Commit Graph
219 Commits
Author SHA1 Message Date
Chenghao Duan 458bfe865a LoongArch: Refactor register restoration in ftrace_common_return
Refactor the register restoration sequence in the ftrace_common_return
function to clearly distinguish between the logic of normal returns and
direct call returns in function tracing scenarios. The logic is as
follows:

1. In the case of a normal return, the execution flow returns to the
traced function, and ftrace must ensure that the register data is
consistent with the state when the function was entered.

ra = parent return address; t0 = traced function return address.

2. In the case of a direct call return, the execution flow jumps to the
custom trampoline function, and ftrace must ensure that the register
data is consistent with the state when ftrace was entered.

ra = traced function return address; t0 = parent return address.

Cc: stable@vger.kernel.org
Fixes: 9cdc3b6a299c ("LoongArch: ftrace: Add direct call support")
Signed-off-by: Chenghao Duan <duanchenghao@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:57 +08:00
Chenghao Duan 61cf49e449 LoongArch: Enable exception fixup for specific ADE subcode
This patch allows the LoongArch BPF JIT to handle recoverable memory
access errors generated by BPF_PROBE_MEM* instructions.

When a BPF program performs memory access operations, the instructions
it executes may trigger ADEM exceptions. The kernel’s built-in BPF
exception table mechanism (EX_TYPE_BPF) will generate corresponding
exception fixup entries in the JIT compilation phase; however, the
architecture-specific trap handling function needs to proactively call
the common fixup routine to achieve exception recovery.

do_ade(): fix EX_TYPE_BPF memory access exceptions for BPF programs,
ensure safe execution.

Relevant test cases: illegal address access tests in module_attach and
subprogs_extable of selftests/bpf.

Signed-off-by: Chenghao Duan <duanchenghao@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:57 +08:00
Huacai Chen 0ef58a7238 LoongArch: Set correct protection_map[] for VM_NONE/VM_SHARED
For 32BIT platform _PAGE_PROTNONE is 0, so set a VMA to be VM_NONE or
VM_SHARED will make pages non-present, then cause Oops with kernel page
fault.

Fix it by set correct protection_map[] for VM_NONE/VM_SHARED, replacing
_PAGE_PROTNONE with _PAGE_PRESENT.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:56 +08:00
Binbin Zhou ac7ff67d5b LoongArch: dts: Add uart new compatible string
Add loongson,ls2k*-uart compatible string on uarts.

Co-developed-by: Haowei Zheng <zhenghaowei@loongson.cn>
Signed-off-by: Haowei Zheng <zhenghaowei@loongson.cn>
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://patch.msgid.link/8e0c08459fa5bddefd898648fea28a9f2fde701a.1760166651.git.zhoubinbin@loongson.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:56 +08:00
Thomas Bogendoerfer 9d2148bb75 MIPS: kernel: Fix random segmentation faults
Commit 69896119dc9d ("MIPS: vdso: Switch to generic storage
implementation") switches to a generic vdso storage, which increases
the number of data pages from 1 to 4. But there is only one page
reserved, which causes segementation faults depending where the VDSO
area is randomized to. To fix this use the same size of reservation
and allocation of the VDSO data pages.

Fixes: 69896119dc9d ("MIPS: vdso: Switch to generic storage implementation")
Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:55 +08:00
Huacai Chen b28a928854 LoongArch: Init acpi_gbl_use_global_lock to false
Init acpi_gbl_use_global_lock to false, in order to void error messages
during boot phase:

 ACPI Error: Could not enable GlobalLock event (20240827/evxfevnt-182)
 ACPI Error: No response from Global Lock hardware, disabling lock (20240827/evglock-59)

Fixes: 628c3bb40e9a8cefc0a6 ("LoongArch: Add boot and setup routines")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:52 +08:00
Bibo Mao 5467366210 LoongArch: KVM: Add PTW feature detection on new hardware
With new Loongson-3A6000/3C6000 hardware platforms (or later), hardware
page table walking (PTW) feature is supported on host. So here add this
feature detection on KVM host.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:52 +08:00
Tao Cui 2dc80dae4c LoongArch: KVM: Remove unused returns and semicolons
The default branch has already handled all undefined cases, so the final
return statement is redundant. Redundant semicolons are removed, too.

Cc: stable@vger.kernel.org
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:24 +08:00
Bibo Mao 3ad2337dd6 LoongArch: Remove clockevents shutdown call on offlining
The clockevents core already detached and unregistered it at this stage.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250906064952.3749122-3-maobibo@loongson.cn
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:21 +08:00
Ming Wang ecde857b92 LoongArch: Increase COMMAND_LINE_SIZE up to 4096
The default COMMAND_LINE_SIZE of 512, inherited from asm-generic, is
too small for modern use cases. For example, kdump configurations or
extensive debugging parameters can easily exceed this limit.

Therefore, increase the command line size to 4096 bytes, aligning
LoongArch with the MIPS architecture. This change follows a broader
trend among architectures to raise this limit to support modern needs;
for instance, PowerPC increased its value for similar reasons in the
commit a5980d064fe2 ("powerpc: Bump COMMAND_LINE_SIZE to 2048").

Similar to the change made for RISC-V in the commit 61fc1ee8be26
("riscv: Bump COMMAND_LINE_SIZE value to 1024"), this is considered
a safe change. The broader kernel community has reached a consensus
that modifying COMMAND_LINE_SIZE from UAPI headers does not constitute
a uABI breakage, as well-behaved userspace applications should not
rely on this macro.

Suggested-by: Huang Cun <cunhuang@tencent.com>
Signed-off-by: Ming Wang <wangming01@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:19 +08:00
Tiezhu Yang 4598b900e9 LoongArch: Pass annotate-tablejump option if LTO is enabled
When compiling with LLVM and CONFIG_LTO_CLANG is set, there exist many
objtool warnings "sibling call from callable instruction with modified
stack frame".

For this special case, the related object file shows that there is no
generated relocation section '.rela.discard.tablejump_annotate' for the
table jump instruction jirl, thus objtool can not know that what is the
actual destination address.

It needs to do something on the LLVM side to make sure that there is the
relocation section '.rela.discard.tablejump_annotate' if LTO is enabled,
but in order to maintain compatibility for the current LLVM compiler,
this can be done in the kernel Makefile for now. Ensure it is aware of
linker with LTO, '--loongarch-annotate-tablejump' needs to be passed via
'-mllvm' to ld.lld.

Note that it should also pass the compiler option -mannotate-tablejump
rather than only pass '-mllvm --loongarch-annotate-tablejump' to ld.lld
if LTO is enabled, otherwise there are no jump info for some table jump
instructions.

Fixes: e20ab7d454ee ("LoongArch: Enable jump table for objtool")
Closes: https://lore.kernel.org/loongarch/20250731175655.GA1455142@ax162/
Reported-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Co-developed-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:19 +08:00
Takashi Iwai fc60781fb3 mips: Update HD-audio configs again
The HD-audio codec driver configs have been updated again since the
previous change.  Correct the types and enable all Realtek HD-audio
codecs for loongson, per request.

Fixes: 1d8dd982c409 ("ALSA: hda/realtek: Enable drivers as default")
Fixes: 81231ad173d8 ("ALSA: hda/hdmi: Enable drivers as default")
Cc: linux-mips@vger.kernel.org
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250731091109.16901-4-tiwai@suse.de
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:18 +08:00
Kees Cook 3331eb76af mips: Handle KCOV __init vs inline mismatch
When KCOV is enabled all functions get instrumented, unless
the __no_sanitize_coverage attribute is used. To prepare for
__no_sanitize_coverage being applied to __init functions, we
have to handle differences in how GCC's inline optimizations get
resolved. For mips this requires adding the __init annotation on
init_mips_clocksource().

Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://lore.kernel.org/r/20250717232519.2984886-9-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:17 +08:00
Yulong Han fbe1a13263 LoongArch: KVM: Add tracepoints for CPUCFG and CSR emulation exits
This patch adds tracepoints to track KVM exits caused by CPUCFG and
CSR emulation. Note that IOCSR emulation tracing is already covered
by the generic trace_kvm_iocsr().

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Yulong Han <wheatfox17@icloud.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:17 +08:00
Yury Norov (NVIDIA) bf77f018aa LoongArch: KVM: Simplify kvm_deliver_intr()
The function opencodes for_each_set_bit() macro, which makes it bulky.
Using the proper API makes all the housekeeping code going away.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:17 +08:00
Yury Norov (NVIDIA) 4c0a7d7c53 LoongArch: KVM: Rework kvm_send_pv_ipi()
The function in fact traverses a "bitmap" stored in GPR regs A1 and A2,
but does it in a non-obvious way by creating a single-word bitmap twice.

This patch switches the function to create a single 2-word bitmap, and
also employs for_each_set_bit() macro, as it helps to drop most of the
housekeeping code.

While there, convert the function to return void to not confuse readers
with unchecked result.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:17 +08:00
Mateusz Jończyk c6ce76bd2c mips/malta,loongson2ef: use generic mc146818_get_time function
mc146818_get_cmos_time() is now mostly equivalent to mc146818_get_time()
from drivers/rtc/rtc-mc146818-lib.c, with the latter using a more
advanced algorithm (which checks the UIP bit in the CMOS). The Malta
and Loongson2ef platforms, the only users of mc146818_get_cmos_time()
have RTC devices that should be MC146818 compatible.

So, rewrite mc146818_get_cmos_time() in a way that uses
mc146818_get_time() and add CONFIG_RTC_MC146818_LIB as a dependency of
CONFIG_MIPS_MALTA and CONFIG_CPU_LOONGSON2EF.

The should be safe as:

- malta_defconfig already uses a standard RTC CMOS driver
  (CONFIG_RTC_DRV_CMOS=y). The Malta board has an Intel 82371EB (PIIX4E)
  south bridge with the CMOS RTC, so should work correctly with the
  modification,

- Loongson2e and 2f apparently use the VIA686B south bridge and the AMD
  CS5536 south bridge respectively (at least according to Kconfig). I
  have checked datasheets of both and these appear to be MC146818
  software compatible.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:17 +08:00
Mateusz Jończyk 3785c485aa mips: remove redundant macro mc146818_decode_year
The mc146818_decode_year macro is used only in mc146818_get_cmos_time(),
which in turn is called only in
	arch/mips/loongson2ef/common/time.c
and
	arch/mips/mti-malta/malta-time.c
so on mach-jazz it is unused and can be removed. On other platforms it
is defined in the same way, so it can be safely folded into
mc146818_get_cmos_time().

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:16 +08:00
Mateusz Jończyk 5a512f70fe mips/mach-rm: remove custom mc146818rtc.h file
The mc146818_decode_year macro is used only in mc146818_get_cmos_time,
which in turn is called only in
	arch/mips/loongson2ef/common/time.c
and
	arch/mips/mti-malta/malta-time.c

So no SNI or mach-rm content. SNI did not use mc146818_get_cmos_time
apparently since
commit 06cf5583fd9a ("[MIPS] SNI RM updates")
in 2007.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:16 +08:00
Mateusz Jończyk b5440a58f3 mips: remove unused function mc146818_set_rtc_mmss
I have checked carefully: this function is unused, so remove it.

The last caller appears to have been removed in 2007 in
commit 4b550488f894 ("[MIPS] Deforest the function pointer jungle in the time code.")

mc146818-time.h is included only in three files:
- arch/mips/mti-malta/malta-time.c
- arch/mips/loongson64/numa.c
- arch/mips/loongson2ef/common/time.c

Also, remove unused macros USEC_AFTER/USEC_BEFORE.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:16 +08:00
Takashi Iwai 2df7f11e08 mips: loongson3_defconfig: Update HD-audio configs
Since the reorganization of HD-audio drivers, Realtek driver has been
split.  Update to the new Kconfigs to catch up.

Fixes: aeeb85f26c3b ("ALSA: hda: Split Realtek HD-audio codec driver")
Link: https://patch.msgid.link/20250715075237.28476-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:16 +08:00
Thomas Weißschuh 2eb57d636d MIPS: Don't crash in stack_top() for tasks without ABI or vDSO
Not all tasks have an ABI associated or vDSO mapped,
for example kthreads never do.
If such a task ever ends up calling stack_top(), it will derefence the
NULL ABI pointer and crash.

This can for example happen when using kunit:

    mips_stack_top+0x28/0xc0
    arch_pick_mmap_layout+0x190/0x220
    kunit_vm_mmap_init+0xf8/0x138
    __kunit_add_resource+0x40/0xa8
    kunit_vm_mmap+0x88/0xd8
    usercopy_test_init+0xb8/0x240
    kunit_try_run_case+0x5c/0x1a8
    kunit_generic_run_threadfn_adapter+0x28/0x50
    kthread+0x118/0x240
    ret_from_kernel_thread+0x14/0x1c

Only dereference the ABI point if it is set.

The GIC page is also included as it is specific to the vDSO.
Also move the randomization adjustment into the same conditional.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:15 +08:00
Huacai Chen d08daf3618 MIPS/Loongson: Fix build warnings about export.h
After commit a934a57a42f64a4 ("scripts/misc-check: check missing #include
<linux/export.h> when W=1") and 7d95680d64ac8e836c ("scripts/misc-check:
check unnecessary #include <linux/export.h> when W=1"), we get some build
warnings with W=1:

arch/mips/loongson64/setup.c: warning: EXPORT_SYMBOL() is not used, but #include <linux/export.h> is present

So fix these build warnings for MIPS/Loongson.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:39:15 +08:00
maoxiaochuan d1e8fab20f ls2k300_Pi:dts:Add node for aht20
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:56 +08:00
tao89959 a546555363 2k300: pai: fix func1 dts device node
Changelog: 修复2k300pai上func1的dts设备节点
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:56 +08:00
maoxiaochuan 28d1952150 ls2k300_pi:dts:update pin configuration
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:55 +08:00
Huacai Chen 18ec5348cd LoongArch: Add new PCI ID for pci_fixup_vgadev()
Loongson-2K3000 has a new PCI ID (0x7a46) for its display controller,
Add it for pci_fixup_vgadev() since we prefer a discrete graphics card
as default boot device if present.

Cc: stable@vger.kernel.org
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:21 +08:00
Song Gao a232521b9c LoongArch: Add and use some macros for AVEC
Add and use some macros for AVEC interrupt controller, instead of using
magic numbers.

Signed-off-by: Song Gao <gaosong@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:21 +08:00
Qiang Ma 2b1a526a7c LoongArch: Correct the calculation logic of thread_count
For thread_count, the current calculation method has a maximum of 255,
which may not be sufficient in the future. Therefore, we are correcting
it now.

Reference: SMBIOS Specification, 7.5 Processor Information (Type 4)[1]

[1]: https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.9.0.pdf

Cc: stable@vger.kernel.org
Signed-off-by: Qiang Ma <maqianga@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:21 +08:00
Tiezhu Yang 4dfcb53c12 LoongArch: Use unsigned long for _end and _text
It is better to use unsigned long rather than long for _end and _text to
calculate the kernel length.

Cc: stable@vger.kernel.org # v6.3+
Fixes: e5f02b51fa0c ("LoongArch: Add support for kernel address space layout randomization (KASLR)")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:21 +08:00
maoxiaochuan 61f607d374 LoongArch: Use __pmd()/__pte() for swap entry conversions
The __pmd() and __pte() helper macros provide the correct initialization
syntax and abstraction for the pmd_t and pte_t types.

Use __pmd() to fix follow warning about __swp_entry_to_pmd() with gcc-15
under specific configs [1] :

  In file included from ./include/linux/pgtable.h:6,
                   from ./include/linux/mm.h:31,
                   from ./include/linux/pagemap.h:8,
                   from arch/loongarch/mm/init.c:14:
  ./include/linux/swapops.h: In function ‘swp_entry_to_pmd’:
  ./arch/loongarch/include/asm/pgtable.h:302:34: error: missing braces around initializer [-Werror=missing-braces]
    302 | #define __swp_entry_to_pmd(x)   ((pmd_t) { (x).val | _PAGE_HUGE })
        |                                  ^
  ./include/linux/swapops.h:559:16: note: in expansion of macro ‘__swp_entry_to_pmd’
    559 |         return __swp_entry_to_pmd(arch_entry);
        |                ^~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

Also update __swp_entry_to_pte() to use __pte() for consistency.

[1]. https://download.01.org/0day-ci/archive/20251119/202511190316.luI90kAo-lkp@intel.com/config

Cc: stable@vger.kernel.org
Signed-off-by: Yuli Wang <wangyl5933@chinaunicom.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:20 +08:00
Huacai Chen 2d50f3b912 LoongArch: Fix arch_dup_task_struct() for CONFIG_RANDSTRUCT
Now the optimized version of arch_dup_task_struct() for LoongArch
assumes 'thread' is the last member of 'task_struct'. But this is
not true if CONFIG_RANDSTRUCT is enabled after Linux-6.16.

So fix the arch_dup_task_struct() function for CONFIG_RANDSTRUCT by
copying the whole 'task_struct'.

Cc: stable@vger.kernel.org   # 6.16+
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:20 +08:00
Huacai Chen da5a1c3d57 LoongArch: Fix build errors for CONFIG_RANDSTRUCT
When CONFIG_RANDSTRUCT enabled, members of task_struct are randomized.
There is a chance that TASK_STACK_CANARY be out of 12bit immediate's
range and causes build errors. TASK_STACK_CANARY is naturally aligned,
so fix it by replacing ld.d/st.d with ldptr.d/stptr.d which have 14bit
immediates.

Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202511240656.0NaPcJs1-lkp@intel.com/
Suggested-by: Rui Wang <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:20 +08:00
Xi Ruoyao 7ab68dc972 LoongArch: Simplify __arch_bitrev32() implementation
LoongArch has the bitrev.w instruction to reverse bits in a 32-bit
integer, thus there's no need to reverse the bytes and use bitrev.4b.

Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:20 +08:00
Xi Ruoyao c8ae6731c5 LoongArch: Select HAVE_ARCH_BITREVERSE in Kconfig
Without HAVE_ARCH_BITREVERSE, the architecture-optimized bit reverse
implementations in arch/loongarch/include/asm/bitrev.h are not used at
all.

Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:20 +08:00
maoxiaochuan da3522f798 loongson_2k300_defconfig:Update defconfig for enable usbnet and usb_serial
4g module use usb or serial to transfer data

Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2026-02-04 16:38:19 +08:00
Huacai Chen 1872d882b2 LoongArch: Mask all interrupts during kexec/kdump
If the default state of the interrupt controllers in the first kernel
don't mask any interrupts, it may cause the second kernel to potentially
receive interrupts (which were previously allocated by the first kernel)
immediately after a CPU becomes online during its boot process. These
interrupts cannot be properly routed, leading to bad IRQ issues.

This patch calls machine_kexec_mask_interrupts() to mask all interrupts
during the kexec/kdump process.

Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-24 15:13:12 +08:00
Eliav Farber 33cf4b0a6a kexec: Consolidate machine_kexec_mask_interrupts() implementation
Consolidate the machine_kexec_mask_interrupts implementation into a common
function located in a new file: kernel/irq/kexec.c. This removes duplicate
implementations from architecture-specific files in arch/arm, arch/arm64,
arch/powerpc, and arch/riscv, reducing code duplication and improving
maintainability.

The new implementation retains architecture-specific behavior for
CONFIG_GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD, which was previously implemented
for ARM64. When enabled (currently for ARM64), it clears the active state
of interrupts forwarded to virtual machines (VMs) before handling other
interrupt masking operations.

Signed-off-by: Eliav Farber <farbere@amazon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241204142003.32859-2-farbere@amazon.com
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-24 15:13:12 +08:00
Vincent Li 318501a4d4 LoongArch: BPF: Disable trampoline for kernel module function trace
The current LoongArch BPF trampoline implementation is incompatible
with tracing functions in kernel modules. This causes several severe
and user-visible problems:

* The `bpf_selftests/module_attach` test fails consistently.
* Kernel lockup when a BPF program is attached to a module function [1].
* Critical kernel modules like WireGuard experience traffic disruption
  when their functions are traced with fentry [2].

Given the severity and the potential for other unknown side-effects, it
is safest to disable the feature entirely for now. This patch prevents
the BPF subsystem from allowing trampoline attachments to kernel module
functions on LoongArch.

This is a temporary mitigation until the core issues in the trampoline
code for kernel module handling can be identified and fixed.

[root@fedora bpf]# ./test_progs -a module_attach -v
bpf_testmod.ko is already unloaded.
Loading bpf_testmod.ko...
Successfully loaded bpf_testmod.ko.
test_module_attach:PASS:skel_open 0 nsec
test_module_attach:PASS:set_attach_target 0 nsec
test_module_attach:PASS:set_attach_target_explicit 0 nsec
test_module_attach:PASS:skel_load 0 nsec
libbpf: prog 'handle_fentry': failed to attach: -ENOTSUPP
libbpf: prog 'handle_fentry': failed to auto-attach: -ENOTSUPP
test_module_attach:FAIL:skel_attach skeleton attach failed: -524
Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED
Successfully unloaded bpf_testmod.ko.

[1]: https://lore.kernel.org/loongarch/CAK3+h2wDmpC-hP4u4pJY8T-yfKyk4yRzpu2LMO+C13FMT58oqQ@mail.gmail.com/
[2]: https://lore.kernel.org/loongarch/CAK3+h2wYcpc+OwdLDUBvg2rF9rvvyc5amfHT-KcFaK93uoELPg@mail.gmail.com/

Cc: stable@vger.kernel.org
Fixes: f9b6b41f0cf3 ("LoongArch: BPF: Add basic bpf trampoline support")
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Vincent Li <vincent.mc.li@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-24 15:13:12 +08:00
Huacai Chen 57e0cc30b3 LoongArch: Don't panic if no valid cache info for PCI
If there is no valid cache info detected (may happen in virtual machine)
for pci_dfl_cache_line_size, kernel shouldn't panic. Because in the PCI
core it will be evaluated to (L1_CACHE_BYTES >> 2).

Cc: <stable@vger.kernel.org>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-24 15:13:12 +08:00
Bibo Mao a71cef48e1 LoongArch: Fix NUMA node parsing with numa_memblks
On physical machine, NUMA node id comes from high bit 44:48 of physical
address. However it is not true on virt machine. With general method, it
comes from ACPI SRAT table.

Here the common function numa_memblks_init() is used to parse NUMA node
information with numa_memblks.

Cc: <stable@vger.kernel.org>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-24 15:13:11 +08:00
maoxiaochuan 75187a098c LoongArch: Consolidate CPU names in /proc/cpuinfo
Some processors have no IOCSR.VENDOR and IOCSR.CPUNAME, some processors
have these registers but there is no valid information.

Consolidate CPU names in /proc/cpuinfo:
1. Add "PRID" to display the PRID & Core-Name;
2. Let "Model Name" display "Unknown" if no valid name.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-24 15:13:11 +08:00
Thomas Weißschuh 9874bd9749 LoongArch: Use UAPI types in ptrace UAPI header
The kernel UAPI headers already contain fixed-width integer types, there
is no need to rely on the libc types. There may not be a libc available
or the libc may not provides the <stdint.h>, like for example on nolibc.

This also aligns the header with the rest of the LoongArch UAPI headers.

Fixes: 803b0fc5c3f2 ("LoongArch: Add process management")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-24 15:13:11 +08:00
maoxiaochuan f9d47373c9 LoongArch: Consolidate max_pfn & max_low_pfn calculation
Now there 5 places which calculate max_pfn & max_low_pfn:
1. in fdt_setup() for FDT systems;
2. in memblock_init() for ACPI systems;
3. in init_numa_memory() for NUMA systems;
4. in arch_mem_init() to recalculate for "mem=" cmdline;
5. in paging_init() to recalculate for NUMA systems.

Since memblock_init() is called both for ACPI and FDT systems, move the
calculation out of the for_each_efi_memory_desc() loop can eliminate the
first case. The last case is very questionable (may be derived from the
MIPS/Loongson code) and breaks the "mem=" cmdline, so should be removed.
And then the NUMA version of paging_init() can be also eliminated.

After consolidation there are 3 places of calculation:
1. in memblock_init() for both ACPI and FDT systems;
2. in init_numa_memory() to recalculate for NUMA systems;
3. in arch_mem_init() to recalculate for the "mem=" cmdline.

For all cases the calculation is:
max_pfn = PFN_DOWN(memblock_end_of_DRAM());
max_low_pfn = min(PFN_DOWN(HIGHMEM_START), max_pfn);

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-20 16:55:52 +08:00
Qiang Ma 1462ebe51a LoongArch: kexec: Print out debugging message if required
When specifying '-d' for kexec_file_load interface, loaded locations of
kernel/initrd/cmdline etc can be printed out to help debug.

Commit eb7622d908a0 ("kexec_file, riscv: print out debugging message if
required") fixes the same issue on RISC-V.

So, remove kexec_image_info() because the content has been printed out
in generic code.

And on Loongson-3A5000, the printed messages look like below:

 kexec_file: kernel: 00000000d9aad283 kernel_size: 0x2e77f30
 kexec_file(EFI): No LoongArch PE image header.
 kexec_file: Loaded initrd at 0x80000000 bufsz=0x1637cd0 memsz=0x1638000
 kexec_file(ELF): Loaded kernel at 0x9c20000 bufsz=0x27f1800 memsz=0x2950000
 kexec_file: nr_segments = 2
 kexec_file: segment[0]: buf=0x00000000cc3e6c33 bufsz=0x27f1800 mem=0x9c20000 memsz=0x2950000
 kexec_file: segment[1]: buf=0x00000000bb75a541 bufsz=0x1637cd0 mem=0x80000000 memsz=0x1638000
 kexec_file: kexec_file_load: type:0, start:0xb15d000 head:0x18db60002 flags:0x8

Signed-off-by: Qiang Ma <maqianga@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-20 16:55:51 +08:00
Youling Tang 39dd81dc92 LoongArch: kexec: Initialize the kexec_buf structure
The kexec_buf structure was previously declared without initialization.
commit bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
added a field that is always read but not consistently populated by all
architectures. This un-initialized field will contain garbage.

This is also triggering a UBSAN warning when the uninitialized data is
accessed:

        ------------[ cut here ]------------
        UBSAN: invalid-load in ./include/linux/kexec.h:210:10
        load of value 252 is not a valid value for type '_Bool'

Zero-initializing kexec_buf at declaration ensures all fields are
cleanly set, preventing future instances of uninitialized memory being
used.

Fixes: bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
Link: https://lore.kernel.org/r/20250827-kbuf_all-v1-2-1df9882bb01a@debian.org
Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-20 16:55:51 +08:00
Huacai Chen 05213bb9e0 LoongArch: Use correct accessor to read FWPC/MWPC
CSR.FWPC and CSR.MWPC are 32bit registers, so use csr_read32() rather
than csr_read64() to read the values of FWPC/MWPC.

Cc: stable@vger.kernel.org
Fixes: edffa33c7bb5a73 ("LoongArch: Add hardware breakpoints/watchpoints support")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-20 16:55:51 +08:00
Tiezhu Yang be01faecdf LoongArch: Refine the init_hw_perf_events() function
(1) Use the existing CPUCFG6_PMNUM_SHIFT macro definition instead of
the magic value 4 to get the PMU number.

(2) Detect the value of PMU bits via CPUCFG instruction according to
the ISA manual instead of hard-coded as 64, because the value may be
different for various micro-architectures.

Link: https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#_cpucfg
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-20 16:55:51 +08:00
Vishal Moola (Oracle) 9a1f71f4f7 LoongArch: Remove __GFP_HIGHMEM masking in pud_alloc_one()
Remove the unnecessary __GFP_HIGHMEM masking in pud_alloc_one(), which
was introduced with commit 382739797f79ec2 ("loongarch: convert various
functions to use ptdescs"). GFP_KERNEL doesn't contain __GFP_HIGHMEM.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-20 16:55:51 +08:00
Tianyang Zhang 648effcbc1 LoongArch: Let {pte,pmd}_modify() record the status of _PAGE_DIRTY
Now if the PTE/PMD is dirty with _PAGE_DIRTY but without _PAGE_MODIFIED,
after {pte,pmd}_modify() we lose _PAGE_DIRTY, then {pte,pmd}_dirty()
return false and lead to data loss. This can happen in certain scenarios
such as HW PTW doesn't set _PAGE_MODIFIED automatically, so here we need
_PAGE_MODIFIED to record the dirty status (_PAGE_DIRTY).

The new modification involves checking whether the original PTE/PMD has
the _PAGE_DIRTY flag. If it exists, the _PAGE_MODIFIED bit is also set,
ensuring that the {pte,pmd}_dirty() interface can always return accurate
information.

Cc: stable@vger.kernel.org
Co-developed-by: Liupu Wang <wangliupu@loongson.cn>
Signed-off-by: Liupu Wang <wangliupu@loongson.cn>
Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
2025-11-20 16:55:50 +08:00