Commit Graph

11 Commits

Author SHA1 Message Date
Tiezhu Yang
1dd3e8a8ee LoongArch: Define instruction formats for AM{SWAP/ADD}.{B/H} and DBAR
The 8 and 16 bit read-modify-write atomic instructions amadd.{b/h} and
amswap.{b/h} were newly added in the latest LoongArch Reference Manual,
define the instruction format and check whether support via CPUCFG.

Furthermore, define the instruction format for DBAR which will be used
to support BPF load-acquire and store-release instructions.

This is preparation for later patches.

Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2026-04-22 15:45:13 +08:00
George Guo
48543c4283 LoongArch: Add detection for SC.Q support
Check the CPUCFG2_SCQ bit to determine if the current CPU supports the
SC.Q instruction.

Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com>
Tested-by: Hengqi Chen <hengqi.chen@gmail.com>
Co-developed-by: Yangyang Lian <lianyangyang@kylinos.cn>
Signed-off-by: Yangyang Lian <lianyangyang@kylinos.cn>
Signed-off-by: George Guo <guodongtai@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2026-02-10 19:31:06 +08:00
Huacai Chen
1c004609fd 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>
2025-11-20 14:42:05 +08:00
Huacai Chen
f28abb9f96 LoongArch: Clarify 3 MSG interrupt features
LoongArch's MSG interrupt features are used across multiple subsystems.
Clarify these features to avoid misuse, existing users will be adjusted
if necessary.

MSGINT: Infrastructure, means the CPU core supports message interupts.
Indicated by CPUCFG1.MSGINT.

AVECINT: AVEC interrupt controller based on MSGINT, means the CPU chip
supports direct message interrupts. Indicated by IOCSR.FEATURES.DMSI.

REDIRECTINT: REDIRECT interrupt controller based on MSGINT and AVECINT,
means the CPU chip supports redirect message interrupts. Indicated by
IOCSR.FEATURES.RMSI.

For example:
Loongson-3A5000/3C5000 doesn't support MSGINT/AVECINT/REDIRECTINT;
Loongson-3A6000 supports MSGINT but doesn't support AVECINT/REDIRECTINT;
Loongson-3C6000 supports MSGINT/AVECINT/REDIRECTINT.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-11-10 08:37:06 +08:00
Thomas Huth
f0ef0b02af LoongArch: Replace __ASSEMBLY__ with __ASSEMBLER__ in headers
While the GCC and Clang compilers already define __ASSEMBLER__
automatically when compiling assembler code, __ASSEMBLY__ is a macro
that only gets defined by the Makefiles in the kernel. This is bad
since macros starting with two underscores are names that are reserved
by the C language. It can also be very confusing for the developers
when switching between userspace and kernelspace coding, or when
dealing with uapi headers that rather should use __ASSEMBLER__ instead.
So let's now standardize on the __ASSEMBLER__ macro that is provided
by the compilers.

This is almost a completely mechanical patch (done with a simple
"sed -i" statement), with one comment tweaked manually in the
arch/loongarch/include/asm/cpu.h file (it was missing the trailing
underscores).

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-06-26 20:07:10 +08:00
Jiaxun Yang
34e3c4500c LoongArch: Rework CPU feature probe from CPUCFG/IOCSR
Probe ISA level, TLB, IOCSR information from CPUCFG to improve kernel
resilience to different core implementations.

BTW, IOCSR register definition appears to be a platform-specific spec
instead of an architecture spec, even for the Loongson CPUs there is no
guarantee that IOCSR will always present.

Thus it's dangerous to perform IOCSR probing without checking CPU type
and instruction availability.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-09-24 15:32:20 +08:00
Huacai Chen
843ed9317b LoongArch: Architectural preparation for AVEC irqchip
Add architectural preparation for AVEC irqchip, including:
1. CPUCFG feature bits definition for AVEC;
2. Detection of AVEC irqchip in cpu_probe();
3. New IPI type definition (IPI_CLEAR_VECTOR) for AVEC;
4. Provide arch_probe_nr_irqs() for large NR_IRQS;
5. Other related changes about the number of interrupts.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240823103936.25092-2-zhangtianyang@loongson.cn
2024-08-23 20:40:27 +02:00
Huacai Chen
01158487af LoongArch: Introduce hardware page table walker
Loongson-3A6000 and newer processors have hardware page table walker
(PTW) support. PTW can handle all fastpaths of TLBI/TLBL/TLBS/TLBM
exceptions by hardware, software only need to handle slowpaths (page
faults).

BTW, PTW doesn't append _PAGE_MODIFIED for page table entries, so we
change pmd_dirty() and pte_dirty() to also check _PAGE_DIRTY for the
"dirty" attribute.

Signed-off-by: Liang Gao <gaoliang@loongson.cn>
Signed-off-by: Jun Yi <yijun@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-06-29 20:58:44 +08:00
Huacai Chen
df83033604 LoongArch: Fix probing of the CRC32 feature
Not all LoongArch processors support CRC32 instructions. This feature
is indicated by CPUCFG1.CRC32 (Bit25) but it is wrongly defined in the
previous versions of the ISA manual (and so does in loongarch.h). The
CRC32 feature is set unconditionally now, so fix it.

BTW, expose the CRC32 feature in /proc/cpuinfo.

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-04-18 19:38:58 +08:00
Jinyang He
fd200632d0 LoongArch: Fix Chinese comma in cpu.h
Fix Chinese comma introduced by accident in cpu.h.

Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-02-25 22:12:16 +08:00
Huacai Chen
f2ac457a61 LoongArch: Add CPU definition headers
Add common headers (CPU definition and address space layout) for basic
LoongArch support.

Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-06-03 20:09:28 +08:00