9)
Reviewed by: kib (previous revision), marius
Differential Revision: https://reviews.freebsd.org/D10729
This fixes a tautological pointer comparison warning, but would also a
real bug for a platform where bus_dmamap_unload of a static allocation
is not a no-op.
gracefully fail if the /dev/megaraid_sas_ioctl_node symlink already exists.
This can happen if mfi(4) and mrsas(4) are both attached to cards and
providing Linux emulation support. Let the first one win. An equivalent
change needs to be done to mrsas(4). Extra credit would be to pass the
Linux emulation call to the other driver when appropriate. This will
probably be a rare case and the user can manually change where the symlink
points to.
MFC after: 3 days
years for head. However, it is continuously misused as the mpsafe argument
for callout_init(9). Deprecate the flag and clean up callout_init() calls
to make them more consistent.
Differential Revision: https://reviews.freebsd.org/D2613
Reviewed by: jhb
MFC after: 2 weeks
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
While this prevents commands getting stuck forever there is no way to guarantee
that data from the command hasn't been committed to the device.
In addition older mfi firmware has a bug that would cause the controller to
frequently stall IO for over our timeout value, which when combined with
a forced timeout often resulted in panics in UFS; which would otherwise be
avoided when the command eventually completed if left alone.
For reference this timeout issue is resolved in Dell FW package 21.2.1-0000.
Fixed FW package version for none Dell controller will likely vary.
MFC after: 2 days
without first removing the command from the relavent queue.
This was causing panics in the queue functions which check to ensure a command
is not on another queue.
Fixed some cases where the error from mfi_mapcmd was lost and where the command
was never released / dequeued in error cases.
Ensure that all failures to mfi_mapcmd are logged.
Fixed possible null pointer exception in mfi_aen_setup if mfi_get_log_state
failed.
Fixed mfi_parse_entries & mfi_aen_setup not returning possible errors.
Corrected MFI_DUMP_CMDS calls with invalid vars SC vs sc.
Commands which have timed out now set cm_error to ETIMEDOUT and call
mfi_complete which prevents them getting stuck in the busy queue forever.
Fixed possible use of NULL pointer in mfi_tbolt_get_cmd.
Changed output formats to be more easily recognisable when debugging.
Optimised mfi_cmd_pool_tbolt cleanup.
Made information about driver limiting commands always display as for modern
cards this can be severe.
Fixed mfi_tbolt_alloc_cmd out of memory case which previously didnt return an
error.
Added malloc checks for request_desc_pool including free when subsiquent errors
are detected.
Fixed overflow error in SIMD reply descriptor check.
Fixed tbolt_cmd leak in mfi_build_and_issue_cmd if there's an error during IO
build.
Elimintated double checks on sc->mfi_aen_cm & sc->mfi_map_sync_cm in
mfi_shutdown.
Move local hdr calculation after error check in mfi_aen_complete.
Fixed wakeup on NULL in mfi_aen_complete.
Fixed mfi_aen_cm cleanup in mfi_process_fw_state_chg_isr not checking if it was
NULL.
Changed mfi_alloc_commands to error if bus_dmamap_create fails. Previously we
would try to continue with the number of allocated commands but lots of places
in the driver assume sc->mfi_max_fw_cmds is whats available so its unsafe to do
this without lots of changes.
Removed mfi_total_cmds as its no longer used due the above change.
Corrected mfi_tbolt_alloc_cmd to return ENOMEM where appropriate.
Fixed timeouts actually firing at double what they should.
Setting hw.mfi.max_cmds=-1 now configures to use the controller max.
A few style (9) fixes e.g. braced single line conditions and double blank lines
Cleaned up queuing macros
Removed invalid queuing tests for multiple queues
Trap and deal with errors when doing sends in mfi_data_cb
Refactored frame sending into one method with error checking of the return
code so we can ensure commands aren't left on the queue after error. This
ensures that mfi_mapcmd & mfi_data_cb leave the queue in a valid state.
Refactored how commands are cleaned up, mfi_release_command now ensures
that all queues and command state is maintained in a consistent state.
Prevent NULL pointer use in mfi_tbolt_complete_cmd
Fixed use of NULL sc->mfi_map_sync_cm in wakeup
Added defines to help with output of mfi_cmd and header flags.
Fixed mfi_tbolt_init_MFI_queue invalidating cm_index of the acquired mfi_cmd.
Reset now reinitialises sync map as well as AEN.
Fixed possible use of NULL pointer in mfi_build_and_issue_cmd
Fixed mfi_tbolt_init_MFI_queue call to mfi_process_fw_state_chg_isr causing
panic on failure.
Ensure that tbolt cards always initialise next_host_reply_index and
free_host_reply_index (based off mfi_max_fw_cmds) on both startup and
reset as per the linux driver.
Fixed mfi_tbolt_complete_cmd not acknowledging unknown commands so
it didn't clear the controller.
Prevent locks from being dropped and re-acquired in the following functions
which was allowing multiple threads to enter critical methods such as
mfi_tbolt_complete_cmd & mfi_process_fw_state_chg_isr:-
* mfi_tbolt_init_MFI_queue
* mfi_aen_complete / mfi_aen_register
* mfi_tbolt_sync_map_info
* mfi_get_log_state
* mfi_parse_entries
The locking for these functions was promoting to higher level methods. This
also fixed MFI_LINUX_SET_AEN_2 which was already acquiring the lock, so would
have paniced for recursive lock.
This also required changing malloc of ld_sync in mfi_tbolt_sync_map_info to
M_NOWAIT which can hence now fail but this was already expected as its return
was being tested.
Removed the assignment of cm_index in mfi_tbolt_init_MFI_queue which breaks
the world if the cmd returned by mfi_dequeue_free isn't the first cmd.
Fixed locking in mfi_data_cb, this is an async callback from bus_dmamap_load
which could hence be called after the caller has dropped the lock. If we
don't have the lock we aquire it and ensure we unlock before returning.
Fixed locking mfi_comms_init when mfi_dequeue_free fails.
Fixed mfi_build_and_issue_cmd not returning tbolt cmds aquired to the pool
on error.
Fixed mfi_abort not dropping the io lock when mfi_dequeue_free fails.
Added hw.mfi.polled_cmd_timeout sysctl that enables tuning of polled
timeouts. This shouldn't be reduced below 50 seconds as its used for
firmware patching which can take quite some time.
Added hw.mfi.fw_reset_test sysctl which is avaliable when compiled with
MFI_DEBUG and allows the testing of controller reset that was provoking a
large number of the issues encountered here.
Reviewed by: Doug Ambrisko
Approved by: pjd (mentor)
MFC after: 1 month
Removes a mtx_unlock call for mfi_io_lock which is never aquired
While I'm here fix a braceing style issue.
Reviewed by: Doug Ambrisko
Approved by: pjd (mentor)
MFC after: 1 month
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>)
function use that for JBOD and Thunderbolt disk write command. Now
we only have one implementation in mfi.
- Fix dumping on Thunderbolt cards. Polled IO commands do not seem to
be normally acknowledged by changing cmd_status to MFI_STAT_OK.
In order to get acknowledgement of the IO is complete, the Thunderbolt
command queue needs to be run through. I added a flag MFI_CMD_SCSI
to indicate this command is being polled and to complete the
Thunderbolt wrapper and indicate the result. This flag needs to be
set in the JBOD case in case if that us using Thunderbolt card.
When in the polling loop check for completed commands.
- Remove mfi_tbolt_is_ldio and just do the check when needed.
- Fix an issue when attaching of disk device happens when a device is
already scheduled to be attached but hasn't attached.
- add a tunable to allow raw disk attachment to CAM via:
hw.mfi.allow_cam_disk_passthrough=1
- fixup aborting of commands (AEN and LD state change). Use a generic
abort function and only wait the command being aborted not both.
Thunderbolt cards don't seem to abort commands so the abort times
out.
command properly. Without this change, mfi(4) always sends 10 byte READ
and WRITE commands, which will cause data corruption when device is
larger than 2^32 sectors.
PR: kern/173291
Submitted by: Steven Hartland <steven.hartland multiplay.co.uk>
Reviewed by: mav
MFC after: 2 weeks
The new driver changed the size of the mfi_dcmd_frame structure in such a
way that a MFI_IOC_PASSTHRU ioctl from an old amd64 binary is treated as an
MFI_IOC_PASSTHRU32 ioctl in the new driver. As a result, the user pointer
is treated as the buffer length. mfi_user_command() doesn't have a bounds
check on the buffer length, so it passes a really big value to malloc()
which panics when it tries to exhaust the kmem_map. Fix this two ways:
- Only honor MFI_IOC_PASSTHRU32 if the binary has the SV_ILP32 flag set,
otherwise treat it as an unknown ioctl.
- Add a bounds check on the buffer length passed by the user. For now
it fails any user attempts to use a buffer larger than 1MB.
While here, fix a few other nits:
- Remove an unnecessary check for a NULL return from malloc(M_WAITOK).
- Use the ENOTTY errno for invalid ioctl commands instead of ENOENT.
MFC after: 3 days
ThunderBolt cannot read sector >= 2^32 or 2^21
with supplied patch.
Second the bigger change, fix RAID operation on ThunderBolt base
card such as physically removing a disk from a RAID and replacing
it. The current situation is the RAID firmware effectively hangs
waiting for an acknowledgement from the driver. This is due to
the firmware support of the driver actually accessing the RAID
from under the firmware. This is an interesting feature that
the FreeBSD driver does not use. However, when the firmare
detects the driver has attached it then expects the driver will
synchronize LD's with the firmware. If the driver does not sync.
then the management part of the firmware will hang waiting for
it so a pulled driver will listed as still there.
The fix for this problem isn't extremely difficult. However,
figuring out why some of the code was the way it was and then
redoing it was involved. Not have a spec. made it harder to
try to figure out. The existing driver would send a
MFI_DCMD_LD_MAP_GET_INFO command in write mode to acknowledge
a LD state change. In read mode it gets the RAID map from the
firmware. The FreeBSD driver doesn't do that currently. It
could be added in the future with the appropriate structures.
To simplify things, get the current LD state and then build
the MFI_DCMD_LD_MAP_GET_INFO/write command so that it sends
an acknowledgement for each LD. The map would probably state
which LD's changed so then the driver could probably just
acknowledge the LD's that changed versus all. This doesn't seem
to be a problem. When a MFI_DCMD_LD_MAP_GET_INFO/write command
is sent to the firmware, it will complete later when a change
to the LD's happen. So it is very much like an AEN command
returning when something happened. When the
MFI_DCMD_LD_MAP_GET_INFO/write command completes, we refire the
sync'ing of the LD state. This needs to be done in as an event
so that MFI_DCMD_LD_GET_LIST can wait for that command to
complete before issuing the MFI_DCMD_LD_MAP_GET_INFO/write.
The prior code didn't use the call-back function and tried
to intercept the MFI_DCMD_LD_MAP_GET_INFO/write command when
processing an interrupt. This added a bunch of code complexity
to the interrupt handler. Using the call-back that is done
for other commands got rid of this need. So the interrupt
handler is greatly simplified. It seems that even commands
that shouldn't be acknowledged end up in the interrupt handler.
To deal with this, code was added to check to see if a command
is in the busy queue or not. This might have contributed to the
interrupt storm happening without MSI enabled on these cards.
Note that MFI_DCMD_LD_MAP_GET_INFO/read returns right away.
It would be interesting to see what other complexity could
be removed from the ThunderBolt driver that really isn't
needed in our mode of operation. Letting the RAID firmware
do all of the I/O to disks is a lot faster since it can
use its caches. It greatly simplifies what the driver has
to do and potential bugs if the driver and firmware are
not in sync.
Simplify the aen_abort/cm_map_abort and put it in the softc
versus in the command structure.
This should get merged to 9 before the driver is merged to
8.
PR: 167226
Submitted by: Petr Lampa
MFC after: 3 days
First cut of new HW support from LSI and merge into FreeBSD.
Supports Drake Skinny and ThunderBolt cards.
MFhead_mfi r227574
Style
MFhead_mfi r227579
Use bus_addr_t instead of uintXX_t.
MFhead_mfi r227580
MSI support
MFhead_mfi r227612
More bus_addr_t and remove "#ifdef __amd64__".
MFhead_mfi r227905
Improved timeout support from Scott.
MFhead_mfi r228108
Make file.
MFhead_mfi r228208
Fixed botched merge of Skinny support and enhanced handling
in call back routine.
MFhead_mfi r228279
Remove superfluous !TAILQ_EMPTY() checks before TAILQ_FOREACH().
MFhead_mfi r228310
Move mfi_decode_evt() to taskqueue.
MFhead_mfi r228320
Implement MFI_DEBUG for 64bit S/G lists.
MFhead_mfi r231988
Restore structure layout by reverting the array header to
use [0] instead of [1].
MFhead_mfi r232412
Put wildcard pattern later in the match table.
MFhead_mfi r232413
Use lower case for hexadecimal numbers to match surrounding
style.
MFhead_mfi r232414
Add more Thunderbolt variants.
MFhead_mfi r232888
Don't act on events prior to boot or when shutting down.
Add hw.mfi.detect_jbod_change to enable or disable acting
on JBOD type of disks being added on insert and removed on
removing. Switch hw.mfi.msi to 1 by default since it works
better on newer cards.
MFhead_mfi r233016
Release driver lock before taking Giant when deleting children.
Use TAILQ_FOREACH_SAFE when items can be deleted. Make code a
little simplier to follow. Fix a couple more style issues.
MFhead_mfi r233620
Update mfi_spare/mfi_array with the actual number of elements
for array_ref and pd. Change these max. #define names to avoid
name space collisions. This will require an update to mfiutil
It avoids mfiutil having to do a magic calculation.
Add a note and #define to state that a "SYSTEM" disk is really
what the firmware calls a "JBOD" drive.
Thanks to the many that helped, LSI for the initial code drop,
mav, delphij, jhb, sbruno that all helped with code and testing.
can be enabled via the hw.mfi.msi tunable. Many mfi(4) controllers also
support MSI-X, but in testing it seems that many adapters do not work with
MSI-X but do work with MSI.
MFC after: 2 weeks
ensuring that everything is really, truly consistent.
This fixes certain cases where one will see various:
mfi0: COMMAND 0xffffffXXXXXXXXXX TIMEOUT AFTER XX SECONDS
MFC after: 3 days
Submitted by: scottl
Ok'ed by: jhb
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
Specifically, add support for "Drake Skinny" and "ThunderBolt" LSI
cards.
Initial code was supplied by LSI under BSD license. Several improvements
were done by myself. Such things like making it work in a static kernel,
be able to boot of the RAID, performance improvements. I removed some
fairly complicated code that seemed to directly access the disks under
the firmware. It doesn't seem to be needed and significantly slowed
down the performance of the driver and caused tons of sense errors to
be reported.
This code is being checked in this area so others can help me get it into
shape to commit into the FreeBSD tree. Assistance has been volunteered
by iXsystems.
We might want to re-work the JBOD attachment that creates /dev/mfisyspd?
node for each disk.
Performance is faster then prior cards. It works okay with WITNESS
and INVARIANTS on amd64 and i386. I recall seeing a use after
free time bug with FreeBSD 8 and a Drake Skinny card with WITNESS
and INVARIANTS on.
First task is get all of the new structures to be named in FreeBSD
style format.
Next is probably to deal with the 64bit addressing changes that are
mostly around the #ifdef __amd64__ checks.
Thanks to LSI for providing the initial code.
Obtained from: LSI
by present MegaCLI version. It has some special meaning for the first s/g
list entry, while the main s/g list begins from the the second entry, and
those lists should remain separate after loading to the busdma map.
- Fix bug in 32bit ioctl compatibility shims when s/g list consists of
more then on element.
Sponsored by: iXsystems, inc.
MFC after: 3 days
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.
Reviewed by: rwatson
Approved by: re (bz)
These cause problems when trying to include the header in a C++ project.
Rename them to 'evt_class', and track the change in mfi and mfiutil.
Submitted by: Mark Johnston
Sponsored by: Sandvine Incorporated
Reviewed by: jhb@
MFC after: 1 week
The newbus lock is responsible for protecting newbus internIal structures,
device states and devclass flags. It is necessary to hold it when all
such datas are accessed. For the other operations, softc locking should
ensure enough protection to avoid races.
Newbus lock is automatically held when virtual operations on the device
and bus are invoked when loading the driver or when the suspend/resume
take place. For other 'spourious' operations trying to access/modify
the newbus topology, newbus lock needs to be automatically acquired and
dropped.
For the moment Giant is also acquired in some key point (modules subsystem)
in order to avoid problems before the 8.0 release as module handlers could
make assumptions about it. This Giant locking should go just after
the release happens.
Please keep in mind that the public interface can be expanded in order
to provide more support, if there are really necessities at some point
and also some bugs could arise as long as the patch needs a bit of
further testing.
Bump __FreeBSD_version in order to reflect the newbus lock introduction.
Reviewed by: ed, hps, jhb, imp, mav, scottl
No answer by: ariff, thompsa, yongari
Tested by: pho,
G. Trematerra <giovanni dot trematerra at gmail dot com>,
Brandon Gooch <jamesbrandongooch at gmail dot com>
Sponsored by: Yahoo! Incorporated
Approved by: re (ksmith)
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
