The newbus lock is responsible for protecting newbus internIal structures,
device states and devclass flags. It is necessary to hold it when all
such datas are accessed. For the other operations, softc locking should
ensure enough protection to avoid races.
Newbus lock is automatically held when virtual operations on the device
and bus are invoked when loading the driver or when the suspend/resume
take place. For other 'spourious' operations trying to access/modify
the newbus topology, newbus lock needs to be automatically acquired and
dropped.
For the moment Giant is also acquired in some key point (modules subsystem)
in order to avoid problems before the 8.0 release as module handlers could
make assumptions about it. This Giant locking should go just after
the release happens.
Please keep in mind that the public interface can be expanded in order
to provide more support, if there are really necessities at some point
and also some bugs could arise as long as the patch needs a bit of
further testing.
Bump __FreeBSD_version in order to reflect the newbus lock introduction.
Reviewed by: ed, hps, jhb, imp, mav, scottl
No answer by: ariff, thompsa, yongari
Tested by: pho,
G. Trematerra <giovanni dot trematerra at gmail dot com>,
Brandon Gooch <jamesbrandongooch at gmail dot com>
Sponsored by: Yahoo! Incorporated
Approved by: re (ksmith)
probe. The current device order is unchanged. This commit just adds the
infrastructure and ABI changes so that it is easier to merge later changes
into 8.x.
- Driver attachments now have an associated pass level. Attachments are
not allowed to probe or attach to drivers until the system-wide pass level
is >= the attachment's pass level. By default driver attachments use the
"last" pass level (BUS_PASS_DEFAULT). Driver's that wish to probe during
an earlier pass use EARLY_DRIVER_MODULE() instead of DRIVER_MODULE() which
accepts the pass level as an additional parameter.
- A new method BUS_NEW_PASS has been added to the bus interface. This
method is invoked when the system-wide pass level is changed to kick off
a rescan of the device tree so that drivers that have just been made
"eligible" can probe and attach.
- The bus_generic_new_pass() function provides a default implementation of
BUS_NEW_PASS(). It first allows drivers that were just made eligible for
this pass to identify new child devices. Then it propogates the rescan to
child devices that already have an attached driver by invoking their
BUS_NEW_PASS() method. It also reprobes devices without a driver.
- BUS_PROBE_NOMATCH() is only invoked for devices that do not have
an attached driver after being scanned during the final pass.
- The bus_set_pass() function is used during boot to raise the pass level.
Currently it is only called once during root_bus_configure() to raise
the pass level to BUS_PASS_DEFAULT. This has the effect of probing all
devices in a single pass identical to previous behavior.
Reviewed by: imp
Approved by: re (kib)
to the devctl notification queue. Empty strings cause devctl read
call to return 0 and result in devd exiting prematurely.
The actual offender (ugen notes for root hubs) will be fixed
by separate commit.
was introduced. If you have a bus, say cardbus, that is derived from
a base-bus (say PCI), then ordinarily all PCI drivers would attach to
cardbus devices. However, there had been one exception: kldload
wouldn't work.
The problem is in devclass_add_driver. In this routine, all we did
was call to the pci device's BUS_DRIVER_ADDED routine. However, since
cardbus bus instances had a different devclass, none of them were
called.
The solution is to call all subclass devclasses, recursively down the
tree, of the class that was loaded. Since we don't have a 'children
class' pointer, we search the whole list of devclasses for a class
whose parent matches. Since just done a kldload time, this isn't as
bad as it sounds. In addition, we short-circuit the whole process by
marking those classes with subclasses with a flag. We'll likely have
to reevaluate this method the number of devclasses with subclasses
gets large.
This means we can remove the "cardbus" lines from all the PCI drivers
since we have no cardbus specific attach device attachments in the
tree.
# Also: minor tweak to an error message
Attach call without devclass set crashes the system.
On resume AHCI driver sometimes tries to create duplicate adX device.
It is surely his own problem, but IMHO it is not a reason to crash here.
Other reasons are also possible.
- An "at" hint now reserves a device name.
- A new BUS_HINT_DEVICE_UNIT method is added to the bus interface. When
determining the unit number of a device, this method is invoked to
let the bus driver specify the unit of a device given a specific
devclass. This is the only way a device can be given a name reserved
via an "at" hint.
- Implement BUS_HINT_DEVICE_UNIT() for the acpi(4) and isa(4) bus drivers.
Both of these busses implement this by comparing the resources for a
given hint device with the resources enumerated by ACPI/PnPBIOS and
wire a unit if the hint resources are a subset of the "real" resources.
- Use bus_hinted_children() for adding hinted devices on isa(4) busses
now instead of doing it by hand.
- Remove the unit kludging from sio(4) as it is no longer necessary.
Prodding from: peter, imp
OK'd by: marcel
MFC after: 1 month
designed drivers would never hit, but was exposed in diving into
another problem...
When expanding the devclass array, free the old memory after updating
the pointer to the new memory. For the following single race case,
this helps:
allocate new memory
copy to new memory
free old memory
<interrupt> read pointer to freed memory
update pointer to new memory
Now we do
allocate new memory
copy to new memory
update pointer to new memory
free old memory
Which closes this problem, but doesn't even begin to address the
multicpu races, which all should be covered by Giant at the moment,
but likely aren't completely.
Note: reviewers were ok with this fix, but suggested the use case
wasn't one we wanted to encourage.
Reviewed by: jhb, scottl.
devsoftc.async_proc != NULL because the latter might not be true
sometimes.
This way /etc/rc.suspend gets executed.
Reviwed by: njl
Submitted by: Mitsuru IWASAKI <iwasaki at jp.FreeBSD.org>
Tested also by: Andreas Wetzel <mickey242 at gmx.net>
MFC after: 1 week
resource to a CPU. The default method is to pass the request up to the
parent similar to BUS_CONFIG_INTR() so that all busses don't have to
explicitly implement bus_bind_intr. A bus_bind_intr(9) wrapper routine
similar to bus_setup/teardown_intr() is added for device drivers to use.
Unbinding an interrupt is done by binding it to NOCPU. The IRQ resource
must be allocated, but it can happen in any order with respect to
bus_setup_intr(). Currently it is only supported on amd64 and i386 via
nexus(4) methods that simply call the intr_bind() routine.
Tested by: gallatin
know if has siblings that need an actual probe. Introduce a specail
return value called BUS_PROBE_NOOWILDCARD. If the driver returns
this, the probe is only successful for devices that have had a
specific devclass set for them.
Reviewed by: current@, jhb@, grehan@
framework for non-MPSAFE network protocols:
- Remove debug_mpsafenet variable, sysctl, and tunable.
- Remove NET_NEEDS_GIANT() and associate SYSINITSs used by it to force
debug.mpsafenet=0 if non-MPSAFE protocols are compiled into the kernel.
- Remove logic to automatically flag interrupt handlers as non-MPSAFE if
debug.mpsafenet is set for an INTR_TYPE_NET handler.
- Remove logic to automatically flag netisr handlers as non-MPSAFE if
debug.mpsafenet is set.
- Remove references in a few subsystems, including NFS and Cronyx drivers,
which keyed off debug_mpsafenet to determine various aspects of their own
locking behavior.
- Convert NET_LOCK_GIANT(), NET_UNLOCK_GIANT(), and NET_ASSERT_GIANT into
no-op's, as their entire behavior was determined by the value in
debug_mpsafenet.
- Alias NET_CALLOUT_MPSAFE to CALLOUT_MPSAFE.
Many remaining references to NET_.*_GIANT() and NET_CALLOUT_MPSAFE are still
present in subsystems, and will be removed in followup commits.
Reviewed by: bz, jhb
Approved by: re (kensmith)
device_add_child_ordered(). Previously, a device driver that wanted to
add a new child device in its identify routine had to know if the parent
driver had a custom bus_add_child method and use BUS_ADD_CHILD() in that
case, otherwise use device_add_child(). Getting it wrong in either
direction would result in panics or failure to add the child device. Now,
BUS_ADD_CHILD() always works isolating child drivers from having to know
intimate details about the parent driver.
Discussed with: imp
MFC after: 1 week
required by arches like sparc64 (not yet implemented) and sun4v where there
are seperate IOMMU's for each PCI bus... For all other arches, it will
end up returning NULL, which makes it a no-op...
Convert a few drivers (the ones we've been working w/ on sun4v) to the
new convection... Eventually all drivers will need to replace the parent
tag of NULL, w/ bus_get_dma_tag(dev), though dev is usually different for
each driver, and will require hand inspection...
Reviewed by: scottl (earlier version)
to use the hinted child system. Bus drivers that use this need to
implmenet the bus_hinted_child method, where they actually add the
child to their bus, as they see fit. The bus is repsonsible for
getting the attribtues for the child, adding it in the right order,
etc. ISA hinting will be updated to use this method.
MFC After: 3 days
used by utilities to reset moused(8), for example. The syntax is:
!system=kern subsystem=power type=resume
Note that it would be nice to have notification of suspend, but it's more
difficult since there would have to be a method of doing request/ack
to userland and automatically timing out if no response. apm(4) has a
similar mechanism.
MFC after: 2 weeks
devclass's parent pointer if the two drivers share the same devclass. This
can happen if the drivers use the same new-bus name. For example, we
currently have 3 drivers that use the name "pci": the generic PCI bus
driver, the ACPI PCI bus driver, and the OpenFirmware PCI bus driver. If
the ACPI PCI bus driver was defined as a subclass of the generic PCI bus
driver, then without this check the "pci" devclass would point to itself
as its parent and device_probe_child() would spin forever when it
encountered the first PCI device that did have a matching driver.
Reviewed by: dfr, imp, new-bus@
and bus_free_resources(). These functions take a list of resources
and handle them all in one go. A flag makes it possible to mark
a resource as optional.
A typical device driver can save 10-30 lines of code by using these.
Usage examples will follow RSN.
MFC: A good idea, eventually.
1. Copy a NULL-terminated string into a fixed-length buffer, and
2. copyout that buffer to userland,
we really ought to
0. Zero the entire buffer
first.
Security: FreeBSD-SA-05:08.kmem
instances in a given devclass. This is useful for systems that want to
call code in driver static methods, similar to device_identify().
Reviewed by: dfr
MFC after: 2 weeks
in a devclass. All the other uses of maxunit are correct and this one was
safe since it checks the return value of devclass_get_device(), which would
always say that the highest unit device doesn't exist.
Reviewed by: dfr
MFC after: 3 days
last in the list rather than first.
This makes the resouces print in the 4.x order rather than the 5.x order
(eg fdc0 at 0x3f0-0x3f5,0x3f7 is 4.x, but 0x3f7,0x3f0-0x3f5 is 5.x). This
also means that the pci code will once again print the resources in BAR
ascending order.
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.
and that I've verified things seem to basically work. I was able to
boot and hot plug usb devices. Please let me know if this causes
problems for anybody.
The push down of giant has proceeded to the point that this will start
to matter more and more.
* Get flags first, in case there is no devclass.
* Reset flags after each probe in case the next driver has no hints so it
doesn't inherit the old ones.
* Set them again before the winning probe.
Tested ok both with and without ACPI for ISA device flags.
Reviewed by: imp
MFC after: 1 day
this in my tree for a while and in its disabled state there are no
issues. It isn't enabled yet because some drivers (in acpi) have side
effects in their probe routines that need to be resolved in some
manner before this can be turned on. The consensus at the last
developer's summit was to provide a static method for each driver
class that will return characteristics of the driver, one of which is
if can be reprobed idempotently.
address I've lost, that move the location information to the atttach
routine as well. While one could use devinfo to get this data, that
is difficult and error prone and subject to races for short lived
devices.
Would make a good MT5 candidate.
for unknown events.
A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".
devremoved events. This reduces the races around these events. We
now include the pnp info in both. This lets one do more interesting
thigns with devd on device insertion.
Submitted by: Bernd Walter
tree, output an empty string instead of "?". This is already what
happened with DEVICE_SYSCTL_LOCATION and DEVICE_SYSCTL_PNPINFO. This
makes the output of "sysctl dev" much nicer (it won't display those
empty sysctls).
Reviewed by: des
class variables in addition to per-device variables. In plain English,
this means that dev.foo0.bar is now called dev.foo.0.bar, and it is
possible to to have dev.foo.bar as well.
Introduce d_version field in struct cdevsw, this must always be
initialized to D_VERSION.
Flip sense of D_NOGIANT flag to D_NEEDGIANT, this involves removing
four D_NOGIANT flags and adding 145 D_NEEDGIANT flags.
o move it from subr_bus.c to netisr.c where it more properly belongs
o add NET_PICKUP_GIANT and NET_DROP_GIANT macros that will be used to
grab Giant as needed when MPSAFE operation is enabled
Supported by: FreeBSD Foundation
classes and if a method is not found in a given class, its base classes
are searched (in the order they were declared). This search is recursive,
i.e. a method may be define in a base class of a base class.
* Change the kobj method lookup algorithm to one which is SMP-safe. This
relies only on the constraint that an observer of a sequence of writes
of pointer-sized values will see exactly one of those values, not a
mixture of two or more values. This assumption holds for all processors
which FreeBSD supports.
* Add locking to kobj class initialisation.
* Add a simpler form of 'inheritance' for devclasses. Each devclass can
have a parent devclass. Searches for drivers continue up the chain of
devclasses until either a matching driver is found or a devclass is
reached which has no parent. This can allow, for instance, pci drivers
to match cardbus devices (assuming that cardbus declares pci as its
parent devclass).
* Increment __FreeBSD_version.
This preserves the driver API entirely except for one minor feature used
by the ISA compatibility shims. A workaround for ISA compatibility will
be committed separately. The kobj and newbus ABI has changed - all modules
must be recompiled.
accesses softc after it is freed. Use a different malloc type for
softc than the rest of the bus code to make it more clear when these
things happen that it is the driver that's at fault, not the bus code.
Suggested by: sam and/or phk (I think)
about interrupt trigger mode and interrupt polarity. This allows ACPI
for example to pass interrupt resource information up the hierarchy.
The default implementation of the method therefore is to pass the
request to the parent.
Reviewed by: jhb, njl
and/or INTR_FAST. This belongs elsehwere and perhaps under bootverbose;
I'm committing it for now as it's uesful to know which drivers have
been converted and which have not.
