For the discovery phase of SD/eMMC we need to do some transaction in a async
way.
The classic CAM XPT_{GET,SET}_TRAN_SETTING cannot be used in a async way.
This also allow us to split the discovery phase into a more complete state
machine and we don't mtx_sleep with a random number to wait for completion
of the tasks.
For mmc_sim we now do the SET_TRAN_SETTING in a taskqueue so we can call
the needed function for regulators/clocks without the cam lock(s). This part is
still needed to be done for sdhci.
We also now save the host OCR in the discovery phase as it wasn't done before and
only worked because the same ccb was reused.
Reviewed by: imp, kibab, bz
Differential Revision: https://reviews.freebsd.org/D30038
This patch makes it possible for CAM to use small CCBs allocated
from an periph-specific UMA zone instead of the usual, huge ones.
The end result is that CCBs issued via da(4) take 544B (size of
ccb_scsiio) instead of the usual 2kB (size of 'union ccb', ~1.5kB,
rounded up by malloc(9)). For ATA it's 272B. We waste less
memory, we avoid zeroing the unused 1kB, and it should be easier
to allocate those CCBs in low memory conditions. It should also
be possible to use uma_zone_reserve(9) to improve behaviour
in low memory conditions even further.
Note that this does not change the size, or the layout, of CCBs
as such. CCBs get allocated in various different ways, in particular
on the stack, and I don't want to redo all that. Instead, this
provides an opt-in mechanism for the periph to declare "my start()
callback is fine with receiving a CCB allocated from this UMA zone".
In other words, most of the code works exactly as it used to; the
change only happens to IOs issued by xpt_run_allockq(), which
is - conveniently - pretty much all that matters for performance.
The reason for doing it this way is that it's pretty small, localized
change, and can be implemented gradually and iteratively: take a
periph, make sure its start() callback only casts the CCBs it takes
to a particular type of CCB, for example ccb_scsiio, and that it only
casts CCBs returned by cam_periph_getccb() to that type, then add UMA
zone for that size, and declare it safe to XPT.
This is disabled by default. Set 'kern.cam.ada.enable_uma_ccbs=1'
and 'kern.cam.da.enable_uma_ccbs=1' tunables to enable it. Testing
is welcome; I will flip the default to enable in two weeks from now.
Reviewed By: imp
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D28674
This is required for small CCBs support, where we need to track
whether the CCB was allocated from an UMA zone or not. There are
no (intended) functional changes with the current source.
Reviewed By: imp
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D29484
Queue all XPT_ASYNC ccb's and run those in a new cam async thread. This thread
is allowed to sleep for things like memory. This should allow us to make all the
registration routines for cam periph drivers simpler since they can assume they
can always allocate memory. This is a separate thread so that any I/O that's
completed in xpt_done_td isn't held up.
This should fix the panics for WAITOK alloations that are elsewhere in the
storage stack that aren't so easy to convert to NOWAIT. Additional future work
will convert other allocations in the registration path to WAITOK should
detailed analysis show it to be safe.
Reviewed by: chs@, rpokala@
Differential Revision: https://reviews.freebsd.org/D29210
Some CAM sim drivers do not support polling (notably iscsi(4)).
Rather than using a no-op poll routine that always times out requests,
permit a SIM to set a NULL poll callback. cam_periph_runccb() will
fail polled requests non-pollable sims immediately as if they had
timed out.
Reviewed by: scottl, mav (earlier version)
Reviewed by: imp
MFC after: 2 weeks
Sponsored by: Chelsio
Differential Revision: https://reviews.freebsd.org/D28453
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
In xpt_release_device(), callout_stop() was being called without
holding the mutex (send_mtx) that is used to protect the callout.
So, move the mtx_unlock() call so that it is protected.
MFC after: 1 week
Sponsored by: Spectra Logic
Print the pointer to ccb so we can find it (for what good it does)
as well as the type of operation in flight when the cam_path has
been freed out from under us. This helps both core analysis as well
as automated systems that collect panic strings but little else.
declarations.
We typically don't use them elsewhere in the kernel, and they aren't
needed here: the actual functions are a few lines away and aren't
mutually recursive.
It's used in exactly one place. In that place it's used so we can hold the lock
on the device associated with the path (since we do a xpt_path_lock and unlock
pair around the callback). Instead, inline taking and dropping the reference to
the device so we can ensure we can unlock the mutex after the callback finishes
if the path in the ccb that's queued to be processed by xpt_scanner_thread is
destroyed while being processed. We don't actually need the path itself for
anything other than dereferencing it to get the device to do the lock and
unlock.
This also makes the locking / use model for cam_path a little cleaner by
eliminating a case where we needlessly copy the object.
Reviewed by: chuck, chs, ken
Differential Revision: https://reviews.freebsd.org/D24008
of xpt_done(). Add the missing XPT_ASYNC case to xpt_action_default. xpt_async
wants to use the side-effect of the xpt_done() routine to queue this to the
camisr thread so it can be done in that context. However, this breaks the
symmetry that you create a ccb and call xpt_action() for it to be
dispatched. Restore that symmetry by having it go through that path. As far as I
can tell, this is the only CCB that we create and call xpt_done() on directly.
Consistently omit /* FALLTHROUGH */ when we have a case statement that does
nothing. Since compilers don't warn about stacked case statements, and we were
inconsistent, resolve by removing extras.
Before this change CAM used config_intrhook_establish() for this purpose,
but that approach does not allow to delay it again after releasing once.
USB stack uses root_mount_hold() to delay boot until bus scan is complete.
But once it is, CAM had no time to scan SCSI bus, registered by umass(4),
if it already done other scans and called config_intrhook_disestablish().
The new approach makes it work smooth, assuming the USB device is found
during the initial bus scan. Devices appearing on USB bus later may still
require setting kern.cam.boot_delay, but hopefully those are minority.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
Do not allocate temporary buffer for attributes we are going to return
as-is, just make sure to NUL-terminate them. Do not zero temporary 64KB
buffer for CDAI_TYPE_SCSI_DEVID, XPT tells us how much data it filled
and there are also length fields inside the returned data also.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
The panic message lead people to believe some userland CAM request had
caused a problem when in reallity it was for a kernel request (eg the
USER bit was cleared). Reword message. Also, improve a couple of
comments to reflect that the periph shouldn't be completely torn down
before we get here (so the path and sim pointers should be valid, but
aren't and the code is designed to be robust enough in the face of
that to give a specific panic message).
xpt_sim_poll takes the sim to poll as an argument. It will do the
proper locking protocol, call the SIM polling routine, and then call
camisr_runqueue to process completions on any CCBs the SIM's poll
routine completed. It will be used during late shutdown when a SIM is
waiting for CCBs it sent during shutdown to finish and the scheduler
isn't running because we've panic'd.
This sequence was used twice in cam_xpt, so refactor those to use this
new function.
Sponsored by: Netflix
Differential Review: https://reviews.freebsd.org/D16663
It's likely that the header was needed in the past for swi(9).
But now that code does not use swi(9) or any other interfaces defined
in sys/interrupt.h.
MFC after: 1 week
- Remove layering violation, when NVMe SIM code accessed CAM internal
device structures to set pointers on controller and namespace data.
Instead make NVMe XPT probe fetch the data directly from hardware.
- Cleanup NVMe SIM code, fixing support for multiple namespaces per
controller (reporting them as LUNs) and adding controller detach support
and run-time namespace change notifications.
- Add initial support for namespace change async events. So far only
in CAM mode, but it allows run-time namespace arrival and departure.
- Add missing nvme_notify_fail_consumers() call on controller detach.
Together with previous changes this allows NVMe device detach/unplug.
Non-CAM mode still requires a lot of love to stay on par, but at least
CAM mode code should not stay in the way so much, becoming much more
self-sufficient.
Reviewed by: imp
MFC after: 1 month
Sponsored by: iXsystems, Inc.
device still wind up in xpt_done after the path has been
invalidated. Since we don't always need sim or devq, add some guard
rails to only fail if we have to use them.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D14040
Make it possible to retrieve mmc parameters via the XPT_GET_ADVINFO
call instead. Convert camcontrol to the new scheme.
Reviewed by: imp. kibab
Sponsored by: Netflix
Differential Revision: D13868
This provides a nice wrarpper around the XPT_PATH_INQ ccb creation and
calling.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D13387
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.
In xpt_bus_register(), remove superfluous call to free(). This was mostly
benign since free(9) checks for NULL before doing anything, and
xpt_create_path() is nice enough to NULL out the pointer on failure.
However, it could've segfaulted if malloc(9) failed during
xpt_create_path().
Submitted by: gibbs
MFC after: 3 weeks
Sponsored by: Spectra Logic Corp
This patch changes the way XPT_GDEV_TYPE works for NVMe. The current
ccb_getdev structure includes pointers to the NVMe Identify Controller
and Namespace structures, but these are kernel virtual addresses which
are not accessible from user space.
As an alternative, the patch changes the pointers into padding in
ccb_getdev and adds two new types to ccb_dev_advinfo to retrieve the
Identify Controller (CDAI_TYPE_NVME_CNTRL) and Namespace
(CDAI_TYPE_NVME_NS) data structures.
Reviewed By: rpokala, imp
Differential Revision: https://reviews.freebsd.org/D10466
Submitted by: Chuck Tuffli
o Allow I/O scheduler to gather times on 32-bit systems. We do this by shifting
the sbintime_t over by 8 bits and truncating to 32-bits. This gives us 8.24
time. This is sufficient both in range (256 seconds is about 128x what current
users need) and precision (60ns easily meets the 1ms smallest bucket size
measurements). 64-bit systems are unchanged. Centralize all the time math so
it's easy to tweak tha range / precision tradeoffs in the future.
o While I'm here, the I/O scheduler should be using periph_data rather than
sim_data since it is operating on behalf of the periph.
Differential Review: https://reviews.freebsd.org/D12119
the IO type (Admin or NVM) using XPT op-codes XPT_NVME_ADMIN or
XPT_NVME_IO.
Submitted by: Chuck Tuffli <chuck@tuffli.net>
Differential Revision: https://reviews.freebsd.org/D10247
Implement the MMC/SD/SDIO protocol within a CAM framework. CAM's
flexible queueing will make it easier to write non-storage drivers
than the legacy stack. SDIO drivers from both the kernel and as
userland daemons are possible, though much of that functionality will
come later.
Some of the CAM integration isn't complete (there are sleeps in the
device probe state machine, for example), but those minor issues can
be improved in-tree more easily than out of tree and shouldn't gate
progress on other fronts. Appologies to reviews if specific items
have been overlooked.
Submitted by: Ilya Bakulin
Reviewed by: emaste, imp, mav, adrian, ian
Differential Review: https://reviews.freebsd.org/D4761
merge with first commit, various compile hacks.
using a driver-supplied sbuf for printing device discovery
announcements. This helps ensure that messages to the console
will be properly serialized (through sbuf_putbuf) and not be
truncated and interleaved with other messages. The
infrastructure mirrors the existing xpt_announce_periph()
entry point and is opt-in for now. No content or formatting
changes are visible to the operator other than the new coherency.
While here, eliminate the stack usage of the temporary
announcement buffer in some of the drivers. It's moved to the
softc for now, but future work will eliminate it entirely by
making the code flow more linear. Future work will also address
locking so that the sbufs can be dynamically sized.
The scsi_da, scs_cd, scsi_ses, and ata_da drivers are converted
at this point, other drivers can be converted at a later date.
A tunable+sysctl, kern.cam.announce_nosbuf, exists for testing
purposes but will be removed later.
TODO:
Eliminate all of the code duplication and temporary buffers. The
old printf-based methods will be retired, and xpt_announce_periph()
will just be a wrapper that uses a dynamically sized sbuf. This
requires that the register and deregister paths be made malloc-safe,
which they aren't currently.
Sponsored by: Netflix
For three years now CAM does not use SIM lock, but still enforces SIM to
use it. Remove this requirement, allowing SIMs to have any locking they
prefer, if they pass no mutex to cam_sim_alloc().
MFC after: 2 weeks
Queue statistics has nothing to do with presence or absence of INQUIRY
data, etc. Target mode devices are never configured, but have queues.
MFC after: 2 weeks
