// SPDX-License-Identifier: GPL-2.0 /* * Copyright IBM Corp. 2005, 2011 * * Author(s): Rolf Adelsberger, * Heiko Carstens <heiko.carstens@de.ibm.com> * Michael Holzheu <holzheu@linux.vnet.ibm.com> */ #include <linux/device.h> #include <linux/mm.h> #include <linux/kexec.h> #include <linux/delay.h> #include <linux/reboot.h> #include <linux/ftrace.h> #include <linux/debug_locks.h> #include <linux/suspend.h> #include <asm/cio.h> #include <asm/setup.h> #include <asm/pgtable.h> #include <asm/pgalloc.h> #include <asm/smp.h> #include <asm/ipl.h> #include <asm/diag.h> #include <asm/elf.h> #include <asm/asm-offsets.h> #include <asm/cacheflush.h> #include <asm/os_info.h> #include <asm/set_memory.h> #include <asm/stacktrace.h> #include <asm/switch_to.h> #include <asm/nmi.h> typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long); extern const unsigned char relocate_kernel[]; extern const unsigned long long relocate_kernel_len; #ifdef CONFIG_CRASH_DUMP /* * PM notifier callback for kdump */ static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action, void *ptr) { switch (action) { case PM_SUSPEND_PREPARE: case PM_HIBERNATION_PREPARE: if (kexec_crash_image) arch_kexec_unprotect_crashkres(); break; case PM_POST_SUSPEND: case PM_POST_HIBERNATION: if (kexec_crash_image) arch_kexec_protect_crashkres(); break; default: return NOTIFY_DONE; } return NOTIFY_OK; } static int __init machine_kdump_pm_init(void) { pm_notifier(machine_kdump_pm_cb, 0); return 0; } arch_initcall(machine_kdump_pm_init); /* * Reset the system, copy boot CPU registers to absolute zero, * and jump to the kdump image */ static void __do_machine_kdump(void *image) { int (*start_kdump)(int); unsigned long prefix; /* store_status() saved the prefix register to lowcore */ prefix = (unsigned long) S390_lowcore.prefixreg_save_area; /* Now do the reset */ s390_reset_system(); /* * Copy dump CPU store status info to absolute zero. * This need to be done *after* s390_reset_system set the * prefix register of this CPU to zero */ memcpy((void *) __LC_FPREGS_SAVE_AREA, (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512); __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA); start_kdump = (void *)((struct kimage *) image)->start; start_kdump(1); /* Die if start_kdump returns */ disabled_wait(); } /* * Start kdump: create a LGR log entry, store status of all CPUs and * branch to __do_machine_kdump. */ static noinline void __machine_kdump(void *image) { struct mcesa *mcesa; union ctlreg2 cr2_old, cr2_new; int this_cpu, cpu; lgr_info_log(); /* Get status of the other CPUs */ this_cpu = smp_find_processor_id(stap()); for_each_online_cpu(cpu) { if (cpu == this_cpu) continue; if (smp_store_status(cpu)) continue; } /* Store status of the boot CPU */ mcesa = (struct mcesa *)(S390_lowcore.mcesad & MCESA_ORIGIN_MASK); if (MACHINE_HAS_VX) save_vx_regs((__vector128 *) mcesa->vector_save_area); if (MACHINE_HAS_GS) { __ctl_store(cr2_old.val, 2, 2); cr2_new = cr2_old; cr2_new.gse = 1; __ctl_load(cr2_new.val, 2, 2); save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area); __ctl_load(cr2_old.val, 2, 2); } /* * To create a good backchain for this CPU in the dump store_status * is passed the address of a function. The address is saved into * the PSW save area of the boot CPU and the function is invoked as * a tail call of store_status. The backchain in the dump will look * like this: * restart_int_handler -> __machine_kexec -> __do_machine_kdump * The call to store_status() will not return. */ store_status(__do_machine_kdump, image); } static unsigned long do_start_kdump(unsigned long addr) { struct kimage *image = (struct kimage *) addr; int (*start_kdump)(int) = (void *)image->start; int rc; __arch_local_irq_stnsm(0xfb); /* disable DAT */ rc = start_kdump(0); __arch_local_irq_stosm(0x04); /* enable DAT */ return rc; } #endif /* CONFIG_CRASH_DUMP */ /* * Check if kdump checksums are valid: We call purgatory with parameter "0" */ static bool kdump_csum_valid(struct kimage *image) { #ifdef CONFIG_CRASH_DUMP int rc; preempt_disable(); rc = CALL_ON_STACK(do_start_kdump, S390_lowcore.nodat_stack, 1, image); preempt_enable(); return rc == 0; #else return false; #endif } #ifdef CONFIG_CRASH_DUMP void crash_free_reserved_phys_range(unsigned long begin, unsigned long end) { unsigned long addr, size; for (addr = begin; addr < end; addr += PAGE_SIZE) free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT)); size = begin - crashk_res.start; if (size) os_info_crashkernel_add(crashk_res.start, size); else os_info_crashkernel_add(0, 0); } static void crash_protect_pages(int protect) { unsigned long size; if (!crashk_res.end) return; size = resource_size(&crashk_res); if (protect) set_memory_ro(crashk_res.start, size >> PAGE_SHIFT); else set_memory_rw(crashk_res.start, size >> PAGE_SHIFT); } void arch_kexec_protect_crashkres(void) { crash_protect_pages(1); } void arch_kexec_unprotect_crashkres(void) { crash_protect_pages(0); } #endif /* * Give back memory to hypervisor before new kdump is loaded */ static int machine_kexec_prepare_kdump(void) { #ifdef CONFIG_CRASH_DUMP if (MACHINE_IS_VM) diag10_range(PFN_DOWN(crashk_res.start), PFN_DOWN(crashk_res.end - crashk_res.start + 1)); return 0; #else return -EINVAL; #endif } int machine_kexec_prepare(struct kimage *image) { void *reboot_code_buffer; if (image->type == KEXEC_TYPE_CRASH) return machine_kexec_prepare_kdump(); /* We don't support anything but the default image type for now. */ if (image->type != KEXEC_TYPE_DEFAULT) return -EINVAL; /* Get the destination where the assembler code should be copied to.*/ reboot_code_buffer = (void *) page_to_phys(image->control_code_page); /* Then copy it */ memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len); return 0; } void machine_kexec_cleanup(struct kimage *image) { } void arch_crash_save_vmcoreinfo(void) { VMCOREINFO_SYMBOL(lowcore_ptr); VMCOREINFO_SYMBOL(high_memory); VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS); vmcoreinfo_append_str("SDMA=%lx\n", __sdma); vmcoreinfo_append_str("EDMA=%lx\n", __edma); vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note()); } void machine_shutdown(void) { } void machine_crash_shutdown(struct pt_regs *regs) { set_os_info_reipl_block(); } /* * Do normal kexec */ static void __do_machine_kexec(void *data) { relocate_kernel_t data_mover; struct kimage *image = data; s390_reset_system(); data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page); __arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */ /* Call the moving routine */ (*data_mover)(&image->head, image->start); /* Die if kexec returns */ disabled_wait(); } /* * Reset system and call either kdump or normal kexec */ static void __machine_kexec(void *data) { __arch_local_irq_stosm(0x04); /* enable DAT */ pfault_fini(); tracing_off(); debug_locks_off(); #ifdef CONFIG_CRASH_DUMP if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH) __machine_kdump(data); #endif __do_machine_kexec(data); } /* * Do either kdump or normal kexec. In case of kdump we first ask * purgatory, if kdump checksums are valid. */ void machine_kexec(struct kimage *image) { if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image)) return; tracer_disable(); smp_send_stop(); smp_call_ipl_cpu(__machine_kexec, image); }