1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright IBM Corp. 2005, 2011
  4 *
  5 * Author(s): Rolf Adelsberger,
 
  6 *	      Michael Holzheu <holzheu@linux.vnet.ibm.com>
  7 */
  8
  9#include <linux/device.h>
 10#include <linux/mm.h>
 11#include <linux/kexec.h>
 12#include <linux/delay.h>
 13#include <linux/reboot.h>
 14#include <linux/ftrace.h>
 15#include <linux/debug_locks.h>
 16#include <asm/guarded_storage.h>
 17#include <asm/pfault.h>
 18#include <asm/cio.h>
 19#include <asm/fpu.h>
 20#include <asm/setup.h>
 
 
 21#include <asm/smp.h>
 
 22#include <asm/ipl.h>
 23#include <asm/diag.h>
 24#include <asm/elf.h>
 25#include <asm/asm-offsets.h>
 26#include <asm/cacheflush.h>
 27#include <asm/abs_lowcore.h>
 28#include <asm/os_info.h>
 29#include <asm/set_memory.h>
 30#include <asm/stacktrace.h>
 31#include <asm/nmi.h>
 32#include <asm/sclp.h>
 33
 34typedef void (*relocate_kernel_t)(unsigned long, unsigned long, unsigned long);
 35typedef int (*purgatory_t)(int);
 36
 37extern const unsigned char relocate_kernel[];
 38extern const unsigned long long relocate_kernel_len;
 39
 40#ifdef CONFIG_CRASH_DUMP
 41
 42/*
 43 * Reset the system, copy boot CPU registers to absolute zero,
 44 * and jump to the kdump image
 45 */
 46static void __do_machine_kdump(void *data)
 47{
 48	struct kimage *image = data;
 49	purgatory_t purgatory;
 50	unsigned long prefix;
 51
 52	purgatory = (purgatory_t)image->start;
 53
 54	/* store_status() saved the prefix register to lowcore */
 55	prefix = (unsigned long)get_lowcore()->prefixreg_save_area;
 56
 57	/* Now do the reset  */
 58	s390_reset_system();
 59
 60	/*
 61	 * Copy dump CPU store status info to absolute zero.
 62	 * This need to be done *after* s390_reset_system set the
 63	 * prefix register of this CPU to zero
 64	 */
 65	memcpy(absolute_pointer(get_lowcore()->floating_pt_save_area),
 66	       phys_to_virt(prefix + __LC_FPREGS_SAVE_AREA), 512);
 67
 68	call_nodat(1, int, purgatory, int, 1);
 69
 70	/* Die if kdump returns */
 71	disabled_wait();
 
 
 72}
 73
 74/*
 75 * Start kdump: create a LGR log entry, store status of all CPUs and
 76 * branch to __do_machine_kdump.
 77 */
 78static noinline void __machine_kdump(void *image)
 79{
 80	struct mcesa *mcesa;
 81	union ctlreg2 cr2_old, cr2_new;
 82	int this_cpu, cpu;
 83
 84	lgr_info_log();
 85	/* Get status of the other CPUs */
 86	this_cpu = smp_find_processor_id(stap());
 
 87	for_each_online_cpu(cpu) {
 88		if (cpu == this_cpu)
 89			continue;
 90		if (smp_store_status(cpu))
 91			continue;
 
 92	}
 93	/* Store status of the boot CPU */
 94	mcesa = __va(get_lowcore()->mcesad & MCESA_ORIGIN_MASK);
 95	if (cpu_has_vx())
 96		save_vx_regs((__vector128 *) mcesa->vector_save_area);
 97	if (MACHINE_HAS_GS) {
 98		local_ctl_store(2, &cr2_old.reg);
 99		cr2_new = cr2_old;
100		cr2_new.gse = 1;
101		local_ctl_load(2, &cr2_new.reg);
102		save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
103		local_ctl_load(2, &cr2_old.reg);
 
 
 
 
 
 
 
 
 
 
 
 
104	}
105	/*
106	 * To create a good backchain for this CPU in the dump store_status
107	 * is passed the address of a function. The address is saved into
108	 * the PSW save area of the boot CPU and the function is invoked as
109	 * a tail call of store_status. The backchain in the dump will look
110	 * like this:
111	 *   restart_int_handler ->  __machine_kexec -> __do_machine_kdump
112	 * The call to store_status() will not return.
113	 */
114	store_status(__do_machine_kdump, image);
115}
116
117#endif /* CONFIG_CRASH_DUMP */
 
 
 
 
 
 
118
119/*
120 * Check if kdump checksums are valid: We call purgatory with parameter "0"
121 */
122static bool kdump_csum_valid(struct kimage *image)
123{
124#ifdef CONFIG_CRASH_DUMP
125	purgatory_t purgatory = (purgatory_t)image->start;
126	int rc;
127
128	rc = call_nodat(1, int, purgatory, int, 0);
129	return rc == 0;
130#else
131	return false;
132#endif
133}
134
135#ifdef CONFIG_CRASH_DUMP
136
137void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
 
138{
139	unsigned long addr, size;
 
 
140
141	for (addr = begin; addr < end; addr += PAGE_SIZE)
142		free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
143	size = begin - crashk_res.start;
144	if (size)
145		os_info_crashkernel_add(crashk_res.start, size);
146	else
147		os_info_crashkernel_add(0, 0);
148}
149
150static void crash_protect_pages(int protect)
 
 
 
151{
152	unsigned long size;
153
154	if (!crashk_res.end)
155		return;
156	size = resource_size(&crashk_res);
157	if (protect)
158		set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
159	else
160		set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
 
 
 
 
161}
162
163void arch_kexec_protect_crashkres(void)
 
 
 
164{
165	crash_protect_pages(1);
166}
167
168void arch_kexec_unprotect_crashkres(void)
 
 
 
169{
170	crash_protect_pages(0);
171}
172
173#endif
174
175/*
176 * Give back memory to hypervisor before new kdump is loaded
177 */
178static int machine_kexec_prepare_kdump(void)
179{
180#ifdef CONFIG_CRASH_DUMP
181	if (MACHINE_IS_VM)
182		diag10_range(PFN_DOWN(crashk_res.start),
183			     PFN_DOWN(crashk_res.end - crashk_res.start + 1));
184	return 0;
185#else
186	return -EINVAL;
187#endif
188}
189
190int machine_kexec_prepare(struct kimage *image)
191{
192	void *reboot_code_buffer;
193
 
 
 
 
194	if (image->type == KEXEC_TYPE_CRASH)
195		return machine_kexec_prepare_kdump();
196
197	/* We don't support anything but the default image type for now. */
198	if (image->type != KEXEC_TYPE_DEFAULT)
199		return -EINVAL;
200
201	/* Get the destination where the assembler code should be copied to.*/
202	reboot_code_buffer = page_to_virt(image->control_code_page);
203
204	/* Then copy it */
205	memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
206	return 0;
207}
208
209void machine_kexec_cleanup(struct kimage *image)
210{
211}
212
 
 
 
 
 
 
 
213void machine_shutdown(void)
214{
215}
216
217void machine_crash_shutdown(struct pt_regs *regs)
218{
219	set_os_info_reipl_block();
220}
221
222/*
223 * Do normal kexec
224 */
225static void __do_machine_kexec(void *data)
226{
227	unsigned long data_mover, entry, diag308_subcode;
228	struct kimage *image = data;
229
230	data_mover = page_to_phys(image->control_code_page);
231	entry = virt_to_phys(&image->head);
232	diag308_subcode = DIAG308_CLEAR_RESET;
233	if (sclp.has_iplcc)
234		diag308_subcode |= DIAG308_FLAG_EI;
235	s390_reset_system();
236
237	call_nodat(3, void, (relocate_kernel_t)data_mover,
238		   unsigned long, entry,
239		   unsigned long, image->start,
240		   unsigned long, diag308_subcode);
241
242	/* Die if kexec returns */
243	disabled_wait();
244}
245
246/*
247 * Reset system and call either kdump or normal kexec
248 */
249static void __machine_kexec(void *data)
250{
 
 
 
251	pfault_fini();
252	tracing_off();
253	debug_locks_off();
254#ifdef CONFIG_CRASH_DUMP
255	if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
256		__machine_kdump(data);
257#endif
258	__do_machine_kexec(data);
 
 
259}
260
261/*
262 * Do either kdump or normal kexec. In case of kdump we first ask
263 * purgatory, if kdump checksums are valid.
264 */
265void machine_kexec(struct kimage *image)
266{
267	if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
268		return;
269	tracer_disable();
270	smp_send_stop();
271	smp_call_ipl_cpu(__machine_kexec, image);
272}

 
  1/*
  2 * Copyright IBM Corp. 2005, 2011
  3 *
  4 * Author(s): Rolf Adelsberger,
  5 *	      Heiko Carstens <heiko.carstens@de.ibm.com>
  6 *	      Michael Holzheu <holzheu@linux.vnet.ibm.com>
  7 */
  8
  9#include <linux/device.h>
 10#include <linux/mm.h>
 11#include <linux/kexec.h>
 12#include <linux/delay.h>
 13#include <linux/reboot.h>
 14#include <linux/ftrace.h>
 15#include <linux/debug_locks.h>
 16#include <linux/suspend.h>
 
 17#include <asm/cio.h>
 
 18#include <asm/setup.h>
 19#include <asm/pgtable.h>
 20#include <asm/pgalloc.h>
 21#include <asm/smp.h>
 22#include <asm/reset.h>
 23#include <asm/ipl.h>
 24#include <asm/diag.h>
 25#include <asm/elf.h>
 26#include <asm/asm-offsets.h>
 
 
 27#include <asm/os_info.h>
 
 
 
 
 28
 29typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
 
 30
 31extern const unsigned char relocate_kernel[];
 32extern const unsigned long long relocate_kernel_len;
 33
 34#ifdef CONFIG_CRASH_DUMP
 35
 36/*
 37 * Create ELF notes for one CPU
 
 38 */
 39static void add_elf_notes(int cpu)
 40{
 41	struct save_area *sa = (void *) 4608 + store_prefix();
 42	void *ptr;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 43
 44	memcpy((void *) (4608UL + sa->pref_reg), sa, sizeof(*sa));
 45	ptr = (u64 *) per_cpu_ptr(crash_notes, cpu);
 46	ptr = fill_cpu_elf_notes(ptr, sa);
 47	memset(ptr, 0, sizeof(struct elf_note));
 48}
 49
 50/*
 51 * Initialize CPU ELF notes
 
 52 */
 53static void setup_regs(void)
 54{
 55	unsigned long sa = S390_lowcore.prefixreg_save_area + SAVE_AREA_BASE;
 56	int cpu, this_cpu;
 
 57
 
 
 58	this_cpu = smp_find_processor_id(stap());
 59	add_elf_notes(this_cpu);
 60	for_each_online_cpu(cpu) {
 61		if (cpu == this_cpu)
 62			continue;
 63		if (smp_store_status(cpu))
 64			continue;
 65		add_elf_notes(cpu);
 66	}
 67	/* Copy dump CPU store status info to absolute zero */
 68	memcpy((void *) SAVE_AREA_BASE, (void *) sa, sizeof(struct save_area));
 69}
 70
 71/*
 72 * PM notifier callback for kdump
 73 */
 74static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
 75			       void *ptr)
 76{
 77	switch (action) {
 78	case PM_SUSPEND_PREPARE:
 79	case PM_HIBERNATION_PREPARE:
 80		if (crashk_res.start)
 81			crash_map_reserved_pages();
 82		break;
 83	case PM_POST_SUSPEND:
 84	case PM_POST_HIBERNATION:
 85		if (crashk_res.start)
 86			crash_unmap_reserved_pages();
 87		break;
 88	default:
 89		return NOTIFY_DONE;
 90	}
 91	return NOTIFY_OK;
 
 
 
 
 
 
 
 
 
 92}
 93
 94static int __init machine_kdump_pm_init(void)
 95{
 96	pm_notifier(machine_kdump_pm_cb, 0);
 97	return 0;
 98}
 99arch_initcall(machine_kdump_pm_init);
100#endif
101
102/*
103 * Start kdump: We expect here that a store status has been done on our CPU
104 */
105static void __do_machine_kdump(void *image)
106{
107#ifdef CONFIG_CRASH_DUMP
108	int (*start_kdump)(int) = (void *)((struct kimage *) image)->start;
 
109
110	setup_regs();
111	__load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
112	start_kdump(1);
 
113#endif
114}
115
116/*
117 * Check if kdump checksums are valid: We call purgatory with parameter "0"
118 */
119static int kdump_csum_valid(struct kimage *image)
120{
121#ifdef CONFIG_CRASH_DUMP
122	int (*start_kdump)(int) = (void *)image->start;
123	int rc;
124
125	__arch_local_irq_stnsm(0xfb); /* disable DAT */
126	rc = start_kdump(0);
127	__arch_local_irq_stosm(0x04); /* enable DAT */
128	return rc ? 0 : -EINVAL;
129#else
130	return -EINVAL;
131#endif
132}
133
134/*
135 * Map or unmap crashkernel memory
136 */
137static void crash_map_pages(int enable)
138{
139	unsigned long size = resource_size(&crashk_res);
140
141	BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN ||
142	       size % KEXEC_CRASH_MEM_ALIGN);
143	if (enable)
144		vmem_add_mapping(crashk_res.start, size);
145	else {
146		vmem_remove_mapping(crashk_res.start, size);
147		if (size)
148			os_info_crashkernel_add(crashk_res.start, size);
149		else
150			os_info_crashkernel_add(0, 0);
151	}
152}
153
154/*
155 * Map crashkernel memory
156 */
157void crash_map_reserved_pages(void)
158{
159	crash_map_pages(1);
160}
161
162/*
163 * Unmap crashkernel memory
164 */
165void crash_unmap_reserved_pages(void)
166{
167	crash_map_pages(0);
168}
169
 
 
170/*
171 * Give back memory to hypervisor before new kdump is loaded
172 */
173static int machine_kexec_prepare_kdump(void)
174{
175#ifdef CONFIG_CRASH_DUMP
176	if (MACHINE_IS_VM)
177		diag10_range(PFN_DOWN(crashk_res.start),
178			     PFN_DOWN(crashk_res.end - crashk_res.start + 1));
179	return 0;
180#else
181	return -EINVAL;
182#endif
183}
184
185int machine_kexec_prepare(struct kimage *image)
186{
187	void *reboot_code_buffer;
188
189	/* Can't replace kernel image since it is read-only. */
190	if (ipl_flags & IPL_NSS_VALID)
191		return -EOPNOTSUPP;
192
193	if (image->type == KEXEC_TYPE_CRASH)
194		return machine_kexec_prepare_kdump();
195
196	/* We don't support anything but the default image type for now. */
197	if (image->type != KEXEC_TYPE_DEFAULT)
198		return -EINVAL;
199
200	/* Get the destination where the assembler code should be copied to.*/
201	reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
202
203	/* Then copy it */
204	memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
205	return 0;
206}
207
208void machine_kexec_cleanup(struct kimage *image)
209{
210}
211
212void arch_crash_save_vmcoreinfo(void)
213{
214	VMCOREINFO_SYMBOL(lowcore_ptr);
215	VMCOREINFO_SYMBOL(high_memory);
216	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
217}
218
219void machine_shutdown(void)
220{
221}
222
223void machine_crash_shutdown(struct pt_regs *regs)
224{
 
225}
226
227/*
228 * Do normal kexec
229 */
230static void __do_machine_kexec(void *data)
231{
232	relocate_kernel_t data_mover;
233	struct kimage *image = data;
234
235	data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
 
 
 
 
 
 
 
 
 
 
236
237	/* Call the moving routine */
238	(*data_mover)(&image->head, image->start);
239}
240
241/*
242 * Reset system and call either kdump or normal kexec
243 */
244static void __machine_kexec(void *data)
245{
246	struct kimage *image = data;
247
248	__arch_local_irq_stosm(0x04); /* enable DAT */
249	pfault_fini();
250	tracing_off();
251	debug_locks_off();
252	if (image->type == KEXEC_TYPE_CRASH) {
253		lgr_info_log();
254		s390_reset_system(__do_machine_kdump, data);
255	} else {
256		s390_reset_system(__do_machine_kexec, data);
257	}
258	disabled_wait((unsigned long) __builtin_return_address(0));
259}
260
261/*
262 * Do either kdump or normal kexec. In case of kdump we first ask
263 * purgatory, if kdump checksums are valid.
264 */
265void machine_kexec(struct kimage *image)
266{
267	if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
268		return;
269	tracer_disable();
270	smp_send_stop();
271	smp_call_ipl_cpu(__machine_kexec, image);
272}