1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright IBM Corp. 2005, 2011
5 * Author(s): Rolf Adelsberger,
6 * Heiko Carstens <heiko.carstens@de.ibm.com>
7 * Michael Holzheu <holzheu@linux.vnet.ibm.com>
10 #include <linux/device.h>
12 #include <linux/kexec.h>
13 #include <linux/delay.h>
14 #include <linux/reboot.h>
15 #include <linux/ftrace.h>
16 #include <linux/debug_locks.h>
17 #include <linux/suspend.h>
19 #include <asm/setup.h>
20 #include <asm/pgtable.h>
21 #include <asm/pgalloc.h>
23 #include <asm/reset.h>
27 #include <asm/asm-offsets.h>
28 #include <asm/cacheflush.h>
29 #include <asm/os_info.h>
30 #include <asm/set_memory.h>
31 #include <asm/switch_to.h>
34 typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
36 extern const unsigned char relocate_kernel[];
37 extern const unsigned long long relocate_kernel_len;
39 #ifdef CONFIG_CRASH_DUMP
42 * PM notifier callback for kdump
44 static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
48 case PM_SUSPEND_PREPARE:
49 case PM_HIBERNATION_PREPARE:
50 if (kexec_crash_image)
51 arch_kexec_unprotect_crashkres();
54 case PM_POST_HIBERNATION:
55 if (kexec_crash_image)
56 arch_kexec_protect_crashkres();
64 static int __init machine_kdump_pm_init(void)
66 pm_notifier(machine_kdump_pm_cb, 0);
69 arch_initcall(machine_kdump_pm_init);
72 * Reset the system, copy boot CPU registers to absolute zero,
73 * and jump to the kdump image
75 static void __do_machine_kdump(void *image)
77 int (*start_kdump)(int);
80 /* store_status() saved the prefix register to lowcore */
81 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
83 /* Now do the reset */
87 * Copy dump CPU store status info to absolute zero.
88 * This need to be done *after* s390_reset_system set the
89 * prefix register of this CPU to zero
91 memcpy((void *) __LC_FPREGS_SAVE_AREA,
92 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
94 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
95 start_kdump = (void *)((struct kimage *) image)->start;
98 /* Die if start_kdump returns */
99 disabled_wait((unsigned long) __builtin_return_address(0));
103 * Start kdump: create a LGR log entry, store status of all CPUs and
104 * branch to __do_machine_kdump.
106 static noinline void __machine_kdump(void *image)
109 unsigned long cr2_old, cr2_new;
113 /* Get status of the other CPUs */
114 this_cpu = smp_find_processor_id(stap());
115 for_each_online_cpu(cpu) {
118 if (smp_store_status(cpu))
121 /* Store status of the boot CPU */
122 mcesa = (struct mcesa *)(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
124 save_vx_regs((__vector128 *) mcesa->vector_save_area);
125 if (MACHINE_HAS_GS) {
126 __ctl_store(cr2_old, 2, 2);
127 cr2_new = cr2_old | (1UL << 4);
128 __ctl_load(cr2_new, 2, 2);
129 save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
130 __ctl_load(cr2_old, 2, 2);
133 * To create a good backchain for this CPU in the dump store_status
134 * is passed the address of a function. The address is saved into
135 * the PSW save area of the boot CPU and the function is invoked as
136 * a tail call of store_status. The backchain in the dump will look
138 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
139 * The call to store_status() will not return.
141 store_status(__do_machine_kdump, image);
146 * Check if kdump checksums are valid: We call purgatory with parameter "0"
148 static int kdump_csum_valid(struct kimage *image)
150 #ifdef CONFIG_CRASH_DUMP
151 int (*start_kdump)(int) = (void *)image->start;
154 __arch_local_irq_stnsm(0xfb); /* disable DAT */
156 __arch_local_irq_stosm(0x04); /* enable DAT */
157 return rc ? 0 : -EINVAL;
163 #ifdef CONFIG_CRASH_DUMP
165 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
167 unsigned long addr, size;
169 for (addr = begin; addr < end; addr += PAGE_SIZE)
170 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
171 size = begin - crashk_res.start;
173 os_info_crashkernel_add(crashk_res.start, size);
175 os_info_crashkernel_add(0, 0);
178 static void crash_protect_pages(int protect)
184 size = resource_size(&crashk_res);
186 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
188 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
191 void arch_kexec_protect_crashkres(void)
193 crash_protect_pages(1);
196 void arch_kexec_unprotect_crashkres(void)
198 crash_protect_pages(0);
204 * Give back memory to hypervisor before new kdump is loaded
206 static int machine_kexec_prepare_kdump(void)
208 #ifdef CONFIG_CRASH_DUMP
210 diag10_range(PFN_DOWN(crashk_res.start),
211 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
218 int machine_kexec_prepare(struct kimage *image)
220 void *reboot_code_buffer;
222 /* Can't replace kernel image since it is read-only. */
223 if (ipl_flags & IPL_NSS_VALID)
226 if (image->type == KEXEC_TYPE_CRASH)
227 return machine_kexec_prepare_kdump();
229 /* We don't support anything but the default image type for now. */
230 if (image->type != KEXEC_TYPE_DEFAULT)
233 /* Get the destination where the assembler code should be copied to.*/
234 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
237 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
241 void machine_kexec_cleanup(struct kimage *image)
245 void arch_crash_save_vmcoreinfo(void)
247 VMCOREINFO_SYMBOL(lowcore_ptr);
248 VMCOREINFO_SYMBOL(high_memory);
249 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
250 mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
253 void machine_shutdown(void)
257 void machine_crash_shutdown(struct pt_regs *regs)
264 static void __do_machine_kexec(void *data)
266 relocate_kernel_t data_mover;
267 struct kimage *image = data;
270 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
272 __arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
273 /* Call the moving routine */
274 (*data_mover)(&image->head, image->start);
276 /* Die if kexec returns */
277 disabled_wait((unsigned long) __builtin_return_address(0));
281 * Reset system and call either kdump or normal kexec
283 static void __machine_kexec(void *data)
285 __arch_local_irq_stosm(0x04); /* enable DAT */
289 #ifdef CONFIG_CRASH_DUMP
290 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
291 __machine_kdump(data);
293 __do_machine_kexec(data);
297 * Do either kdump or normal kexec. In case of kdump we first ask
298 * purgatory, if kdump checksums are valid.
300 void machine_kexec(struct kimage *image)
302 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
306 smp_call_ipl_cpu(__machine_kexec, image);