cpuidle,arch: Mark all regular cpuidle_state:: Enter methods __cpuidle

For all cpuidle drivers that do not use CPUIDLE_FLAG_RCU_IDLE (iow,
the simple ones) make sure all the functions are marked __c

cpuidle,arch: Mark all regular cpuidle_state:: Enter methods __cpuidle

For all cpuidle drivers that do not use CPUIDLE_FLAG_RCU_IDLE (iow,
the simple ones) make sure all the functions are marked __cpuidle.

( due to lack of noinstr validation on these platforms it is entirely
possible this isn't complete )

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230112195542.335211484@infradead.org

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arch/idle: Change arch_cpu_idle() behavior: always exit with IRQs disabled

Current arch_cpu_idle() is called with IRQs disabled, but will return
with IRQs enabled.

However, the very first thing the

arch/idle: Change arch_cpu_idle() behavior: always exit with IRQs disabled

Current arch_cpu_idle() is called with IRQs disabled, but will return
with IRQs enabled.

However, the very first thing the generic code does after calling
arch_cpu_idle() is raw_local_irq_disable(). This means that
architectures that can idle with IRQs disabled end up doing a
pointless 'enable-disable' dance.

Therefore, push this IRQ disabling into the idle function, meaning
that those architectures can avoid the pointless IRQ state flipping.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Acked-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Guo Ren <guoren@kernel.org>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.618076436@infradead.org

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MIPS: fix typos in comments

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Thomas Bogendoerfer <tsbo

MIPS: fix typos in comments

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

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MIPS: Remove TX39XX support

No (active) developer owns this hardware, so let's remove Linux support.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Guenter Roeck <linux@ro

MIPS: Remove TX39XX support

No (active) developer owns this hardware, so let's remove Linux support.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>

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MIPS: Remove NETLOGIC support

No (active) developer owns this hardware, so let's remove Linux support.

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

Revert "MIPS: Remove unused R4300 CPU support"

This reverts commit f9065b54d437c4660e3d974ad9ce5188c068cd76.

We're adding Nintendo 64 support, so the VR4300 is no longer unused.

Signed-off-by: Lau

Revert "MIPS: Remove unused R4300 CPU support"

This reverts commit f9065b54d437c4660e3d974ad9ce5188c068cd76.

We're adding Nintendo 64 support, so the VR4300 is no longer unused.

Signed-off-by: Lauri Kasanen <cand@gmx.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

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sched/idle: Fix arch_cpu_idle() vs tracing

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() i

sched/idle: Fix arch_cpu_idle() vs tracing

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 <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org

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MIPS: Use fallthrough for arch/mips

Convert the various /* fallthrough */ comments to the pseudo-keyword
fallthrough;

Done via script:
https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e1789

MIPS: Use fallthrough for arch/mips

Convert the various /* fallthrough */ comments to the pseudo-keyword
fallthrough;

Done via script:
https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/

Signed-off-by: Liangliang Huang <huangll@lemote.com>
Reviewed-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

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MIPS: Kernel: Identify Loongson-2K processors

Loongson-2K (Loongson64 Reduced) is a family of SoC shipped with
gs264e core.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thoma

MIPS: Kernel: Identify Loongson-2K processors

Loongson-2K (Loongson64 Reduced) is a family of SoC shipped with
gs264e core.

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

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MIPS: Loongson: Rename LOONGSON1 to LOONGSON32

Now old Loongson-2E/2F use LOONGSON2EF and will be removed in future,
newer Loongson-2/3 use LOONGSON64. So rename LOONGSON1 to LOONGSON32
will make th

MIPS: Loongson: Rename LOONGSON1 to LOONGSON32

Now old Loongson-2E/2F use LOONGSON2EF and will be removed in future,
newer Loongson-2/3 use LOONGSON64. So rename LOONGSON1 to LOONGSON32
will make the naming style more unified.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
[paulburton@kernel.org: Fix checkpatch whitespace warning in irqflags.h]
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-mips@vger.kernel.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhuacai@gmail.com>

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MIPS: Loongson64: Rename CPU TYPES

CPU_LOONGSON2 -> CPU_LOONGSON2EF
CPU_LOONGSON3 -> CPU_LOONGSON64

As newer loongson-2 products (2G/2H/2K1000) can share kernel
implementation with loongson-3 while

MIPS: Loongson64: Rename CPU TYPES

CPU_LOONGSON2 -> CPU_LOONGSON2EF
CPU_LOONGSON3 -> CPU_LOONGSON64

As newer loongson-2 products (2G/2H/2K1000) can share kernel
implementation with loongson-3 while 2E/2F are less similar with
other LOONGSON64 products.

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

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MIPS: Loongson: Add Loongson-3A R4 basic support

All Loongson-3 CPU family:

Code-name Brand-name PRId
Loongson-3A R1 Loongson-3A1000 0x6305
Loongson-3A R2 Loongson-3A2000 0x63

MIPS: Loongson: Add Loongson-3A R4 basic support

All Loongson-3 CPU family:

Code-name Brand-name PRId
Loongson-3A R1 Loongson-3A1000 0x6305
Loongson-3A R2 Loongson-3A2000 0x6308
Loongson-3A R2.1 Loongson-3A2000 0x630c
Loongson-3A R3 Loongson-3A3000 0x6309
Loongson-3A R3.1 Loongson-3A3000 0x630d
Loongson-3A R4 Loongson-3A4000 0xc000
Loongson-3B R1 Loongson-3B1000 0x6306
Loongson-3B R2 Loongson-3B1500 0x6307

Features of R4 revision of Loongson-3A:

- All R2/R3 features, including SFB, V-Cache, FTLB, RIXI, DSP, etc.
- Support variable ASID bits.
- Support MSA and VZ extensions.
- Support CPUCFG (CPU config) and CSR (Control and Status Register)
extensions.
- 64 entries of VTLB (classic TLB), 2048 entries of FTLB (8-way
set-associative).

Now 64-bit Loongson processors has three types of PRID.IMP: 0x6300 is
the classic one so we call it PRID_IMP_LOONGSON_64C (e.g., Loongson-2E/
2F/3A1000/3B1000/3B1500/3A2000/3A3000), 0x6100 is for some processors
which has reduced capabilities so we call it PRID_IMP_LOONGSON_64R
(e.g., Loongson-2K), 0xc000 is supposed to cover all new processors in
general (e.g., Loongson-3A4000+) so we call it PRID_IMP_LOONGSON_64G.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-mips@vger.kernel.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhuacai@gmail.com>

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MIPS: Remove unused R4300 CPU support

Our R4300 CPU support can only be included if a system selects
CONFIG_SYS_HAS_CPU_R4300. No system does, making all R4300-related CPU
support dead code. Remove

MIPS: Remove unused R4300 CPU support

Our R4300 CPU support can only be included if a system selects
CONFIG_SYS_HAS_CPU_R4300. No system does, making all R4300-related CPU
support dead code. Remove it.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org

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MIPS: Rename JZRISC to XBURST

The real name of the CPU present in the JZ line of SoCs from Ingenic is
XBurst, not JZRISC.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
[paul.burton@mips.com:

MIPS: Rename JZRISC to XBURST

The real name of the CPU present in the JZ line of SoCs from Ingenic is
XBurst, not JZRISC.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
[paul.burton@mips.com: Leave /proc/cpuinfo string as-is.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: od@zcrc.me
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

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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 th

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>

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MIPS: Loongson: Add Loongson-3A R2.1 basic support

Loongson-3A R2.1 is the bugfix revision of Loongson-3A R2.

All Loongson-3 CPU family:

Code-name Brand-name PRId
Loongson-3A R1 L

MIPS: Loongson: Add Loongson-3A R2.1 basic support

Loongson-3A R2.1 is the bugfix revision of Loongson-3A R2.

All Loongson-3 CPU family:

Code-name Brand-name PRId
Loongson-3A R1 Loongson-3A1000 0x6305
Loongson-3A R2 Loongson-3A2000 0x6308
Loongson-3A R2.1 Loongson-3A2000 0x630c
Loongson-3A R3 Loongson-3A3000 0x6309
Loongson-3A R3.1 Loongson-3A3000 0x630d
Loongson-3B R1 Loongson-3B1000 0x6306
Loongson-3B R2 Loongson-3B1500 0x6307

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21128/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <james.hogan@mips.com>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>

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MIPS: Avoid using .set mips0 to restore ISA

We currently have 2 commonly used methods for switching ISA within
assembly code, then restoring the original ISA.

1) Using a pair of .set push & .set

MIPS: Avoid using .set mips0 to restore ISA

We currently have 2 commonly used methods for switching ISA within
assembly code, then restoring the original ISA.

1) Using a pair of .set push & .set pop directives. For example:

.set push
.set mips32r2
<some_insn>
.set pop

2) Using .set mips0 to restore the ISA originally specified on the
command line. For example:

.set mips32r2
<some_insn>
.set mips0

Unfortunately method 2 does not work with nanoMIPS toolchains, where the
assembler rejects the .set mips0 directive like so:

Error: cannot change ISA from nanoMIPS to mips0

In preparation for supporting nanoMIPS builds, switch all instances of
method 2 in generic non-platform-specific code to use push & pop as in
method 1 instead. The .set push & .set pop is arguably cleaner anyway,
and if nothing else it's good to consistently use one method.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21037/
Cc: linux-mips@linux-mips.org

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MIPS: Annotate cpu_wait implementations with __cpuidle

Annotate cpu_wait implementations using the __cpuidle macro which
places these functions in the .cpuidle.text section. This allows
cpu_in_idle(

MIPS: Annotate cpu_wait implementations with __cpuidle

Annotate cpu_wait implementations using the __cpuidle macro which
places these functions in the .cpuidle.text section. This allows
cpu_in_idle() to return true for PC values which fall within these
functions, allowing nmi_backtrace() to produce cleaner output for CPUs
running idle functions. For example:

# echo l >/proc/sysrq-trigger
[ 38.587170] sysrq: SysRq : Show backtrace of all active CPUs
[ 38.593657] NMI backtrace for cpu 1
[ 38.597611] CPU: 1 PID: 161 Comm: sh Not tainted 4.18.0-rc1+ #27
[ 38.604306] Stack : 00000000 00000004 00000006 80486724 00000000 00000000 00000000 00000000
[ 38.613647] 80e17eda 00000034 00000000 00000000 80d20000 80b67e98 8e559c90 0ffe1e88
[ 38.622986] 00000000 00000000 80e70000 00000000 8f61db18 38312e34 722d302e 202b3163
[ 38.632324] 8e559d3c 8e559adc 00000001 6b636162 80d20000 80000000 00000000 80d1cfa4
[ 38.641664] 00000001 80d20000 80d19520 00000000 00000003 80836724 00000004 80e10004
[ 38.650993] ...
[ 38.653724] Call Trace:
[ 38.656499] [<8040cdd0>] show_stack+0xa0/0x144
[ 38.661475] [<80b67e98>] dump_stack+0xe8/0x120
[ 38.666455] [<80b6f6d4>] nmi_cpu_backtrace+0x1b4/0x1cc
[ 38.672189] [<80b6f81c>] nmi_trigger_cpumask_backtrace+0x130/0x1e4
[ 38.679081] [<808295d8>] __handle_sysrq+0xc0/0x180
[ 38.684421] [<80829b84>] write_sysrq_trigger+0x50/0x64
[ 38.690176] [<8061c984>] proc_reg_write+0xd0/0xfc
[ 38.695447] [<805aac1c>] __vfs_write+0x54/0x194
[ 38.700500] [<805aaf24>] vfs_write+0xe0/0x18c
[ 38.705360] [<805ab190>] ksys_write+0x7c/0xf0
[ 38.710238] [<80416018>] syscall_common+0x34/0x58
[ 38.715558] Sending NMI from CPU 1 to CPUs 0,2-3:
[ 38.720916] NMI backtrace for cpu 0 skipped: idling at r4k_wait_irqoff+0x2c/0x34
[ 38.729186] NMI backtrace for cpu 3 skipped: idling at r4k_wait_irqoff+0x2c/0x34
[ 38.737449] NMI backtrace for cpu 2 skipped: idling at r4k_wait_irqoff+0x2c/0x34

Without this we get register value & backtrace output from all CPUs,
which is generally useless for those running the idle function & serves
only to overwhelm & obfuscate the meaningful output from non-idle CPUs.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/19598/

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MIPS: Include linux/cpu.h for arch_cpu_idle()

arch/mips/kernel/idle.c provides our implementation of the
arch_cpu_idle() function, but doesn't include the linux/cpu.h header
which declares it. This

MIPS: Include linux/cpu.h for arch_cpu_idle()

arch/mips/kernel/idle.c provides our implementation of the
arch_cpu_idle() function, but doesn't include the linux/cpu.h header
which declares it. This leads to a warning from sparse:

arch/mips/kernel/idle.c:256:6: warning: symbol 'arch_cpu_idle' was not
declared. Should it be static?

Fix this by including linux/cpu.h to get the declaration of
arch_cpu_idle().

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17169/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

show more ...

MIPS: Loongson: Add Loongson-3A R2 basic support

Loongson-3 CPU family:

Code-name Brand-name PRId
Loongson-3A R1 Loongson-3A1000 0x6305
Loongson-3A R2 Loongson-3A2000 0x6308
Loongso

MIPS: Loongson: Add Loongson-3A R2 basic support

Loongson-3 CPU family:

Code-name Brand-name PRId
Loongson-3A R1 Loongson-3A1000 0x6305
Loongson-3A R2 Loongson-3A2000 0x6308
Loongson-3B R1 Loongson-3B1000 0x6306
Loongson-3B R2 Loongson-3B1500 0x6307

Features of R2 revision of Loongson-3A:

- Primary cache includes I-Cache, D-Cache and V-Cache (Victim Cache).
- I-Cache, D-Cache and V-Cache are 16-way set-associative, linesize is
64 bytes.
- 64 entries of VTLB (classic TLB), 1024 entries of FTLB (8-way
set-associative).
- Supports DSP/DSPv2 instructions, UserLocal register and Read-Inhibit/
Execute-Inhibit.

[ralf@linux-mips.org: Resolved merge conflicts.]

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12751/
Patchwork: https://patchwork.linux-mips.org/patch/13136/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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MIPS: idle: add case for CPU_5KE

While the 5KE processors have never been taped out, they exists though
a CP0.PRId and experimental RTLs or QEMU implementations. Add a case
entry in the idle code, a

MIPS: idle: add case for CPU_5KE

While the 5KE processors have never been taped out, they exists though
a CP0.PRId and experimental RTLs or QEMU implementations. Add a case
entry in the idle code, as they can use the standard idle loop like the
5K processors.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11099/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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MIPS: Always use r4k_wait_irqoff for MIPSr6

Prior to release 6 of the MIPS architecture it has been implementation
dependent whether masked interrupts cause a wait instruction to return,
so the kern

MIPS: Always use r4k_wait_irqoff for MIPSr6

Prior to release 6 of the MIPS architecture it has been implementation
dependent whether masked interrupts cause a wait instruction to return,
so the kernel has effectively had to maintain a whitelist of cores upon
which it is safe to use the r4k_wait_irqoff cpu_wait implementation.
With MIPSr6 this is no longer implementation dependent and
r4k_wait_irqoff can always be used.

Remove the existing I6400 case which will no longer ever be hit, and was
incorrect anyway since I6400 & r6 in general doesn't have the WII bit.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11210/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

show more ...

MIPS: Switch BMIPS5000 to use r4k_wait_irqoff()

BCM7425 CPU Interface Zephyr Processor, pages 5-309 and 5-310
BCM7428B0 CPU Interface Zephyr Processor, pages 5-337 and 5-338

WAIT instruction:
Threa

MIPS: Switch BMIPS5000 to use r4k_wait_irqoff()

BCM7425 CPU Interface Zephyr Processor, pages 5-309 and 5-310
BCM7428B0 CPU Interface Zephyr Processor, pages 5-337 and 5-338

WAIT instruction:
Thread enters wait state. No instructions are executed until an
interrupt occurs. The processor's clocks are stopped if both threads
are in idle mode.

Description:
Execution of this instruction puts the thread into wait state, an idle
mode in which no instructions are fetched or executed. The thread remains
in wait state until an interrupt occurs that is not masked by the
interrupt mask field in the Status register. Then, if interrupts are
enabled by the IE bit in the Status register, the interrupt is serviced.
The ERET instruction returns to the instruction following the WAIT
instruction. If interrupts are disabled, the processor resumes executing
instructions with the next sequential instruction.

Programming notes:
The WAIT instruction should be executed while interrupts are disabled
by the IE bit in the Status register. This avoids a potential timing
hazard, which occurs if an interrupt is taken between testing the counter
and executing the WAIT instruction. In this hazard case, the interrupt
will have been completed before the WAIT instruction is executed, so
the processor will remain indefinitely in wait state until the next
interrupt.

Signed-off-by: Petri Gynther <pgynther@google.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: cernekee@gmail.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11322/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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MIPS: Add cases for CPU_I6400

Add a CPU_I6400 case to various switch statements, doing the same thing
as for CPU_P5600.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@li

MIPS: Add cases for CPU_I6400

Add a CPU_I6400 case to various switch statements, doing the same thing
as for CPU_P5600.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10635/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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MIPS: idle: Workaround wait + FDC problems

On certain cores (namely proAptiv and P5600) incoming data via a Fast
Debug Channel (FDC) while the core is blocked on a wait instruction will
cause the wa

MIPS: idle: Workaround wait + FDC problems

On certain cores (namely proAptiv and P5600) incoming data via a Fast
Debug Channel (FDC) while the core is blocked on a wait instruction will
cause the wait not to wake up even when another interrupt is received.
This makes an idle target stop as soon as you send FDC data to it, until
the debug probe interrupts it and restarts the wait instruction.

This is worked around by avoiding using r4k_wait on these cores if
CONFIG_MIPS_EJTAG_FDC_TTY is enabled (which would imply the user intends
to use the FDC).

[ralf@linux-mips.org: Fix conflict.]

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9144/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

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