In the current code, CONFIG_SMP can be set as N by user on the Loongson
platform, then there exists the following build error under !CONFIG_SMP:

  CC      arch/mips/kernel/asm-offsets.s
In file included from ./include/linux/gfp.h:9:0,
                 from ./include/linux/xarray.h:14,
                 from ./include/linux/radix-tree.h:18,
                 from ./include/linux/fs.h:15,
                 from ./include/linux/compat.h:17,
                 from arch/mips/kernel/asm-offsets.c:12:
./include/linux/topology.h: In function 'numa_node_id':
./include/linux/topology.h:119:2: error: implicit declaration of function 'cpu_logical_map' [-Werror=implicit-function-declaration]
  return cpu_to_node(raw_smp_processor_id());
  ^
cc1: some warnings being treated as errors
scripts/Makefile.build:117: recipe for target 'arch/mips/kernel/asm-offsets.s' failed
make[1]: *** [arch/mips/kernel/asm-offsets.s] Error 1

Select SMP in Kconfig to avoid the above build error and then remove
CONFIG_SMP=y in loongson3_defconfig.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

These boards are used in
- Ubiquiti EdgeRouter (E200),
- Ubiquiti EdgeRouter Pro (E200) and
- Ubiquiti Security Gateway Pro 4 (E220).
Signed-off-by: Mikhail Gusarov <dottedmag@dottedmag.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

SGI-IP28 systems only use broken R10k rev 2.5 CPUs, which could lock
up, if ll/sc sequences are issued in certain order. Since those systems
are all non-SMP, we can disable ll/sc usage in kernel.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

tx4939_add_memory_regions() is only used in txx9/rbtx4939/prom.c.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

There are no users of PAGE_USERIO.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

All boards have the same prom_init() function. Move it to common code and
delete the duplicates.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Only include wm97xx touchscreen probing code, if driver is enabled.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/kernel/process.c:696:15: error: no previous prototype for 'arch_align_stack' [-Werror=missing-prototypes]
Signed-off-by: Pujin Shi <shipujin.t@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

This commit adds a prototype to fix warning at W=1:

  arch/mips/kernel/process.c:95:5: error: no previous prototype for 'arch_dup_task_struct' [-Werror=missing-prototypes]
Signed-off-by: Pujin Shi <shipujin.t@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

This commit adds a prototype to fix warning at W=1:

  arch/mips/kernel/idle.c:126:13: error: no previous prototype for 'check_wait' [-Werror=missing-prototypes]
Signed-off-by: Pujin Shi <shipujin.t@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

There is nothing that prevents us from using lower maximum values.
It's something that we actually want, when using bigger page sizes on
devices with low RAM.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

1.Fix bugs when detecting ways value of JZ4775's L2 cache.
2.Fix bugs when detecting sets value and ways value of X1000E's L2 cache.
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Add JZ4775, X1000E, X2000, and X2000E system type for cat /proc/cpuinfo
to give out JZ4775, X1000E, X2000 and X2000E.
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Add bindings for Ingenic X2000E based board, prepare for later dts.
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

This reverts commit 0ee69c58.

Resource is still needed later in the code, so using
devm_platform_ioremap_resource is no win at all.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

When the kernel crashkernel parameter is specified with just a size,
we are supposed to allocate a region from RAM to store the crashkernel.
However, MIPS merely reserves physical address zero with no checking
that there is even RAM there.

Fix this by lifting similar code from x86, importing it to MIPS with the
MIPS specific parameters added. In the absence of any platform specific
information, we allocate the crashkernel region from the first 512MB of
physical memory (limited to CKSEG0 or KSEG0 address range).

When X is not specified, crash_base defaults to 0 (crashkernel=YM@XM).

E.g. without this patch:

The environment as follows:
[    0.000000] MIPS: machine is loongson,loongson64c-4core-ls7a
...
[    0.000000] Kernel command line: root=/dev/sda2 crashkernel=96M ...

The warning as follows:
[    0.000000] Invalid memory region reserved for crash kernel

And the iomem as follows:
00200000-0effffff : System RAM
  00200000-00b47f87 : Kernel code
  00b47f88-00dfffff : Kernel data
  00e60000-01f73c7f : Kernel bss
1a000000-1bffffff : pci@1a000000
...

With this patch:

After increasing crash_base <= 0 handling.

And the iomem as follows:
00200000-0effffff : System RAM
  00200000-00b47f87 : Kernel code
  00b47f88-00dfffff : Kernel data
  00e60000-01f73c7f : Kernel bss
  04000000-09ffffff : Crash kernel
1a000000-1bffffff : pci@1a000000
...
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

When I update the latest kernel on the Loongson platform used with
LS7A bridge chip, the serial console has no output, this is because
the machine uses LS7A UART0 instead of CPU UART0, add UART node for
LS7A PCH to enhance the compatibility.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Add 'cpus' node to the jz4725b.dtsi, jz4740.dtsi, jz4770.dtsi,
jz4780.dtsi, x1000.dtsi, and x1830.dtsi files.
Tested-by: H. Nikolaus Schaller <hns@goldelico.com>
Tested-by: Paul Boddie <paul@boddie.org.uk>
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

To clean up mach-* directories move external declaration of malta_dt_shim()
to mips-boards/malta.h and remove malta-dtshim.h.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Remove unused heasder file asm/mach-malta/malta-pm.h.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Remove unused config option ALCHEMY_GPIOINT_AU1000.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Remove unused config option ALCHEMY_GPIOINT_AU1300 and related code.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Move HEART specific parts of mach-ip30/irq.h to asm/sgi/heart.h and IP30
specific parts to sgi-ip30/ip30-common.h.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Loongson-3 has 16-bytes load/store instructions: gslq and gssq. This
patch calculate ra properly when unwinding the stack, if ra is saved
by gssq and restored by gslq.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Loongson-3's COP2 is Multi-Media coprocessor, it is disabled in kernel
mode by default. However, gslq/gssq (16-bytes load/store instructions)
overrides the instruction format of lwc2/swc2. If we wan't to use gslq/
gssq for optimization in kernel, we should enable COP2 usage in kernel.

Please pay attention that in this patch we only enable COP2 in kernel,
which means it will lose ST0_CU2 when a process go to user space (try
to use COP2 in user space will trigger an exception and then grab COP2,
which is similar to FPU). And as a result, we need to modify the context
switching code because the new scheduled process doesn't contain ST0_CU2
in its THERAD_STATUS probably.

For zboot, we disable gslq/gssq be generated by toolchain.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Some processors (such as Loongson-3) need to enable CU2 in kernel mode,
current set/clear method will lose Status.CU2 during context switching,
so use save/restore method instead.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/kernel/branch.c:876:5: error: no previous prototype for '__insn_is_compact_branch' [-Werror=missing-prototypes]
Signed-off-by: Pujin Shi <shipujin.t@gmail.com>
Signed-off-by: Pujin Shi <shipj@lemote.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

This addresses the following sparse warning:

arch/mips/kernel/setup.c:446:33: warning: symbol 'setup_elfcorehdr_size'
was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Support for Ingenic chips has been moved to the generic MIPS platform.
Update the paths accordingly.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

For each board the MACH_INGENIC_SOC option was selected instead of
MACH_INGENIC. Nothing else was changed in the menuconfig.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Now that all the jz4740 platform code has been removed, and we're left
with only a Kconfig and the cpu-feature-overrides.h file, finalize the
cleanup process by renaming the jz4740 and include/mach-jz4740 folders
to ingenic and include/mach-ingenic.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Support for Ingenic SoCs is now provided by the arch/mips/generic/ code,
so all files in the arch/mips/jz4740/ folder can dropped, except for the
Kconfig, and the cpu-feature-overrides.h header file.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Add support for Ingenic SoCs in arch/mips/generic/.

The Kconfig changes are here to ensure that it is possible to compile
either a generic kernel that supports Ingenic SoCs, or a Ingenic-only
kernel, both using the same code base, to avoid duplicated code.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

128 IRQs is not enough to support Ingenic SoCs.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

There is no reason we can't create compressed kernels here, so select
the option SYS_SUPPORTS_ZBOOT.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

The plat_get_fdt() checked that the kernel was booted using UHI before
reading the 'fw_passed_dtb' variable. However, this variable is also set
when the DT has been appended, or when it has been built into the kernel.

Support these usecases by removing the UHI check.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

The function bootcmdline_init() in arch/mips/kernel/setup.c will
populate the boot_command_line string using the parameters hardcoded in
the kernel, and those provided in the devicetree file. Then, it would
append the content of the arcs_cmdline variable, which is filled by the
board's plat_mem_setup() function.

The plat_mem_setup() function for the generic MIPS board would just copy
the current boot_command_line to arcs_cmdline, which is nonsense for two
reasons:
- the result will be appended to the boot_command_line anyway, so all it
  does is duplicate every single parameter on the command line;
- the code did not perform at all what it's supposed to, which is to
  retrieve the parameters passed by the bootloader.

Fix this by calling fw_init_cmdline() in plat_mem_setup(), which will
properly initialize arcs_cmdline to the parameters passed by the
bootloader.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Check for the system_type variable in the get_system_type() function. If
non-NULL, return it as the system type.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

The MIPS_GENERIC symbol now won't select any other configuration option.
The MIPS_GENERIC_KERNEL will select all the options that the previous
MIPS_GENERIC option did select, and will select MIPS_GENERIC as well.

The whole point of this, is that it now becomes possible to compile a
kernel for a SoC supported by the arch/mips/generic/ code, without
making that kernel generic itself.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

The previous code was doing:
BUG_ON(!__builtin_constant_p(cpu_has_counter) || cpu_has_counter);

This only worked as the "cpu_has_counter" macro was overridden in
<cpu-feature-overrides.h>. The default "cpu_has_counter" macro is
non-constant, which triggered the BUG_ON() independently of the value
returned by the macro.

What we want to check here, is that *if* the macro was overridden to a
compile-time constant, then must be defined to zero, otherwise it's a
bug.

So the correct check is:
BUG_ON(__builtin_constant_p(cpu_has_counter) && cpu_has_counter);
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>