Call the detach routine for every device in the device tree, starting
with the leaves and moving toward the root, expecting that each
(pseudo-)device driver will use the opportunity to gracefully commit
outstandings transactions to the underlying (pseudo-)device and to
relinquish control of the hardware to the system BIOS.
Detaching devices is not suitable for every shutdown: in an emergency,
or if the system state is inconsistent, we should resort to a fast,
simple shutdown that uses only the pmf(9) shutdown hooks and the
(deprecated) shutdownhooks. For now, if the flag RB_NOSYNC is set in
boothowto, opt for the fast, simple shutdown.
Add a device flag, DVF_DETACH_SHUTDOWN, that indicates by its presence
that it is safe to detach a device during shutdown. Introduce macros
CFATTACH_DECL3() and CFATTACH_DECL3_NEW() for creating autoconf
attachments with default device flags. Add DVF_DETACH_SHUTDOWN
to configuration attachments for atabus(4), atw(4) at cardbus(4),
cardbus(4), cardslot(4), com(4) at isa(4), elanpar(4), elanpex(4),
elansc(4), gpio(4), npx(4) at isa(4), nsphyter(4), pci(4), pcib(4),
pcmcia(4), ppb(4), sip(4), wd(4), and wdc(4) at isa(4).
Add a device-detachment "reason" flag, DETACH_SHUTDOWN, that tells the
autoconf code and a device driver that the reason for detachment is
system shutdown.
Add a sysctl, kern.detachall, that tells the system to try to detach
every device at shutdown, regardless of any device's DVF_DETACH_SHUTDOWN
flag. The default for kern.detachall is 0. SET IT TO 1, PLEASE, TO
HELP TEST AND DEBUG DEVICE DETACHMENT AT SHUTDOWN.
This is a work in progress. In future work, I aim to treat
pseudo-devices more thoroughly, and to gracefully tear down a stack of
(pseudo-)disk drivers and filesystems, including cgd(4), vnd(4), and
raid(4) instances at shutdown.
Also commit some changes that are not easily untangled from the rest:
(1) begin to simplify device_t locking: rename struct pmf_private to
device_lock, and incorporate device_lock into struct device.
(2) #include <sys/device.h> in sys/pmf.h in order to get some
definitions that it needs. Stop unnecessarily #including <sys/device.h>
in sys/arch/x86/include/pic.h to keep the amd64, xen, and i386 releases
building.
register com_cleanup() as the shutdown hook.
Add a generic suspend routine. Suspend and resume com@isa.
Protect against dereferencing a NULL softc in comioctl().
Destroy both a mutex and a callout in com_detach().
Cosmetic: use aprint_*_dev(). Use PMF_FN_ARGS, PMF_FN_PROTO.
This allows us to convert aucom to just another com attachment, and cleanup
some code in the com_arbus.c.
Additionally, we use a common com_cleanup routine rather than having a
zillion copies of it in the attachment points.
This has been tested on a number architectures, and it has been shown to get
close to comparable performance when COM_REGMAP is defined, and comparable
when it is not defined.
Approved by core@. Fixes PR port-evbmips/32362.
by the isa.c bus driver and the "address/whatever not specified"
argument passed to leaf device drivers.
The former is "ISACF_XXX_DEFAULT" as generaterd by config(8), the latter
"ISA_UNKNOWN_XXX", defined in isavar.h.
This way we save a dependency of every ISA device driver on "locators.h".
configuration of devices logically attached to the ISA bus:
* Change the isa_attach_args to have arrays of io, mem, irq, drq
resources.
* Add a "pnpnames" and a linked list of "pnpcompatnames" to the
isa_attach_args. If either of these members are non-NULL,
direct configuration of the bus is being performed. Add an
ISA_DIRECT_CONFIG() macro to test for this.
* Drivers are not allowed to modify the isa_attach_args unless
direct configuration is not being performed and the probe fucntion
is returning success.
* Adapt device drivers -- currently, all driver probe routines return
"no match" if ISA_DIRECT_CONFIG() evaluates to true.
Instead, print a diagnostic and return. (Some drivers do this already.)
Also, normalize the diagnostic message, and fix some places where the
printfs were getting ugly.
* support chip clocks != COM_FREQ, by introducing sc_frequency (for the
mainline code) and adding a frequency parameter right after the rate
parameter to comcnattach() and com_kgdb_attach().
- Make com_isa and com_multi initialize sc_frequency to COM_FREQ.
- Make i386/machdep.c and alpha/dec_xxx.c call com*attach() with the freq.
parameter.
* supio_attach_args get two more fields: a sc_ipl and a sc_arg, both ints.
- com_supio uses the first for interupt establishment (all childs will, as
soon as they exist) and the 2nd for sc_frequency.
- drsupio passes sc_ipl alway as 5, and for the "com"s, sc_arg as 16*115200
- hyper will pass sc_ipl as 6, and sc_arg as 16 * 460800
-Separate KGDB port initialization and softc related stuff to allow
KGDB to be attached in early system startup, before autoconfiguration.
-Export the variables needed by md code to hand-craft bus tag/handle.
-Fix initialization to enable interrupt by line break.
-Call DDB/KGDB at line break (move DDB call from the softirq handler
to the hard handler because it should work without a tty attached too).
