CVS log for src/sys/dev/misc/ppi/ppi.c

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Rename printf -> kprintf in sys/ and add some defines where necessary
(files which are used in userland, too).

Do a major clean-up of the BUSDMA architecture.  A large number of
essentially machine-independant drivers use the structures and definitions
in machine-dependant directories that are really machine-independant in
nature.

Split <machine/bus_dma.h> into machine-depdendant and machine-independant parts
and make the primary access run through <sys/bus_dma.h>.

Remove <machine/bus.h>, <machine/bus_memio.h> and <machine/bus_pio.h>.  The
optimizations related to bus_memio.h and bus_pio.h made a huge mess,
introduced machine-specific knowledge into essentially machine-independant
drivers, and required specific #include file orderings to do their job.
They may be reintroduced in some other form later on.

Move <machine/resource.h> to <sys/bus_resource.h>.  The contents of the file
is machine-independant or can be made a superset across many platforms.

Make <sys/bus.h> include <sys/bus_dma.h> and <sys/bus_resource.h> and
include <sys/bus.h> where necessary. Remove all #include's of
<machine/resource.h> and <machine/bus.h>.  That is, make the BUSDMA
infrastructure integral to I/O-mapped and memory-mapped accesses to devices
and remove a large chunk of machine-specific dependancies from drivers.
bus_if.h and device_if.h are now required to be present when using <sys/bus.h>.

Change the kernel dev_t, representing a pointer to a specinfo structure,
to cdev_t.  Change struct specinfo to struct cdev.  The name 'cdev' was taken
from FreeBSD.  Remove the dev_t shim for the kernel.

This commit generally removes the overloading of 'dev_t' between userland and
the kernel.

Also fix a bug in libkvm where a kernel dev_t (now cdev_t) was not being
properly converted to a userland dev_t.

MASSIVE reorganization of the device operations vector.  Change cdevsw
to dev_ops.  dev_ops is a syslink-compatible operations vector structure
similar to the vop_ops structure used by vnodes.

Remove a huge number of instances where a thread pointer is still being
passed as an argument to various device ops and other related routines.
The device OPEN and IOCTL calls now take a ucred instead of a thread pointer,
and the CLOSE call no longer takes a thread pointer.

Cleanup some of the newbus infrastructure.

* Change the device_identify API to return success/failure, like
  most of the other newbus methods.  This may be used for conflict
  resolution in the future.

* Clearly document the device_identify method and formalize its use
  by adding discrimination between initial bus probes and bus rescans.
  Do not re-execute static identification code that has already been run
  every time a new driver is added at run-time.

* Clearly document the do-ISA-last hack.

* Provide generic routines for the most common device_identify operations
  (psueo or synthesized devices that operate under other devices, such as
  lpt operating under ppbus, which are not 'scanned' by the parent bus).

* Remove the hacks that install and initialize the nexus device.  Instead,
  use the existing DRIVER_MODULE infrastructure to install nexus under
  root_bus.

* Document the boot-time initialization path so it doesn't take the next
  guy 8 hours to figure out what code is actually being run when.

Remove the INTR_TYPE_* flags.  The interrupt type is no longer used to
figure out which spl*() set an interrupt belongs to, because, well, spl's
no longer exist.

Get rid of bus_{disable,enable}_intr(), it wasn't generic enough for
our needs.

Implement some generic atomic.h functions to aid in the implementation of
a low level mutex.

Implement a generic low level sleep-mutex serializer, kern/lwkt_serialize.c.
The serializer is designed to be a replacement for SPL calls but may also
be used for other very low level work (e.g. lockmgr interlocks).

Add a serializer argument to BUS_SETUP_INTR().  When non-NULL, the interrupt
handler will no longer be protected by an SPL so e.g. spl*() will no
longer protect against that device's interrupts.

The IF queueing and dequeueing mechanisms may no longer depend on outside
SPL state because network driver interrupt handlers are no longer required to
enter splnet().  Use critical sections for the moment.  The IFQ and
IFF_OACTIVE interactions are not yet MP safe.

Device layer rollup commit.

* cdevsw_add() is now required.  cdevsw_add() and cdevsw_remove() may specify
  a mask/match indicating the range of supported minor numbers.  Multiple
  cdevsw_add()'s using the same major number, but distinctly different
  ranges, may be issued.  All devices that failed to call cdevsw_add() before
  now do.

* cdevsw_remove() now automatically marks all devices within its supported
  range as being destroyed.

* vnode->v_rdev is no longer resolved when the vnode is created.  Instead,
  only v_udev (a newly added field) is resolved.  v_rdev is resolved when
  the vnode is opened and cleared on the last close.

* A great deal of code was making rather dubious assumptions with regards
  to the validity of devices associated with vnodes, primarily due to
  the persistence of a device structure due to being indexed by (major, minor)
  instead of by (cdevsw, major, minor).  In particular, if you run a program
  which connects to a USB device and then you pull the USB device and plug
  it back in, the vnode subsystem will continue to believe that the device
  is open when, in fact, it isn't (because it was destroyed and recreated).

  In particular, note that all the VFS mount procedures now check devices
  via v_udev instead of v_rdev prior to calling VOP_OPEN(), since v_rdev
  is NULL prior to the first open.

* The disk layer's device interaction has been rewritten.  The disk layer
  (i.e. the slice and disklabel management layer) no longer overloads
  its data onto the device structure representing the underlying physical
  disk.  Instead, the disk layer uses the new cdevsw_add() functionality
  to register its own cdevsw using the underlying device's major number,
  and simply does NOT register the underlying device's cdevsw.  No
  confusion is created because the device hash is now based on
  (cdevsw,major,minor) rather then (major,minor).

  NOTE: This also means that underlying raw disk devices may use the entire
  device minor number instead of having to reserve the bits used by the disk
  layer, and also means that can we (theoretically) stack a fully
  disklabel-supported 'disk' on top of any block device.

* The new reference counting scheme prevents this by associating a device
  with a cdevsw and disconnecting the device from its cdevsw when the cdevsw
  is removed.  Additionally, all udev2dev() lookups run through the cdevsw
  mask/match and only successfully find devices still associated with an
  active cdevsw.

* Major work on MFS:  MFS no longer shortcuts vnode and device creation.  It
  now creates a real vnode and a real device and implements real open and
  close VOPs.  Additionally, due to the disk layer changes, MFS is no longer
  limited to 255 mounts.  The new limit is 16 million.  Since MFS creates a
  real device node, mount_mfs will now create a real /dev/mfs<PID> device
  that can be read from userland (e.g. so you can dump an MFS filesystem).

* BUF AND DEVICE STRATEGY changes.  The struct buf contains a b_dev field.
  In order to properly handle stacked devices we now require that the b_dev
  field be initialized before the device strategy routine is called.  This
  required some additional work in various VFS implementations.  To enforce
  this requirement, biodone() now sets b_dev to NODEV.  The new disk layer
  will adjust b_dev before forwarding a request to the actual physical
  device.

* A bug in the ISO CD boot sequence which resulted in a panic has been fixed.

Testing by: lots of people, but David Rhodus found the most aggregious bugs.

device switch 1/many: Remove d_autoq, add d_clone (where d_autoq was).

d_autoq was used to allow the device port dispatch to mix old-style synchronous
calls with new style messaging calls within a particular device.  It was never
used for that purpose.

d_clone will be more fully implemented as work continues.  We are going to
install d_port in the dev_t (struct specinfo) structure itself and d_clone
will be needed to allow devices to 'revector' the port on a minor-number
by minor-number basis, in particular allowing minor numbers to be directly
dispatched to distinct threads.  This is something we will be needing later
on.

kernel tree reorganization stage 1: Major cvs repository work (not logged as
commits) plus a major reworking of the #include's to accomodate the
relocations.

    * CVS repository files manually moved.  Old directories left intact
      and empty (temporary).

    * Reorganize all filesystems into vfs/, most devices into dev/,
      sub-divide devices by function.

    * Begin to move device-specific architecture files to the device
      subdirs rather then throwing them all into, e.g. i386/include

    * Reorganize files related to system busses, placing the related code
      in a new bus/ directory.  Also move cam to bus/cam though this may
      not have been the best idea in retrospect.

    * Reorganize emulation code and place it in a new emulation/ directory.

    * Remove the -I- compiler option in order to allow #include file
      localization, rename all config generated X.h files to use_X.h to
      clean up the conflicts.

    * Remove /usr/src/include (or /usr/include) dependancies during the
      kernel build, beyond what is normally needed to compile helper
      programs.

    * Make config create 'machine' softlinks for architecture specific
      directories outside of the standard <arch>/include.

    * Bump the config rev.

    WARNING! after this commit /usr/include and /usr/src/sys/compile/*
    should be regenerated from scratch.

DEV messaging stage 1/4: Rearrange struct cdevsw and add a message port
and auto-queueing mask.  The mask will tell us which message functions
can be safely queued to another thread and which still need to run in the
context of the caller.   Primary configuration fields (name, cmaj, flags,
port, autoq mask) are now at the head of the structure.  Function vectors,
which may eventually go away, are at the end.  The port and autoq fields
are non-functional in this stage.

The old BDEV device major number support has also been removed from cdevsw,
and code has been added to translate the bootdev passed from the boot code
(the boot code has always passed the now defunct block device major numbers
and we obviously need to keep that compatibility intact).

Remove the priority part of the priority|flags argument to tsleep().  Only
flags are passed now.  The priority was a user scheduler thingy that is not
used by the LWKT subsystem.  For process statistics assume sleeps without
P_SINTR set to be disk-waits, and sleeps with it set to be normal sleeps.

This commit should not contain any operational changes.

proc->thread stage 2: MAJOR revamping of system calls, ucred, jail API,
and some work on the low level device interface (proc arg -> thread arg).
As -current did, I have removed p_cred and incorporated its functions
into p_ucred.  p_prison has also been moved into p_ucred and adjusted
accordingly.  The jail interface tests now uses ucreds rather then processes.

The syscall(p,uap) interface has been changed to just (uap).  This is inclusive
of the emulation code.  It makes little sense to pass a proc pointer around
which confuses the MP readability of the code, because most system call code
will only work with the current process anyway.  Note that eventually
*ALL* syscall emulation code will be moved to a kernel-protected userland
layer because it really makes no sense whatsoever to implement these
emulations in the kernel.

suser() now takes no arguments and only operates with the current process.
The process argument has been removed from suser_xxx() so it now just takes
a ucred and flags.

The sysctl interface was adjusted somewhat.

Add the DragonFly cvs id and perform general cleanups on cvs/rcs/sccs ids.  Most
ids have been removed from !lint sections and moved into comment sections.

import from FreeBSD RELENG_4 1.21.2.3