Make the 16550 and real mode 16550 use tail recursion like the scc code
instead of repeating the routine except for the character sent.

Gcc recoginizes the tail recursion and handles it efficently without
stack allocations.  The maple real putc shrinks from 188 to 104 bytes
of instructions.  udbg_putc drops from 188 to 140 bytes.
Signed-off-by: NMilton Miller <miltonm@bga.com>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Now that xmon is fixed we should not need the dummy getc routines.
Signed-off-by: NMilton Miller <miltonm@bga.com>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

udbg_getc_poll is a ppc_md function.   don't call directly into udbg.c
Signed-off-by: NMilton Miller <miltonm@bga.com>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

inline pmac_call_feature references ppc_md so include asm/machdep.h
in asm/pmac_feature.h
Signed-off-by: NMilton Miller <miltonm@bga.com>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Automated merge from

	master.kernel.org:/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog

failed due to duplicate different changes to Kconfig file. Manually fixed
up. Hopefully.

Fix reboot with a disconnected 3270 console.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

On s390 the lock value used for spinlocks consists of the lower 32 bits of the
PSW that holds the lock.  If this address happens to be on a four gigabyte
boundary the lock is left unlocked.  This allows other cpus to grab the same
lock and enter a lock protected code path concurrently.  In theory this can
happen if the vmalloc area for the code of a module crosses a 4 GB boundary.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use TIF bit to tell if a process is running in 31 bit mode instead of checking
the addressing mode bits of the PSW.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

crypto device driver update:

 - Suppress syslog messages for some return codes.

 - Fix incorrect bounds checking in /proc interface.

 - Remove hotplug calls.

 - Remove linux version checks.

 - Remove device workqueue on module unload.
Signed-off-by: NEric Rossman <edrossma@us.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There is a race in pfault_interrupt.  That function gets called two times for
each pfault notification.  Once with a subcode of 0 to indicate that a real
page is not available and once with a subcode of 0x80 to indicate that the
page is present again.

Since the two external interrupts can be delivered on two different cpus the
order in which the two calls are made is unpredictable.  It is possible that
the subcode 0x80 interrupt is completed before the subcode 0x00 interrupt has
done the wake_up() call.

To avoid calling wake_up() on an already removed task structure proper task
structure reference counting is needed.  Increase the reference counter in the
subcode 0x00 interrupt before setting pfault_wait to zero and return the
reference after the wake_up call.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Common i/o layer changes:

- Collect the irb at the correct subchannel when waiting for the clear
  interrupt during subchannel cleaning befor reIPL - don't stop at the first
  interrupt that comes in.

- Change "extern __inline__" to "static inline".

- Remove unneeded qdio includes.
Signed-off-by: NCornelia Huck <cohuck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add support for diag 250 access to dasd devices for 64 bit kernels.  In
addition fix detach/attach for diag disks.  The VM control block needs to get
recreated by a call to mdsk_init_io.
Signed-off-by: NHorst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Reintroduce a read-only copy of the devmap features in the device struct.
This is necessary to solve a deadlock on the dasd_devmap_lock which is
acquired by dasd_get_features called from the dasd tasklet.  The current
implementation of devmap doesn't allow to call any devmap function from
interrupt or softirq context.
Signed-off-by: NHorst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

debug feature changes/bug fixes:

- Use get_clock() function instead of private inline assembly.

- Use 'struct timeval' instead of 'struct timespec' for call to
  tod_to_timeval().  Now the microsecond part of the timestamp is correct
  again.

- Fix a locking problem: when creating a snapshot of the current content
  of the debug areas, lock the entire debug_info object.
Signed-off-by: NMichael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The new machine check handler still has a few bugs.

1) The system entry time has to be stored in the machine check handler,

2) the machine check return psw may not be stored at the usual place
   because it might overwrite the return psw of the interrupted context,

3) the return address for the call to s390_handle_mcck in the i/o interrupt
   handler is not correct,

4) the system call cleanup has to take the different save area of the
   machine check handler into account,

5) the machine check handler may not call UPDATE_VTIME before
   CREATE_STACK_FRAME, and

6) the io leave path needs a critical section cleanup to make sure that the
   TIF_MCCK_PENDING bit is really checked before switching back to user space.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This file seems to be an accident.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NChris Zankel <chris@zankel.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

"extern inline" doesn't make sense.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NChris Zankel <chris@zankel.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We were leaking pmd pages when 3_LEVEL_PGTABLES was enabled.  This fixes that.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

cleanup and fix the check for advanced sysemu (PTRACE_SYSEMU_SINGLESTEP
option)
Signed-off-by: NBodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add new cmdline setups:
  - noprocmm
  - noptracefaultinfo
In case of testing, they can be used to switch off usage of
/proc/mm and PTRACE_FAULTINFO independently.
Signed-off-by: NBodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Change syscall-stub's data to include a "expected retval".

Stub now checks syscalls retval and aborts execution of syscall list, if
retval != expected retval.

run_syscall_stub prints the data of the failed syscall, using the data pointer
and retval written by the stub to the beginning of the stack.

one_syscall_stub is removed, to simplify code, because only some instructions
are saved by one_syscall_stub, no host-syscall.

Using the stub with additional data (modify_ldt via stub)
is prepared also.
Signed-off-by: NBodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This change enables SKAS0/SKAS3 to work with all combinations of /proc/mm and
PTRACE_FAULTINFO being available or not.

Also it changes the initialization of proc_mm and ptrace_faultinfo slightly,
to ease forcing SKAS0 on a patched host.  Forcing UML to run without /proc/mm
or PTRACE_FAULTINFO by cmdline parameter can be implemented with a setup
resetting the related variable.
Signed-off-by: NBodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from process.c file under os-Linux dir and join
process.c and process_kern.c files.
Signed-off-by: NGennady Sharapov <gennady.v.sharapov@intel.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This adds AIO support to the ubd driver.

The driver breaks a struct request into IO requests to the host, based on the
hardware segments in the request and on any COW blocks covered by the request.

The ubd IO thread is gone, since there is now an equivalent thread in the AIO
module.

There is provision for multiple outstanding requests now.  Requests aren't
retired until all pieces of it have been completed.  The AIO requests have a
shared count, which is decremented as IO operations come in until it reaches
0.  This can be possibly moved to the request struct - haven't looked at this
yet.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch makes UML use host AIO support when it (and
/usr/include/linux/aio_abi.h) are present.  This is only the support, with no
consumers - a consumer is coming in the next patch.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Added missing include list to uml AFLAGS

Killed magic for stubs.  [So] - it was needed only because of messed AFLAGS
Switched segv_stubs.c to kernel CFLAGS sans profile, instead of user ones
Killed STUBS_CFLAGS - it's not needed and the only remaining use had been
gratitious - it only polluted CFLAGS
Signed-off-by: NAl Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This merges two sets of files which had no business being split apart in the
first place.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There is a lot of code which is duplicated between the 2 and 3 level
implementation, with the only difference that the 3-level implementation is a
bit more generalized (instead of accessing directly pte_t.pte, it uses the
appropriate access macros).

So this code is joined together.

As obvious, a "core code nice cleanup" is not a "stability-friendly patch" so
usual care applies.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This adds VM op batching to skas0.  Rather than having a context switch to and
from the userspace stub for each address space change, we write a number of
operations to the stub data page and invoke a different stub which loops over
them and executes them all in one go.

The operations are stored as [ system call number, arg1, arg2, ... ] tuples.

The set is terminated by a system call number of 0.  Single operations, i.e.
page faults, are handled in the old way, since that is slightly more
efficient.

For a kernel build, a minority (~1/4) of the operations are part of a set.
These sets averaged ~100 in length, so for this quarter, the context switching
overhead is greatly reduced.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Al Viro <viro@parcelfarce.linux.theplanet.co.uk> spotted a bunch of duplicated
exports - this removes them.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Noticed by Al Viro <viro@parcelfarce.linux.theplanet.co.uk> - SMP on x86_64 is
fundamentally broken due to UML's reuse of the host arch's percpu stuff.  This
is OK on x86, but the x86_64 pda stuff just won't work for UML.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove an unneeded reference to libc.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>