MIPS: Fix typos

Fix typos, most reported by "codespell arch/mips". Only touches comments,
no code changes.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-mips@vger.kernel.org
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

mips, kexec: fix the incorrect ifdeffery and dependency of CONFIG_KEXEC

The select of KEXEC for CRASH_DUMP in kernel/Kconfig.kexec will be
dropped, then compiling errors will be triggered if below config items are
set:

===
CONFIG_CRASH_CORE=y
CONFIG_KEXEC_CORE=y
CONFIG_CRASH_DUMP=y
===

--------------------------------------------------------------------
mipsel-linux-ld: kernel/kexec_core.o: in function `kimage_free':
kernel/kexec_core.c:(.text+0x2200): undefined reference to `machine_kexec_cleanup'
mipsel-linux-ld: kernel/kexec_core.o: in function `__crash_kexec':
kernel/kexec_core.c:(.text+0x2480): undefined reference to `machine_crash_shutdown'
mipsel-linux-ld: kernel/kexec_core.c:(.text+0x2488): undefined reference to `machine_kexec'
mipsel-linux-ld: kernel/kexec_core.o: in function `kernel_kexec':
kernel/kexec_core.c:(.text+0x29b8): undefined reference to `machine_shutdown'
mipsel-linux-ld: kernel/kexec_core.c:(.text+0x29c0): undefined reference to `machine_kexec'
--------------------------------------------------------------------

Here, change the dependency of building kexec_core related object files,
and the ifdeffery in mips from CONFIG_KEXEC to CONFIG_KEXEC_CORE.

Link: https://lkml.kernel.org/r/20231208073036.7884-4-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311302042.sn8cDPIX-lkp@intel.com/
Cc: Eric DeVolder <eric_devolder@yahoo.com>
Cc: Ignat Korchagin <ignat@cloudflare.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

MIPS: Loongson64: Fix more __iomem attributes

There are some __iomem type casting being missed in previous patch.
Fix them here.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307020639.QCZOKp8B-lkp@intel.com/
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: SMP_CPS: Switch to hotplug core state synchronization

Switch to the CPU hotplug core state tracking and synchronization
mechanim. This unfortunately requires to add dead reporting to the non CPS
platforms as CPS is the only user, but it allows an overall consolidation
of this functionality.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Link: https://lore.kernel.org/r/20230512205256.803238859@linutronix.de

MIPS: Loongson64: smp: Correct nudge_writes usage

Previously every write to SMP regisers are followed by nudge_writes,
this incures a huge performance penalty because nudge_writes involves
SYNC, which will be globalized on chip.

Only set off nudge_writes when we really want other cores to see the
result ASAP. Also replace read/write functions to relaxed version because
we don't need extra barriers to protect against DMA.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Loongson64: smp: Use nudge_writes instead of wbflush

wbflush here intends to let other cores see the results ASAP,
nudge_writes fits this purpose better.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Loongson64: Prefix ipi register address pointers with __iomem

They are truely mmio pointers, so give them proper prefix.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

mips/cpu: Make sure play_dead() doesn't return

play_dead() doesn't return. Make that more explicit with a BUG().

BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/b195e4da190bb06b7d4af15d66ce6129e2347630.1676358308.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

mips/cpu: Expose play_dead()'s prototype definition

Include <asm/smp.h> to make sure play_dead() matches its prototype going
forward.

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lkml.kernel.org/r/20230216184249.ogaqsaykottpxtcb@treble
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

MIPS: loongson64: Drop call to irq_cpu_offline()

Also loongson64 calls irq_cpu_offline(), none of its interrupt
controllers implement the .irq_cpu_offline callback.

It is thus obvious that this call only serves the dubious purpose
of wasting precious CPU cycles by iterating over all interrupts.

Get rid of the call altogether.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20211021170414.3341522-2-maz@kernel.org

MIPS: Loongson64: Make some functions static in smp.c

Make some functions static to fix the following sparse warnings:

arch/mips/loongson64/smp.c:54:5: sparse: sparse: symbol 'ipi_read_clear' was not declared. Should it be static?
arch/mips/loongson64/smp.c:55:6: sparse: sparse: symbol 'ipi_write_action' was not declared. Should it be static?
arch/mips/loongson64/smp.c:56:6: sparse: sparse: symbol 'ipi_write_enable' was not declared. Should it be static?
arch/mips/loongson64/smp.c:57:6: sparse: sparse: symbol 'ipi_clear_buf' was not declared. Should it be static?
arch/mips/loongson64/smp.c:58:6: sparse: sparse: symbol 'ipi_write_buf' was not declared. Should it be static?

Fixes: fed4955f304e ("MIPS: Loongson64: Add Mail_Send support for 3A4000+ CPU")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: loongson64: smp.c: Fix block comment coding style

This patch fixes:
"WARNING: Block comments use a trailing */ on a separate line"
by checkpatch.pl

Signed-off-by: siyanteng <siyanteng@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Loongson64: Set cluster for cores

cluster is required for cacheinfo to set shared_cpu_map correctly.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Reviewed-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Huacai Chen <chenhuacai@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: No need to check CPU 0 in {loongson3,bmips,octeon}_cpu_disable()

After commit 9cce844abf07 ("MIPS: CPU#0 is not hotpluggable"),
c->hotpluggable is 0 for CPU 0 and it will not generate a control
file in sysfs for this CPU:

[root@linux loongson]# cat /sys/devices/system/cpu/cpu0/online
cat: /sys/devices/system/cpu/cpu0/online: No such file or directory
[root@linux loongson]# echo 0 > /sys/devices/system/cpu/cpu0/online
bash: /sys/devices/system/cpu/cpu0/online: Permission denied

So no need to check CPU 0 in {loongson3,bmips,octeon}_cpu_disable(),
just remove them.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Loongson64: SMP: Fix up play_dead jump indicator

In play_dead function, the whole 64-bit PC mailbox was used as a indicator
to determine if the master core had written boot jump information.

However, after we introduced CSR mailsend, the hardware will not guarante
an atomic write for the 64-bit PC mailbox. Thus we have to use the lower
32-bit which is written at the last as the jump indicator instead.

Signed-off-by: Lu Zeng <zenglu@loongson.cn>
Signed-off-by: Jun Yi <yijun@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Loongson64: Add Mail_Send support for 3A4000+ CPU

Loongson 3A4000+ CPU has per-core Mail_Send register to send mail,
there is no need to maintain register address of each core and node,
just simply specify cpu number.

Signed-off-by: Lu Zeng <zenglu@loongson.cn>
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Loongson64: Set IPI_Enable register per core by itself

In the current code, for example, core 1 sets Core[0, 1, 2, 3]_IPI_Enalbe
register and core 2, 3 do the same thing on the 1-way Loongson64 platform,
this is not necessary. Set IPI_Enable register per core by itself to avoid
duplicate operations and make the logic more clear.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Loongson64: Drop asm/clock.h include

This include isn't used by this file, so just remove it.

Acked-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Paul Burton <paulburton@kernel.org>
Cc: <linux-mips@vger.kernel.org>
Cc: <chenhc@lemote.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lkml.kernel.org/r/20200409064416.83340-10-sboyd@kernel.org
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

mips: loongsoon2ef: remove private clk api

As platforms are moving to COMMON_CLK in general, loongson2ef
stuck out as something that has a private implementation but
does not actually use it except for setting the frequency of
the CPU itself from the loongson2_cpufreq driver.

Change that driver to call the register setting function directly
and remove the rest of the stub implementation.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Loongson64: Drop legacy IRQ code

We've made generic irqchip drivers for Loongson-3 platform, it's time
to say goodbye to these legacy code.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Co-developed-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Loongson64: Move files to the top-level directory

Current Loongson-3 code can share among all Loongson64 processors.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: chenhc@lemote.com
Cc: paul.burton@mips.com