From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/arm64/kernel/machine_kexec.c | 363 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 363 insertions(+) create mode 100644 arch/arm64/kernel/machine_kexec.c (limited to 'arch/arm64/kernel/machine_kexec.c') diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c new file mode 100644 index 000000000..ce3d40120 --- /dev/null +++ b/arch/arm64/kernel/machine_kexec.c @@ -0,0 +1,363 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * kexec for arm64 + * + * Copyright (C) Linaro. + * Copyright (C) Huawei Futurewei Technologies. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/** + * kexec_image_info - For debugging output. + */ +#define kexec_image_info(_i) _kexec_image_info(__func__, __LINE__, _i) +static void _kexec_image_info(const char *func, int line, + const struct kimage *kimage) +{ + unsigned long i; + + pr_debug("%s:%d:\n", func, line); + pr_debug(" kexec kimage info:\n"); + pr_debug(" type: %d\n", kimage->type); + pr_debug(" start: %lx\n", kimage->start); + pr_debug(" head: %lx\n", kimage->head); + pr_debug(" nr_segments: %lu\n", kimage->nr_segments); + pr_debug(" dtb_mem: %pa\n", &kimage->arch.dtb_mem); + pr_debug(" kern_reloc: %pa\n", &kimage->arch.kern_reloc); + pr_debug(" el2_vectors: %pa\n", &kimage->arch.el2_vectors); + + for (i = 0; i < kimage->nr_segments; i++) { + pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n", + i, + kimage->segment[i].mem, + kimage->segment[i].mem + kimage->segment[i].memsz, + kimage->segment[i].memsz, + kimage->segment[i].memsz / PAGE_SIZE); + } +} + +void machine_kexec_cleanup(struct kimage *kimage) +{ + /* Empty routine needed to avoid build errors. */ +} + +/** + * machine_kexec_prepare - Prepare for a kexec reboot. + * + * Called from the core kexec code when a kernel image is loaded. + * Forbid loading a kexec kernel if we have no way of hotplugging cpus or cpus + * are stuck in the kernel. This avoids a panic once we hit machine_kexec(). + */ +int machine_kexec_prepare(struct kimage *kimage) +{ + if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) { + pr_err("Can't kexec: CPUs are stuck in the kernel.\n"); + return -EBUSY; + } + + return 0; +} + +/** + * kexec_segment_flush - Helper to flush the kimage segments to PoC. + */ +static void kexec_segment_flush(const struct kimage *kimage) +{ + unsigned long i; + + pr_debug("%s:\n", __func__); + + for (i = 0; i < kimage->nr_segments; i++) { + pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n", + i, + kimage->segment[i].mem, + kimage->segment[i].mem + kimage->segment[i].memsz, + kimage->segment[i].memsz, + kimage->segment[i].memsz / PAGE_SIZE); + + dcache_clean_inval_poc( + (unsigned long)phys_to_virt(kimage->segment[i].mem), + (unsigned long)phys_to_virt(kimage->segment[i].mem) + + kimage->segment[i].memsz); + } +} + +/* Allocates pages for kexec page table */ +static void *kexec_page_alloc(void *arg) +{ + struct kimage *kimage = (struct kimage *)arg; + struct page *page = kimage_alloc_control_pages(kimage, 0); + void *vaddr = NULL; + + if (!page) + return NULL; + + vaddr = page_address(page); + memset(vaddr, 0, PAGE_SIZE); + + return vaddr; +} + +int machine_kexec_post_load(struct kimage *kimage) +{ + int rc; + pgd_t *trans_pgd; + void *reloc_code = page_to_virt(kimage->control_code_page); + long reloc_size; + struct trans_pgd_info info = { + .trans_alloc_page = kexec_page_alloc, + .trans_alloc_arg = kimage, + }; + + /* If in place, relocation is not used, only flush next kernel */ + if (kimage->head & IND_DONE) { + kexec_segment_flush(kimage); + kexec_image_info(kimage); + return 0; + } + + kimage->arch.el2_vectors = 0; + if (is_hyp_nvhe()) { + rc = trans_pgd_copy_el2_vectors(&info, + &kimage->arch.el2_vectors); + if (rc) + return rc; + } + + /* Create a copy of the linear map */ + trans_pgd = kexec_page_alloc(kimage); + if (!trans_pgd) + return -ENOMEM; + rc = trans_pgd_create_copy(&info, &trans_pgd, PAGE_OFFSET, PAGE_END); + if (rc) + return rc; + kimage->arch.ttbr1 = __pa(trans_pgd); + kimage->arch.zero_page = __pa_symbol(empty_zero_page); + + reloc_size = __relocate_new_kernel_end - __relocate_new_kernel_start; + memcpy(reloc_code, __relocate_new_kernel_start, reloc_size); + kimage->arch.kern_reloc = __pa(reloc_code); + rc = trans_pgd_idmap_page(&info, &kimage->arch.ttbr0, + &kimage->arch.t0sz, reloc_code); + if (rc) + return rc; + kimage->arch.phys_offset = virt_to_phys(kimage) - (long)kimage; + + /* Flush the reloc_code in preparation for its execution. */ + dcache_clean_inval_poc((unsigned long)reloc_code, + (unsigned long)reloc_code + reloc_size); + icache_inval_pou((uintptr_t)reloc_code, + (uintptr_t)reloc_code + reloc_size); + kexec_image_info(kimage); + + return 0; +} + +/** + * machine_kexec - Do the kexec reboot. + * + * Called from the core kexec code for a sys_reboot with LINUX_REBOOT_CMD_KEXEC. + */ +void machine_kexec(struct kimage *kimage) +{ + bool in_kexec_crash = (kimage == kexec_crash_image); + bool stuck_cpus = cpus_are_stuck_in_kernel(); + + /* + * New cpus may have become stuck_in_kernel after we loaded the image. + */ + BUG_ON(!in_kexec_crash && (stuck_cpus || (num_online_cpus() > 1))); + WARN(in_kexec_crash && (stuck_cpus || smp_crash_stop_failed()), + "Some CPUs may be stale, kdump will be unreliable.\n"); + + pr_info("Bye!\n"); + + local_daif_mask(); + + /* + * Both restart and kernel_reloc will shutdown the MMU, disable data + * caches. However, restart will start new kernel or purgatory directly, + * kernel_reloc contains the body of arm64_relocate_new_kernel + * In kexec case, kimage->start points to purgatory assuming that + * kernel entry and dtb address are embedded in purgatory by + * userspace (kexec-tools). + * In kexec_file case, the kernel starts directly without purgatory. + */ + if (kimage->head & IND_DONE) { + typeof(cpu_soft_restart) *restart; + + cpu_install_idmap(); + restart = (void *)__pa_symbol(cpu_soft_restart); + restart(is_hyp_nvhe(), kimage->start, kimage->arch.dtb_mem, + 0, 0); + } else { + void (*kernel_reloc)(struct kimage *kimage); + + if (is_hyp_nvhe()) + __hyp_set_vectors(kimage->arch.el2_vectors); + cpu_install_ttbr0(kimage->arch.ttbr0, kimage->arch.t0sz); + kernel_reloc = (void *)kimage->arch.kern_reloc; + kernel_reloc(kimage); + } + + BUG(); /* Should never get here. */ +} + +static void machine_kexec_mask_interrupts(void) +{ + unsigned int i; + struct irq_desc *desc; + + for_each_irq_desc(i, desc) { + struct irq_chip *chip; + int ret; + + chip = irq_desc_get_chip(desc); + if (!chip) + continue; + + /* + * First try to remove the active state. If this + * fails, try to EOI the interrupt. + */ + ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false); + + if (ret && irqd_irq_inprogress(&desc->irq_data) && + chip->irq_eoi) + chip->irq_eoi(&desc->irq_data); + + if (chip->irq_mask) + chip->irq_mask(&desc->irq_data); + + if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) + chip->irq_disable(&desc->irq_data); + } +} + +/** + * machine_crash_shutdown - shutdown non-crashing cpus and save registers + */ +void machine_crash_shutdown(struct pt_regs *regs) +{ + local_irq_disable(); + + /* shutdown non-crashing cpus */ + crash_smp_send_stop(); + + /* for crashing cpu */ + crash_save_cpu(regs, smp_processor_id()); + machine_kexec_mask_interrupts(); + + pr_info("Starting crashdump kernel...\n"); +} + +void arch_kexec_protect_crashkres(void) +{ + int i; + + for (i = 0; i < kexec_crash_image->nr_segments; i++) + set_memory_valid( + __phys_to_virt(kexec_crash_image->segment[i].mem), + kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 0); +} + +void arch_kexec_unprotect_crashkres(void) +{ + int i; + + for (i = 0; i < kexec_crash_image->nr_segments; i++) + set_memory_valid( + __phys_to_virt(kexec_crash_image->segment[i].mem), + kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 1); +} + +#ifdef CONFIG_HIBERNATION +/* + * To preserve the crash dump kernel image, the relevant memory segments + * should be mapped again around the hibernation. + */ +void crash_prepare_suspend(void) +{ + if (kexec_crash_image) + arch_kexec_unprotect_crashkres(); +} + +void crash_post_resume(void) +{ + if (kexec_crash_image) + arch_kexec_protect_crashkres(); +} + +/* + * crash_is_nosave + * + * Return true only if a page is part of reserved memory for crash dump kernel, + * but does not hold any data of loaded kernel image. + * + * Note that all the pages in crash dump kernel memory have been initially + * marked as Reserved as memory was allocated via memblock_reserve(). + * + * In hibernation, the pages which are Reserved and yet "nosave" are excluded + * from the hibernation iamge. crash_is_nosave() does thich check for crash + * dump kernel and will reduce the total size of hibernation image. + */ + +bool crash_is_nosave(unsigned long pfn) +{ + int i; + phys_addr_t addr; + + if (!crashk_res.end) + return false; + + /* in reserved memory? */ + addr = __pfn_to_phys(pfn); + if ((addr < crashk_res.start) || (crashk_res.end < addr)) { + if (!crashk_low_res.end) + return false; + + if ((addr < crashk_low_res.start) || (crashk_low_res.end < addr)) + return false; + } + + if (!kexec_crash_image) + return true; + + /* not part of loaded kernel image? */ + for (i = 0; i < kexec_crash_image->nr_segments; i++) + if (addr >= kexec_crash_image->segment[i].mem && + addr < (kexec_crash_image->segment[i].mem + + kexec_crash_image->segment[i].memsz)) + return false; + + return true; +} + +void crash_free_reserved_phys_range(unsigned long begin, unsigned long end) +{ + unsigned long addr; + struct page *page; + + for (addr = begin; addr < end; addr += PAGE_SIZE) { + page = phys_to_page(addr); + free_reserved_page(page); + } +} +#endif /* CONFIG_HIBERNATION */ -- cgit v1.2.3