designated initializers.
I have not built every extant kernel so I have probably broken at
least one build; however I've also found and fixed some wrong
cdevsw/bdevsw entries so even if so I think we come out ahead.
read/write/accept, then the expectation is that the blocked thread will
exit and the close complete.
Since only one fd is affected, but many fd can refer to the same file,
the close code can only request the fs code unblock with ERESTART.
Fixed for pipes and sockets, ERESTART will only be generated after such
a close - so there should be no change for other programs.
Also rename fo_abort() to fo_restart() (this used to be fo_drain()).
Fixes PR/26567
do drain' in many places, whereas fo_drain() was called in order to force
blocking read()/write() etc calls to return to userspace so that a close()
call from a different thread can complete.
In the sockets code comment out the broken code in the inner function,
it was being called from compat code.
and make suspension by self, by drvctl(8), and by ACPI system sleep
play nice together. Start solidifying some temporary API changes.
1. Extract a new header file, <sys/device_if.h>, from <sys/device.h> and
#include it from <sys/pmf.h> instead of <sys/device.h> to break the
circular dependency between <sys/device.h> and <sys/pmf.h>.
2. Introduce pmf_qual_t, an aggregate of qualifications on a PMF
suspend/resume call. Start to replace instances of PMF_FN_PROTO,
PMF_FN_ARGS, et cetera, with a pmf_qual_t.
3. Introduce the notion of a "suspensor," an entity that holds a
device in suspension. More than one suspensor may hold a device
at once. A device stays suspended as long as at least one
suspensor holds it. A device resumes when the last suspensor
releases it.
Currently, the kernel defines three suspensors,
3a the system-suspensor: for system suspension, initiated
by 'sysctl -w machdep.sleep_state=3', by lid closure, by
power-button press, et cetera,
3b the drvctl-suspensor: for device suspension by /dev/drvctl
ioctl, e.g., drvctl -S sip0.
3c the system self-suspensor: for device drivers that suspend
themselves and their children. Several drivers for network
interfaces put the network device to sleep while it is not
administratively up, that is, after the kernel calls if_stop(,
1). The self-suspensor should not be used directly. See
the description of suspensor delegates, below.
A suspensor can have one or more "delegates". A suspensor can
release devices that its delegates hold suspended. Right now,
only the system self-suspensor has delegates. For each device
that a self-suspending driver attaches, it creates the device's
self-suspensor, a delegate of the system self-suspensor.
Suspensors stop a system-wide suspend/resume cycle from waking
devices that the operator put to sleep with drvctl before the cycle.
They also help self-suspension to work more simply, safely, and in
accord with expectations.
4. Add the notion of device activation level, devact_level_t,
and a routine for checking the current activation level,
device_activation(). Current activation levels are DEVACT_LEVEL_BUS,
DEVACT_LEVEL_DRIVER, and DEVACT_LEVEL_CLASS, which respectively
indicate that the device's bus is active, that the bus and device are
active, and that the bus, device, and the functions of the device's
class (network, audio) are active.
Suspend/resume calls can be qualified with a devact_level_t.
The power-management framework treats a devact_level_t that
qualifies a device suspension as the device's current activation
level; it only runs hooks to reduce the activation level from
the presumed current level to the fully suspended state. The
framework treats a devact_level_t qualifying device resumption
as the target activation level; it only runs hooks to raise the
activation level to the target.
5. Use pmf_qual_t, devact_level_t, and self-suspensors in several
drivers.
6. Temporarily add an unused power-management workqueue that I will
remove or replace, soon.
than one active reference to a file descriptor. It should dislodge threads
sleeping while holding a reference to the descriptor. Implemented only for
sockets but should be extended to pipes, fifos, etc.
Fixes the case of a multithreaded process doing something like the
following, which would have hung until the process got a signal.
thr0 accept(fd, ...)
thr1 close(fd)
Improve PMF-ability.
Add a 'flags' argument to suspend/resume handlers and
callers such as pmf_system_suspend().
Define a flag, PMF_F_SELF, which indicates to PMF that a
device is suspending/resuming itself. Add helper routines,
pmf_device_suspend_self(dev) and pmf_device_resume_self(dev),
that call pmf_device_suspend(dev, PMF_F_SELF) and
pmf_device_resume(dev, PMF_F_SELF), respectively. Use
PMF_F_SELF to suspend/resume self in ath(4), audio(4),
rtw(4), and sip(4).
In ath(4) and in rtw(4), replace the icky sc_enable/sc_disable
callbacks, provided by the bus front-end, with
self-suspension/resumption. Also, clean up the bus
front-ends. Make sure that the interrupt handler is
disestablished during suspension. Get rid of driver-private
flags (e.g., RTW_F_ENABLED, ath_softc->sc_invalid); use
device_is_active()/device_has_power() calls, instead.
In the network-class suspend handler, call if_stop(, 0)
instead of if_stop(, 1), because the latter is superfluous
(bus- and driver-suspension hooks will 'disable' the NIC),
and it may cause recursion.
In the network-class resume handler, prevent infinite
recursion through if_init() by getting out early if we are
self-suspending (PMF_F_SELF).
rtw(4) improvements:
Destroy rtw(4) callouts when we detach it. Make rtw at
pci detachable. Print some more information with the "rx
frame too long" warning.
Remove activate() methods:
Get rid of rtw_activate() and ath_activate(). The device
activate() methods are not good for much these days.
Make ath at cardbus resume with crypto functions intact:
Introduce a boolean device property, "pmf-powerdown". If
pmf-powerdown is present and false, it indicates that a
bus back-end should not remove power from a device.
Honor this property in cardbus_child_suspend().
Set this property to 'false' in ath_attach(), since removing
power from an ath at cardbus seems to lobotomize the WPA
crypto engine. XXX Should the pmf-powerdown property
propagate toward the root of the device tree?
Miscellaneous ath(4) changes:
Warn if ath(4) tries to write crypto keys to suspended
hardware.
Reduce differences between FreeBSD and NetBSD in ath(4)
multicast filter setup.
Make ath_printrxbuf() print an rx descriptor's status &
key index, to help debug crypto errors.
Shorten a staircase in ath_ioctl(). Don't check for
ieee80211_ioctl() return code ERESTART, it never happens.
Add a device iterator object, deviter_t, and methods deviter_init(),
deviter_first(), and deviter_next() for visiting each device in
the device tree.
Take care not to re-shutdown a device in the event that the machine
panics during reboot and the operator types 'reboot' at the kernel
debugger prompt.
While I'm here, sprinkle PMF_FN_ARGS, PMF_FN_PROTO, et cetera.
by config_detach_children(), because the latter can work recursively
and remove any number of devices, so rewrite config_detach_children()
to restart list traversal after each call of config_detach(), and since
only one user of device_foreach_child() is left (in kern_drvctl.c),
and it is simpler to open-code the loop than to deal with callbacks,
just remove it.
"execute a command" ioctl that takes a dictionary as an argument
(specifying the command and arguments) and returns a dictionary
with the results (error code, optional error message, optional
result data).
- Define and implement a "get-properties" command for DRVCTLCOMMAND
that returns the properties dictionary of the specified device.
- Add a -p flag to drvctl(8) to fetch and display the properties of
the specified device.
This is a great example of how to use prop_dictionary_sendrecv_ioctl().
christos