xtensa: drop platform_halt and platform_power_off

Instead of using xtensa-specific platform_halt and platform_power_off
callbacks use do_kernel_power_off in the machine_halt and
machine_power_off and reimplement existing platform_halt and
platform_power_off users with register_sys_off_handler.

Drop platform_halt and platform_power_off declarations and default
implementations.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: drop platform_restart

Instead of using xtensa-specific platform_restart callback use
do_kernel_restart in the machine_restart implementation and reimplement
existing platform_restart users with register_restart_handler.
Drop platform_restart declaration and default implementation.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: drop platform_heartbeat

platform_heartbeat is called from the timer interrupt handler, but
there may be no periodic timer interrupts on xtensa, so the frequency of
platform_heartbeat calls may be unrelated to HZ. Drop the callback and
reimplement its only user with a timer.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: xt2000: drop empty platform_init

platform_init doesn't do anything for xt2000, drop it.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: no need to initialise statics to 0

Static variables do not need to be initialised to 0, because compiler
will initialise all uninitialised statics to 0. Thus, remove the
unneeded initializations.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Message-Id: <20220508022910.98481-1-wangborong@cdjrlc.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

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

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>

xtensa: extract common CPU reset code into separate function

platform_restart implementatations do the same thing to reset CPU.
Don't duplicate that code, move it to a function and call it from
platform_restart.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

tty: stop defining STD_COM_FLAGS in drivers

STD_COM_FLAGS is mostly a bad name for what the drivers thinks it is.
Stop using it and pass the flags directly.

cyclades defines it as 0, so we do not assign anything to freshly
tty_port_init'ed structure.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: Fix ASYNC_* => UPF_* flags misuse

The UPF_* flags are the correct values to use for struct uart_port
and struct old_serial_port/SERIAL_PORT_DFNS.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

xtensa: fixes for configs without loop option

Build-time fixes:
- make lbeg/lend/lcount save/restore conditional on kernel entry;
- don't clear lcount in platform_restart functions unconditionally.

Run-time fixes:
- use correct end of range register in __endla paired with __loopt, not
the unused temporary register. This fixes .bss zero-initialization.
Update comments in asmmacro.h;
- don't clobber a10 in the usercopy that leads to access to unmapped
memory.

Cc: <stable@vger.kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: xt2000: drop redundant sysmem initialization

sysmem structure initialization in xt2000 platform_init is identical to
the one done in init_arch just before the call to platform_init.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: fix ibreakenable register update

Only set the register when there is at least one ibreak register,
otherwise the build fails:
arch/xtensa/kernel/head.S:105: Error: invalid register 'ibreakenable'
for 'wsr' instruction
arch/xtensa/platforms/iss/setup.c:67: Error: invalid register
'ibreakenable' for 'wsr' instruction

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

xtensa: reorganize SR referencing

- reference SRs by names where possible, not by numbers;
- get rid of __stringify around SR names where possible;
- remove unneeded SR names from asm/regs.h;
- add SREG_ prefix to remaining SR names;

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

xtensa: Add xt2000 support files.

The last check-in to support the xt2000 development platform was missing
some files.

Signed-off-by: Chris Zankel <chris@zankel.net>