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3 Commits

Author SHA1 Message Date
Bill Paul
9b307fe2be This commit makes a bunch of changes, some big, some not so big.
- Remove the old task threads from kern_ndis.c and reimplement them in
  subr_ntoskrnl.c, in order to more properly emulate the Windows DPC
  API. Each CPU gets its own DPC queue/thread, and each queue can
  have low, medium and high importance DPCs. New APIs implemented:
  KeSetTargetProcessorDpc(), KeSetImportanceDpc() and KeFlushQueuedDpcs().
  (This is the biggest change.)

- Fix a bug in NdisMInitializeTimer(): the k_dpc pointer in the
  nmt_timer embedded in the ndis_miniport_timer struct must be set
  to point to the DPC, also embedded in the struct. Failing to do
  this breaks dequeueing of DPCs submitted via timers, and in turn
  breaks cancelling timers.

- Fix a bug in KeCancelTimer(): if the timer is interted in the timer
  queue (i.e. the timeout callback is still pending), we have to both
  untimeout() the timer _and_ call KeRemoveQueueDpc() to nuke the DPC
  that might be pending. Failing to do this breaks cancellation of
  periodic timers, which always appear to be inserted in the timer queue.

- Make use of the nmt_nexttimer field in ndis_miniport_timer: keep a
  queue of pending timers and cancel them all in ndis_halt_nic(), prior
  to calling MiniportHalt(). Also call KeFlushQueuedDpcs() to make sure
  any DPCs queued by the timers have expired.

- Modify NdisMAllocateSharedMemory() and NdisMFreeSharedMemory() to keep
  track of both the virtual and physical addresses of the shared memory
  buffers that get handed out. The AirGo MIMO driver appears to have a bug
  in it: for one of the segments is allocates, it returns the wrong
  virtual address. This would confuse NdisMFreeSharedMemory() and cause
  a crash. Why it doesn't crash Windows too I have no idea (from reading
  the documentation for NdisMFreeSharedMemory(), it appears to be a violation
  of the API).

- Implement strstr(), strchr() and MmIsAddressValid().

- Implement IoAllocateWorkItem(), IoFreeWorkItem(), IoQueueWorkItem() and
  ExQueueWorkItem(). (This is the second biggest change.)

- Make NdisScheduleWorkItem() call ExQueueWorkItem(). (Note that the
  ExQueueWorkItem() API is deprecated by Microsoft, but NDIS still uses
  it, since NdisScheduleWorkItem() is incompatible with the IoXXXWorkItem()
  API.)

- Change if_ndis.c to use the NdisScheduleWorkItem() interface for scheduling
  tasks.

With all these changes and fixes, the AirGo MIMO driver for the Belkin
F5D8010 Pre-N card now works. Special thanks to Paul Robinson
(paul dawt robinson at pwermedia dawt net) for the loan of a card
for testing.
2005-05-05 03:56:09 +00:00
Bill Paul
d02239a3af Create new i386 windows/bsd thunking layer, similar to the amd64 thunking
layer, but with a twist.

The twist has to do with the fact that Microsoft supports structured
exception handling in kernel mode. On the i386 arch, exception handling
is implemented by hanging an exception registration list off the
Thread Environment Block (TEB), and the TEB is accessed via the %fs
register. The problem is, we use %fs as a pointer to the pcpu stucture,
which means any driver that tries to write through %fs:0 will overwrite
the curthread pointer and make a serious mess of things.

To get around this, Project Evil now creates a special entry in
the GDT on each processor. When we call into Windows code, a context
switch routine will fix up %fs so it points to our new descriptor,
which in turn points to a fake TEB. When the Windows code returns,
or calls out to an external routine, we swap %fs back again. Currently,
Project Evil makes use of GDT slot 7, which is all 0s by default.
I fully expect someone to jump up and say I can't do that, but I
couldn't find any code that makes use of this entry anywhere. Sadly,
this was the only method I could come up with that worked on both
UP and SMP. (Modifying the LDT works on UP, but becomes incredibly
complicated on SMP.) If necessary, the context switching stuff can
be yanked out while preserving the convention calling wrappers.

(Fortunately, it looks like Microsoft uses some special epilog/prolog
code on amd64 to implement exception handling, so the same nastiness
won't be necessary on that arch.)

The advantages are:

- Any driver that uses %fs as though it were a TEB pointer won't
  clobber pcpu.
- All the __stdcall/__fastcall/__regparm stuff that's specific to
  gcc goes away.

Also, while I'm here, switch NdisGetSystemUpTime() back to using
nanouptime() again. It turns out nanouptime() is way more accurate
than just using ticks(). On slower machines, the Atheros drivers
I tested seem to take a long time to associate due to the loss
in accuracy.
2005-04-11 02:02:35 +00:00
Bill Paul
63ba67b69c - Correct one aspect of the driver_object/device_object/IRP framework:
when we create a PDO, the driver_object associated with it is that
  of the parent driver, not the driver we're trying to attach. For
  example, if we attach a PCI device, the PDO we pass to the NdisAddDevice()
  function should contain a pointer to fake_pci_driver, not to the NDIS
  driver itself. For PCI or PCMCIA devices this doesn't matter because
  the child never needs to talk to the parent bus driver, but for USB,
  the child needs to be able to send IRPs to the parent USB bus driver, and
  for that to work the parent USB bus driver has to be hung off the PDO.

  This involves modifying windrv_lookup() so that we can search for
  bus drivers by name, if necessary. Our fake bus drivers attach themselves
  as "PCI Bus," "PCCARD Bus" and "USB Bus," so we can search for them
  using those names.

  The individual attachment stubs now create and attach PDOs to the
  parent bus drivers instead of hanging them off the NDIS driver's
  object, and in if_ndis.c, we now search for the correct driver
  object depending on the bus type, and use that to find the correct PDO.

  With this fix, I can get my sample USB ethernet driver to deliver
  an IRP to my fake parent USB bus driver's dispatch routines.

- Add stub modules for USB support: subr_usbd.c, usbd_var.h and
  if_ndis_usb.c. The subr_usbd.c module is hooked up the build
  but currently doesn't do very much. It provides the stub USB
  parent driver object and a dispatch routine for
  IRM_MJ_INTERNAL_DEVICE_CONTROL. The only exported function at
  the moment is USBD_GetUSBDIVersion(). The if_ndis_usb.c stub
  compiles, but is not hooked up to the build yet. I'm putting
  these here so I can keep them under source code control as I
  flesh them out.
2005-02-24 21:49:14 +00:00