linux-toradex.git/arch/powerpc/kernel/idle.c, branch v5.18

powerpc/mm: Switch obsolete dssall to .long

2021-12-23T11:35:13+00:00

The dssall ("Data Stream Stop All") instruction is obsolete altogether
with other Data Cache Instructions since ISA 2.03 (year 2006).

LLVM IAS does not support it but PPC970 seems to be using it.
This switches dssall to .long as there is no much point in fixing LLVM.

Signed-off-by: Alexey Kardashevskiy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20211221055904.555763-6-aik@ozlabs.ru

sched/idle: Fix arch_cpu_idle() vs tracing

2020-11-24T15:47:35+00:00

We call arch_cpu_idle() with RCU disabled, but then use
local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.

Switch all arch_cpu_idle() implementations to use
raw_local_irq_{en,dis}able() and carefully manage the
lockdep,rcu,tracing state like we do in entry.

(XXX: we really should change arch_cpu_idle() to not return with
interrupts enabled)

Reported-by: Sven Schnelle 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Mark Rutland 
Tested-by: Mark Rutland 
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org

powerpc: Move arch_cpu_idle_dead() into smp.c

2020-09-18T09:59:43+00:00

arch_cpu_idle_dead() is in idle.c, which makes sense, but it's inside
a CONFIG_HOTPLUG_CPU block.

It would be more at home in smp.c, inside the existing
CONFIG_HOTPLUG_CPU block. Note that CONFIG_HOTPLUG_CPU depends on
CONFIG_SMP so even though smp.c is not built for SMP=n builds, that's
fine.

Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200819015634.1974478-1-mpe@ellerman.id.au

powerpc/64s: Reimplement power4_idle code in C

2020-01-16T04:59:37+00:00

This implements the tricky tracing and soft irq handling bits in C,
leaving the low level bit to asm.

A functional difference is that this redirects the interrupt exit to
a return stub to execute blr, rather than the lr address itself. This
is probably barely measurable on real hardware, but it keeps the link
stack balanced.

Tested with QEMU.

Signed-off-by: Nicholas Piggin 
[mpe: Move power4_fixup_nap back into exceptions-64s.S]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20190711022404.18132-1-npiggin@gmail.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

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 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman

powerpc/idle: Convert use of typedef ctl_table to struct ctl_table

2013-07-01T01:10:35+00:00

This typedef is unnecessary and should just be removed.

Signed-off-by: Joe Perches 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Use generic idle loop

2013-04-08T15:39:27+00:00

Signed-off-by: Thomas Gleixner 
Cc: Linus Torvalds 
Cc: Rusty Russell 
Cc: Paul McKenney 
Cc: Peter Zijlstra 
Reviewed-by: Cc: Srivatsa S. Bhat 
Cc: Magnus Damm 
Cc: Benjamin Herrenschmidt 
Link: http://lkml.kernel.org/r/20130321215235.026838003@linutronix.de
Signed-off-by: Thomas Gleixner

powerpc: Remove no longer used ppc_md.idle_loop()

2012-11-15T02:00:20+00:00

The last user of ppc_md.idle_loop() was removed when we dropped the
legacy iSeries code, in commit 8ee3e0d.

Signed-off-by: Michael Ellerman 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Remove unused cpu_idle_wait()

2012-05-08T10:35:07+00:00

cpuidle uses a generic function now. Remove the cruft.

Signed-off-by: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Benjamin Herrenschmidt 
Link: http://lkml.kernel.org/r/20120507175652.330322737@linutronix.de

powerpc: Fix broken cpu_idle_wait() implementation

2012-05-08T10:35:05+00:00

commit 771dae818 (powerpc/cpuidle: Add cpu_idle_wait() to allow
switching of idle routines) implemented cpu_idle_wait() for powerpc.

The changelog says:
 "The equivalent routine for x86 is in arch/x86/kernel/process.c
  but the powerpc implementation is different.":

Unfortunately the changelog is completely useless as it does not tell
_WHY_ it is different.

Aside of being different the implementation is patently wrong.

The rescheduling IPI is async. That means that there is no guarantee,
that the other cores have executed the IPI when cpu_idle_wait()
returns. But that's the whole purpose of this function: to guarantee
that no CPU uses the old idle handler anymore.

Use the smp_functional_call() based implementation, which fulfils the
requirements.

[ This code is going to replaced by a core version to remove all the
  pointless copies in arch/*, but this one should go to stable ]

Signed-off-by: Thomas Gleixner 
Acked-by: Peter Zijlstra 
Cc: Deepthi Dharwar 
Cc: Trinabh Gupta 
Cc: Arun R Bharadwaj 
Acked-by: Benjamin Herrenschmidt 
Link: http://lkml.kernel.org/r/20120507175651.980164748@linutronix.de
Cc: stable@vger.kernel.org