Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

On TOD/TB errors timebase register stops/freezes until HMI error recovery
gets TOD/TB back into running state. On successful recovery, TB starts
running again and udelay() that relies on TB value continues to function
properly. But in case when HMI fails to recover from TOD/TB errors, the
TB register stay freezed. With TB not running the __delay() function
keeps looping and never return. If __delay() is called while in panic
path then system hangs and never reboots after panic.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Remove duplicate headers inclusions.

Signed-off-by: Jagadeesh Pagadala <jagdsh.linux@gmail.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Remove linux/rtc.h which is included more than once

Signed-off-by: Brajeswar Ghosh <brajeswar.linux@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

If CONFIG_PPC_SPLPAR is not selected, steal_time will always
be NUL, so accounting it is pointless

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

scaled cputime is only meaningfull when the processor has
SPURR and/or PURR, which means only on PPC64.

Removing it on PPC32 significantly reduces the size of
vtime_account_system() and vtime_account_idle() on an 8xx:

Before:
00000000 l     F .text	000000a8 vtime_delta
00000280 g     F .text	0000010c vtime_account_system
0000038c g     F .text	00000048 vtime_account_idle

After:
(vtime_delta gets inlined inside the two functions)
000001d8 g     F .text	000000a0 vtime_account_system
00000278 g     F .text	00000038 vtime_account_idle

In terms of performance, we also get approximatly 7% improvement on
task switch. The following small benchmark app is run with perf stat:

void *thread(void *arg)
{
	int i;

	for (i = 0; i < atoi((char*)arg); i++)
		pthread_yield();
}

int main(int argc, char **argv)
{
	pthread_t th1, th2;

	pthread_create(&th1, NULL, thread, argv[1]);
	pthread_create(&th2, NULL, thread, argv[1]);
	pthread_join(th1, NULL);
	pthread_join(th2, NULL);

	return 0;
}

Before the patch:

 Performance counter stats for 'chrt -f 98 ./sched 100000' (50 runs):

       8228.476465      task-clock (msec)         #    0.954 CPUs utilized            ( +-  0.23% )
            200004      context-switches          #    0.024 M/sec                    ( +-  0.00% )

After the patch:

 Performance counter stats for 'chrt -f 98 ./sched 100000' (50 runs):

       7649.070444      task-clock (msec)         #    0.955 CPUs utilized            ( +-  0.27% )
            200004      context-switches          #    0.026 M/sec                    ( +-  0.00% )

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

scaled cputime is only meaningfull when the processor has
SPURR and/or PURR, which means only on PPC64.

In preparation of the following patch that will remove
CONFIG_ARCH_HAS_SCALED_CPUTIME on PPC32, this patch moves
all scaled cputing accounting logic into dedicated functions.

This patch doesn't change any functionality. It's only code
reorganisation.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

In the recent commit 8b78fdb045de ("powerpc/time: Use
clockevents_register_device(), fixing an issue with large
decrementer") we changed the way we initialise the decrementer
clockevent(s).

We no longer initialise the mult & shift values of
decrementer_clockevent itself.

This has the effect of breaking PR KVM, because it uses those values
in kvmppc_emulate_dec(). The symptom is guest kernels spin forever
mid-way through boot.

For now fix it by assigning back to decrementer_clockevent the mult
and shift values.

Fixes: 8b78fdb045de ("powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

If CONFIG_PPC_WATCHDOG is enabled we always cap the decrementer to
0x7fffffff:

       if (IS_ENABLED(CONFIG_PPC_WATCHDOG))
                set_dec(0x7fffffff);
        else
                set_dec(decrementer_max);

If there are no future events, we don't reprogram the decrementer
after this and we end up with 0x7fffffff even on a large decrementer
capable system.

As suggested by Nick, add a set_state_oneshot_stopped callback
so we program the decrementer with decrementer_max if there are
no future events.

Signed-off-by: Anton Blanchard <anton@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

We currently cap the decrementer clockevent at 4 seconds, even on systems
with large decrementer support. Fix this by converting the code to use
clockevents_register_device() which calculates the upper bound based on
the max_delta passed in.

Signed-off-by: Anton Blanchard <anton@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>