attempting to duplicate Windows spinlocks. Windows spinlocks differ
from FreeBSD spinlocks in the way they block preemption. FreeBSD
spinlocks use critical_enter(), which masks off _all_ interrupts.
This prevents any other threads from being scheduled, but it also
prevents ISRs from running. In Windows, preemption is achieved by
raising the processor IRQL to DISPATCH_LEVEL, which prevents other
threads from preempting you, but does _not_ prevent device ISRs
from running. (This is essentially what Solaris calls dispatcher
locks.) The Windows spinlock itself (kspin_lock) is just an integer
value which is atomically set when you acquire the lock and atomically
cleared when you release it.
FreeBSD doesn't have IRQ levels, so we have to cheat a little by
using thread priorities: normal thread priority is PASSIVE_LEVEL,
lowest interrupt thread priority is DISPATCH_LEVEL, highest thread
priority is DEVICE_LEVEL (PI_REALTIME) and critical_enter() is
HIGH_LEVEL. In practice, only PASSIVE_LEVEL and DISPATCH_LEVEL
matter to us. The immediate benefit of all this is that I no
longer have to rely on a mutex pool.
Now, I'm sure many people will be seized by the urge to criticize
me for doing an end run around our own spinlock implementation, but
it makes more sense to do it this way. Well, it does to me anyway.
Overview of the changes:
- Properly implement hal_lock(), hal_unlock(), hal_irql(),
hal_raise_irql() and hal_lower_irql() so that they more closely
resemble their Windows counterparts. The IRQL is determined by
thread priority.
- Make ntoskrnl_lock_dpc() and ntoskrnl_unlock_dpc() do what they do
in Windows, which is to atomically set/clear the lock value. These
routines are designed to be called from DISPATCH_LEVEL, and are
actually half of the work involved in acquiring/releasing spinlocks.
- Add FASTCALL1(), FASTCALL2() and FASTCALL3() macros/wrappers
that allow us to call a _fastcall function in spite of the fact
that our version of gcc doesn't support __attribute__((__fastcall__))
yet. The macros take 1, 2 or 3 arguments, respectively. We need
to call hal_lock(), hal_unlock() etc... ourselves, but can't really
invoke the function directly. I could have just made the underlying
functions native routines and put _fastcall wrappers around them for
the benefit of Windows binaries, but that would create needless bloat.
- Remove ndis_mtxpool and all references to it. We don't need it
anymore.
- Re-implement the NdisSpinLock routines so that they use hal_lock()
and friends like they do in Windows.
- Use the new spinlock methods for handling lookaside lists and
linked list updates in place of the mutex locks that were there
before.
- Remove mutex locking from ndis_isr() and ndis_intrhand() since they're
already called with ndis_intrmtx held in if_ndis.c.
- Put ndis_destroy_lock() code under explicit #ifdef notdef/#endif.
It turns out there are some drivers which stupidly free the memory
in which their spinlocks reside before calling ndis_destroy_lock()
on them (touch-after-free bug). The ADMtek wireless driver
is guilty of this faux pas. (Why this doesn't clobber Windows I
have no idea.)
- Make NdisDprAcquireSpinLock() and NdisDprReleaseSpinLock() into
real functions instead of aliasing them to NdisAcaquireSpinLock()
and NdisReleaseSpinLock(). The Dpr routines use
KeAcquireSpinLockAtDpcLevel() level and KeReleaseSpinLockFromDpcLevel(),
which acquires the lock without twiddling the IRQL.
- In ndis_linksts_done(), do _not_ call ndis_80211_getstate(). Some
drivers may call the status/status done callbacks as the result of
setting an OID: ndis_80211_getstate() gets OIDs, which means we
might cause the driver to recursively access some of its internal
structures unexpectedly. The ndis_ticktask() routine will call
ndis_80211_getstate() for us eventually anyway.
- Fix the channel setting code a little in ndis_80211_setstate(),
and initialize the channel to IEEE80211_CHAN_ANYC. (The Microsoft
spec says you're not supposed to twiddle the channel in BSS mode;
I may need to enforce this later.) This fixes the problems I was
having with the ADMtek adm8211 driver: we were setting the channel
to a non-standard default, which would cause it to fail to associate
in BSS mode.
- Use hal_raise_irql() to raise our IRQL to DISPATCH_LEVEL when
calling certain miniport routines, per the Microsoft documentation.
I think that's everything. Hopefully, other than fixing the ADMtek
driver, there should be no apparent change in behavior.
case we should wait for the resetdone handler to be called before
returning.
- When providing resources via ndis_query_resources(), uses the
computed rsclen when using bcopy() to copy out the resource data
rather than the caller-supplied buffer length.
- Avoid using ndis_reset_nic() in if_ndis.c unless we really need
to reset the NIC because of a problem.
- Allow interrupts to be fielded during ndis_attach(), at least
as far as allowing ndis_isr() and ndis_intrhand() to run.
- Use ndis_80211_rates_ex when probing for supported rates. Technically,
this isn't supposed to work since, although Microsoft added the extended
rate structure with the NDIS 5.1 update, the spec still says that
the OID_802_11_SUPPORTED_RATES OID uses ndis_80211_rates. In spite of
this, it appears some drivers use it anyway.
- When adding in our guessed rates, check to see if they already exist
so that we avoid any duplicates.
- Add a printf() to ndis_open_file() that alerts the user when a
driver attempts to open a file under /compat/ndis.
With these changes, I can get the driver for the SMC 2802W 54g PCI
card to load and run. This board uses a Prism54G chip. Note that in
order for this driver to work, you must place the supplied smc2802w.arm
firmware image under /compat/ndis. (The firmware is not resident on
the device.)
Note that this should also allow the 3Com 3CRWE154G72 card to work
as well; as far as I can tell, these cards also use a Prism54G chip.
resource_var.h.
In kern_ndis.c:ndis_convert_res(), fill in the cprd_flags and
cprd_sharedisp fields as best we can.
In if_ndis.c:ndis_setmulti(), don't bother updating the multicast
filter if our multicast address list is empty.
Add some missing updates to ndis_var.h and ntoskrnl_var.h that I
forgot to check in when I added the KeDpc stuff.
variable length, so we should not be trying to copy it into a fixed
length buffer, especially one on the stack. malloc() a buffer of the
right size and return a pointer to that instead.
Fixes a crash I discovered when testing whe a Cisco AP in infrastructure
mode, which returns several information elements that make the
ndis_wlan_bssid_ex structure larger than expected.
(NIC would claim to establish a link with an ad-hoc net but it couldn't
send/receive packets). It turns out that every time the checkforhang
handler was called by ndis_ticktask(), the driver would generate a new
media connect event. The NDIS spec says the checkforhang handler is
called "approximately every 2 seconds" but using exactly 2 seconds seems
too fast. Using 3 seconds makes it happy again, so we'll go with that
for now.
are actually layered on top of the KeTimer API in subr_ntoskrnl.c, just
as it is in Windows. This reduces code duplication and more closely
imitates the way things are done in Windows.
- Modify ndis_encode_parm() to deal with the case where we have
a registry key expressed as a hex value ("0x1") which is being
read via NdisReadConfiguration() as an int. Previously, we tried
to decode things like "0x1" with strtol() using a base of 10, which
would always yield 0. This is what was causing problems with the
Intel 2200BG Centrino 802.11g driver: the .inf file that comes
with it has a key called RadioEnable with a value of 0x1. We
incorrectly decoded this value to '0' when it was queried, hence
the driver thought we wanted the radio turned off.
- In if_ndis.c, most drivers don't accept NDIS_80211_AUTHMODE_AUTO,
but NDIS_80211_AUTHMODE_SHARED may not be right in some cases,
so for now always use NDIS_80211_AUTHMODE_OPEN.
NOTE: There is still one problem with the Intel 2200BG driver: it
happens that the kernel stack in Windows is larger than the kernel
stack in FreeBSD. The 2200BG driver sometimes eats up more than 2
pages of stack space, which can lead to a double fault panic.
For the moment, I got things to work by adding the following to
my kernel config file:
options KSTACK_PAGES=8
I'm pretty sure 8 is too big; I just picked this value out of a hat
as a test, and it happened to work, so I left it. 4 pages might be
enough. Unfortunately, I don't think you can dynamically give a
thread a larger stack, so I'm not sure how to handle this short of
putting a note in the man page about it and dealing with the flood
of mail from people who never read man pages.
for Windows are deserialized miniports. Such drivers maintain their own
queues and do their own locking. This particular driver is not deserialized
though, and we need special support to handle it correctly.
Typically, in the ndis_rxeof() handler, we pass all incoming packets
directly to (*ifp->if_input)(). This in turn may cause another thread
to run and preempt us, and the packet may actually be processed and
then released before we even exit the ndis_rxeof() routine. The
problem with this is that releasing a packet calls the ndis_return_packet()
function, which hands the packet and its buffers back to the driver.
Calling ndis_return_packet() before ndis_rxeof() returns will screw
up the driver's internal queues since, not being deserialized,
it does no locking.
To avoid this problem, if we detect a serialized driver (by checking
the attribute flags passed to NdisSetAttributesEx(), we use an alternate
ndis_rxeof() handler, ndis_rxeof_serial(), which puts the call to
(*ifp->if_input)() on the NDIS SWI work queue. This guarantees the
packet won't be processed until after ndis_rxeof_serial() returns.
Note that another approach is to always copy the packet data into
another mbuf and just let the driver retain ownership of the ndis_packet
structure (ndis_return_packet() never needs to be called in this
case). I'm not sure which method is faster.
if_ndis.c has been split into if_ndis_pci.c and if_ndis_pccard.c.
The ndiscvt(8) utility should be able to parse device info for PCMCIA
devices now. The ndis_alloc_amem() has moved from kern_ndis.c to
if_ndis_pccard.c so that kern_ndis.c no longer depends on pccard.
NOTE: this stuff is not guaranteed to work 100% correctly yet. So
far I have been able to load/init my PCMCIA Cisco Aironet 340 card,
but it crashes in the interrupt handler. The existing support for
PCI/cardbus devices should still work as before.
that Asus provides on its CDs has both a MiniportSend() routine
and a MiniportSendPackets() function. The Microsoft NDIS docs say
that if a driver has both, only the MiniportSendPackets() routine
will be used. Although I think I implemented the support correctly,
calling the MiniportSend() routine seems to result in no packets going
out on the air, even though no error status is returned. The
MiniportSendPackets() function does work though, so at least in
this case it doesn't matter.
In if_ndis.c:ndis_getstate_80211(), if ndis_get_assoc() returns
an error, don't bother trying to obtain any other state since the
calls may fail, or worse cause the underlying driver to crash.
(The above two changes make the Asus-supplied Centrino work.)
Also, when calling the OID_802_11_CONFIGURATION OID, remember
to initialize the structure lengths correctly.
In subr_ndis.c:ndis_open_file(), set the current working directory
to rootvnode if we're in a thread that doesn't have a current
working directory set.
is for an 802.11 device or not. At least one driver I have does not
support the OID_802_11_NETWORK_TYPES_SUPPORTED OID.
Also, for now, don't do anything special in the ndis_suspend() method.
I originally wanted to shut down the NIC but leave the IFF_UP flag alone
since technically the interface is meant to remain up, but an interrupt
may be delivered to the ISR on suspend, and if this happens while the
NIC is halted, we will crash, since none of the miniport driver methods
will function.
This needs to be dealt with properly later, but for now this prevents
a panic, and the resume method properly re-inits the NIC.
won't associate in BSS mode if you use AUTHMODE_SHARED. I probably don't
understand enough to know when SHARED should be used vs. OPEN or WPA.
For now, go back to what works.
on an SIOCSIFADDR (by way of brain damage in net80211).
Also, avoid trying to set NDIS_80211_AUTHMODE_AUTO since the Microsoft
documentation I have recommends not using it, and the Centrino driver
seems to dislike being told to use it.
problem with using taskqueue_swi is that some of the things we defer
into threads might block for up to several seconds. This is an unfriendly
thing to do to taskqueue_swi, since it is assumed the taskqueue threads
will execute fairly quickly once a task is submitted. Reorganized the
locking in if_ndis.c in the process.
Cleaned up ndis_write_cfg() and ndis_decode_parm() a little.
the definitions for NDIS_BUS_SPACE_IO and NDIS_BUS_SPACE_MEM logically
belong in hal_var.h. At least, that's my story, and I'm sticking to it.
Also, remove definition of __stdcall from if_ndis.c now that it's pulled
in from pe_var.h.
these add support for listing BSSIDs via wicontrol -l. I added code
to call OID_802_11_BSSID_LIST_SCAN to allow scanning for any nearby
wirelsss nets.
Convert from using individual mutexes to a mutex pool, created in
subr_ndis.c. This deals with the problem of drivers creating locks
in their DriverEntry() routines which might get trashed later.
Put some messages under IFF_DEBUG.
which has two important flags in it: the 'allocated by NDIS' flag
and the 'media specific info present' flag. There are two Windows macros
for getting/setting media specific info fields within the ndis_packet
structure which can behave improperly if these flags are not initialized
correctly when a packet is allocated. It seems the correct thing
to do is always set the NDIS_PACKET_ALLOCATED_BY_NDIS flag on
all newly allocated packets.
This fixes the crashes with the Intel Centrino wireless driver.
My sample card now seems to work correctly.
Also, fix a potential LOR involving ndis_txeof() in if_ndis.c.
the ni_dpccountlock member is an ndis_kspin_lock, not an
ndis_spin_lock (the latter is too big).
Run if_ndis.c:ndis_tick() via taskqueue_schedule(). Also run
ndis_start() via taskqueue in certain circumstances.
Using these tweaks, I can now get the Broadcom BCM5701 NDIS
driver to load and run. Unfortunately, the version I have seems
to suffer from the same bug as the SMC 83820 driver, which is
that it creates a spinlock during its DriverEntry() routine.
I'm still debating the right way to deal with this.
the RT_MESSAGETABLE resources that some driver binaries have.
This allows us to print error messages in ndis_syslog().
- Correct the implementation of InterlockedIncrement() and
InterlockedDecrement() -- they return uint32_t, not void.
- Correct the declarations of the 64-bit arithmetic shift
routines in subr_ntoskrnl.c (_allshr, allshl, etc...). These
do not follow the _stdcall convention: instead, they appear
to be __attribute__((regparm(3)).
- Change the implementation of KeInitializeSpinLock(). There is
no complementary KeFreeSpinLock() function, so creating a new
mutex on each call to KeInitializeSpinLock() leaks resources
when a driver is unloaded. For now, KeInitializeSpinLock()
returns a handle to the ntoskrnl interlock mutex.
- Use a driver's MiniportDisableInterrupt() and MiniportEnableInterrupt()
routines if they exist. I'm not sure if I'm doing this right
yet, but at the very least this shouldn't break any currently
working drivers, and it makes the Intel PRO/1000 driver work.
- In ndis_register_intr(), save some state that might be needed
later, and save a pointer to the driver's interrupt structure
in the ndis_miniport_block.
- Save a pointer to the driver image for use by ndis_syslog()
when it calls pe_get_message().
and MiniportHandleInterrupt() is fired off later via a task queue in
ndis_intrtask(). This more accurately follows the NDIS interrupt handling
model, where the ISR does a minimal amount of work in interrupt context
and the handler is defered and run at a lower priority.
Create a separate ndis_intrmtx mutex just for the guarding the ISR.
Modify NdisSynchronizeWithInterrupt() to aquire the ndis_intrmtx
mutex before invoking the synchronized procedure. (The purpose of
this function is to provide mutual exclusion for code that shares
variables with the ISR.)
Modify NdisMRegisterInterrupt() to save a pointer to the miniport
block in the ndis_miniport_interrupt structure so that
NdisSynchronizeWithInterrupt() can grab it later and derive
ndis_intrmtx from it.
driver was compiled with.
Remove debug printf from ndis_assicn_pcirsc(). It doesn't serve
much purpose.
Implement NdisMIndicateStatus() and NdisMIndicateStatusComplete()
as functions in subr_ndis.c. In NDIS 4.0, they were functions. In
NDIS 5.0 and later, they're just macros.
Allocate a few extra packets/buffers beyond what the driver asks
for since sometimes it seems they can lie about how many they really
need, and some extra stupid ones don't check to see if NdisAllocatePacket()
and/or NdisAllocateBuffer() actually succeed.
calling the haltfunc. If an interrupt is triggered by the init
or halt func, the IFF_UP flag must be set in order for us to be able
to service it.
In kern_ndis.c: implement a handler for NdisMSendResourcesAvailable()
(currently does nothing since we don't really need it).
In subr_ndis.c:
- Correct ndis_init_string() and ndis_unicode_to_ansi(),
which were both horribly broken.
- Implement NdisImmediateReadPciSlotInformation() and
NdisImmediateWritePciSlotInformation().
- Implement NdisBufferLength().
- Work around my first confirmed NDIS driver bug.
The SMC 9462 gigE driver (natsemi 83820-based copper)
incorrectly creates a spinlock in its DriverEntry()
routine and then destroys it in its MiniportHalt()
handler. This is wrong: spinlocks should be created
in MiniportInit(). In a Windows environment, this is
often not a problem because DriverEntry()/MiniportInit()
are called once when the system boots and MiniportHalt()
or the shutdown handler is called when the system halts.
With this stuff in place, this driver now seems to work:
ndis0: <SMC EZ Card 1000> port 0xe000-0xe0ff mem 0xda000000-0xda000fff irq 10 at device 9.0 on pci0
ndis0: assign PCI resources...
ndis_open_file("FLASH9.hex", 18446744073709551615)
ndis0: Ethernet address: 00:04:e2:0e:d3:f0
copyrights to the inf parser files.
Add a -n flag to ndiscvt to allow the user to override the default
device name of NDIS devices. Instead of "ndis0, ndis1, etc..."
you can have "foo0, foo1, etc..." This allows you to have more than
one kind of NDIS device in the kernel at the same time.
Convert from printf() to device_printf() in if_ndis.c, kern_ndis.c
and subr_ndis.c.
Create UMA zones for ndis_packet and ndis_buffer structs allocated
on transmit. The zones are created and destroyed in the modevent
handler in kern_ndis.c.
printf() and UMA changes submitted by green@freebsd.org
peter and jhb: use __volatile__ to prevent gcc from possibly reordering
code, use a null inline instruction instead of a no-op movl (I would
have done this myself if I knew it was allowed) and combine two register
assignments into a single asm statement.
- if_ndis.c: set the NDIS_STATUS_PENDING flag on all outgoing packets
in ndis_start(), make the resource allocation code a little smarter
about how it selects the altmem range, correct a lock order reversal
in ndis_tick().
ndis_var.h
- In kern_ndis.c:ndis_send_packets(), avoid dereferencing NULL pointers
created when the driver's send routine immediately calls the txeof
handler (which releases the packets for us anyway).
- In if_ndis.c:ndis_80211_setstate(), implement WEP support.
method with something a little more intelligent: use BUS_GET_RESOURCE_LIST()
to run through all resources allocated to us and map them as needed. This
way we know exactly what resources need to be mapped and what their RIDs
are without having to guess. This simplifies both ndis_attach() and
ndis_convert_res(), and eliminates the unfriendly "ndisX: couldn't map
<foo>" messages that are sometimes emitted during driver load.
For received packets, an status of NDIS_STATUS_RESOURCES means we need
to copy the packet data and return the ndis_packet to the driver immediatel.
NDIS_STATUS_SUCCESS means we get to hold onto the packet, but we have
to set the status to NDIS_STATUS_PENDING so the driver knows we're
going to hang onto it for a while.
For transmit packets, NDIS_STATUS_PENDING means the driver will
asynchronously return the packet to us via the ndis_txeof() routine,
and NDIS_STATUS_SUCCESS means the driver sent the frame, and NDIS
(i.e. the OS) retains ownership of the packet and can free it
right away.
evaluate them. Whatever they're meant to do, they're doing it wrong.
Also:
- Clean up last bits of NULL fallout in subr_pe
- Don't let ndis_ifmedia_sts() do anything if the IFF_UP flag isn't set
- Implement NdisSystemProcessorCount() and NdisQueryMapRegisterCount().
flag isn't set.
- In ndis_attach(), halt the NIC before exiting the routine. Calling
ndis_init() will bring it up again, and we don't want it running
(and potentially generating interrupts) until we're ready to deal
with it.
mbuf<->packet housekeeping. Instead, add a couple of extra fields
to the end of ndis_packet. These should be invisible to the Windows
driver module.
This also lets me get rid of a little bit of evil from ndis_ptom()
(frobbing of the ext_buf field instead of relying on the MEXTADD()
macro).
- Fix ndis_time().
- Implement NdisGetSystemUpTime().
- Implement RtlCopyUnicodeString() and RtlUnicodeStringToAnsiString().
- In ndis_getstate_80211(), use sc->ndis_link to determine connect
status.
Submitted by: Brian Feldman <green@freebsd.org>
- Add explicit cardbus attachment in if_ndis.c
- Clean up after moving bus_setup_intr() in ndis_attach().
- When setting an ssid, program an empty ssid as a 1-byte string
with a single 0 byte. The Microsoft documentation says this is
how you're supposed to tell the NIC to attach to 'any' ssid.
- Keep trace of callout handles for timers externally from the
ndis_miniport_timer structs, and run through and clobber them
all after invoking the haltfunc just in case the driver left one
running. (We need to make sure all timers are cancelled on driver
unload.)
- Handle the 'cancelled' argument in ndis_cancel_timer() correctly.
supposed to be opaque to the driver, however it is exposed through
several macros which expect certain behavior. In my original
implementation, I used the mappedsystemva member of the structure
to hold a pointer to the buffer and bytecount to hold the length.
It turns out you must use the startva pointer to point to the
page containing the start of the buffer and set byteoffset to
the offset within the page where the buffer starts. So, for a buffer
with address 'baseva,' startva is baseva & ~(PAGE_SIZE -1) and
byteoffset is baseva & (PAGE_SIZE -1). We have to maintain this
convention everywhere that ndis_buffers are used.
Fortunately, Microsoft defines some macros for initializing and
manipulating NDIS_BUFFER structures in ntddk.h. I adapted some
of them for use here and used them where appropriate.
This fixes the discrepancy I observed between how RX'ed packet sizes
were being reported in the Broadcom wireless driver and the sample
ethernet drivers that I've tested. This should also help the
Intel Centrino wireless driver work.
Also try to properly initialize the 802.11 BSS and IBSS channels.
(Sadly, the channel value is meaningless since there's no way
in the existing NDIS API to get/set the channel, but this should
take care of any 'invalid channel (NULL)' messages printed on
the console.
- Make ndis_get_info()/ndis_set_info() sleep on the setdone/getdone
routines if they get back NDIS_STATUS_PENDING.
- Add a bunch of net80211 support so that 802.11 cards can be twiddled
with ifconfig. This still needs more work and is not guaranteed to
work for everyone. It works on my 802.11b/g card anyway.
The problem here is Microsoft doesn't provide a good way to a) learn
all the rates that a card supports (if it has more than 8, you're
kinda hosed) and b) doesn't provide a good way to distinguish between
802.11b, 802.11b/g an 802.11a/b/g cards, so you sort of have to guess.
Setting the SSID and switching between infrastructure/adhoc modes
should work. WEP still needs to be implemented. I can't find any API
for getting/setting the channel other than the registry/sysctl keys.
definitions for more than one device (usually differentiated by
the PCI subvendor/subdevice ID). Each device also has its own tree
of registry keys. In some cases, each device has the same keys, but
sometimes each device has a unique tree but with overlap. Originally,
I just had ndiscvt(8) dump out all the keys it could find, and we
would try to apply them to every device we could find. Now, each key
has an index number that matches it to a device in the device ID list.
This lets us create just the keys that apply to a particular device.
I also added an extra field to the device list to hold the subvendor
and subdevice ID.
Some devices are generic, i.e. there is no subsystem definition. If
we have a device that doesn't match a specific subsystem value and
we have a generic entry, we use the generic entry.
