powerpc: Refactor verification of MSR_RI

40x and BOOKE don't have MSR_RI therefore all tests involving
MSR_RI may be problematic on those plateforms.

Create helpers to check or set MSR_RI in regs, and use them
in common code.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c2fb93708196734f4176dda334aaa3055f213b89.1629707037.git.christophe.leroy@csgroup.eu

powerpc/pasemi: Fix fall-through warning for Clang

Fix the following fallthrough warning:

arch/powerpc/platforms/pasemi/idle.c:45:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/60efbf18.d9n6eXv275OJcc7T%25lkp@intel.com/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

powerpc/64s: avoid reloading (H)SRR registers if they are still valid

When an interrupt is taken, the SRR registers are set to return to where
it left off. Unless they are modified in the meantime, or the return
address or MSR are modified, there is no need to reload these registers
when returning from interrupt.

Introduce per-CPU flags that track the validity of SRR and HSRR
registers. These are cleared when returning from interrupt, when
using the registers for something else (e.g., OPAL calls), when
adjusting the return address or MSR of a context, and when context
switching (which changes the return address and MSR).

This improves the performance of interrupt returns.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fold in fixup patch from Nick]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333

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 version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 59 temple place suite 330 boston ma 02111
1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 136 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.384967451@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

powerpc/pasemi: Use pr_err/pr_warn... for kernel messages

Pasemi code still uses printk(KERN_ERR/KERN_WARN ... change these to
pr_err(, pr_warn(... to match other powerpc arch code.

No functional changes.

Signed-off-by: Darren Stevens <darren@stevens-zone.net>
[mpe: Unsplit some strings while we're at it]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/pasemi: Do not process external or decrementer interrupts from sreset

PA Semi will wake from low power state at the system reset interrupt,
with the event encoded in SRR1, rather than waking at the interrupt
vector that corresponds to that event.

The system reset handler for this platform decodes SRR1 event reason
and calls the interrupt handler to process it directly from the system
reset handlre.

A subsequent change will treat the system reset interrupt as a Linux NMI
with its own per-CPU stack, and this will no longer work. Remove the
external and decrementer handlers from the system reset handler.

- The external exception remains raised and will fire again at the
EE interrupt vector when system reset returns.

- The decrementer is set to 1 so it will be raised again and fire when
the system reset returns.

It is possible to branch to an idle handler from the system reset
interrupt (like POWER does), then restore a normal stack and restore
this optimisation. But simplicity wins for now.

Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc: ARRAY_SIZE changes in pasemi and powermac code

These changes were a direct result of using a semantic patch
More information can be found at http://www.emn.fr/x-info/coccinelle/

Signed-off-by: Stoyan Gaydarov <sgayda2@uiuc.edu>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[POWERPC] pasemi: Use machine_*_initcall() hooks in platform code

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Olof Johansson <olof@lixom.net>

[POWERPC] pasemi: Move pasemi_idle_init() to late_initcall()

Move pasemi_idle_init() to be a late_initcall instead of being called from
setup_arch(). This way the cpufreq driver has a chance to initialize and
save away the boot time astate before we go to idle for the first time.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] pasemi idle uses hard_smp_processor_id

and so needs to include asm/smp.h so a UP build works.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] Add missed include

fixes:
arch/powerpc/platforms/pasemi/idle.c: In function 'pasemi_system_reset_exception':
arch/powerpc/platforms/pasemi/idle.c:55: warning: implicit declaration of function 'do_IRQ'

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] pasemi: Cpufreq driver

Cpufreq driver for PA Semi PWRficient processors.

Signed-off-by: Egor Martovetsky <egor@pasemi.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] pasemi: Idle loops

Powersave support on PA6T. Right now it only uses 'doze' mode, and
will default to no savings (spin).

Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>