LoongArch: Add support for relocating the kernel with RELR relocation

RELR as a relocation packing format for relative relocations for
reducing the size of relative relocation records. In a positio

LoongArch: Add support for relocating the kernel with RELR relocation

RELR as a relocation packing format for relative relocations for
reducing the size of relative relocation records. In a position
independent executable there are often many relative relocation
records, and our vmlinux is a PIE.

The LLD linker (since 17.0.0) and the BFD linker (since 2.43) supports
packing the relocations in the RELR format for LoongArch, with the flag
-z pack-relative-relocs.

Commits 5cf896fb6be3eff ("arm64: Add support for relocating the kernel
with RELR relocations") and ccb2d173b983984bfa ("Makefile: use -z
pack-relative-relocs") have already added the framework to use RELR.
We just need to wire it up and process the RELR relocation records in
relocate_relative() in addition to the RELA relocation records.

A ".p2align 3" directive is added to la_abs macro or the BFD linker
cannot pack the relocation records against the .la_abs section (the
". = ALIGN(8);" directive in vmlinux.lds.S is too late in the linking
process).

With defconfig and CONFIG_RELR vmlinux.efi is 2.1 MiB (6%) smaller, and
vmlinuz.efi (using gzip compression) is 384 KiB (2.8%) smaller.

Link: https://groups.google.com/d/topic/generic-abi/bX460iggiKg
Link: https://reviews.llvm.org/D138135#4531389
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d89ecf33ab6d
Signed-off-by: Xi Ruoyao <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: Fix entry point in kernel image header

Currently kernel entry in head.S is in DMW address range, firmware is
instructed to jump to this address after loading the kernel image.

However ke

LoongArch: Fix entry point in kernel image header

Currently kernel entry in head.S is in DMW address range, firmware is
instructed to jump to this address after loading the kernel image.

However kernel should not make any assumption on firmware's DMW
setting, thus the entry point should be a physical address falls into
direct translation region.

Fix by converting entry address to physical and amend entry calculation
logic in libstub accordingly.

BTW, use ABSOLUTE() to calculate variables to make Clang/LLVM happy.

Cc: [email protected]
Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: Add ORC stack unwinder support

The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is
similar in concept to a DWARF unwinder. The difference is that the format
of the OR

LoongArch: Add ORC stack unwinder support

The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is
similar in concept to a DWARF unwinder. The difference is that the format
of the ORC data is much simpler than DWARF, which in turn allows the ORC
unwinder to be much simpler and faster.

The ORC data consists of unwind tables which are generated by objtool.
After analyzing all the code paths of a .o file, it determines information
about the stack state at each instruction address in the file and outputs
that information to the .orc_unwind and .orc_unwind_ip sections.

The per-object ORC sections are combined at link time and are sorted and
post-processed at boot time. The unwinder uses the resulting data to
correlate instruction addresses with their stack states at run time.

Most of the logic are similar with x86, in order to get ra info before ra
is saved into stack, add ra_reg and ra_offset into orc_entry. At the same
time, modify some arch-specific code to silence the objtool warnings.

Co-developed-by: Jinyang He <[email protected]>
Signed-off-by: Jinyang He <[email protected]>
Co-developed-by: Youling Tang <[email protected]>
Signed-off-by: Youling Tang <[email protected]>
Signed-off-by: Tiezhu Yang <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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efi/loongarch: Directly position the loaded image file

The use of the 'kernel_offset' variable to position the image file that
has been loaded by UEFI or GRUB is unnecessary, because we can directly

efi/loongarch: Directly position the loaded image file

The use of the 'kernel_offset' variable to position the image file that
has been loaded by UEFI or GRUB is unnecessary, because we can directly
position the loaded image file through using the image_base field of the
efi_loaded_image struct provided by UEFI.

Replace kernel_offset with image_base to position the image file that has
been loaded by UEFI or GRUB.

Signed-off-by: Wang Yao <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>

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LoongArch: Fix lockdep static memory detection

Since commit 0a6b58c5cd0d ("lockdep: fix static memory detection even
more") the lockdep code uses is_kernel_core_data(), is_kernel_rodata()
and init_s

LoongArch: Fix lockdep static memory detection

Since commit 0a6b58c5cd0d ("lockdep: fix static memory detection even
more") the lockdep code uses is_kernel_core_data(), is_kernel_rodata()
and init_section_contains() to verify if a lock is located inside a
kernel static data section.

This change triggers a failure on LoongArch, for which the vmlinux.lds.S
script misses to put the locks (as part of in the .data.rel symbols)
into the Linux data section.

This patch fixes the lockdep problem by moving *(.data.rel*) symbols
into the kernel data section (from _sdata to _edata).

Additionally, move other wrongly assigned symbols too:
- altinstructions into the _initdata section,
- PLT symbols behind the read-only section, and
- *(.la_abs) into the data section.

Cc: stable <[email protected]> # v6.4+
Fixes: 0a6b58c5cd0d ("lockdep: fix static memory detection even more")
Reported-by: Guenter Roeck <[email protected]>
Tested-by: Guenter Roeck <[email protected]>
Signed-off-by: Helge Deller <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: Calculate various sizes in the linker script

Taking the address delta between symbols in different sections is not
supported by the LLVM IAS. Instead, do this in the linker script, so
the

LoongArch: Calculate various sizes in the linker script

Taking the address delta between symbols in different sections is not
supported by the LLVM IAS. Instead, do this in the linker script, so
the same data can be properly referenced in assembly.

Signed-off-by: WANG Rui <[email protected]>
Signed-off-by: WANG Xuerui <[email protected]>
[chenhuacai: Fix build with !CONFIG_EFI_STUB]
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: Add support for kernel relocation

This config allows to compile kernel as PIE and to relocate it at any
virtual address at runtime: this paves the way to KASLR.

Runtime relocation is pos

LoongArch: Add support for kernel relocation

This config allows to compile kernel as PIE and to relocate it at any
virtual address at runtime: this paves the way to KASLR.

Runtime relocation is possible since relocation metadata are embedded
into the kernel.

Signed-off-by: Youling Tang <[email protected]>
Signed-off-by: Xi Ruoyao <[email protected]> # Use arch_initcall
Signed-off-by: Jinyang He <[email protected]> # Provide la_abs relocation code
Signed-off-by: Huacai Chen <[email protected]>

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objtool/idle: Validate __cpuidle code as noinstr

Idle code is very like entry code in that RCU isn't available. As
such, add a little validation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infra

objtool/idle: Validate __cpuidle code as noinstr

Idle code is very like entry code in that RCU isn't available. As
such, add a little validation.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Tested-by: Tony Lindgren <[email protected]>
Tested-by: Ulf Hansson <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Acked-by: Frederic Weisbecker <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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LoongArch: Add alternative runtime patching mechanism

Introduce the "alternative" mechanism from ARM64 and x86 for LoongArch
to apply runtime patching. The main purpose of this patch is to provide
a

LoongArch: Add alternative runtime patching mechanism

Introduce the "alternative" mechanism from ARM64 and x86 for LoongArch
to apply runtime patching. The main purpose of this patch is to provide
a framework. In future we can use this mechanism (i.e., the ALTERNATIVE
and ALTERNATIVE_2 macros) to optimize hotspot functions according to cpu
features.

Signed-off-by: Jun Yi <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: extable: Add `type` and `data` fields

This is a LoongArch port of commit d6e2cc564775 ("arm64: extable: add
`type` and `data` fields").

Subsequent patches will add specialized handlers f

LoongArch: extable: Add `type` and `data` fields

This is a LoongArch port of commit d6e2cc564775 ("arm64: extable: add
`type` and `data` fields").

Subsequent patches will add specialized handlers for fixups, in addition
to the simple PC fixup we have today. In preparation, this patch adds a
new `type` field to struct exception_table_entry, and uses this to
distinguish the fixup and other cases. A `data` field is also added so
that subsequent patches can associate data specific to each exception
site (e.g. register numbers).

Handlers are named ex_handler_*() for consistency, following the example
of x86. At the same time, get_ex_fixup() is split out into a helper so
that it can be used by other ex_handler_*() functions in the subsequent
patches.

Signed-off-by: Youling Tang <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: Adjust symbol addressing for AS_HAS_EXPLICIT_RELOCS

If explicit relocation hints are used by the toolchain, -Wa,-mla-*
options will be useless for the C code. So only use them for the
!CO

LoongArch: Adjust symbol addressing for AS_HAS_EXPLICIT_RELOCS

If explicit relocation hints are used by the toolchain, -Wa,-mla-*
options will be useless for the C code. So only use them for the
!CONFIG_AS_HAS_EXPLICIT_RELOCS case.

Replace "la" with "la.pcrel" in head.S to keep the semantic consistent
with new and old toolchains for the low level startup code.

For per-CPU variables, the "address" of the symbol is actually an offset
from $r21. The value is near the loading address of main kernel image,
but far from the loading address of modules. So we use model("extreme")
attibute to tell the compiler that a PC-relative addressing with 32-bit
offset is not sufficient for local per-CPU variables.

The behavior with different assemblers and compilers are summarized in
the following table:

AS has CC has
explicit relocs explicit relocs * Behavior
==============================================================
No No Use la.* macros.
No change from Linux 6.0.
--------------------------------------------------------------
No Yes Disable explicit relocs.
No change from Linux 6.0.
--------------------------------------------------------------
Yes No Not supported.
--------------------------------------------------------------
Yes Yes Enable explicit relocs.
No -Wa,-mla* options used.
==============================================================
*: We assume CC must have model attribute if it has explicit relocs.
Both features are added in GCC 13 development cycle, so any GCC
release >= 13 should be OK. Using early GCC 13 development snapshots
may produce modules with unsupported relocations.

Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=f09482a
Link: https://gcc.gnu.org/r13-1834
Link: https://gcc.gnu.org/r13-2199
Tested-by: WANG Xuerui <[email protected]>
Signed-off-by: Xi Ruoyao <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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efi/loongarch: Add efistub booting support

This patch adds efistub booting support, which is the standard UEFI boot
protocol for LoongArch to use.

We use generic efistub, which means we can pass bo

efi/loongarch: Add efistub booting support

This patch adds efistub booting support, which is the standard UEFI boot
protocol for LoongArch to use.

We use generic efistub, which means we can pass boot information (i.e.,
system table, memory map, kernel command line, initrd) via a light FDT
and drop a lot of non-standard code.

We use a flat mapping to map the efi runtime in the kernel's address
space. In efi, VA = PA; in kernel, VA = PA + PAGE_OFFSET. As a result,
flat mapping is not identity mapping, SetVirtualAddressMap() is still
needed for the efi runtime.

Tested-by: Xi Ruoyao <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
[ardb: change fpic to fpie as suggested by Xi Ruoyao]
Signed-off-by: Ard Biesheuvel <[email protected]>

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LoongArch: Avoid orphan input sections

Ensure that all input sections are listed explicitly in the linker
script, and issue a warning otherwise. This ensures that the binary
image matches the PE/COF

LoongArch: Avoid orphan input sections

Ensure that all input sections are listed explicitly in the linker
script, and issue a warning otherwise. This ensures that the binary
image matches the PE/COFF and other image metadata exactly, which is
important for things like code signing.

Signed-off-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: Fix the _stext symbol address

_stext means the start of .text section (see __is_kernel_text()), but we
put its definition in .ref.text by mistake. Fix it by defining it in the
vmlinux.lds

LoongArch: Fix the _stext symbol address

_stext means the start of .text section (see __is_kernel_text()), but we
put its definition in .ref.text by mistake. Fix it by defining it in the
vmlinux.lds.S.

Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: vmlinux.lds.S: Add missing ELF_DETAILS

Commit c604abc3f6e ("vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG")
splits ELF_DETAILS from STABS_DEBUG, resulting in missing ELF_DETAILS
infor

LoongArch: vmlinux.lds.S: Add missing ELF_DETAILS

Commit c604abc3f6e ("vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG")
splits ELF_DETAILS from STABS_DEBUG, resulting in missing ELF_DETAILS
information in LoongArch architecture, so add it.

Fixes: c604abc3f6e ("vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG")
Signed-off-by: Youling Tang <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: Add multi-processor (SMP) support

LoongArch-based procesors have 4, 8 or 16 cores per package. This patch
adds multi-processor (SMP) support for LoongArch.

Reviewed-by: WANG Xuerui <git@

LoongArch: Add multi-processor (SMP) support

LoongArch-based procesors have 4, 8 or 16 cores per package. This patch
adds multi-processor (SMP) support for LoongArch.

Reviewed-by: WANG Xuerui <[email protected]>
Reviewed-by: Jiaxun Yang <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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LoongArch: Add build infrastructure

Add Kbuild, Makefile, Kconfig and link script for LoongArch build
infrastructure.

Reviewed-by: Guo Ren <[email protected]>
Reviewed-by: WANG Xuerui <[email protected]

LoongArch: Add build infrastructure

Add Kbuild, Makefile, Kconfig and link script for LoongArch build
infrastructure.

Reviewed-by: Guo Ren <[email protected]>
Reviewed-by: WANG Xuerui <[email protected]>
Reviewed-by: Jiaxun Yang <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

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