From nobody Tue Apr 7 10:40:52 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9C54ECAAD4 for ; Mon, 29 Aug 2022 04:37:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229695AbiH2Ehb (ORCPT ); Mon, 29 Aug 2022 00:37:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229643AbiH2EhS (ORCPT ); Mon, 29 Aug 2022 00:37:18 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 31D973ED44 for ; Sun, 28 Aug 2022 21:37:16 -0700 (PDT) Received: from bogon.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxvmtvQgxjO6YLAA--.39821S3; Mon, 29 Aug 2022 12:37:06 +0800 (CST) From: Youling Tang To: Huacai Chen , Baoquan He , Eric Biederman Cc: WANG Xuerui , Vivek Goyal , Dave Young , Guo Ren , Jiaxun Yang , kexec@lists.infradead.org, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 1/3] LoongArch: Add kexec support Date: Mon, 29 Aug 2022 12:37:01 +0800 Message-Id: <1661747823-23745-2-git-send-email-tangyouling@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1661747823-23745-1-git-send-email-tangyouling@loongson.cn> References: <1661747823-23745-1-git-send-email-tangyouling@loongson.cn> X-CM-TRANSID: AQAAf8DxvmtvQgxjO6YLAA--.39821S3 X-Coremail-Antispam: 1UD129KBjvAXoW3uF45Xr4rAFWrKw48tFykAFb_yoW8JrWkKo ZFqa1UKw18KryUCw1Ykr98JFWDXryqgr93ZrW3ZwsxWry2yryYqr90kryYy34xtw1kW3yx C343Zwsxu397Jrn5n29KB7ZKAUJUUUU5529EdanIXcx71UUUUU7v73VFW2AGmfu7bjvjm3 AaLaJ3UjIYCTnIWjp_UUUOe7k0a2IF6w4kM7kC6x804xWl14x267AKxVW5JVWrJwAFc2x0 x2IEx4CE42xK8VAvwI8IcIk0rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87 I2jVAFwI0_Jr4l82xGYIkIc2x26xkF7I0E14v26r4j6ryUM28lY4IEw2IIxxk0rwA2F7IY 1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20x vEc7CjxVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280 aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzV Aqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S 6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7Mx kIecxEwVAFwVW8XwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s02 6c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw 0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvE c7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14 v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x 07bcR6wUUUUU= X-CM-SenderInfo: 5wdqw5prxox03j6o00pqjv00gofq/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Add three new files, kexec.h, machine_kexec.c and relocate_kernel.S to the LoongArch architecture that add support for the kexec re-boot mechanis (CONFIG_KEXEC) on LoongArch platforms. Supports loading vmlinux (vmlinux.elf) in ELF format and vmlinux.efi in PE format. I tested this on LoongArch 3A5000 machine and works as expected, $ sudo kexec -l /boot/vmlinux.efi --reuse-cmdline $ sudo kexec -e Signed-off-by: Youling Tang --- arch/loongarch/Kconfig | 11 ++ arch/loongarch/include/asm/kexec.h | 58 ++++++++ arch/loongarch/kernel/Makefile | 2 + arch/loongarch/kernel/head.S | 7 +- arch/loongarch/kernel/machine_kexec.c | 178 ++++++++++++++++++++++++ arch/loongarch/kernel/relocate_kernel.S | 125 +++++++++++++++++ 6 files changed, 380 insertions(+), 1 deletion(-) create mode 100644 arch/loongarch/include/asm/kexec.h create mode 100644 arch/loongarch/kernel/machine_kexec.c create mode 100644 arch/loongarch/kernel/relocate_kernel.S diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 45364cffc793..903c82fa958d 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -409,6 +409,17 @@ config FORCE_MAX_ZONEORDER The page size is not necessarily 4KB. Keep this in mind when choosing a value for this option. =20 +config KEXEC + bool "Kexec system call" + select KEXEC_CORE + help + kexec is a system call that implements the ability to shutdown your + current kernel, and to start another kernel. It is like a reboot + but it is independent of the system firmware. And like a reboot + you can start any kernel with it, not just Linux. + + The name comes from the similarity to the exec system call. + config SECCOMP bool "Enable seccomp to safely compute untrusted bytecode" depends on PROC_FS diff --git a/arch/loongarch/include/asm/kexec.h b/arch/loongarch/include/as= m/kexec.h new file mode 100644 index 000000000000..5c9e7b5eccb8 --- /dev/null +++ b/arch/loongarch/include/asm/kexec.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * kexec.h for kexec + * + * Copyright (C) 2022 Loongson Technology Corporation Limited + */ + +#ifndef _ASM_KEXEC_H +#define _ASM_KEXEC_H + +#include +#include + +/* Maximum physical address we can use pages from */ +#define KEXEC_SOURCE_MEMORY_LIMIT (-1UL) +/* Maximum address we can reach in physical address mode */ +#define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL) + /* Maximum address we can use for the control code buffer */ +#define KEXEC_CONTROL_MEMORY_LIMIT (-1UL) + +/* Reserve a page for the control code buffer */ +#define KEXEC_CONTROL_PAGE_SIZE PAGE_SIZE + +/* The native architecture */ +#define KEXEC_ARCH KEXEC_ARCH_LOONGARCH + +static inline void crash_setup_regs(struct pt_regs *newregs, + struct pt_regs *oldregs) +{ + if (oldregs) + memcpy(newregs, oldregs, sizeof(*newregs)); + else + prepare_frametrace(newregs); +} + +#define ARCH_HAS_KIMAGE_ARCH + +struct kimage_arch { + unsigned long boot_flag; + unsigned long fdt_addr; +}; + +typedef void (*do_kexec_t)(unsigned long boot_flag, + unsigned long fdt_addr, + unsigned long first_ind_entry, + unsigned long jump_addr); + +struct kimage; +extern const unsigned char relocate_new_kernel[]; +extern const size_t relocate_new_kernel_size; + +#ifdef CONFIG_SMP +extern atomic_t kexec_ready_to_reboot; +extern const unsigned char kexec_smp_wait[]; +extern void kexec_reboot(void); +#endif + +#endif /* !_ASM_KEXEC_H */ diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile index a213e994db68..20b64ac3f128 100644 --- a/arch/loongarch/kernel/Makefile +++ b/arch/loongarch/kernel/Makefile @@ -17,6 +17,8 @@ obj-$(CONFIG_CPU_HAS_FPU) +=3D fpu.o obj-$(CONFIG_MODULES) +=3D module.o module-sections.o obj-$(CONFIG_STACKTRACE) +=3D stacktrace.o =20 +obj-$(CONFIG_KEXEC) +=3D machine_kexec.o relocate_kernel.o + obj-$(CONFIG_PROC_FS) +=3D proc.o =20 obj-$(CONFIG_SMP) +=3D smp.o diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S index 01bac62a6442..22bdf4928325 100644 --- a/arch/loongarch/kernel/head.S +++ b/arch/loongarch/kernel/head.S @@ -20,7 +20,12 @@ =20 _head: .word MZ_MAGIC /* "MZ", MS-DOS header */ - .org 0x3c /* 0x04 ~ 0x3b reserved */ + .org 0x8 + .quad 0 /* Image load offset from start of RAM */ + .dword _end - _text /* Effective size of kernel image */ + .quad 0 + .dword kernel_entry /* Kernel entry point */ + .org 0x3c /* 0x28 ~ 0x3b reserved */ .long pe_header - _head /* Offset to the PE header */ =20 pe_header: diff --git a/arch/loongarch/kernel/machine_kexec.c b/arch/loongarch/kernel/= machine_kexec.c new file mode 100644 index 000000000000..4ffcd4cd9c8c --- /dev/null +++ b/arch/loongarch/kernel/machine_kexec.c @@ -0,0 +1,178 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * machine_kexec.c for kexec + * + * Copyright (C) 2022 Loongson Technology Corporation Limited + */ +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +/* 0x100000 ~ 0x200000 is safe */ +#define KEXEC_CTRL_CODE TO_CACHE(0x100000UL) +#define KEXEC_BLOB_ADDR TO_CACHE(0x108000UL) + +static unsigned long reboot_code_buffer; +#ifdef CONFIG_SMP +void (*relocated_kexec_smp_wait)(void *); +atomic_t kexec_ready_to_reboot =3D ATOMIC_INIT(0); +#endif + +static unsigned long jump_addr; +static unsigned long first_ind_entry; +static unsigned long boot_flag; +static unsigned long fdt_addr; + +static void kexec_image_info(const struct kimage *kimage) +{ + unsigned long i; + + pr_debug("kexec kimage info:\n"); + pr_debug("\ttype: %d\n", kimage->type); + pr_debug("\tstart: %lx\n", kimage->start); + pr_debug("\thead: %lx\n", kimage->head); + pr_debug("\tnr_segments: %lu\n", kimage->nr_segments); + + for (i =3D 0; i < kimage->nr_segments; i++) { + pr_debug("\t segment[%lu]: %016lx - %016lx", i, + kimage->segment[i].mem, + kimage->segment[i].mem + kimage->segment[i].memsz); + pr_debug("\t\t0x%lx bytes, %lu pages\n", + (unsigned long)kimage->segment[i].memsz, + (unsigned long)kimage->segment[i].memsz / PAGE_SIZE); + } +} + +int machine_kexec_prepare(struct kimage *kimage) +{ + int i; + void *dtb =3D (void *)KEXEC_BLOB_ADDR; + + kexec_image_info(kimage); + + /* Find the Flattened Device Tree */ + for (i =3D 0; i < kimage->nr_segments; i++) { + if (!fdt_check_header(kimage->segment[i].buf)) { + memcpy(dtb, kimage->segment[i].buf, SZ_64K); + kimage->arch.boot_flag =3D fw_arg0; + kimage->arch.fdt_addr =3D (unsigned long) dtb; + break; + } + continue; + } + + /* kexec need a safe page to save reboot_code_buffer */ + kimage->control_code_page =3D virt_to_page((void *)KEXEC_CTRL_CODE); + + reboot_code_buffer =3D + (unsigned long)page_address(kimage->control_code_page); + memcpy((void *)reboot_code_buffer, relocate_new_kernel, + relocate_new_kernel_size); + + /* All secondary cpus now may jump to kexec_smp_wait cycle */ + relocated_kexec_smp_wait =3D reboot_code_buffer + + (void *)(kexec_smp_wait - relocate_new_kernel); + + return 0; +} + +void machine_kexec_cleanup(struct kimage *kimage) +{ +} + +#ifdef CONFIG_SMP +void kexec_reboot(void) +{ + do_kexec_t do_kexec =3D NULL; + + /* All secondary cpus go to kexec_smp_wait */ + if (smp_processor_id() > 0) { + relocated_kexec_smp_wait(NULL); + unreachable(); + } + + do_kexec =3D (void *)reboot_code_buffer; + do_kexec(boot_flag, fdt_addr, first_ind_entry, jump_addr); + + unreachable(); +} + +static void kexec_shutdown_secondary(void *) +{ + local_irq_disable(); + while (!atomic_read(&kexec_ready_to_reboot)) + cpu_relax(); + + kexec_reboot(); +} + +void machine_crash_shutdown(struct pt_regs *regs) +{ +} +#endif + +void machine_shutdown(void) +{ + smp_call_function(kexec_shutdown_secondary, NULL, 0); +} + +void machine_kexec(struct kimage *image) +{ + unsigned long entry; + unsigned long *ptr; + struct kimage_arch *internal =3D &image->arch; + + boot_flag =3D internal->boot_flag; + fdt_addr =3D internal->fdt_addr; + + jump_addr =3D (unsigned long)phys_to_virt(image->start); + + first_ind_entry =3D (unsigned long)phys_to_virt(image->head & PAGE_MASK); + + /* + * The generic kexec code builds a page list with physical + * addresses. they are directly accessible through XKPRANGE + * hence the phys_to_virt() call. + */ + for (ptr =3D &image->head; (entry =3D *ptr) && !(entry & IND_DONE); + ptr =3D (entry & IND_INDIRECTION) ? + phys_to_virt(entry & PAGE_MASK) : ptr + 1) { + if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION || + *ptr & IND_DESTINATION) + *ptr =3D (unsigned long) phys_to_virt(*ptr); + } + + /* Mark offline before disabling local irq. */ + set_cpu_online(smp_processor_id(), false); + + /* we do not want to be bothered. */ + local_irq_disable(); + + pr_notice("Will call new kernel at %lx\n", jump_addr); + pr_notice("FDT image at %lx\n", fdt_addr); + pr_notice("Bye ...\n"); + + /* Make reboot code buffer available to the boot CPU. */ + flush_cache_all(); + + atomic_set(&kexec_ready_to_reboot, 1); + + /* + * We know we were online, and there will be no incoming IPIs at + * this point. + */ + set_cpu_online(smp_processor_id(), true); + + /* Ensure remote CPUs observe that we're online before rebooting. */ + smp_mb__after_atomic(); + + kexec_reboot(); +} diff --git a/arch/loongarch/kernel/relocate_kernel.S b/arch/loongarch/kerne= l/relocate_kernel.S new file mode 100644 index 000000000000..d1f242f74ea8 --- /dev/null +++ b/arch/loongarch/kernel/relocate_kernel.S @@ -0,0 +1,125 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * relocate_kernel.S for kexec + * + * Copyright (C) 2022 Loongson Technology Corporation Limited + */ + +#include + +#include +#include +#include +#include +#include +#include + +#define IPI_REG_BASE 0x1fe01000 + +SYM_CODE_START(relocate_new_kernel) + /* + * s0: Boot flag passed to the new kernel + * s1: Virt address of the FDT image + * s2: Pointer to the current entry + * s3: Virt address to jump to after relocation + */ + move s0, a0 + move s1, a1 + move s2, a2 + move s3, a3 + +process_entry: + PTR_L s4, s2, 0 + PTR_ADDI s2, s2, SZREG + + /* destination page */ + andi s5, s4, IND_DESTINATION + beqz s5, 1f + li.w t0, ~0x1 + and s6, s4, t0 /* store destination addr in s6 */ + b process_entry + +1: + /* indirection page, update s2 */ + andi s5, s4, IND_INDIRECTION + beqz s5, 1f + li.w t0, ~0x2 + and s2, s4, t0 + b process_entry + +1: + /* done page */ + andi s5, s4, IND_DONE + beqz s5, 1f + b done +1: + /* source page */ + andi s5, s4, IND_SOURCE + beqz s5, process_entry + li.w t0, ~0x8 + and s4, s4, t0 + li.w s8, (1 << _PAGE_SHIFT) / SZREG + +copy_word: + /* copy page word by word */ + REG_L s7, s4, 0 + REG_S s7, s6, 0 + PTR_ADDI s6, s6, SZREG + PTR_ADDI s4, s4, SZREG + LONG_ADDI s8, s8, -1 + beqz s8, process_entry + b copy_word + b process_entry + +done: + dbar 0 + + move a0, s0 + move a1, s1 + /* jump to the new kernel */ + jr s3 +SYM_CODE_END(relocate_new_kernel) + +#ifdef CONFIG_SMP +/* + * Other CPUs should wait until code is relocated and + * then start at entry (?) point. + */ +SYM_CODE_START(kexec_smp_wait) + li.d t0, IPI_REG_BASE + li.d t1, UNCACHE_BASE + or t0, t0, t1 + + /* + * s1:initfn + * t0:base t1:cpuid t2:node t3:core t4:count + */ + csrrd t1, LOONGARCH_CSR_CPUID + andi t1, t1, CSR_CPUID_COREID + andi t3, t1, 0x3 + slli.w t3, t3, 8 /* get core id */ + or t0, t0, t3 + andi t2, t1, 0x3c + slli.d t2, t2, 42 /* get node id */ + or t0, t0, t2 + +1: li.w t4, 0x100 /* wait for init loop */ +2: addi.w t4, t4, -1 /* limit mailbox access */ + bnez t4, 2b + ld.w s1, t0, 0x20 /* check PC as an indicator */ + beqz s1, 1b + ld.d s1, t0, 0x20 /* get PC via mailbox */ + ld.d sp, t0, 0x28 /* get SP via mailbox */ + ld.d tp, t0, 0x30 /* get TP via mailbox */ + + li.d t0, CACHE_BASE + or s1, s1, t0 + jr s1 /* jump to initial PC */ +SYM_CODE_END(kexec_smp_wait) +#endif + +relocate_new_kernel_end: + +SYM_DATA_START(relocate_new_kernel_size) + PTR relocate_new_kernel_end - relocate_new_kernel +SYM_DATA_END(relocate_new_kernel_size) --=20 2.36.0 From nobody Tue Apr 7 10:40:52 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C6BFECAAD4 for ; Mon, 29 Aug 2022 04:37:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229683AbiH2Eh1 (ORCPT ); Mon, 29 Aug 2022 00:37:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39334 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229637AbiH2EhS (ORCPT ); Mon, 29 Aug 2022 00:37:18 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 471203ECFA for ; Sun, 28 Aug 2022 21:37:16 -0700 (PDT) Received: from bogon.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxvmtvQgxjO6YLAA--.39821S4; Mon, 29 Aug 2022 12:37:07 +0800 (CST) From: Youling Tang To: Huacai Chen , Baoquan He , Eric Biederman Cc: WANG Xuerui , Vivek Goyal , Dave Young , Guo Ren , Jiaxun Yang , kexec@lists.infradead.org, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 2/3] LoongArch: Add kdump support Date: Mon, 29 Aug 2022 12:37:02 +0800 Message-Id: <1661747823-23745-3-git-send-email-tangyouling@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1661747823-23745-1-git-send-email-tangyouling@loongson.cn> References: <1661747823-23745-1-git-send-email-tangyouling@loongson.cn> X-CM-TRANSID: AQAAf8DxvmtvQgxjO6YLAA--.39821S4 X-Coremail-Antispam: 1UD129KBjvAXoW3ur4kur15XryrAF17Xry3CFg_yoW8Gr1UGo WftF1xtw18GrW29rsYkF1qyFW5Gr1qkFsxZ39Ivw43WF9ay34jqry8KryYy347Jw4kWw4x W343WrWjy397Jr95n29KB7ZKAUJUUUU5529EdanIXcx71UUUUU7v73VFW2AGmfu7bjvjm3 AaLaJ3UjIYCTnIWjp_UUUO57k0a2IF6w4kM7kC6x804xWl14x267AKxVWrJVCq3wAFc2x0 x2IEx4CE42xK8VAvwI8IcIk0rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87 I2jVAFwI0_Jryl82xGYIkIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY 1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Jr0_JF4l84ACjcxK6xIIjxv20x vEc7CjxVAFwI0_Cr0_Gr1UM28EF7xvwVC2z280aVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2 jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4 CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_JrI_JrylYx0Ex4A2jsIE14v26r4j6F4UMcvj eVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxw CY02Avz4vE14v_Gryl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2Iq xVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r 1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY 6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67 AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuY vjxUyoqcDUUUU X-CM-SenderInfo: 5wdqw5prxox03j6o00pqjv00gofq/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This patch adds support for kdump, the 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, like kexec-tools, is responsible for allocating a separate region for the core's ELF header within crash kdump kernel memory and filling it in when executing kexec_load(). Then, its location will be advertised to crash dump kernel via a new device-tree property, "linux,elfcorehdr", and crash dump kernel preserves the region for later use with fdt_reserve_elfcorehdr() at boot time. At the same time, it will also limit the crash kdump kernel to the crashkernel area via a new device-tree property, "linux, usable-memory-rang= e", so as not to destroy the original kernel dump data. On crash dump kernel, /proc/vmcore will access the primary kernel's memory with copy_oldmem_page(). I tested this on LoongArch 3A5000 machine and works as expected (Suggest crashkernel parameter is "crashkernel=3D512M@2320M"), you may test it by triggering a crash through /proc/sysrq_trigger: $ sudo kexec -p /boot/vmlinux-kdump --reuse-cmdline --append=3D"nr_cpus=3D= 1" # echo c > /proc/sysrq_trigger Signed-off-by: Youling Tang --- arch/loongarch/Kconfig | 22 ++++++ arch/loongarch/Makefile | 4 + arch/loongarch/kernel/Makefile | 3 +- arch/loongarch/kernel/crash.c | 100 ++++++++++++++++++++++++ arch/loongarch/kernel/crash_dump.c | 19 +++++ arch/loongarch/kernel/machine_kexec.c | 12 ++- arch/loongarch/kernel/mem.c | 6 ++ arch/loongarch/kernel/relocate_kernel.S | 6 ++ arch/loongarch/kernel/setup.c | 49 ++++++++++++ arch/loongarch/kernel/traps.c | 4 + 10 files changed, 217 insertions(+), 8 deletions(-) create mode 100644 arch/loongarch/kernel/crash.c create mode 100644 arch/loongarch/kernel/crash_dump.c diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 903c82fa958d..7c1b07a5b5bd 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -420,6 +420,28 @@ config KEXEC =20 The name comes from the similarity to the exec system call. =20 +config CRASH_DUMP + bool "Build kdump crash kernel" + help + Generate crash dump after being started by kexec. This should + be normally only set in special crash dump kernels which are + loaded in the main kernel with kexec-tools into a specially + reserved region and then later executed after a crash by + kdump/kexec. + + For more details see Documentation/admin-guide/kdump/kdump.rst + +config PHYSICAL_START + hex "Physical address where the kernel is loaded" + default "0x9000000091000000" if 64BIT + depends on CRASH_DUMP + help + This gives the XKPRANGE address where the kernel is loaded. + If you plan to use kernel for capturing the crash dump change + this value to start of the reserved region (the "X" value as + specified in the "crashkernel=3DYM@XM" command line boot parameter + passed to the panic-ed kernel). + config SECCOMP bool "Enable seccomp to safely compute untrusted bytecode" depends on PROC_FS diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile index 4bc47f47cfd8..7dabd580426d 100644 --- a/arch/loongarch/Makefile +++ b/arch/loongarch/Makefile @@ -48,7 +48,11 @@ KBUILD_CFLAGS_MODULE +=3D -fplt -Wa,-mla-global-with-ab= s,-mla-local-with-abs cflags-y +=3D -ffreestanding cflags-y +=3D $(call cc-option, -mno-check-zero-division) =20 +ifdef CONFIG_PHYSICAL_START +load-y =3D $(CONFIG_PHYSICAL_START) +else load-y =3D 0x9000000000200000 +endif bootvars-y =3D VMLINUX_LOAD_ADDRESS=3D$(load-y) =20 drivers-$(CONFIG_PCI) +=3D arch/loongarch/pci/ diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile index 20b64ac3f128..df5aea129364 100644 --- a/arch/loongarch/kernel/Makefile +++ b/arch/loongarch/kernel/Makefile @@ -17,7 +17,8 @@ obj-$(CONFIG_CPU_HAS_FPU) +=3D fpu.o obj-$(CONFIG_MODULES) +=3D module.o module-sections.o obj-$(CONFIG_STACKTRACE) +=3D stacktrace.o =20 -obj-$(CONFIG_KEXEC) +=3D machine_kexec.o relocate_kernel.o +obj-$(CONFIG_KEXEC) +=3D machine_kexec.o relocate_kernel.o cra= sh.o +obj-$(CONFIG_CRASH_DUMP) +=3D crash_dump.o =20 obj-$(CONFIG_PROC_FS) +=3D proc.o =20 diff --git a/arch/loongarch/kernel/crash.c b/arch/loongarch/kernel/crash.c new file mode 100644 index 000000000000..b4f249ec6301 --- /dev/null +++ b/arch/loongarch/kernel/crash.c @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2022 Loongson Technology Corporation Limited + * + * Derived from MIPS + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static cpumask_t cpus_in_crash =3D CPU_MASK_NONE; + +#ifdef CONFIG_SMP +static void crash_shutdown_secondary(void *passed_regs) +{ + struct pt_regs *regs =3D passed_regs; + int cpu =3D smp_processor_id(); + + /* + * If we are passed registers, use those. Otherwise get the + * regs from the last interrupt, which should be correct, as + * we are in an interrupt. But if the regs are not there, + * pull them from the top of the stack. They are probably + * wrong, but we need something to keep from crashing again. + */ + if (!regs) + regs =3D get_irq_regs(); + if (!regs) + regs =3D task_pt_regs(current); + + local_irq_disable(); + if (!cpumask_test_cpu(cpu, &cpus_in_crash)) + crash_save_cpu(regs, cpu); + cpumask_set_cpu(cpu, &cpus_in_crash); + + while (!atomic_read(&kexec_ready_to_reboot)) + cpu_relax(); + + kexec_reboot(); +} + +/* Override the weak function in kernel/panic.c */ +void crash_smp_send_stop(void) +{ + static int cpus_stopped; + unsigned long timeout; + unsigned int ncpus; + + /* + * This function can be called twice in panic path, but obviously + * we execute this only once. + */ + if (cpus_stopped) + return; + + cpus_stopped =3D 1; + + /* Excluding the panic cpu */ + ncpus =3D num_online_cpus() - 1; + + smp_call_function(crash_shutdown_secondary, NULL, 0); + smp_wmb(); + + /* + * The crash CPU sends an IPI and wait for other CPUs to + * respond. Delay of at least 10 seconds. + */ + pr_emerg("Sending IPI to other cpus...\n"); + timeout =3D USEC_PER_SEC * 10; + while ((cpumask_weight(&cpus_in_crash) < ncpus) && timeout--) { + cpu_relax(); + udelay(1); + } +} + +#endif + +void machine_crash_shutdown(struct pt_regs *regs) +{ + int crashing_cpu; + + local_irq_disable(); + + crashing_cpu =3D smp_processor_id(); + crash_save_cpu(regs, crashing_cpu); + + /* shutdown non-crashing cpus */ + crash_smp_send_stop(); + cpumask_set_cpu(crashing_cpu, &cpus_in_crash); + + pr_info("Starting crashdump kernel...\n"); +} diff --git a/arch/loongarch/kernel/crash_dump.c b/arch/loongarch/kernel/cra= sh_dump.c new file mode 100644 index 000000000000..13e5d2f7870d --- /dev/null +++ b/arch/loongarch/kernel/crash_dump.c @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include + +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) +{ + void *vaddr; + + if (!csize) + return 0; + + vaddr =3D kmap_local_pfn(pfn); + csize =3D copy_to_iter(vaddr + offset, csize, iter); + kunmap_local(vaddr); + + return csize; +} diff --git a/arch/loongarch/kernel/machine_kexec.c b/arch/loongarch/kernel/= machine_kexec.c index 4ffcd4cd9c8c..f793a3ff09a3 100644 --- a/arch/loongarch/kernel/machine_kexec.c +++ b/arch/loongarch/kernel/machine_kexec.c @@ -69,7 +69,7 @@ int machine_kexec_prepare(struct kimage *kimage) continue; } =20 - /* kexec need a safe page to save reboot_code_buffer */ + /* kexec/kdump need a safe page to save reboot_code_buffer */ kimage->control_code_page =3D virt_to_page((void *)KEXEC_CTRL_CODE); =20 reboot_code_buffer =3D @@ -113,10 +113,6 @@ static void kexec_shutdown_secondary(void *) =20 kexec_reboot(); } - -void machine_crash_shutdown(struct pt_regs *regs) -{ -} #endif =20 void machine_shutdown(void) @@ -135,7 +131,8 @@ void machine_kexec(struct kimage *image) =20 jump_addr =3D (unsigned long)phys_to_virt(image->start); =20 - first_ind_entry =3D (unsigned long)phys_to_virt(image->head & PAGE_MASK); + if (image->type =3D=3D KEXEC_TYPE_DEFAULT) + first_ind_entry =3D (unsigned long)phys_to_virt(image->head & PAGE_MASK); =20 /* * The generic kexec code builds a page list with physical @@ -167,7 +164,8 @@ void machine_kexec(struct kimage *image) =20 /* * We know we were online, and there will be no incoming IPIs at - * this point. + * this point. Mark online again before rebooting so that the crash + * analysis tool will see us correctly. */ set_cpu_online(smp_processor_id(), true); =20 diff --git a/arch/loongarch/kernel/mem.c b/arch/loongarch/kernel/mem.c index 7423361b0ebc..c6def6ff81c8 100644 --- a/arch/loongarch/kernel/mem.c +++ b/arch/loongarch/kernel/mem.c @@ -5,6 +5,7 @@ #include #include #include +#include =20 #include #include @@ -61,4 +62,9 @@ void __init memblock_init(void) =20 /* Reserve the initrd */ reserve_initrd_mem(); + + /* Mainly reserved memory for the elf core head */ + early_init_fdt_scan_reserved_mem(); + /* Parse linux,usable-memory-range is for crash dump kernel */ + early_init_dt_check_for_usable_mem_range(); } diff --git a/arch/loongarch/kernel/relocate_kernel.S b/arch/loongarch/kerne= l/relocate_kernel.S index d1f242f74ea8..4ee5ac4ac2d7 100644 --- a/arch/loongarch/kernel/relocate_kernel.S +++ b/arch/loongarch/kernel/relocate_kernel.S @@ -28,6 +28,12 @@ SYM_CODE_START(relocate_new_kernel) move s2, a2 move s3, a3 =20 + /* + * In case of a kdump/crash kernel, the indirection page is not + * populated as the kernel is directly copied to a reserved location + */ + beqz s2, done + process_entry: PTR_L s4, s2, 0 PTR_ADDI s2, s2, SZREG diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c index f938aae3e92c..ea34b77e402f 100644 --- a/arch/loongarch/kernel/setup.c +++ b/arch/loongarch/kernel/setup.c @@ -19,6 +19,8 @@ #include #include #include +#include +#include #include #include #include @@ -186,6 +188,50 @@ static int __init early_parse_mem(char *p) } early_param("mem", early_parse_mem); =20 +static void __init loongarch_parse_crashkernel(void) +{ +#ifdef CONFIG_KEXEC + unsigned long long start; + unsigned long long total_mem; + unsigned long long crash_size, crash_base; + int ret; + + total_mem =3D memblock_phys_mem_size(); + ret =3D parse_crashkernel(boot_command_line, total_mem, + &crash_size, &crash_base); + if (ret !=3D 0 || crash_size <=3D 0) + return; + + + start =3D memblock_phys_alloc_range(crash_size, 1, crash_base, + crash_base + crash_size); + if (start !=3D crash_base) { + pr_warn("Invalid memory region reserved for crash kernel\n"); + return; + } + + crashk_res.start =3D crash_base; + crashk_res.end =3D crash_base + crash_size - 1; +#endif +} + +static void __init request_crashkernel(struct resource *res) +{ +#ifdef CONFIG_KEXEC + int ret; + + if (crashk_res.start =3D=3D crashk_res.end) + return; + + ret =3D request_resource(res, &crashk_res); + if (!ret) + pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n", + (unsigned long)((crashk_res.end - + crashk_res.start + 1) >> 20), + (unsigned long)(crashk_res.start >> 20)); +#endif +} + void __init platform_init(void) { efi_init(); @@ -229,6 +275,8 @@ static void __init arch_mem_init(char **cmdline_p) =20 check_kernel_sections_mem(); =20 + loongarch_parse_crashkernel(); + /* * In order to reduce the possibility of kernel panic when failed to * get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate @@ -290,6 +338,7 @@ static void __init resource_init(void) request_resource(res, &code_resource); request_resource(res, &data_resource); request_resource(res, &bss_resource); + request_crashkernel(res); } } =20 diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c index aa1c95aaf595..0e610872f3f4 100644 --- a/arch/loongarch/kernel/traps.c +++ b/arch/loongarch/kernel/traps.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -246,6 +247,9 @@ void __noreturn die(const char *str, struct pt_regs *re= gs) =20 oops_exit(); =20 + if (regs && kexec_should_crash(current)) + crash_kexec(regs); + if (in_interrupt()) panic("Fatal exception in interrupt"); =20 --=20 2.36.0 From nobody Tue Apr 7 10:40:52 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B46EBECAAA2 for ; Mon, 29 Aug 2022 04:37:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229657AbiH2EhV (ORCPT ); Mon, 29 Aug 2022 00:37:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229447AbiH2EhR (ORCPT ); Mon, 29 Aug 2022 00:37:17 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 468E63ECF9 for ; Sun, 28 Aug 2022 21:37:16 -0700 (PDT) Received: from bogon.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxvmtvQgxjO6YLAA--.39821S5; Mon, 29 Aug 2022 12:37:08 +0800 (CST) From: Youling Tang To: Huacai Chen , Baoquan He , Eric Biederman Cc: WANG Xuerui , Vivek Goyal , Dave Young , Guo Ren , Jiaxun Yang , kexec@lists.infradead.org, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 3/3] LoongArch: Enable CONFIG_KEXEC Date: Mon, 29 Aug 2022 12:37:03 +0800 Message-Id: <1661747823-23745-4-git-send-email-tangyouling@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1661747823-23745-1-git-send-email-tangyouling@loongson.cn> References: <1661747823-23745-1-git-send-email-tangyouling@loongson.cn> X-CM-TRANSID: AQAAf8DxvmtvQgxjO6YLAA--.39821S5 X-Coremail-Antispam: 1UD129KBjvdXoWrZF48WFWUJr1xAw4rXr1fJFb_yoWxCFg_JF y7Gw4Dur48ta97uw4xXw1rWwsrA3W7ZF1FkF17Ar1xX3Wagr13tw4qq3W3C3ZYg3yUWrs3 ZaykAF9Fkr10yjkaLaAFLSUrUUUUbb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbg8YjsxI4VWxJwAYFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I 6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l82xGYIkIc2x26280x7 IE14v26r1rM28IrcIa0xkI8VCY1x0267AKxVW5JVCq3wA2ocxC64kIII0Yj41l84x0c7CE w4AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26r1I6r4UM28EF7xvwVC0I7IYx2IY6x kF7I0E14v26F4j6r4UJwA2z4x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv 6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c 02F40Ex7xfMcIj6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVW8JVWxJwAm72CE 4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc2 xSY4AK67AK6r45MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E 5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtV W8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY 1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI 0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7I U8G-e7UUUUU== X-CM-SenderInfo: 5wdqw5prxox03j6o00pqjv00gofq/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Defaults enable CONFIG_KEXEC to convenient kexec operations. Signed-off-by: Youling Tang --- arch/loongarch/configs/loongson3_defconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/co= nfigs/loongson3_defconfig index 68c9609670d4..52db7a3a79f3 100644 --- a/arch/loongarch/configs/loongson3_defconfig +++ b/arch/loongarch/configs/loongson3_defconfig @@ -45,6 +45,7 @@ CONFIG_SMP=3Dy CONFIG_HOTPLUG_CPU=3Dy CONFIG_NR_CPUS=3D64 CONFIG_NUMA=3Dy +CONFIG_KEXEC=3Dy CONFIG_PAGE_SIZE_16KB=3Dy CONFIG_HZ_250=3Dy CONFIG_ACPI=3Dy --=20 2.36.0