now the preferred typical return value from a probe routine. Discourage
the use of 0 (BUS_PROBE_SPECIFIC) as it should be used very rarely.
Point the reader to the DEVICE_PROBE(9) manpage for more detailed notes
on possible probe return values.
Submitted by: Philip Soeberg philip-dev of soeberg net
unloaded, cleanup, or return ebusy of that's inconvenient.' The
default module hanlder for newbus will now call this when we get a
MOD_QUIESCE event, but in the future may call this at other times.
This shouldn't change any actual behavior until drivers start to use it.
non-device code.
* Re-implement the method dispatch to improve efficiency. The new system
takes about 40ns for a method dispatch on a 300Mhz PII which is only
10ns slower than a direct function call on the same hardware.
This changes the new-bus ABI slightly so make sure you re-compile any
driver modules which you use.
instances to a parent bus.
* Define a new method BUS_ADD_CHILD which can be called from DEVICE_IDENTIFY
to add new instances.
* Add a generic implementation of DEVICE_PROBE which calls DEVICE_IDENTIFY
for each driver attached to the parent's devclass.
* Move the hint-based isa probe from the isa driver to a new isahint driver
which can be shared between i386 and alpha.
through' to the C compiler.
* Allow the interface to specify a default implementation for methods.
* Allow 'static' methods which are not device specific.
* Add a simple scheme for probe routines to return a priority value. To
make life simple, priority values are negative numbers (positive numbers
are standard errno codes) with zero being the highest priority. The
driver which returns the highest priority will be chosen for the device.
- Interface wth the new resource manager.
- Allow for multiple drivers implementing a single devclass.
- Remove ordering dependencies between header files.
- Style cleanup.
- Add DEVICE_SUSPEND and DEVICE_RESUME methods.
- Move to a single-phase interrupt setup scheme.
Kernel builds on the Alpha are brken until Doug gets a chance to incorporate
these changes on that side.
Agreed to in principle by: dfr
Major changes to the generic device framework for FreeBSD/alpha:
* Eliminate bus_t and make it possible for all devices to have
attached children.
* Support dynamically extendable interfaces for drivers to replace
both the function pointers in driver_t and bus_ops_t (which has been
removed entirely. Two system defined interfaces have been defined,
'device' which is mandatory for all devices and 'bus' which is
recommended for all devices which support attached children.
* In addition, the alpha port defines two simple interfaces 'clock'
for attaching various real time clocks to the system and 'mcclock'
for the many different variations of mc146818 clocks which can be
attached to different alpha platforms. This eliminates two more
function pointer tables in favour of the generic method dispatch
system provided by the device framework.
Future device interfaces may include:
* cdev and bdev interfaces for devfs to use in replacement for specfs
and the fixed interfaces bdevsw and cdevsw.
* scsi interface to replace struct scsi_adapter (not sure how this
works in CAM but I imagine there is something similar there).
* various tailored interfaces for different bus types such as pci,
isa, pccard etc.
