// SPDX-License-Identifier: GPL-2.0 /* * Copyright IBM Corp. 2005, 2011 * * Author(s): Rolf Adelsberger, * Michael Holzheu */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include typedef void (*relocate_kernel_t)(unsigned long, unsigned long, unsigned long); typedef int (*purgatory_t)(int); extern const unsigned char relocate_kernel[]; extern const unsigned long long relocate_kernel_len; #ifdef CONFIG_CRASH_DUMP /* * Reset the system, copy boot CPU registers to absolute zero, * and jump to the kdump image */ static void __do_machine_kdump(void *data) { struct kimage *image = data; purgatory_t purgatory; unsigned long prefix; purgatory = (purgatory_t)image->start; /* 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(absolute_pointer(__LC_FPREGS_SAVE_AREA), phys_to_virt(prefix + __LC_FPREGS_SAVE_AREA), 512); call_nodat(1, int, purgatory, int, 1); /* Die if 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 = __va(S390_lowcore.mcesad & MCESA_ORIGIN_MASK); if (cpu_has_vx()) save_vx_regs((__vector128 *) mcesa->vector_save_area); if (MACHINE_HAS_GS) { local_ctl_store(2, &cr2_old.reg); cr2_new = cr2_old; cr2_new.gse = 1; local_ctl_load(2, &cr2_new.reg); save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area); local_ctl_load(2, &cr2_old.reg); } /* * 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); } #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 purgatory_t purgatory = (purgatory_t)image->start; int rc; rc = call_nodat(1, int, purgatory, int, 0); 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 = page_to_virt(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 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) { unsigned long data_mover, entry, diag308_subcode; struct kimage *image = data; data_mover = page_to_phys(image->control_code_page); entry = virt_to_phys(&image->head); diag308_subcode = DIAG308_CLEAR_RESET; if (sclp.has_iplcc) diag308_subcode |= DIAG308_FLAG_EI; s390_reset_system(); call_nodat(3, void, (relocate_kernel_t)data_mover, unsigned long, entry, unsigned long, image->start, unsigned long, diag308_subcode); /* Die if kexec returns */ disabled_wait(); } /* * Reset system and call either kdump or normal kexec */ static void __machine_kexec(void *data) { 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); }