Linux kernel development work - see feature branches https://git.zx2c4.com/linux-dev/atom/arch/loongarch/Kconfig?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 ... 2022-10-12T08:36:20Z Tiezhu Yang yangtiezhu@loongson.cn 2022-10-12T08:36:20Z urn:sha1:5dc615520c4dfb358245680f1904bad61116648e BPF programs are normally handled by a BPF interpreter, add BPF JIT support for LoongArch to allow the kernel to generate native code when a program is loaded into the kernel. This will significantly speed-up processing of BPF programs. Co-developed-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Tiezhu Yang <yangtiezhu@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:sha1:4e62d1d86585e1b62b4f96ee586881dd45a443dc 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> 2022-10-12T08:36:19Z Youling Tang tangyouling@loongson.cn 2022-10-12T08:36:19Z urn:sha1:2d2c395217d2233e752dbddcae3c5d94050b48c1 Inspired by commit 9fb7410f955("arm64/BUG: Use BRK instruction for generic BUG traps"), do similar for LoongArch to use generic BUG() handler. This patch uses the BREAK software breakpoint instruction to generate a trap instead, similarly to most other arches, with the generic BUG code generating the dmesg boilerplate. This allows bug metadata to be moved to a separate table and reduces the amount of inline code at BUG() and WARN() sites. This also avoids clobbering any registers before they can be dumped. To mitigate the size of the bug table further, this patch makes use of the existing infrastructure for encoding addresses within the bug table as 32-bit relative pointers instead of absolute pointers. (Note: this limits the max kernel size to 2GB.) Before patch: [ 3018.338013] lkdtm: Performing direct entry BUG [ 3018.342445] Kernel bug detected[#5]: [ 3018.345992] CPU: 2 PID: 865 Comm: cat Tainted: G D 6.0.0-rc6+ #35 After patch: [ 125.585985] lkdtm: Performing direct entry BUG [ 125.590433] ------------[ cut here ]------------ [ 125.595020] kernel BUG at drivers/misc/lkdtm/bugs.c:78! [ 125.600211] Oops - BUG[#1]: [ 125.602980] CPU: 3 PID: 410 Comm: cat Not tainted 6.0.0-rc6+ #36 Out-of-line file/line data information obtained compared to before. 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: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> 2022-10-12T08:36:14Z Huacai Chen chenhuacai@loongson.cn 2022-10-12T08:36:14Z urn:sha1:5f1e001be579c2b7f37e7d5ff87c208c33e90fca On NUMA system, the performance of qspinlock is better than generic spinlock. Below is the UnixBench test results on a 8 nodes (4 cores per node, 32 cores in total) machine. A. With generic spinlock: System Benchmarks Index Values BASELINE RESULT INDEX Dhrystone 2 using register variables 116700.0 449574022.5 38523.9 Double-Precision Whetstone 55.0 85190.4 15489.2 Execl Throughput 43.0 14696.2 3417.7 File Copy 1024 bufsize 2000 maxblocks 3960.0 143157.8 361.5 File Copy 256 bufsize 500 maxblocks 1655.0 37631.8 227.4 File Copy 4096 bufsize 8000 maxblocks 5800.0 444814.2 766.9 Pipe Throughput 12440.0 5047490.7 4057.5 Pipe-based Context Switching 4000.0 2021545.7 5053.9 Process Creation 126.0 23829.8 1891.3 Shell Scripts (1 concurrent) 42.4 33756.7 7961.5 Shell Scripts (8 concurrent) 6.0 4062.9 6771.5 System Call Overhead 15000.0 2479748.6 1653.2 ======== System Benchmarks Index Score 2955.6 B. With qspinlock: System Benchmarks Index Values BASELINE RESULT INDEX Dhrystone 2 using register variables 116700.0 449467876.9 38514.8 Double-Precision Whetstone 55.0 85174.6 15486.3 Execl Throughput 43.0 14769.1 3434.7 File Copy 1024 bufsize 2000 maxblocks 3960.0 146150.5 369.1 File Copy 256 bufsize 500 maxblocks 1655.0 37496.8 226.6 File Copy 4096 bufsize 8000 maxblocks 5800.0 447527.0 771.6 Pipe Throughput 12440.0 5175989.2 4160.8 Pipe-based Context Switching 4000.0 2207747.8 5519.4 Process Creation 126.0 25125.5 1994.1 Shell Scripts (1 concurrent) 42.4 33461.2 7891.8 Shell Scripts (8 concurrent) 6.0 4024.7 6707.8 System Call Overhead 15000.0 2917278.6 1944.9 ======== System Benchmarks Index Score 3040.1 Signed-off-by: Rui Wang <wangrui@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:d279134168c78ac2caa1f7cd2a846579da1c93ac We can support more cache attributes (e.g., CC, SUC and WUC) and page protection when we use TLB for ioremap(). The implementation is based on GENERIC_IOREMAP. The existing simple ioremap() implementation has better performance so we keep it and introduce ARCH_IOREMAP to control the selection. We move pagetable_init() earlier to make early ioremap() works, and we modify the PCI ecam mapping because the TLB-based version of ioremap() will actually take the size into account. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2022-10-12T08:36:14Z Huacai Chen chenhuacai@loongson.cn 2022-10-12T08:36:14Z urn:sha1:235d074fdc9a69e3720b8bb6efeb7c6d30c12d8e Accidental access to /dev/mem is obviously disastrous, but specific access can be used by people debugging the kernel. So select GENERIC_ LIB_DEVMEM_IS_ALLOWED, as well as define ARCH_HAS_VALID_PHYS_ADDR_RANGE and related helpers, to support access filter to /dev/mem interface. Signed-off-by: Weihao Li <liweihao@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2022-10-12T08:36:08Z Xi Ruoyao xry111@xry111.site 2022-10-12T08:36:08Z urn:sha1:0d8dad7048611e5ba02ae8519539ce4b8b1482d3 GNU as >= 2.40 and GCC >= 13 will support using explicit relocation hints in the assembly code, instead of la.* macros. The usage of explicit relocation hints can improve code generation so it's enabled by default by GCC >= 13. Introduce a Kconfig option AS_HAS_EXPLICIT_RELOCS as the switch for "use explicit relocation hints or not". Tested-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Xi Ruoyao <xry111@xry111.site> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>