In the current code, arch_has_single_step() is not defined on MIPS,
that means MIPS does not support instruction single-step for user mode.

Delve is a debugger for the Go programming language, the ptrace syscall
PtraceSingleStep() failed [1] on MIPS and then the single step function
can not work well, we can see that PtraceSingleStep() definition returns
ptrace(PTRACE_SINGLESTEP) [2].

So it is necessary to support ptrace single step on MIPS.

At the beginning, we try to use the Debug Single Step exception on the
Loongson 3A4000 platform, but it has no effect when set CP0_DEBUG SSt
bit, this is because CP0_DEBUG NoSSt bit is 1 which indicates no
single-step feature available [3], so this way which is dependent on the
hardware is almost impossible.

With further research, we find out there exists a common way used with
break instruction in arch/alpha/kernel/ptrace.c, it is workable.

For the above analysis, define arch_has_single_step(), add the common
function user_enable_single_step() and user_disable_single_step(), set
flag TIF_SINGLESTEP for child process, use break instruction to set
breakpoint.

We can use the following testcase to test it:
tools/testing/selftests/breakpoints/step_after_suspend_test.c

 $ make -C tools/testing/selftests TARGETS=breakpoints
 $ cd tools/testing/selftests/breakpoints

Without this patch:

 $ ./step_after_suspend_test -n
 TAP version 13
 1..4
 # ptrace(PTRACE_SINGLESTEP) not supported on this architecture: Input/output error
 ok 1 # SKIP CPU 0
 # ptrace(PTRACE_SINGLESTEP) not supported on this architecture: Input/output error
 ok 2 # SKIP CPU 1
 # ptrace(PTRACE_SINGLESTEP) not supported on this architecture: Input/output error
 ok 3 # SKIP CPU 2
 # ptrace(PTRACE_SINGLESTEP) not supported on this architecture: Input/output error
 ok 4 # SKIP CPU 3
 # Totals: pass:0 fail:0 xfail:0 xpass:0 skip:4 error:0

With this patch:

 $ ./step_after_suspend_test -n
 TAP version 13
 1..4
 ok 1 CPU 0
 ok 2 CPU 1
 ok 3 CPU 2
 ok 4 CPU 3
 # Totals: pass:4 fail:0 xfail:0 xpass:0 skip:0 error:0

[1] https://github.com/go-delve/delve/blob/master/pkg/proc/native/threads_linux.go#L50
[2] https://github.com/go-delve/delve/blob/master/vendor/golang.org/x/sys/unix/syscall_linux.go#L1573
[3] http://www.t-es-t.hu/download/mips/md00047f.pdf

Reported-by: Guoqi Chen <chenguoqi@loongson.cn>
Signed-off-by: Xingxing Su <suxingxing@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Commit ffe1f935

 ("MAINTAINERS: Add Loongson-2/Loongson-3 maintainers")
adds quite generic file entries for drivers/*/*loongson{2,3}* and
drivers/*/*/*loongson{2,3}* to be informed on changes to all loongson{2,3}
files in drivers.

However, only the pattern 'drivers/*/*loongson2*' matches to one file in
the repository, i.e., drivers/cpufreq/loongson2_cpufreq.c; all other
patterns have no file matches.

Hence, ./scripts/get_maintainer.pl --self-test=patterns complains:

  warning: no file matches    F:    drivers/*/*/*loongson2*
  warning: no file matches    F:    drivers/*/*/*loongson3*
  warning: no file matches    F:    drivers/*/*loongson3*

As in the last two and half years, no further files and drivers have
showed up to match those patterns, just name the one file that matches
explicitly and delete the others without a match.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

According to MIPS EJTAG Specification [1], a Debug Breakpoint
exception occurs when an SDBBP instruction is executed, the
CP0_DEBUG bit DBp indicates that a Debug Breakpoint exception
occurred.

When I read the original code, it looks a little confusing
at first glance, just check bit DBp for SDBBP to make the
code more readable, it will be much easier to understand.

[1] http://www.t-es-t.hu/download/mips/md00047f.pdf

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

As started by commit 05a5f51c

 ("Documentation: Replace lkml.org
links with lore"), replace lkml.org links with lore to better use a
single source that's more likely to stay available long-term.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

This reverts commit 9308579f

.

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

Replace kmap_atomic_pfn() with kmap_local_pfn() which is preemptible and
can take page faults.

Remove the indirection of the dump page and the related cruft which is not
longer required.

Remove unused or redundant header files.

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

This reverts commit 3751cbda.

Originally the patch was created to fix the reserved-memory DT-node
parsing failure on the early stages of the platform memory initialization.
That happened due to the two early memory allocators utilization that
time: bootmem and memblock. At first the platform-specific memory mapping
array was initialized. Then the early_init_fdt_scan_reserved_mem() was
called, which couldn't fully parse the "reserved-memory" DT-node since
neither memblock nor bootmem allocators hadn't been initialized at that
stage, so the fdt_init_reserved_mem() method failed on the memory
allocation calls. Only after that the platform-specific memory mapping
were used to create proper bootmem and memblock structures and let the
early memory allocations work.  That's why we had to call the
fdt_init_reserved_mem() method one more time to retry the initialization
of the features like CMA.

The necessity to have that fix was disappeared after the full memblock
support had been added to the MIPS kernel and all plat_mem_setup() had
been fixed to add the memory regions right into the memblock memory pool.
Let's revert that patch then especially after having Paul reported that
the second fdt_init_reserved_mem() call causes the reserved memory pool
being created twice bigger than implied.

Fixes: a94e4f24

 ("MIPS: init: Drop boot_mem_map")
Reported-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

unwind_stack_by_address and unwind_stack need <asm/stacktrace.h>.
arch_align_stack needs <asm/exec.h>

link: https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org/thread/ZPL2RRA6RZKRQZI5IGOVLFXN2GVZBN3L/
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Commit 1e35918a ("MIPS: Enable Undefined Behavior Sanitizer
UBSAN") added a possibility to build the entire kernel with UBSAN
instrumentation for MIPS, with the exception for VDSO.
However, self-extracting head wasn't been added to exceptions, so
this occurs:

mips-alpine-linux-musl-ld: arch/mips/boot/compressed/decompress.o:
in function `FSE_buildDTable_wksp':
decompress.c:(.text.FSE_buildDTable_wksp+0x278): undefined reference
to `__ubsan_handle_shift_out_of_bounds'
mips-alpine-linux-musl-ld: decompress.c:(.text.FSE_buildDTable_wksp+0x2a8):
undefined reference to `__ubsan_handle_shift_out_of_bounds'
mips-alpine-linux-musl-ld: decompress.c:(.text.FSE_buildDTable_wksp+0x2c4):
undefined reference to `__ubsan_handle_shift_out_of_bounds'
mips-alpine-linux-musl-ld: arch/mips/boot/compressed/decompress.o:
decompress.c:(.text.FSE_buildDTable_raw+0x9c): more undefined references
to `__ubsan_handle_shift_out_of_bounds' follow

Add UBSAN_SANITIZE := n to mips/boot/compressed/Makefile to exclude
it from instrumentation scope and fix this issue.

Fixes: 1e35918a

 ("MIPS: Enable Undefined Behavior Sanitizer UBSAN")
Cc: stable@vger.kernel.org # 5.0+
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

The type of the VMLINUX_LOAD_ADDRESS macro is the (unsigned long long)
in 32bits kernel but (unsigned long) in the 64-bit kernel. Although there
is no error here, avoid using it to calculate kaslr_offset.

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

Provide kaslr_offset() to get the kernel offset when KASLR is enabled.
Error may occur before update_kaslr_offset(), so put it at the end of
the offset branch.

Fixes: a307a4ce

 ("MIPS: Loongson64: Add KASLR support")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Add perf_event_mips_regs/perf_reg_value/perf_reg_validate to support
features HAVE_PERF_REGS/HAVE_PERF_USER_STACK_DUMP in kernel.

[ayan@wavecomp.com: Repick this patch for unwinding userstack backtrace
 by perf and libunwind on MIPS based CPU.]

[ralf@linux-mips.org: Add perf_get_regs_user() which is required after
'commit 88a7c26a ("perf: Move task_pt_regs sampling into arch code")'.]

[yangtiezhu@loongson.cn: Fix build error about perf_get_regs_user() after
commit 76a4efa8

 ("perf/arch: Remove perf_sample_data::regs_user_copy"),
and also separate the original patches into two parts (MIPS kernel and perf
tools) to merge easily.]

The original patches:
https://lore.kernel.org/patchwork/patch/1126521/
https://lore.kernel.org/patchwork/patch/1126520/

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Archer Yan <ayan@wavecomp.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Since commit 02bd530f

 ("MIPS: generic: Increase NR_IRQS to 256")
include/asm/mach-pistachio/irq.h just does nothing.
Remove the file along with mach-pistachio folder and include compiler
directive.

Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Signed-off-by: Bert Vermeulen <bert@biot.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Signed-off-by: Bert Vermeulen <bert@biot.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

This is just enough system to boot the kernel with earlycon working.

Signed-off-by: Bert Vermeulen <bert@biot.com>
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

The RTL838x/839x family of SoCs are Realtek switches with an embedded
MIPS core.

* RTL838x - 500MHz 4kce single core - 1Gbit ports and L2 features
* RTL839x - 700MHz 34Kc single core - 1Gbit ports and L2 features

These switches, depending on the exact part number, will have anywhere
between 8 and 52 ports. The MIPS core is wired to a switch cpu port which
has a tagging feature allowing us to make use of the DSA subsystem.
The SoCs are somewhat basic in certain areas, getting better with more
advanced features on newer series.

The switch functionality is MMIO-mapped via a large MFD region.

The SoCs have the following peripherals
* ethernet
* switch
* uart - ns16550a
* spi-flash interface
* gpio
* wdt
* led

The code was derived from various vendor SDKs based on Linux v2.6
kernels.

This patchset allows us to boot RTL838x/RTL839x units with basic support.
Most of the other drivers are already written and functional, and work to
get them upstream is already in progress.

Signed-off-by: Birger Koblitz <mail@birger-koblitz.de>
Signed-off-by: Bert Vermeulen <bert@biot.com>
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Signed-off-by: Bert Vermeulen <bert@biot.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Reset lines with indices smaller than 8 are currently considered invalid
by the rt2880-reset reset controller.

The MT7621 SoC uses a number of these low reset lines. The DTS defines
reset lines "hsdma", "fe", and "mcm" with respective values 5, 6, and 2.
As a result of the above restriction, these resets cannot be asserted or
de-asserted by the reset controller. In cases where the bootloader does
not de-assert these lines, this results in e.g. the MT7621's internal
switch staying in reset.

Change the reset controller to only ignore the system reset, so all
reset lines with index greater than 0 are considered valid.

Signed-off-by: Sander Vanheule <sander@svanheule.net>
Acked-by: John Crispin <john@phrozen.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Selection of the DTB to be used was burried in more or less readable
code in head.S. Move this code into a inline helper function and
use it.

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

s/logcal/logical/
s/intercpu/inter-CPU/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Eliminate the following coccicheck warning:
./arch/mips/mti-malta/malta-time.c:141:2-3: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Eliminate the following coccicheck warning:
./arch/mips/kvm/mips.c:151:2-3: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Huacai Chen <chenhuacai@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS always save kernel stack pointer in regs[29]

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

Fix the following build error when make M=samples/bpf used with Clang:

  CLANG-bpf  samples/bpf/sockex2_kern.o
In file included from samples/bpf/sockex2_kern.c:7:
In file included from ./include/uapi/linux/if_tunnel.h:7:
In file included from ./include/linux/ip.h:16:
In file included from ./include/linux/skbuff.h:28:
In file included from ./include/net/checksum.h:22:
./arch/mips/include/asm/checksum.h:161:9: error: unsupported inline asm: input with type 'unsigned long' matching output with type '__wsum' (aka 'unsigned int')
        : "0" ((__force unsigned long)daddr),
               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

This is a known issue on MIPS [1], the changed code can be compiled
successfully by both GCC and Clang.

[1] https://lore.kernel.org/linux-mips/CAG_fn=W0JHf8QyUX==+rQMp8PoULHrsQCa9Htffws31ga8k-iw@mail.gmail.com/

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

MIPS can now use the default uncached_access like other archs.

Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

We no longer need the MESA workaround, so remove it.

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

Remove a superfluous semicolon after function definition.

Signed-off-by: Chengyang Fan <cy.fan@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

I couldn't find any user of the dubious vpe_getcwd so far. So remove it and
get rid of another set_fs(KERNEL_DS).

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

kernel test robot throws below warning ->

arch/mips/kernel/cacheinfo.c:112:3: warning: Variable 'level' is
modified but its new value is never used. [unreadVariable]

Remove unnecessary increment of level at the end.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

For those leaf functions, they are likely to have no stack operations.
Add is_jr_ra_ins() to determine whether jr ra has been touched before
the frame_size is found. Without this patch, the get frame_size operation
may be out of range and get the frame_size from the next nested function.

There is no POOL32A format in uapi/asm/inst.h, so some bits here use the
format of r_format instead.
e.g.
---------------------------------------------------------------------
|    format      |  31:26  | 25:21 | 20:16 |    15:6    |    5:0    |
-----------------+---------+-------+-------+------------+------------
| pool32a_format | pool32a |  rt   |  rs   |   jalrc    | pool32axf |
-----------------+---------+-------+-------+------------+------------
|    r_format    |  opcode |  rs   |  rt   | rd:5, re:5 |    func   |
---------------------------------------------------------------------

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

[1]: Commit b6c7a324 ("MIPS: Fix get_frame_info() handling of
                            microMIPS function size")
[2]: Commit 2b424cfc

 ("MIPS: Remove function size check in
                            get_frame_info()")

First patch added a constant to check the number of iterations against.
Second patch fixed the situation that info->func_size is zero.

However, func_size member became useless after the second commit. Without
ip_end, the get frame_size operation may be out of range although KALLSYMS
enabled. Thus, check func_size first. Then make ip_end be the sum of ip
and a constant (512) if func_size is equal to 0. Otherwise make ip_end be
the sum of ip and func_size.

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

mm16_r5_format.rt is 5 bits, so directly judge the value if equal or not.
mm_jalr_op requires 7th to 16th bits. These 10 which bits generated by
shifting u_format.uimmediate by 6 may be affected by sign extension.
Thus, take out the 10 bits for comparison.

Without this patch, errors may occur, such as these bits are all ones.

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

Some headers are not necessary, remove them and sort includes.

Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Reviewed-by: Huacai Chen <chenhuacai@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

I find linux-mips.org too unreliable to rely on, so move to a place
I have proper control over.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

This adds support for the Nintendo 64 console's sound.

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

kgdb fails to build when the FPU support is disabled:

arch/mips/kernel/kgdb.c: In function 'dbg_set_reg':
arch/mips/kernel/kgdb.c:147:35: error: 'struct thread_struct' has no member named 'fpu'
  147 |    memcpy((void *)&current->thread.fpu.fcr31, mem,
      |                                   ^
arch/mips/kernel/kgdb.c:155:34: error: 'struct thread_struct' has no member named 'fpu'
  155 |   memcpy((void *)&current->thread.fpu.fpr[fp_reg], mem,

This is only relevant for CONFIG_EXPERT=y, so disallowing it
in Kconfig is an easier workaround than fixing it properly.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

The kernel test robot keeps reporting the same bug when it
shows up in new files after random unrelated patches:

In file included from arch/mips/include/uapi/asm/byteorder.h:13,
                 from arch/mips/include/asm/bitops.h:20,
                 from include/linux/bitops.h:26,
                 from include/linux/kernel.h:12,
                 from include/linux/clk.h:13,
                 from drivers/base/regmap/regmap-mmio.c:7:
include/linux/byteorder/big_endian.h:8:2: warning: #warning inconsistent configuration, needs CONFIG_CPU_BIG_ENDIAN [-Wcpp]
    8 | #warning inconsistent configuration, needs CONFIG_CPU_BIG_ENDIAN
      |  ^~~~~~~
drivers/base/regmap/regmap-mmio.c: In function 'regmap_mmio_gen_context':
>> drivers/base/regmap/regmap-mmio.c:274:2: error: duplicate case value
  274 |  case REGMAP_ENDIAN_NATIVE:
      |  ^~~~
drivers/base/regmap/regmap-mmio.c:246:2: note: previously used here
  246 |  case REGMAP_ENDIAN_NATIVE:

The problem is that some randconfig builds end up on the MIPS jazz
platform with neither CONFIG_CPU_BIG_ENDIAN nor CONFIG_CPU_LITTLE_ENDIAN
because no specific machine is selected. As it turns out, all jazz
machines support little-endian kernels, so this can simply be allowed
globally.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

The kernel definitions of MIPSInst_FMA_FUNC and MIPSInst_FMA_FFMT are not
consistent with MADD.fmt, NMADD.fmt and NMSUB.fmt in the MIPS64 manual [1],
the field func is bit 5..3 and fmt is bit 2..0, fix them. Otherwise there
exists error when add new instruction simulation.

[1] https://www.mips.com/?do-download=the-mips64-instruction-set-v6-06

Reported-by: Ming Wang <wangming01@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Add support for the Nintendo 64.

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