Linux kernel development work - see feature branches https://git.zx2c4.com/linux-dev/atom/arch/loongarch/kernel/Makefile?h=master 2022-10-12T17:35:20Z 2022-10-12T17:35:20Z Linus Torvalds torvalds@linux-foundation.org 2022-10-12T17:35:20Z urn:sha1:95b8b5953a315081eadbadf49200e57d7e05aae7 Pull LoongArch updates from Huacai Chen: - Use EXPLICIT_RELOCS (ABIv2.0) - Use generic BUG() handler - Refactor TLB/Cache operations - Add qspinlock support - Add perf events support - Add kexec/kdump support - Add BPF JIT support - Add ACPI-based laptop driver - Update the default config file * tag 'loongarch-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: (25 commits) LoongArch: Update Loongson-3 default config file LoongArch: Add ACPI-based generic laptop driver LoongArch: Add BPF JIT support LoongArch: Add some instruction opcodes and formats LoongArch: Move {signed,unsigned}_imm_check() to inst.h LoongArch: Add kdump support LoongArch: Add kexec support LoongArch: Use generic BUG() handler LoongArch: Add SysRq-x (TLB Dump) support LoongArch: Add perf events support LoongArch: Add qspinlock support LoongArch: Use TLB for ioremap() LoongArch: Support access filter to /dev/mem interface LoongArch: Refactor cache probe and flush methods LoongArch: mm: Refactor TLB exception handlers LoongArch: Support R_LARCH_GOT_PC_{LO12,HI20} in modules LoongArch: Support PC-relative relocations in modules LoongArch: Define ELF relocation types added in ABIv2.0 LoongArch: Adjust symbol addressing for AS_HAS_EXPLICIT_RELOCS LoongArch: Add Kconfig option AS_HAS_EXPLICIT_RELOCS ... 2022-10-12T08:36:19Z Youling Tang tangyouling@loongson.cn 2022-10-12T08:36:19Z urn:sha1:4e62d1d86585e1b62b4f96ee586881dd45a443dc This patch adds support for kdump. In kdump case the normal kernel will reserve a region for the crash kernel and jump there on panic. Arch-specific functions are added to allow for implementing a crash dump file interface, /proc/vmcore, which can be viewed as a ELF file. A user-space tool, such as kexec-tools, is responsible for allocating a separate region for the core's ELF header within the crash kdump kernel memory and filling it in when executing kexec_load(). Then, its location will be advertised to the crash dump kernel via a command line argument "elfcorehdr=", and the crash dump kernel will preserve this region for later use with arch_reserve_vmcore() at boot time. At the same time, the crash kdump kernel is also limited within the "crashkernel" area via a command line argument "mem=", so as not to destroy the original kernel dump data. In the crash dump kernel environment, /proc/vmcore is used to access the primary kernel's memory with copy_oldmem_page(). I tested kdump on LoongArch machines (Loongson-3A5000) and it works as expected (suggested crashkernel parameter is "crashkernel=512M@2560M"), you may test it by triggering a crash through /proc/sysrq-trigger: $ sudo kexec -p /boot/vmlinux-kdump --reuse-cmdline --append="nr_cpus=1" # echo c > /proc/sysrq-trigger Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2022-10-12T08:36:19Z Youling Tang tangyouling@loongson.cn 2022-10-12T08:36:19Z urn:sha1:4a03b2ac06a5bcae29371866d9d11f5bfd4c9188 Add three new files, kexec.h, machine_kexec.c and relocate_kernel.S to the LoongArch architecture, so as to add support for the kexec re-boot mechanism (CONFIG_KEXEC) on LoongArch platforms. Kexec supports loading vmlinux.elf in ELF format and vmlinux.efi in PE format. I tested kexec on LoongArch machines (Loongson-3A5000) and it works as expected: $ sudo kexec -l /boot/vmlinux.efi --reuse-cmdline $ sudo kexec -e Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2022-10-12T08:36:14Z Huacai Chen chenhuacai@loongson.cn 2022-10-12T08:36:14Z urn:sha1:dea2df3cc72555633cc7858ce1daa4b757f843ad Add SysRq-x (TLB Dump) support for LoongArch, which is useful for debugging. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2022-10-12T08:36:14Z Huacai Chen chenhuacai@loongson.cn 2022-10-12T08:36:14Z urn:sha1:b37042b2bb7cd751f03b73afb90364a418d870f4 The perf events infrastructure of LoongArch is very similar to old MIPS- based Loongson, so most of the codes are derived from MIPS. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2022-10-02T09:04:05Z Masahiro Yamada masahiroy@kernel.org 2022-09-24T18:19:14Z urn:sha1:3216484550610470013b7ce1c9ed272da0a74589 The objects placed at the head of vmlinux need special treatments: - arch/$(SRCARCH)/Makefile adds them to head-y in order to place them before other archives in the linker command line. - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of obj-y to avoid them going into built-in.a. This commit gets rid of the latter. Create vmlinux.a to collect all the objects that are unconditionally linked to vmlinux. The objects listed in head-y are moved to the head of vmlinux.a by using 'ar m'. With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y for builtin objects. There is no *.o that is directly linked to vmlinux. Drop unneeded code in scripts/clang-tools/gen_compile_commands.py. $(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested by Nathan Chancellor [1]. [1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> 2022-08-12T05:10:11Z Qing Zhang zhangqing@loongson.cn 2022-08-06T08:10:04Z urn:sha1:93a4fa622eb061f75f87f0cf9609ab4e69c67d01 1. Use common arch_stack_walk() infrastructure to avoid duplicated code and avoid taking care of the stack storage and filtering. 2. Add sched_ra (means sched return address) and sched_cfa (means sched call frame address) to thread_info, and store them in switch_to(). 3. Add __get_wchan() implementation. Now we can print the process stack and wait channel by cat /proc/*/stack and /proc/*/wchan. Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2022-08-12T05:10:11Z Qing Zhang zhangqing@loongson.cn 2022-08-06T08:10:03Z urn:sha1:49aef111e2dae176a7708b532118f33f24289248 It unwind the stack frame based on prologue code analyze. CONFIG_KALLSYMS is needed, at least the address and length of each function. Three stages when we do unwind, 1) unwind_start(), the prapare of unwinding, fill unwind_state. 2) unwind_done(), judge whether the unwind process is finished or not. 3) unwind_next_frame(), unwind the next frame. Dividing unwinder helps to add new unwinders in the future, e.g.: unwinder_frame, unwinder_orc, .etc. Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2022-08-12T05:10:11Z Qing Zhang zhangqing@loongson.cn 2022-08-06T08:10:02Z urn:sha1:49232773d8233ed70c4998851bc84e465fc1c788 Name "guess unwinder" comes from x86, it scans the stack and reports every kernel text address it finds. Unwinders can be used by dump_stack() and other stacktrace functions. Three stages when we do unwind, 1) unwind_start(), the prapare of unwinding, fill unwind_state. 2) unwind_done(), judge whether the unwind process is finished or not. 3) unwind_next_frame(), unwind the next frame. Add get_stack_info() to get stack info. At present we have irq stack and task stack. The next_sp is the key info between two types of stacks. Dividing unwinder helps to add new unwinders in the future. Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2022-06-03T12:09:29Z Huacai Chen chenhuacai@loongson.cn 2022-05-31T10:04:12Z urn:sha1:d4b6f1562a3c3284adcef81d6e4f183d7d34b8a9 Add Non-Uniform Memory Access (NUMA) support for LoongArch. LoongArch has 48-bit physical address, but the HyperTransport I/O bus only support 40-bit address, so we need a custom phys_to_dma() and dma_to_phys() to extract the 4-bit node id (bit 44~47) from Loongson-3's 48-bit physical address space and embed it into 40-bit. In the 40-bit dma address, node id offset can be read from the LS7A_DMA_CFG register. Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>