defined and will allow consumers, willing to provide options, file and
line to locking requests, to not worry about options redefining the
interfaces.
This is typically useful when there is the need to build another
locking interface on top of the mutex one.
The introduced functions that consumers can use are:
- mtx_lock_flags_
- mtx_unlock_flags_
- mtx_lock_spin_flags_
- mtx_unlock_spin_flags_
- mtx_assert_
- thread_lock_flags_
Spare notes:
- Likely we can get rid of all the 'INVARIANTS' specification in the
ppbus code by using the same macro as done in this patch (but this is
left to the ppbus maintainer)
- all the other locking interfaces may require a similar cleanup, where
the most notable case is sx which will allow a further cleanup of
vm_map locking facilities
- The patch should be fully compatible with older branches, thus a MFC
is previewed (infact it uses all the underlying mechanisms already
present).
Comments review by: eadler, Ben Kaduk
Discussed with: kib, jhb
MFC after: 1 month
- To avoid having a bunch of locks that end up always getting acquired as
a group, give each ppc(4) device a mutex which it shares with all the
child devices including ppbus(4), lpt(4), plip(4), etc. This mutex
is then used for all the locking.
- Rework the interrupt handling stuff yet again. Now ppbus drivers setup
their interrupt handler during attach and tear it down during detach
like most other drivers. ppbus(4) only invokes the interrupt handler
of the device that currently owns the bus (if any) when an interrupt
occurs, however. Also, interrupt handlers in general now accept their
softc pointers as their argument rather than the device_t. Another
feature of the ppbus interrupt handlers is that they are called with
the parent ppc device's lock already held. This minimizes the number
of lock operations during an interrupt.
- Mark plip(4), lpt(4), pcfclock(4), ppi(4), vpo(4) MPSAFE.
- lpbb(4) uses the ppc lock instead of Giant.
- Other plip(4) changes:
- Add a mutex to protect the global tables in plip(4) and free them on
module unload.
- Add a detach routine.
- Split out the init/stop code from the ioctl routine into separate
functions.
- Other lpt(4) changes:
- Use device_printf().
- Use a dedicated callout for the lptout timer.
- Allocate the I/O buffers at attach and detach rather than during
open and close as this simplifies the locking at the cost of
1024+32 bytes when the driver is attached.
- Other ppi(4) changes:
- Use an sx lock to serialize open and close.
- Remove unused HADBUS flag.
- Add a detach routine.
- Use a malloc'd buffer for each read and write to avoid races with
concurrent read/write.
- Other pps(4) changes:
- Use a callout rather than a callout handle with timeout().
- Conform to the new ppbus requirements (regular mutex, non-filter
interrupt handler). pps(4) is probably going to have to become a
standalone driver that doesn't use ppbus(4) to satisfy it's
requirements for low latency as a result.
- Use an sx lock to serialize open and close.
- Other vpo(4) changes:
- Use the parent ppc device's lock to create the CAM sim instead of
Giant.
- Other ppc(4) changes:
- Fix ppc_isa's detach method to detach instead of calling attach.
Tested by: no one :-(
other fixes:
- Add pointers back to device_t objects in softc structures instead
of storing the unit and using devclass_get_device().
- Add 'lpbb', 'pcf', 'pps', and 'vpo' child devices to every 'ppbus' device
instead of just the first one.
- Store softc pointers in si_drv1 of character devices instead of
pulling the unit number from the minor number and using
devclass_get_softc() and devclass_get_device().
- Store the LP_BYPASS flag in si_drv2 instead of encoding it in the minor
number.
- Destroy character devices for lpt(4) when detaching the device.
- Use bus_print_child_footer() instead of duplicating it in
ppbus_print_child() and fix ppbus_print_child()'s return value.
- Remove unused AVM ivar from ppbus.
- Don't store the 'mode' ivar in the ppbus ivars since we always fetch it
from the parent anyway.
- Try to detach all the child devices before deleting them in
ppbus_detach().
- Use pause() instead of a tsleep() on a dummy address when polling the
ppbus.
- Use if_printf() and device_printf() instead of explicit names with unit
numbers.
Silence on: current@
Note1: the correct interrupt level is invoked correctly for each driver.
For this purpose, drivers request the bus before being able to
call BUS_SETUP_INTR and BUS_TEARDOWN_INTR call is forced by the ppbus
core when drivers release it. Thus, when BUS_SETUP_INTR is called
at ppbus driver level, ppbus checks that the caller owns the
bus and stores the interrupt handler cookie (in order to unregister
it later).
Printing is impossible while plip link is up is still TRUE.
vpo (ZIP driver) and lpt are make in such a way that
using the ZIP and printing concurrently is permitted is also TRUE.
Note2: specific chipset detection is not done by default. PPC_PROBE_CHIPSET
is now needed to force chipset detection. If set, the flags 0x40
still avoid detection at boot.
Port of the pcf(4) driver to the newbus system (was previously directly
connected to the rootbus and attached by a bogus pcf_isa_probe function).
+ ECP parallel port chipset FIFO detection
+ DMA+FIFO parallel I/O handled as chipset specific
+ nlpt updated in order to use the above enhanced parallel I/O.
Use 'lptcontrol -e' to use enhanced I/O
+ Various options documented in LINT
+ Full IEEE1284 NIBBLE and BYTE modes support. See ppbus(4) for
an overview of the IEEE1284 standard
+ Detection of PnP parallel devices at boot
+ Read capability added to nlpt driver to get IEEE1284 compliant
printer status with a simple 'cat /dev/lpt0'
+ IEEE1284 peripheral emulation added to BYTE mode. Two computers
may dialog according to IEEE1284 signaling method.
See PERIPH_1284 option and /sys/dev/ppbus/ppi.c
All this code is supposed to provide basic functions for IEEE1284 programming.
ppi.c and nlpt.c may act as examples.
- ppbus now supports PLIP via the if_plip driver
- ieee1284 infrastructure added, including parallel-port PnP
- port microsequencer added, for scripting the sort of port I/O
that is common with parallel devices without endless calls up and down
through the driver structure.
- improved bus ownership behaviour among the ppbus-using drivers.
- improved I/O chipset feature detection
The vpo driver is now implemented using the microsequencer, leading to
some performance improvements as well as providing an extensive example
of its use.
Reviewed by: msmith
Submitted by: Nicolas Souchu <Nicolas.Souchu@prism.uvsq.fr>
- interrupt-driven printing now works (nlpt)
- Rearrangement of bus-related functions into ppb_base/ppbconf
- Addition of ieee1284 interface functions, preliminary parallel-port
PnP support
Submitted by: Nicolas Souchu <Nicolas.Souchu@prism.uvsq.fr>
