If we want to stop the tick further idle, we need to be
able to account the cputime without using the tick.

Virtual based cputime accounting solves that problem by
hooking into kernel/user boundaries.

However implementing CONFIG_VIRT_CPU_ACCOUNTING require
low level hooks and involves more overhead. But we already
have a generic context tracking subsystem that is required
for RCU needs by archs which plan to shut down the tick
outside idle.

This patch implements a generic virtual based cputime
accounting that relies on these generic kernel/user hooks.

There are some upsides of doing this:

- This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING
if context tracking is already built (already necessary for RCU in full
tickless mode).

- We can rely on the generic context tracking subsystem to dynamically
(de)activate the hooks, so that we can switch anytime between virtual
and tick based accounting. This way we don't have the overhead
of the virtual accounting when the tick is running periodically.

And one downside:

- There is probably more overhead than a native virtual based cputime
accounting. But this relies on hooks that are already set anyway.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>

Linux was granted a new system call to load modules by file descriptor
in commit 34e1169d ("module: add syscall to load module from fd").

Wire it up for ia64 (ready for the Chrome port :-)
Signed-off-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Acked-by: NTony Luck <tony.luck@intel.com>
Tested-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Acked-by: NTony Luck <tony.luck@intel.com>
Tested-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Used to be used by kernel_thread(); dead code for 8 years...
Note that it's not sys_clone/sys_clone2 - those are used just
fine.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

While debugging udev > 170 failure on Debian Wheezy
(http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=648325), it appears
that the issue was in fact due to missing accept4() in ia64.

This patch simply adds accept4() to ia64.
Signed-off-by: NÉmeric Maschino <emeric.maschino@gmail.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Add sys_process_vm_readv and sys_process_vm_writev to ia64
syscall table. Passes tests at http://ozlabs.org/~cyeoh/cma/cma-test-20110718.tgzSigned-off-by: NTony Luck <tony.luck@intel.com>

The nfsservctl system call is now gone, so we should remove all
linkage for it.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add entries in unistd.h and entry.S to make this new syscall visible.
Signed-off-by: NTony Luck <tony.luck@intel.com>

32bit and 64bit on x86 are tested and working.  The rest I have looked
at closely and I can't find any problems.

setns is an easy system call to wire up.  It just takes two ints so I
don't expect any weird architecture porting problems.

While doing this I have noticed that we have some architectures that are
very slow to get new system calls.  cris seems to be the slowest where
the last system calls wired up were preadv and pwritev.  avr32 is weird
in that recvmmsg was wired up but never declared in unistd.h.  frv is
behind with perf_event_open being the last syscall wired up.  On h8300
the last system call wired up was epoll_wait.  On m32r the last system
call wired up was fallocate.  mn10300 has recvmmsg as the last system
call wired up.  The rest seem to at least have syncfs wired up which was
new in the 2.6.39.

v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com>
v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com>
v4: Moved wiring up of the system call to another patch
v5: ported to v2.6.39-rc6
v6: rebased onto parisc-next and net-next to avoid syscall  conflicts.
v7: ported to Linus's latest post 2.6.39 tree.

>  arch/blackfin/include/asm/unistd.h     |    3 ++-
>  arch/blackfin/mach-common/entry.S      |    1 +
Acked-by: NMike Frysinger <vapier@gentoo.org>

Oh - ia64 wiring looks good.
Acked-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Four new syscalls:
	sys_name_to_handle_at
	sys_open_by_handle_at
	sys_clock_adjtime
	sys_syncfs
Signed-off-by: NTony Luck <tony.luck@intel.com>

Three new syscalls for 2.6.36: prlimit64, fanotify_init and
fanotify_mark.  Wire up the ia64 syscall table for them.
Signed-off-by: NTony Luck <tony.luck@intel.com>

This has been broken since May 2008 when Al Viro killed altroot support.
Since nobody has complained, it would appear that there are no users of
this code (A plausible theory since the main OSVs that support ia64 prefer
to use the IA32-EL software emulation).
Signed-off-by: NTony Luck <tony.luck@intel.com>

Meaning receive multiple messages, reducing the number of syscalls and
net stack entry/exit operations.

Next patches will introduce mechanisms where protocols that want to
optimize this operation will provide an unlocked_recvmsg operation.

This takes into account comments made by:

. Paul Moore: sock_recvmsg is called only for the first datagram,
  sock_recvmsg_nosec is used for the rest.

. Caitlin Bestler: recvmmsg now has a struct timespec timeout, that
  works in the same fashion as the ppoll one.

  If the underlying protocol returns a datagram with MSG_OOB set, this
  will make recvmmsg return right away with as many datagrams (+ the OOB
  one) it has received so far.

. Rémi Denis-Courmont & Steven Whitehouse: If we receive N < vlen
  datagrams and then recvmsg returns an error, recvmmsg will return
  the successfully received datagrams, store the error and return it
  in the next call.

This paves the way for a subsequent optimization, sk_prot->unlocked_recvmsg,
where we will be able to acquire the lock only at batch start and end, not at
every underlying recvmsg call.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Assign syscall #1321 for rt_tgsigqueueinfo.
Signed-off-by: NTony Luck <tony.luck@intel.com>

Gerd Hoffmann added these to Linux.  Let ia64 use them.
Signed-off-by: NTony Luck <tony.luck@intel.com>

paravirtualize mov reg = ar.itc.
Signed-off-by: NIsaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Remove __attribute__((weak)) from common code sys_pipe implemantation.
IA64, ALPHA, SUPERH (32bit) and SPARC (32bit) have own implemantations
with the same name. Just rename them.
For sys_pipe2 there is no architecture specific implementation.

Cc: Richard Henderson <rth@twiddle.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

IA64 dynamic ftrace support.
The original _mcount stub for each function is like:
	alloc r40=ar.pfs,12,8,0
	mov r43=r0;;
	mov r42=b0
	mov r41=r1
	nop.i 0x0
	br.call.sptk.many b0 = _mcount;;

The patch convert it to below for nop:
	[MII] nop.m 0x0
	mov r3=ip
	nop.i 0x0
	[MLX] nop.m 0x0
	nop.x 0x0;;
This isn't completely nop, as there is one instuction 'mov r3=ip', but
it should be light and harmless for code follow it.

And below is for call
	[MII] nop.m 0x0
	mov r3=ip
	nop.i 0x0
	[MLX] nop.m 0x0
	brl.many .;;
In this way, only one instruction is changed to convert code between nop
and call. This should meet dyn-ftrace's requirement.
But this requires CPU support brl instruction, so dyn-ftrace isn't
supported for old Itanium system. Assume there are quite few such old
system running.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

IA64 ftrace suppport. In IA64, below code will be added in each function
if -pg is enabled.

alloc r40=ar.pfs,12,8,0
mov r43=r0;;
mov r42=b0
mov r41=r1
nop.i 0x0
br.call.sptk.many b0 = _mcount;;
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Itanium processors can handle some misaligned data accesses. They
also provide a mode where all such accesses are forced to trap. The
kernel was schizophrenic about use of this mode:

* Base kernel code ran in permissive mode where the only traps
  generated were from those cases that the h/w could not handle.
* Interrupt, syscall and trap code ran in strict mode where all
  unaligned accesses caused traps to the 0x5a00 unaligned reference
  vector.

Use strict alignment checking throughout the kernel, but make
sure that we continue to let user mode use more relaxed mode
as the default.
Signed-off-by: NTony Luck <tony.luck@intel.com>

Make IA64 use generic trace hook in some paths.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Six new system calls: signalfd4, eventfd2, epoll_create1,
dup3, pipe2 and inotify_init1.
Signed-off-by: NTony Luck <tony.luck@intel.com>

paravirtualize ia64_swtich_to, ia64_leave_syscall and ia64_leave_kernel.
They include sensitive or performance critical privileged instructions
so that they need paravirtualization.
To paravirtualize them by single source and multi compile
they are converted into indirect jump. And define each pv instances.

Cc: Keith Owens <kaos@ocs.com.au>
Cc: "Dong, Eddie" <eddie.dong@intel.com>
Signed-off-by: NIsaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: NTony Luck <tony.luck@intel.com>

This patch does:
 - make comment at next to resched check more robust
 - move "re-check" comments to next to where change predicate regs
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

[Bug-fix for "[BUG?][2.6.25-mm1] sleeping during IRQ disabled"]

This patch does:
 - enable interrupts before calling schedule() as same as others, ex. x86
 - enable interrupts during ia64_do_signal() and ia64_sync_krbs()
 - do_notify_resume_user() is still called with interrupts disabled, since
   we can take short path of fsys_mode if-statement quickly.
 - pfm_handle_work() is also called with interrupts disabled, since
   it can deal interrupt mask within itself.
 - fix/add some comments/notes
Reported-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

While testing with CONFIG_VIRT_CPU_ACCOUNTING=y, I found that
I occasionally get very huge system time in some threads.

So I dug the issue and finally noticed that it was caused
because of an interrupt which interrupt in the following window:

> [arch/ia64/kernel/entry.S: (!CONFIG_PREEMPT && CONFIG_VIRT_CPU_ACCOUNTING)]
>
> ENTRY(ia64_leave_syscall)
>    :
> (pUStk) rsm psr.i
>         cmp.eq pLvSys,p0=r0,r0          // pLvSys=1: leave from syscall
> (pUStk) cmp.eq.unc p6,p0=r0,r0          // p6 <- pUStk
> .work_processed_syscall:
>         adds r2=PT(LOADRS)+16,r12
> (pUStk) mov.m r22=ar.itc                        // fetch time at leave
>         adds r18=TI_FLAGS+IA64_TASK_SIZE,r13
>         ;;
> <<< window: from here >>>
> (p6)    ld4 r31=[r18]  // load current_thread_info()->flags
>         ld8 r19=[r2],PT(B6)-PT(LOADRS)
>         adds r3=PT(AR_BSPSTORE)+16,r12
>         ;;
>         mov r16=ar.bsp
>         ld8 r18=[r2],PT(R9)-PT(B6)
> (p6)    and r15=TIF_WORK_MASK,r31  // any work other than TIF_SYSCALL_TRACE?
>         ;;
>         ld8 r23=[r3],PT(R11)-PT(AR_BSPSTORE)
> (p6)    cmp4.ne.unc p6,p0=r15, r0               // any special work pending?
> (p6)    br.cond.spnt .work_pending_syscall
>         ;;
>         ld8 r9=[r2],PT(CR_IPSR)-PT(R9)
>         ld8 r11=[r3],PT(CR_IIP)-PT(R11)
> (pNonSys) break 0 // bug check: we shouldn't be here if pNonSys is TRUE!
>         ;;
>         invala
> <<< window: to here >>>
>         rsm psr.i | psr.ic // turn off interrupts and interruption collection

If pUStk is true, it means we are going to return user mode, hence we fetch
ar.itc to get time at leave from system.
It seems that it is not possible to interrupt the window if pUStk is true,
because interrupts are disabled early.  And also disabling interrupt makes
sense because it is safe for referring current_thread_info()->flags.

However interrupting the window while pUStk is true was possible.
The route was:
ia64_trace_syscall
-> .work_pending_syscall_end
-> .work_processed_syscall
Only in case entering the window from this route, interrupts are enabled
during in the window even if pUStk is true.  I suppose interrupts must be
disabled here anyway if pUStk is true.
I'm not sure but afraid that what kind of bad effect were there, other
than crazy system time which I found.

FYI, there was a commit 6f6d7582 that
points out a bug at same point(exit of ia64_trace_syscall) in 2006.
It can be said that there was an another bug.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

This patch implements VIRT_CPU_ACCOUNTING for ia64,
which enable us to use more accurate cpu time accounting.

The VIRT_CPU_ACCOUNTING is an item of kernel config, which s390
and powerpc arch have.  By turning this config on, these archs
change the mechanism of cpu time accounting from tick-sampling
based one to state-transition based one.

The state-transition based accounting is done by checking time
(cycle counter in processor) at every state-transition point,
such as entrance/exit of kernel, interrupt, softirq etc.
The difference between point to point is the actual time consumed
during in the state. There is no doubt about that this value is
more accurate than that of tick-sampling based accounting.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Add ia64 hooks for the new syscalls that were added in
commit 4d672e7aSigned-off-by: NTony Luck <tony.luck@intel.com>

This is the new timerfd API as it is implemented by the following patch:

int timerfd_create(int clockid, int flags);
int timerfd_settime(int ufd, int flags,
		    const struct itimerspec *utmr,
		    struct itimerspec *otmr);
int timerfd_gettime(int ufd, struct itimerspec *otmr);

The timerfd_create() API creates an un-programmed timerfd fd.  The "clockid"
parameter can be either CLOCK_MONOTONIC or CLOCK_REALTIME.

The timerfd_settime() API give new settings by the timerfd fd, by optionally
retrieving the previous expiration time (in case the "otmr" parameter is not
NULL).

The time value specified in "utmr" is absolute, if the TFD_TIMER_ABSTIME bit
is set in the "flags" parameter.  Otherwise it's a relative time.

The timerfd_gettime() API returns the next expiration time of the timer, or
{0, 0} if the timerfd has not been set yet.

Like the previous timerfd API implementation, read(2) and poll(2) are
supported (with the same interface).  Here's a simple test program I used to
exercise the new timerfd APIs:

http://www.xmailserver.org/timerfd-test2.c

[akpm@linux-foundation.org: coding-style cleanups]
[akpm@linux-foundation.org: fix ia64 build]
[akpm@linux-foundation.org: fix m68k build]
[akpm@linux-foundation.org: fix mips build]
[akpm@linux-foundation.org: fix alpha, arm, blackfin, cris, m68k, s390, sparc and sparc64 builds]
[heiko.carstens@de.ibm.com: fix s390]
[akpm@linux-foundation.org: fix powerpc build]
[akpm@linux-foundation.org: fix sparc64 more]
Signed-off-by: NDavide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

sys_fallocate for ia64. This uses an empty slot #1303 erroneously
marked as reserved for move_pages (which had already been allocated
as syscall #1276)
Signed-Off-By: NDave Chinner <dgc@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Signed-off-by: NTony Luck <tony.luck@intel.com>

Another day, another pair of new system calls.
Signed-off-by: NTony Luck <tony.luck@intel.com>

Signed-off-by: NAlexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: NAlexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Preparation for pselect and ppoll.
ia32 compat code not tested. :-(
Signed-off-by: NAlexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: NAlexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

It's not efficient to use a per-cpu variable just to store
how many physical stack register a cpu has.  Ever since the
incarnation of ia64 up till upcoming Montecito processor, that
variable has "glued" to 96. Having a variable in memory means
that the kernel is burning an extra cacheline access on every
syscall and kernel exit path.  Such "static" value is better
served with the instruction patching utility exists today.
Convert ia64_phys_stacked_size_p8 into dynamic insn patching.

This also has a pleasant side effect of eliminating access to
per-cpu area while psr.ic=0 in the kernel exit path. (fixable
for per-cpu DTC work, but why bother?)

There are some concerns with the default value that the instruc-
tion encoded in the kernel image.  It shouldn't be concerned.
The reasons are:

(1) cpu_init() is called at CPU initialization.  In there, we
    find out physical stack register size from PAL and patch
    two instructions in kernel exit code.  The code in question
    can not be executed before the patching is done.

(2) current implementation stores zero in ia64_phys_stacked_size_p8,
    and that's what the current kernel exit path loads the value with.
    With the new code, it is equivalent that we store reg size 96
    in ia64_phys_stacked_size_p8, thus creating a better safety net.
    Given (1) above can never fail, having (2) is just a bonus.

All in all, this patch allow one less memory reference in the kernel
exit path, thus reducing syscall and interrupt return latency; and
avoid polluting potential useful data in the CPU cache.
Signed-off-by: NKen Chen <kenneth.w.chen@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

getcpu system call returns cpu# and node# on which this system call and
its caller are running. This patch hooks up its implementation on IA64.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Changes and updates.

1. Remove fake rendz path and related code according to discuss with Khalid Aziz.
2. fc.i offset fix in relocate_kernel.S.
3. iospic shutdown code eoi and mask race fix from Fujitsu.
4. Warm boot hook in machine_kexec to SN SAL code from Jack Steiner.
5. Send slave to SAL slave loop patch from Jay Lan.
6. Kdump on non-recoverable MCA event patch from Jay Lan
7. Use CTL_UNNUMBERED in kdump_on_init sysctl.
Signed-off-by: NZou Nan hai <nanhai.zou@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Many files include the filename at the beginning, serveral used a wrong one.
Signed-off-by: NUwe Zeisberger <Uwe_Zeisberger@digi.com>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>