Since the decrementer and timekeeping code was moved over to using
the generic clockevents and timekeeping infrastructure, several
variables and functions have been obsolete and effectively unused.
This deletes them.

In particular, wakeup_decrementer() is no longer needed since the
generic code reprograms the decrementer as part of the process of
resuming the timekeeping code, which happens during sysdev resume.
Thus the wakeup_decrementer calls in the suspend_enter methods for
52xx platforms have been removed.  The call in the powermac cpu
frequency change code has been replaced by set_dec(1), which will
cause a timer interrupt as soon as interrupts are enabled, and the
generic code will then reprogram the decrementer with the correct
value.

This also simplifies the generic_suspend_en/disable_irqs functions
and makes them static since they are not referenced outside time.c.
The preempt_enable/disable calls are removed because the generic
code has disabled all but the boot cpu at the point where these
functions are called, so we can't be moved to another cpu.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Since we started using the generic timekeeping code, we haven't had a
powerpc-specific version of do_gettimeofday, and hence there is now
nothing that reads the do_gtod variable in arch/powerpc/kernel/time.c.
This therefore removes it and the code that sets it.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

from include/asm-powerpc.  This is the result of a

mkdir arch/powerpc/include/asm
git mv include/asm-powerpc/* arch/powerpc/include/asm

Followed by a few documentation/comment fixups and a couple of places
where <asm-powepc/...> was being used explicitly.  Of the latter only
one was outside the arch code and it is a driver only built for powerpc.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Make a few things static in lparcfg.c
Make init and exit routines static in rtas_flash.c
Make things static in rtas_pci.c
Make some functions static in rtas.c
Make fops static in rtas-proc.c
Remove unneeded extern for do_gtod in smp.c
Make clocksource_init() static in time.c
Make last_tick_len and ticklen_to_xs static in time.c
Move the declaration of the pvr per-cpu into smp.h
Make kexec_smp_down() and kexec_stack static in machine_kexec_64.c
Don't return void in arch_teardown_msi_irqs() in msi.c
Move declaration of GregorianDay()into asm/time.h
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The commit fa13a5a1 (sched: restore
deterministic CPU accounting on powerpc), unconditionally calls
update_process_tick() in system context.  In the deterministic
accounting case this is the correct thing to do.  However, in the
non-deterministic accounting case we need to not do this, since doing
this results in the time accounted as hardware irq time being
artificially elevated.

Also this collapses 2 consecutive '#ifdef CONFIG_VIRT_CPU_ACCOUNTING'
checks in time.h into one for neatness.
Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The decrementer in Book E and 4xx processors interrupts on the
transition from 1 to 0, rather than on the 0 to -1 transition as on
64-bit server and 32-bit "classic" (6xx/7xx/7xxx) processors.  At the
moment we subtract 1 from the count of how many decrementer ticks are
required before the next interrupt before putting it into the
decrementer, which is correct for server/classic processors, but could
possibly cause the interrupt to happen too early on Book E and 4xx if
the timebase/decrementer frequency is low.

This fixes the problem by making set_dec subtract 1 from the count for
server and classic processors, instead of having the callers subtract
1.  Since set_dec already had a bunch of ifdefs to handle different
processor types, there is no net increase in ugliness. :)

Note that calling set_dec(0) may not generate an interrupt on some
processors.  To make sure that decrementer_set_next_event always calls
set_dec with an interval of at least 1 tick, we set min_delta_ns of
the decrementer_clockevent to correspond to 2 ticks (2 rather than 1
to compensate for truncations in the conversions between ticks and
ns).

This also removes a redundant call to set the decrementer to
0x7fffffff - it was already set to that earlier in timer_interrupt.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This registers a clock event structure for the decrementer and turns
on CONFIG_GENERIC_CLOCKEVENTS, which means that we now don't need
most of timer_interrupt(), since the work is done in generic code.
For secondary CPUs, their decrementer clockevent is registered when
the CPU comes up (the generic code automatically removes the
clockevent when the CPU goes down).
Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Recent changes to the timekeeping code broke support for the PowerPC 601
processor which doesn't have the usual timebase facility but a slightly
different thing called (yuck) the RTC.

This fixes it, boot tested on an old 601 based PowerMac 7200.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Allow generic_calibrate_decr to work for 40x platforms.  Given that the hardware
behavior is identical, this also changes the set_dec function to reload the PIT
on 40x to match the behavior 44x currently has.
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>

Currently iSeries will recalibrate the cputime_factors in the first
settimeofday() call.

It seems the reason for doing this is to ensure a resaonable time delta after
time_init().  On current kernels (with udev), this call is made 40-60 seconds
into the boot process, by moving it to a late initcall it is called
approximately 5 seconds after time_init() is called.  This is sufficient to
recalibrate the timebase.
Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

For POWERPC, stolen time accounts for cycles lost to the hypervisor or
PURR cycles attributed to the other SMT thread.  Hence, when a PURR is
available, we should still calculate stolen time, irrespective of being
virtualised.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This covers common CPM access functions, CPM interrupt controller code,
micropatch and a few compatibility things to kee the same driver base
working with arch/ppc. This version is refined with all the comments
(mostly PIC-related) addressed.
Signed-off-by: NVitaly Bordug <vbordug@ru.mvista.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This reverts commit 7a69af63.

As advised by David Brownell:

http://marc.theaimsgroup.com/?l=linux-kernel&m=116387226902131&w=2Signed-off-by: NKim Phillips <kim.phillips@freescale.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The Cell CPU timebase has an erratum. When reading the entire 64 bits
of the timebase with one mftb instruction, there is a handful of cycles
window during which one might read a value with the low order 32 bits
already reset to 0x00000000 but the high order bits not yet incremeted
by one. This fixes it by reading the timebase again until the low order
32 bits is no longer 0. That might introduce occasional latencies if
hitting mftb just at the wrong time, but no more than 70ns on a cell
blade, and that was considered acceptable.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Add powerpc get/set_rtc_time interface to new generic rtc class. This
abstracts rtc chip specific code from the platform code for rtc-over-i2c
platforms.  Specific RTC chip support is now configured under
Device Drivers -> Real Time Clock. Setting time of day from the RTC
on startup is also configurable.

this time without the potentially platform breaking initcall.
Signed-off-by: NKim Phillips <kim.phillips@freescale.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This fixes a hang on ppc32.

The problem was that I was comparing a 32-bit quantity with a 64-bit
quantity, and consequently time wasn't advancing.  This makes us use a
64-bit quantity on all platforms, which ends up simplifying the code
since we can now get rid of the tb_last_stamp variable (which actually
fixes another bug that Ben H and I noticed while going carefully through
the code).

This works fine on my G4 tibook.  Let me know how it goes on your
machines.
Acked-by: NOlaf Hering <olaf@aepfle.de>
Acked-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This fixes a problem introduced in 5db9fa95.
The last_jiffy per-cpu variable is only 32 bits on 32-bit machines, but it
was being compared with a 64-bit quantity (tb_next_jiffy), which resulted in
time not advancing.

This fixes it by changing last_jiffy to be 64 bits on all platforms.  With
this, we no longer need tb_last_stamp as a 32-bit version of tb_last_jiffy,
so this gets rid of tb_last_stamp and we just use tb_last_jiffy instead.
This also fixes a bug when the boot cpu is not online, because using
tb_last_stamp could have caused the wrong timebase origin value to be used
when calculating the time of day.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

If we ever build a combined kernel including iSeries, then this will
be needed.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

This implements accurate task and cpu time accounting for 64-bit
powerpc kernels.  Instead of accounting a whole jiffy of time to a
task on a timer interrupt because that task happened to be running at
the time, we now account time in units of timebase ticks according to
the actual time spent by the task in user mode and kernel mode.  We
also count the time spent processing hardware and software interrupts
accurately.  This is conditional on CONFIG_VIRT_CPU_ACCOUNTING.  If
that is not set, we do tick-based approximate accounting as before.

To get this accurate information, we read either the PURR (processor
utilization of resources register) on POWER5 machines, or the timebase
on other machines on

* each entry to the kernel from usermode
* each exit to usermode
* transitions between process context, hard irq context and soft irq
  context in kernel mode
* context switches.

On POWER5 systems with shared-processor logical partitioning we also
read both the PURR and the timebase at each timer interrupt and
context switch in order to determine how much time has been taken by
the hypervisor to run other partitions ("steal" time).  Unfortunately,
since we need values of the PURR on both threads at the same time to
accurately calculate the steal time, and since we can only calculate
steal time on a per-core basis, the apportioning of the steal time
between idle time (time which we ceded to the hypervisor in the idle
loop) and actual stolen time is somewhat approximate at the moment.

This is all based quite heavily on what s390 does, and it uses the
generic interfaces that were added by the s390 developers,
i.e. account_system_time(), account_user_time(), etc.

This patch doesn't add any new interfaces between the kernel and
userspace, and doesn't change the units in which time is reported to
userspace by things such as /proc/stat, /proc/<pid>/stat, getrusage(),
times(), etc.  Internally the various task and cpu times are stored in
timebase units, but they are converted to USER_HZ units (1/100th of a
second) when reported to userspace.  Some precision is therefore lost
but there should not be any accumulating error, since the internal
accumulation is at full precision.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

At present the lppaca - the structure shared with the iSeries
hypervisor and phyp - is contained within the PACA, our own low-level
per-cpu structure.  This doesn't have to be so, the patch below
removes it, making a separate array of lppaca structures.

This saves approximately 500*NR_CPUS bytes of image size and kernel
memory, because we don't need aligning gap between the Linux and
hypervisor portions of every PACA.  On the other hand it means an
extra level of dereference in many accesses to the lppaca.

The patch also gets rid of several places where we assign the paca
address to a local variable for no particular reason.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Signed-off-by: NKelly Daly <kelly@au.ibm.com>

The 601 doesn't have the timebase register; instead it has an RTCL
register that counts nanoseconds and wraps at 1000000000, and an
RTCU register that counts seconds.  This makes the necessary changes
for the merged time code to use the RTCL/U registers when the kernel
is running on a 601.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This moves smp_space_timers from arch/ppc64/kernel/smp.c to
arch/powerpc/kernel/time.c and makes it initialize last_jiffy[]
instead of paca[].next_jiffy_update_tb, since last_jiffy[] is
now what the time code uses.  It also declares smp_space_timers
in include/asm-powerpc/time.h and gets rid of an ifdef in
div128_by_32.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

I had the sense of the test for when to use the old 601-style RTC
registers inverted.  pmac_calibrate_decr and via_calibrate_decr
weren't setting ppc_tb_freq, on which all the further calculations
depended.  Lastly, update_gtod was losing the top 32 bits of
the new tb_to_xs value.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

We now use the merged time.c for both 32-bit and 64-bit compilation
with ARCH=powerpc, and for ARCH=ppc64, but not for ARCH=ppc32.
This removes setup_default_decr (folds its function into time_init)
and moves wakeup_decrementer into time.c.  This also makes an
asm-powerpc/rtc.h.
Signed-off-by: NPaul Mackerras <paulus@samba.org>