Commit graph

12 commits

Author SHA1 Message Date
Jiaxun Yang
98e720f77d LoongArch: Derive timer max_delta from PRCFG1's timer_bits
As per arch spec, maximum timer bits is configurable and should not be
hardcoded in any way.

Probe timer bits from PRCFG1 and use that to determine the clockevent's
max_delta to be conformance.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-01-25 18:51:33 +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
Qi Hu
bd3c579848 LoongArch: Add Loongson Binary Translation (LBT) extension support
Loongson Binary Translation (LBT) is used to accelerate binary translation,
which contains 4 scratch registers (scr0 to scr3), x86/ARM eflags (eflags)
and x87 fpu stack pointer (ftop).

This patch support kernel to save/restore these registers, handle the LBT
exception and maintain sigcontext.

Signed-off-by: Qi Hu <huqi@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-06 22:53:55 +08:00
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
616500232e LoongArch: Add vector extensions support
Add LoongArch's vector extensions support, which including 128bit LSX
(i.e., Loongson SIMD eXtension) and 256bit LASX (i.e., Loongson Advanced
SIMD eXtension).

Linux kernel doesn't use vector itself, it only handle exceptions and
context save/restore. So it only needs a subset of these instructions:

* Vector load/store:   vld vst vldx vstx xvld xvst xvldx xvstx
* 8bit-elements move:  vpickve2gr.b xvpickve2gr.b vinsgr2vr.b xvinsgr2vr.b
* 16bit-elements move: vpickve2gr.h xvpickve2gr.h vinsgr2vr.h xvinsgr2vr.h
* 32bit-elements move: vpickve2gr.w xvpickve2gr.w vinsgr2vr.w xvinsgr2vr.w
* 64bit-elements move: vpickve2gr.d xvpickve2gr.d vinsgr2vr.d xvinsgr2vr.d
* Elements permute:    vpermi.w vpermi.d xvpermi.w xvpermi.d xvpermi.q

Introduce AS_HAS_LSX_EXTENSION and AS_HAS_LASX_EXTENSION to avoid non-
vector toolchains complains unsupported instructions.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-06-29 20:58:43 +08:00
Huacai Chen
dce5ea1d0f LoongArch: Mark 3 symbol exports as non-GPL
vm_map_base, empty_zero_page and invalid_pmd_table could be accessed
widely by some out-of-tree non-GPL but important file systems or drivers
(e.g. OpenZFS). Let's use EXPORT_SYMBOL() instead of EXPORT_SYMBOL_GPL()
to export them, so as to avoid build errors.

1, Details about vm_map_base:

This is a LoongArch-specific symbol and may be referenced through macros
PCI_IOBASE, VMALLOC_START and VMALLOC_END.

2, Details about empty_zero_page:

As it stands today, only 3 architectures export empty_zero_page as a GPL
symbol: IA64, LoongArch and MIPS. LoongArch gets the GPL export by
inheriting from MIPS, and the MIPS export was first introduced in commit
497d2adcbf ("[MIPS] Export empty_zero_page for sake of the ext4
module."). The IA64 export was similar: commit a7d57ecf42 ("[IA64]
Export three symbols for module use") did so for kvm.

In both IA64 and MIPS, the export of empty_zero_page was done for
satisfying some in-kernel component built as module (kvm and ext4
respectively), and given its reasonably low-level nature, GPL is a
reasonable choice. But looking at the bigger picture it is evident most
other architectures do not regard it as GPL, so in effect the symbol
probably should not be treated as such, in favor of consistency.

3, Details about invalid_pmd_table:

Keep consistency with invalid_pte_table and make it be possible by some
modules.

Cc: stable@vger.kernel.org
Reviewed-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-04-18 19:38:58 +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
Huacai Chen
d52fec86a4 LoongArch: Add HWCAP_LOONGARCH_CPUCFG to elf_hwcap
HWCAP_LOONGARCH_CPUCFG is missing in elf_hwcap, so add it for glibc's
later use.

Cc: stable@vger.kernel.org
Reported-by: Yinyu Cai <caiyinyu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-01-17 11:42:16 +08:00
Jianmin Lv
4b2edd3828 LoongArch: Fix cpu name after CPU-hotplug
Don't overwrite the SMBIOS-provided CPU name on coming back from CPU-
hotplug (including S3/S4) if it is already initialized.

Reviewed-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-10-12 16:36:08 +08:00
Tiezhu Yang
ad82eef3ce LoongArch: Fix wrong fpu version
According to the configuration information accessible by the CPUCFG
instruction in LoongArch Reference Manual [1], FP_ver is stored in
bit [5: 3] of CPUCFG2, the current code to get fpu version is wrong,
use CPUCFG2_FPVERS to fix it.

[1] https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html

Fixes: 628c3bb40e ("LoongArch: Add boot and setup routines")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-06-25 18:05:59 +08:00
Huacai Chen
628c3bb40e LoongArch: Add boot and setup routines
Add basic boot, setup and reset routines for LoongArch. Now, LoongArch
machines use UEFI-based firmware. The firmware passes configuration
information to the kernel via ACPI and DMI/SMBIOS.

Currently an existing interface between the kernel and the bootloader
is implemented. Kernel gets 2 values from the bootloader, passed in
registers a0 and a1; a0 is an "EFI boot flag" distinguishing UEFI and
non-UEFI firmware, while a1 is a pointer to an FDT with systable,
memmap, cmdline and initrd information.

The standard UEFI boot protocol (EFISTUB) will be added later.

Cc: linux-efi@vger.kernel.org
Cc: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Co-developed-by: Yun Liu <liuyun@loongson.cn>
Signed-off-by: Yun Liu <liuyun@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-06-03 20:09:28 +08:00