reacquiring driver lock in Rx handler. re(4) drops a driver lock
before passing received frame to upper stack and reacquire the
lock. During the time window ioctl calls could be executed and if
the ioctl was interface down request, driver will stop the
controller and free allocated mbufs. After that when driver comes
back to Rx handler again it does not know what was happend so it
could access free mbufs which in turn cause panic.
Reported by: Norbert Papke < npapk <> acm dot org >
Tested by: Norbert Papke < npapk <> acm dot org >
from tuning(7). One of the descriptions references tuning(7) because
it is too complex to adequatly describe here (it is not a simple
boolean sysctl) and users should be warned to that.
Reviewed by: alc, kib
Approved by: gnn (mentor)
- Don't write actual length if the actual length pointer is NULL [2]
- correct Linux Compatibility error codes for short isochronous IN transfers
and make status field signed.
Submitted by: Leunam Elebek [1], Manuel Gebele [2]
Fix reference counting bug, when device unreferenced before then
invalidated. To do it, do not handle validity flag as another
reference, but explicitly modify reference count each time flag is
modified.
Discovered by: thompsa
o Move all code into a single file for easier maintenance.
o Use a single global lock to avoid having to handle either
multiple locks or race conditions.
o Make sure to disable the high FP registers after saving
or dropping them.
o use msleep() to wait for the other CPU to save the high
FP registers.
This change fixes the high FP inconsistency panics.
A single global lock typically serializes too much, which may
be noticable when a lot of threads use the high FP registers,
but in that case it's probably better to switch the high FP
context synchronuously. Put differently: cpu_switch() should
switch the high FP registers if the incoming and outgoing
threads both use the high FP registers.
the current value of its argument before atomically replacing it, which
could occasionally return the wrong value on an SMP system. This resulted
in user mutex operations hanging when using threaded applications.
version of this file. When a process forks, any wired pages are immediately
copied because copy-on-write is not supported for wired pages. In other
words, the child process is given its own private copy of each wired page
from its parent's address space. Unfortunately, to date, these copied pages
have been mapped into the child's address space with the wrong permissions,
typically VM_PROT_ALL. This change corrects the permissions.
Reviewed by: kib
do support 64bit addresses, the current SCRIPTS code supports only 32bit
addresses causing data corruption for buffer addresses >4GB. This problem
affects 64bit machines with more than 4GB RAM or amd64 with 4GB and
memory hole remapping.
Work-around this problem with a bus_dma tag that requests bounce-buffers
for addresses >4GB. This causes some overhead, but given the maximum SCSI
bus speed of 160MB/s compared, the effect should hardly be noticeable.
The problem was reported by Mike Watters (mike at mwatters net) who also
verified that this fix cures the problem.
Since this change is a NOOP on systems with less than 4GB RAM and fixes
data corruption (in RAM and on disk) on systems with more than 4GB, I hope
that this change is accepted for 8.0.
MFC after: 3 days (pending approval)
- Remove most of direct relations between ATA(4) peripherial and controller
levels. It makes logic more transparent and is a mandatory step to wrap
ATA(4) controller level into ATA-native CAM SIM.
- Tune AHCI and SATA2 SiI drivers memory allocation a bit to allow bigger
I/O transaction sizes without additional cost.
- Reduce code duplication in ATA XPT and PMP driver.
- Move PIO size setting from ada driver to ATA XPT. It is XPT business
to negotiate transfer details. ada driver is now stateless.
- Report PIO size to SIM. It is required for correct PATA SIM operation.
- Tune PMP scan timings. It workarounds some problems with SiI.
- If reset hapens during PMP initialization - restart it.
- Introduce early-initialized periph drivers, which are used during initial
scan process. Use it for xpt, probe, aprobe and pmp. It gives pmp chance
to finish scan before mountroot and numerate devices in right order.
There is no need to use the lower 4 bits of the unit number to store the
device type number. Just use 0 and 1 to distinguish them. devfs also
guarantees that there can never be an open call on a device that has a
unit number different to 0 and 1, so there is no need to check for this
in open().
d_uid, d_gid and d_mode are unused, because permissions are stored in
cdevpriv nowadays. d_kind doesn't seem to be used at all. We no longer
keep a list of cdevsw's, so d_list is also unused.
uid_t and gid_t are 32 bits, but mode_t is 16 bits, Because of alignment
constraints of d_kind, we can safely turn it into three 32-bit integers.
d_kind and d_list is equal in size to three pointers.
Discussed with: kib
Ensure target/lun passed from user-level supported on this bus.
Scanning unsupported IDs causes different issues from duplicate
devices to system crash.
zfs_access() instead of vaccess() in this case as well.
- If VADMIN is specified with another V* flag (unlikely) call both
zfs_access() and vaccess() after spliting V* flags.
This fixes "dirtying snapshot!" panic.
PR: kern/139806
Reported by: Carl Chave <carl@chave.us>
In co-operation with: jh
MFC after: 3 days
- Don't bother to assign vb until we know we have enough space
- Add variables for sx2, sy2, dx2, dy2 so that these aren't
calculated over and over, also reduce chance of errors.
- Use switch to assign color/format
MFC after: 3 days
- We don't need to check malloc return values with M_WAITOK
- remove variables that we don't really need
- cleanup the error paths by just calling drm_sg_cleanup()
- fix drm_sg_cleanup() to be safe to call at any time
MFC after: 2 weeks
lock and curproc->p_sigacts->ps_mtx. Reschedule_signals may need to have
ps_mtx locked to decide and wakeup a thread, causing recursion on the
mutex.
Inform kern_sigprocmask() and reschedule_signals() about lock state
of the ps_mtx by new flag SIGPROCMASK_PS_LOCKED to avoid recursion.
Reported and tested by: keramida
MFC after: 1 month
obsoleted in 1996 by ATA-2, and crashes some modern hardware like some
revisions of the Serverworks K2 SATA controller. Even very ancient
hardware seems not to require it. In the unlikely event this causes
problems, the previous behavior can be re-enabled by defining
ATA_LEGACY_SUPPORT at the top of this file.
Reviewed by: Alexander Motin <mav@freebsd.org>
partially fixed on amd64 earlier. Rather than forcing linux_mmap_common()
to use a 32-bit offset, have it accept a 64-bit file offset. This offset
is then passed to the real mmap() call. Rather than inventing a structure
to hold the normal linux_mmap args that has a 64-bit offset, just pass
each of the arguments individually to linux_mmap_common() since that more
closes matches the existing style of various kern_foo() functions.
Submitted by: Christian Zander @ Nvidia
MFC after: 1 week
well-known race condition, which elimination was the reason for the
function appearance in first place. If sigmask supplied as argument to
pselect() enables a signal, the signal might be delivered before thread
called select(2), causing lost wakeup. Reimplement pselect() in kernel,
making change of sigmask and sleep atomic.
Since signal shall be delivered to the usermode, but sigmask restored,
set TDP_OLDMASK and save old mask in td_oldsigmask. The TDP_OLDMASK
should be cleared by ast() in case signal was not gelivered during
syscall execution.
Reviewed by: davidxu
Tested by: pho
MFC after: 1 month
while in kernel mode, and later changing signal mask to block the
signal, was fixed for sigprocmask(2) and ptread_exit(3). The same race
exists for sigreturn(2), setcontext(2) and swapcontext(2) syscalls.
Use kern_sigprocmask() instead of direct manipulation of td_sigmask to
reschedule newly blocked signals, closing the race.
Reviewed by: davidxu
Tested by: pho
MFC after: 1 month
kern_sigprocmask() to properly notify other possible candidate threads
for signal delivery.
Since sigsuspend() shall only return to usermode after a signal was
delivered, do cursig/postsig loop immediately after waiting for
signal, repeating the wait if wakeup was spurious due to race with
other thread fetching signal from the process queue before us. Add
thread_suspend_check() call to allow the thread to be stopped or killed
while in loop.
Modify last argument of kern_sigprocmask() from boolean to flags,
allowing the function to be called with locked proc. Convertion of the
callers that supplied 1 to the old argument will be done in the next
commit, and due to SIGPROCMASK_OLD value equial to 1, code is formally
correct in between.
Reviewed by: davidxu
Tested by: pho
MFC after: 1 month
install new shadow object behind the map entry and copy the pages
from the underlying objects to it. This makes the mprotect(2) call to
actually perform the requested operation instead of silently do nothing
and return success, that causes SIGSEGV on later write access to the
mapping.
Reuse vm_fault_copy_entry() to do the copying, modifying it to behave
correctly when src_entry == dst_entry.
Reviewed by: alc
MFC after: 3 weeks
no matter whether we are compiled as module or if our default of the
net.inet6.ip6.v6only sysctl already matches what we would set.
This avoids unnecessary complications with modules, VIMAGES, INET6 and
the sysctl value, especially considering that most users will use
linux compat as a module.
Discussed with: kib, rwatson (weeks ago)
Reviewed by: rwatson
MFC after: 6 weeks
more stack hungry as compared to the old one that my RX2660 gets
a machine check and spontaneously reboots at the time the USB DVD
drive is found and attached to CAM as a mass storage device. This
doesn't happen always, but definitely varies per kernel build.
Likewise when using a 128-byte printf buffer. The additional 128
bytes that printf needs seems to be enough to have the memory stack
and register stack collide and causing a machine check.
Thus: Bump KSTACK_PAGES from 4 to 5.
* iwnfw has now been split into individual modules so autoloading of
firmware module(s) does work again.
* Changes have been made to RUN -> AUTH transition, this should fix the
issue reported by Glen and others.
* Brandon reported issues in iwn_cmd() with large commands, those have
been fixed to.
* DEAUTH is now handled correctly.
Submitted by: Bernhard Schmidt <bschmidt at techwires.net>
Have the early USB takeover enabled for i386 and amd64
by default.
This also avoids a panic on PowerPC where the resource
isn't released properly and we find a busy resource
when the USB host controller wants to allocate it...
- Teach it to read gang blocks. (essentially untested)
If you see "ZFS: gang block detected!", please let
me know, so we can either remove the printf if it
works, or fix it if it doesn't.
- If multiple partitions exist on a disk, probe them all.
We also need to reset dsk->start to 0 to read the right
sector here.
- With GPT, we can have 128 partitions.
- If the bootfs property has ever been set on a pool
it seems that it never goes away. zpool won't allow
you to add to the pool with the bootfs property set.
However, if you clear the property back to default
we end up getting 0 for the object number and read
a bogus block pointer and fail to boot.
- Fix some error printfs. The printf in the loader is
only capable of c,s and u formats.
- Teach printf how to display %llu
Reviewed by: dfr, jhb
MFC after: 2 weeks
function may not work properly if we don't. Turn off hardware cursor as
vesa_set_mode() does.
- Add VBE 3.0 specific fields in VESA mode structure and pack it. Note
the padding is 190 bytes although VBE 3.0 says 189 bytes. It must be wrong
because the size of structure becomes 255 bytes and the specification says
it must be 256 bytes in total. In fact, an example code in the spec. does
it right, though. While we are at it, fix some i386-isms.
- Remove state buffer size limitation. It is no longer necessary since
sys/compat/x86bios/x86bios.c r198251.
- Move int 0x10 vector test into vesa_bios_post() as we always do it anyway.
td_name[] arrays are actually MAXCOMLEN + 1 in size and a few places that
created shadow copies of these arrays were just using MAXCOMLEN.
- Prefer using sizeof() of an array type to explicit constants for the
array length in a few places.
- Ensure that all of p_comm[] and td_name[] is always zero'd during
execve() to guard against any possible information leaks. Previously
trailing garbage in p_comm[] could be leaked to userland in ktrace
record headers via td_name[].
Reviewed by: bde
only used in real mode and keeping them mapped only serves to make NULL
a valid address, which results in silent NULL pointer deferences.
Suggested by: Patrick Kerharo
Obtained from: projects/ppc64
at least on my Xserve, getting the decrementer and timebase on APs to tick
requires setting up a clock chip over I2C, which is not yet done.
While here, correct the 64-bit tlbie function to set the CPU to 64-bit
mode correctly.
Hardware donated by: grehan
sooner so it is always valid when a driver's identify routine is
called. Previously, new-bus would attempt to create the devclass for
a newly loaded driver in two separate places, once in
devclass_add_driver(), and again after devclass_add_driver() returned
in driver_module_handler(). Only the second lookup attempted to set a
device class' parent and set the devclass_t pointer specified in the
DRIVER_MODULE() macro. However, by the time it was executed, the
driver was already added to existing instances of the parent driver at
which point in time the new driver's identify routine would have been
invoked. The fix is to merge the two attempts and only create the
devclass once in devclass_add_driver() including setting the
devclass_t pointer passed to DRIVER_MODULE() before the driver is
added to any existing bus devices.
Reported by: avg
Reviewed by: imp
MFC after: 2 weeks
the memory or D-cache, depending on the semantics of the platform.
vm_sync_icache() is basically a wrapper around pmap_sync_icache(),
that translates the vm_map_t argumument to pmap_t.
o Introduce pmap_sync_icache() to all PMAP implementation. For powerpc
it replaces the pmap_page_executable() function, added to solve
the I-cache problem in uiomove_fromphys().
o In proc_rwmem() call vm_sync_icache() when writing to a page that
has execute permissions. This assures that when breakpoints are
written, the I-cache will be coherent and the process will actually
hit the breakpoint.
o This also fixes the Book-E PMAP implementation that was missing
necessary locking while trying to deal with the I-cache coherency
in pmap_enter() (read: mmu_booke_enter_locked).
The key property of this change is that the I-cache is made coherent
*after* writes have been done. Doing it in the PMAP layer when adding
or changing a mapping means that the I-cache is made coherent *before*
any writes happen. The difference is key when the I-cache prefetches.
Separate CAM_DEV_IDENTIFY_DATA_VALID flag from CAM_DEV_INQUIRY_DATA_VALID.
Add workaround for very old devices without support for mode setting.
Add some PATA bus scanning support.
Remove some SCSIsms.
Add support for PIO-only devices.
Fix maxio values and 256 sectors transactions for 28bits commands.
Implement periodic ordered commands insertion, sames as da driver does.
Remove some SCSIsms.
splitting in bce(4) instead of (ab)using ZERO_COPY_SOCKETS that was not
propagated into if_bce.c anyway. It is disabled by default.
Approved by: davidch
MFC after: 3 days
On error, freeze device queue, to allow periph driver to do proper recovery.
Freeze SIM queue only in some cases, when it is needed to protect SIM.
Implement better command timeout detection logic for non-queued commands.
This fixes false positives when command with short timeout waiting for the
long one. For example, when hald tastes CD during burning process.
Read and clear SERR register on interrupt.
instead of POSTREAD: the hardware do not touch this memory (CPU
updates it). It is already synchronized as PREWRITE after the
processing is done.
- Synchronize RX return ring memory in rx_eof. This is needed
as the deviced updates this memory when receives packets.
- Decouple the synchronization of BGE status block in the interrupt
service routine: perfrom PREREAD synchronization only all accesses
to this block are finished. This seems to be more natural.
Reviewed by: yongari, marius
MFC after: 2 weeks
has been yanked, this works around a cam recounting bug when
CAM_DEV_UNCONFIGURED is set late in the detach. In certain conditions the
reference to the XPT device would not be released which would cause the usb
explore thread to sleep forever on "simfree", preventing any new usb devices to
be found/ejected on the bus.
This is intended to be a quick workaround to the problem without touching CAM
so it can be merged to 8.0.
Suggested by: mav
MFC after: 3 days
during system initialization time. Since the flow-table is
designed to maintain per CPU flow cache, the existing code
did not check whether "smp_started" is true before calling
sched_bind() and sched_unbind(), which triggers a page fault.
Reviewed by: jeff
MFC after: immediately
by checking PCI config space when the NIC is not
transmitting. Previously, a h/w fault would not have been
detected if the NIC was down, or handling an RX only
workload.
is compared against the entry expiration time value (that was set based
on time_second) to check if the current time is larger than the set
expiration time. Due to the +/- timer granularity value, the comparison
returns false, causing the alternative code to be executed. The
alternative code path freed the memory without removing that entry
from the table list, causing a use-after-free bug.
Reviewed by: discussed with kmacy
MFC after: immediately
Verified by: rnoland, yongari
- Introduce new SI_SUB_RANDOM point in boot sequence to make it
clear from where one may start using random(9). It should be as
early as possible, so place it just after SI_SUB_CPU where we
have some randomness on most platforms via get_cyclecount().
- Move stack protector initialization to be after SI_SUB_RANDOM
as before this point we have no randomness at all. This fixes
stack protector to actually protect stack with some random guard
value instead of a well-known one.
Note that this patch doesn't try to address arc4random(9) issues.
With current code, it will be implicitly seeded by stack protector
and hence will get the same entropy as random(9). It will be
securely reseeded once /dev/random is feeded by some entropy from
userland.
Submitted by: Maxim Dounin <mdounin@mdounin.ru>
MFC after: 3 days
support unloading. It's not trivial to implement newnfslock unloading so
for now just admit that unloading is unsupported and refuse to attempt
unload in all nfscl module event handlers.
Reviewed by: rmacklem
Approved by: trasz (mentor)
be called after ncl_uninit() when unloading the nfscl module because
ncl_uninit() uses ncl_iod_mutex which is destroyed in nfscl_modevent().
Reviewed by: rmacklem
Approved by: trasz (mentor)
the race where interrupt thread can complete the request for which
timeout has fired and while mpt_timeout has blocked on mpt_lock.
Do a best effort to keep 4.x ang Giant-locked configurartions
compiling still.
Reported by: ups
Reviewed by: scottl
- Do not map entire real mode memory (1MB). Instead, we map IVT/BDA and
ROM area separately. Most notably, ROM area is mapped as device memory
(uncacheable) as it should be. User memory is dynamically allocated and
free'ed with contigmalloc(9) and contigfree(9). Remove now redundant and
potentially dangerous x86bios_alloc.c. If this emulator ever grows to
support non-PC hardware, we may implement it with rman(9) later.
- Move all host-specific initializations from x86emu_util.c to x86bios.c and
remove now unnecessary x86emu_util.c. Currently, non-PC hardware is not
supported. We may use bus_space(9) later when the KPI is fixed.
- Replace all bzero() calls for emulated registers with more obviously named
x86bios_init_regs(). This function also initializes DS and SS properly.
- Add x86bios_get_intr(). This function checks if the interrupt vector is
available for the platform. It is not necessary for PC-compatible hardware
but it may be needed later. ;-)
- Do not try turning off monitor if DPMS does not support the state.
- Allocate stable memory for VESA OEM strings instead of just holding
pointers to them. They may or may not be accessible always. Fix a memory
leak of video mode table while I am here.
- Add (experimental) BIOS POST call for vesa(4). This function calls VGA
BIOS POST code from the current VGA option ROM. Some video controllers
cannot save and restore the state properly even if it is claimed to be
supported. Usually the symptom is blank display after resuming from suspend
state. If the video mode does not match the previous mode after restoring,
we try BIOS POST and force the known good initial state. Some magic was
taken from NetBSD (and it was taken from vbetool, I believe.)
- Add a loader tunable for vgapci(4) to give a hint to dpms(4) and vesa(4)
to identify who owns the VESA BIOS. This is very useful for multi-display
adapter setup. By default, the POST video controller is automatically
probed and the tunable "hw.pci.default_vgapci_unit" is set to corresponding
vgapci unit number. You may override it from loader but it is very unlikely
to be necessary. Unfortunately only AGP/PCI/PCI-E controllers can be
matched because ISA controller does not have necessary device IDs.
- Fix a long standing bug in state save/restore function. The state buffer
pointer should be ES:BX, not ES:DI according to VBE 3.0. If it ever worked,
that's because BX was always zero. :-)
- Clean up register initializations more clearer per VBE 3.0.
- Fix a lot of style issues with vesa(4).
* fix the processing of RANN frames
* the originator and target addresses were swapped and while it worked
fine, it was not spec compliant.
MFC after: 3 days
Now that buffers are deallocated lazily, we should not use
tty*q_getsize() to obtain the buffer size to calculate the low
watermarks. Doing this may cause the watermark to be placed outside the
typical buffer size.
This caused some regressions after my previous commit to the TTY code,
which allows pseudo-devices to resize the buffers as well.
Reported by: yongari, dougb
MFC after: 1 week
Devices that don't implement param() (which means they don't support
hardware parameters such as flow control, baud rate) hardcode the baud
rate to TTYDEF_SPEED. This means the buffer size cannot be configured,
which is a little inconvenient when using canonical mode with big lines
of input, etc.
Make it adjustable, but do clamp it between B50 and B115200 to prevent
awkward buffer sizes. Remove the baud rate assignment from
/etc/gettytab. Trust the kernel to fill in a proper value.
Reported by: Mikolaj Golub <to my trociny gmail com>
MFC after: 1 month
It turned out I did add the code to use the init state devices to set
the termios structure when opening the device, but it seems I totally
forgot to add the bits required to force the actual locking of flags
through the lock state devices.
Reported by: ru
MFC after: 1 week (to be discussed)
compiled to use the Medium/Low code model, which we currently default
to for the userland. GNU/Linux has moved their default to Medium/Middle
some time ago, which probably explains why the current GNU ld(1) uses
a base in the range between 32 and 44 bits instead.
Submitted by: kib
and do not relocate the binary to ET_DYN_LOAD_ADDR. This allows for the
binary author to influence address map of the process. In particular,
when the binary is actually an interpeter, this allows to have almost
usual process address map.
Communicate the relocation bias of the mapping for interpeter-less
ET_DYN binary, that is interperter itself, in AT_BASE aux entry. This
way, rtld is able to find its dynamic structure and relocate itself.
Note that mapbase in the rtld is still wrong and requires further
fixing.
Reported and tested by: rwatson
Discussed with: kan
MFC after: 3 days
Call priv_check(PRIV_VM_SWAP_NORLIMIT) only when per-uid limit is
actually exceed.
Both changes aim at calling priv_check(9) only for the cases when
privilege is actually exercised by the process.
Reported and tested by: rwatson
Reviewed by: alc
MFC after: 3 days
was major changes to initialize RF chipset and set H/W registers and
removed a lot of magic numbers on code. Details are as follows:
- uses the endpoint 0x89 to get TX status information which used to
get TX complete or retry numbers or get a beacon interrupt. It's
only valuable for RTL8187B.
- removes urtw_write[8|16|32]_i functions that it's useless now.
- uses ic->ic_updateslot to set SLOT, SIFS, DIES, EIFS, CW_VAL
registers that doesn't set these whenever the channel is changed.
- code for initializing RF chipset for RTL8187B changed a lot that
there was many problems on TX transfers so it doesn't work properly
even if just for a ping/pong. Now it becomes more stable than
before that TX throughputs using netperf(1) were about 15 ~ 17Mbps/s
though sometimes it encounters packet losses.
- removes a lot of magic numbers that in the previous all of
representing RX and TX descriptors were consisted of magic numbers
and structures. It'd be more readable rather than before.
- calculates TX duration more accurately for urtw(4) devices.
- style(9)
Applications like shells expect EOF to give no graphical output, while
our implementation prints ^D by default (tunable with stty echoctl).
Make the new implementation behave like the old TTY code. Print two
backspaces afterwards.
Reported by: koitsu
MFC after: 1 month
Specifically, clients only trust -ve cache entries while the directory
remains unchanged and discard any -ve cache entries for a directory when
they notice that the modification time of a directory entry changes. The
race involves two concurrent lookups as follows:
- Thread A does a lookup for file 'foo' which sends a lookup RPC to the
server. The lookup fails and the server replies.
- The 'foo' file is created (either by the same client or a different
client) updating the modification time on the parent directory of 'foo'.
- Thread B does a lookup for a different file 'bar' which updates the
cached attributes of the parent directory of 'foo' to reflect the new
modification time after 'foo' was created.
- Thread A finally resumes execution to parse the reply from the NFS
server. It adds a -ve cache entry and sets the cached value of the
directory's modification time that is used for invalidating -ve cached
lookups to the new modification time set by thread B.
At this point, future lookups of 'foo' will honor the -ve cached entry
until the cached entry is pushed out of the name cache's LRU or the
modification time of the parent directory is changed again by some other
change. The fix is to read the directory's modification time before
sending the lookup RPC and use that cached modification time when setting
the directory's cached modification time. Also, we do not add a -ve cache
entry if another thread has added -ve cache entry that set the directory's
cached modification time to a newer value than the value we read before
sending the lookup RPC.
Reviewed by: rmacklem
MFC after: 1 week
all host controllers at the same time, we avoid problems where the BIOS will
actually write to the USB registers of all the USB host controllers every time
we handover one of them, and consequently reset the OS programmed values.
Submitted by: avg
Reviewed by: jhb
handlers. This is primarily intended as a way to allow devices that use
multiple interrupts (e.g. MSI) to meaningfully distinguish the various
interrupt handlers.
- Add a new BUS_DESCRIBE_INTR() method to the bus interface to associate
a description with an active interrupt handler setup by BUS_SETUP_INTR.
It has a default method (bus_generic_describe_intr()) which simply passes
the request up to the parent device.
- Add a bus_describe_intr() wrapper around BUS_DESCRIBE_INTR() that supports
printf(9) style formatting using var args.
- Reserve MAXCOMLEN bytes in the intr_handler structure to hold the name of
an interrupt handler and copy the name passed to intr_event_add_handler()
into that buffer instead of just saving the pointer to the name.
- Add a new intr_event_describe_handler() which appends a description string
to an interrupt handler's name.
- Implement support for interrupt descriptions on amd64 and i386 by having
the nexus(4) driver supply a custom bus_describe_intr method that invokes
a new intr_describe() MD routine which in turn looks up the associated
interrupt event and invokes intr_event_describe_handler().
Requested by: many
Reviewed by: scottl
MFC after: 2 weeks
