This reverts commit 7c86ff99.

There are too many special cases for MIPS not covered by this patch.
In the end it might be better to implement single stepping in userland
than emulating it in the kernel.

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

LKP triggered lots of LD orphan warnings [0]:

mipsel-linux-ld: warning: orphan section `.data.$Lubsan_data299' from
`init/do_mounts_rd.o' being placed in section `.data.$Lubsan_data299'
mipsel-linux-ld: warning: orphan section `.data.$Lubsan_data183' from
`init/do_mounts_rd.o' being placed in section `.data.$Lubsan_data183'
mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type3' from
`init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type3'
mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type2' from
`init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type2'
mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type0' from
`init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type0'

[...]

Seems like "unnamed data" isn't the only type of symbols that UBSAN
instrumentation can emit.
Catch these into .data with the wildcard as well.

[0] https://lore.kernel.org/linux-mm/202102160741.k57GCNSR-lkp@intel.com



Fixes: f41b233d ("vmlinux.lds.h: catch UBSAN's "unnamed data" into data")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

With the removal of set_fs() calls kgdb_call_nmi_hook() is now the same as
the default implementation, so we can remove it.

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

There is no git tree for KVM/mips in MAINTAINERS, it is not
convinent to rebase, add it.

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

"elfcorehdr" can be parsed at kernel/crash_dump.c

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

protected_cache_op is only used for flushing user addresses, so
we only need to define protected_cache_op different in EVA mode and
be done with it.

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

This reverts commit 6ebda44f.

All icache flushes in this code paths are done via flush_icache_range(),
which only uses normal cache instruction. And this is the correct thing
for EVA mode, too. So no need to do set_fs(KERNEL_DS) here.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Just select DMA_NONCOHERENT and ARCH_HAS_SETUP_DMA_OPS from the
MIPS_GENERIC platform instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Huacai Chen <chenhuacai@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

CONFIG_DMA_MAYBE_COHERENT just guards two early init options now.  Just
enable them unconditionally for CONFIG_DMA_NONCOHERENT.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Lift the dma_default_coherent variable from the mips architecture code
to the driver core.  This allows an architecture to sdefault all device
to be DMA coherent at run time, even if the kernel is build with support
for DMA noncoherent device.  By allowing device_initialize to set the
->dma_coherent field to this default the amount of arch hooks required
for this behavior can be greatly reduced.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Replace the global coherentio enum, and the hw_coherentio (fake) boolean
variables with a single boolean dma_default_coherent flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Factor out a alchemy_dma_coherent helper that determines if the platform
is DMA coherent.  Also stop initializing the hw_coherentio variable, given
that is only ever set to a non-zero value by the malta setup code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Given that plat_mem_setup runs before earlyparams are handled and malta
selects CONFIG_DMA_MAYBE_COHERENT, coherentio can only be set to
IO_COHERENCE_DEFAULT at this point.  So remove the checking for other
options and merge plat_enable_iocoherency into plat_setup_iocoherency
to simplify the code a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

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>