| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * kexec for arm64 |
| * |
| * Copyright (C) Linaro. |
| * Copyright (C) Huawei Futurewei Technologies. |
| */ |
| |
| #include <linux/interrupt.h> |
| #include <linux/irq.h> |
| #include <linux/kernel.h> |
| #include <linux/kexec.h> |
| #include <linux/page-flags.h> |
| #include <linux/set_memory.h> |
| #include <linux/smp.h> |
| |
| #include <asm/cacheflush.h> |
| #include <asm/cpu_ops.h> |
| #include <asm/daifflags.h> |
| #include <asm/memory.h> |
| #include <asm/mmu.h> |
| #include <asm/mmu_context.h> |
| #include <asm/page.h> |
| #include <asm/sections.h> |
| #include <asm/trans_pgd.h> |
| |
| /** |
| * 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(function_nocfi(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 */ |