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/cacheflush.h>
 28#include <asm/os_info.h>
 
 
 29#include <asm/switch_to.h>
 
 30
 31typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
 32
 33extern const unsigned char relocate_kernel[];
 34extern const unsigned long long relocate_kernel_len;
 35
 36#ifdef CONFIG_CRASH_DUMP
 37
 38/*
 39 * PM notifier callback for kdump
 40 */
 41static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
 42			       void *ptr)
 43{
 44	switch (action) {
 45	case PM_SUSPEND_PREPARE:
 46	case PM_HIBERNATION_PREPARE:
 47		if (kexec_crash_image)
 48			arch_kexec_unprotect_crashkres();
 49		break;
 50	case PM_POST_SUSPEND:
 51	case PM_POST_HIBERNATION:
 52		if (kexec_crash_image)
 53			arch_kexec_protect_crashkres();
 54		break;
 55	default:
 56		return NOTIFY_DONE;
 57	}
 58	return NOTIFY_OK;
 59}
 60
 61static int __init machine_kdump_pm_init(void)
 62{
 63	pm_notifier(machine_kdump_pm_cb, 0);
 64	return 0;
 65}
 66arch_initcall(machine_kdump_pm_init);
 67
 68/*
 69 * Reset the system, copy boot CPU registers to absolute zero,
 70 * and jump to the kdump image
 71 */
 72static void __do_machine_kdump(void *image)
 73{
 74	int (*start_kdump)(int);
 75	unsigned long prefix;
 76
 77	/* store_status() saved the prefix register to lowcore */
 78	prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
 79
 80	/* Now do the reset  */
 81	s390_reset_system();
 82
 83	/*
 84	 * Copy dump CPU store status info to absolute zero.
 85	 * This need to be done *after* s390_reset_system set the
 86	 * prefix register of this CPU to zero
 87	 */
 88	memcpy((void *) __LC_FPREGS_SAVE_AREA,
 89	       (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
 90
 91	__load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
 92	start_kdump = (void *)((struct kimage *) image)->start;
 93	start_kdump(1);
 94
 95	/* Die if start_kdump returns */
 96	disabled_wait((unsigned long) __builtin_return_address(0));
 97}
 98
 99/*
100 * Start kdump: create a LGR log entry, store status of all CPUs and
101 * branch to __do_machine_kdump.
102 */
103static noinline void __machine_kdump(void *image)
104{
 
 
105	int this_cpu, cpu;
106
107	lgr_info_log();
108	/* Get status of the other CPUs */
109	this_cpu = smp_find_processor_id(stap());
110	for_each_online_cpu(cpu) {
111		if (cpu == this_cpu)
112			continue;
113		if (smp_store_status(cpu))
114			continue;
115	}
116	/* Store status of the boot CPU */
 
117	if (MACHINE_HAS_VX)
118		save_vx_regs((void *) &S390_lowcore.vector_save_area);
 
 
 
 
 
 
 
 
119	/*
120	 * To create a good backchain for this CPU in the dump store_status
121	 * is passed the address of a function. The address is saved into
122	 * the PSW save area of the boot CPU and the function is invoked as
123	 * a tail call of store_status. The backchain in the dump will look
124	 * like this:
125	 *   restart_int_handler ->  __machine_kexec -> __do_machine_kdump
126	 * The call to store_status() will not return.
127	 */
128	store_status(__do_machine_kdump, image);
129}
130#endif
131
132/*
133 * Check if kdump checksums are valid: We call purgatory with parameter "0"
134 */
135static int kdump_csum_valid(struct kimage *image)
136{
137#ifdef CONFIG_CRASH_DUMP
138	int (*start_kdump)(int) = (void *)image->start;
139	int rc;
140
141	__arch_local_irq_stnsm(0xfb); /* disable DAT */
142	rc = start_kdump(0);
143	__arch_local_irq_stosm(0x04); /* enable DAT */
144	return rc ? 0 : -EINVAL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
145#else
146	return -EINVAL;
147#endif
148}
149
150#ifdef CONFIG_CRASH_DUMP
151
152void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
153{
154	unsigned long addr, size;
155
156	for (addr = begin; addr < end; addr += PAGE_SIZE)
157		free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
158	size = begin - crashk_res.start;
159	if (size)
160		os_info_crashkernel_add(crashk_res.start, size);
161	else
162		os_info_crashkernel_add(0, 0);
163}
164
165static void crash_protect_pages(int protect)
166{
167	unsigned long size;
168
169	if (!crashk_res.end)
170		return;
171	size = resource_size(&crashk_res);
172	if (protect)
173		set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
174	else
175		set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
176}
177
178void arch_kexec_protect_crashkres(void)
179{
180	crash_protect_pages(1);
181}
182
183void arch_kexec_unprotect_crashkres(void)
184{
185	crash_protect_pages(0);
186}
187
188#endif
189
190/*
191 * Give back memory to hypervisor before new kdump is loaded
192 */
193static int machine_kexec_prepare_kdump(void)
194{
195#ifdef CONFIG_CRASH_DUMP
196	if (MACHINE_IS_VM)
197		diag10_range(PFN_DOWN(crashk_res.start),
198			     PFN_DOWN(crashk_res.end - crashk_res.start + 1));
199	return 0;
200#else
201	return -EINVAL;
202#endif
203}
204
205int machine_kexec_prepare(struct kimage *image)
206{
207	void *reboot_code_buffer;
208
209	/* Can't replace kernel image since it is read-only. */
210	if (ipl_flags & IPL_NSS_VALID)
211		return -EOPNOTSUPP;
212
213	if (image->type == KEXEC_TYPE_CRASH)
214		return machine_kexec_prepare_kdump();
215
216	/* We don't support anything but the default image type for now. */
217	if (image->type != KEXEC_TYPE_DEFAULT)
218		return -EINVAL;
219
220	/* Get the destination where the assembler code should be copied to.*/
221	reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
222
223	/* Then copy it */
224	memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
225	return 0;
226}
227
228void machine_kexec_cleanup(struct kimage *image)
229{
230}
231
232void arch_crash_save_vmcoreinfo(void)
233{
234	VMCOREINFO_SYMBOL(lowcore_ptr);
235	VMCOREINFO_SYMBOL(high_memory);
236	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
 
 
 
 
237}
238
239void machine_shutdown(void)
240{
241}
242
243void machine_crash_shutdown(struct pt_regs *regs)
244{
 
245}
246
247/*
248 * Do normal kexec
249 */
250static void __do_machine_kexec(void *data)
251{
252	relocate_kernel_t data_mover;
253	struct kimage *image = data;
254
255	s390_reset_system();
256	data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
257
 
258	/* Call the moving routine */
259	(*data_mover)(&image->head, image->start);
260
261	/* Die if kexec returns */
262	disabled_wait((unsigned long) __builtin_return_address(0));
263}
264
265/*
266 * Reset system and call either kdump or normal kexec
267 */
268static void __machine_kexec(void *data)
269{
270	__arch_local_irq_stosm(0x04); /* enable DAT */
271	pfault_fini();
272	tracing_off();
273	debug_locks_off();
274#ifdef CONFIG_CRASH_DUMP
275	if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
276		__machine_kdump(data);
277#endif
278	__do_machine_kexec(data);
279}
280
281/*
282 * Do either kdump or normal kexec. In case of kdump we first ask
283 * purgatory, if kdump checksums are valid.
284 */
285void machine_kexec(struct kimage *image)
286{
287	if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
288		return;
289	tracer_disable();
290	smp_send_stop();
291	smp_call_ipl_cpu(__machine_kexec, image);
292}

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright IBM Corp. 2005, 2011
  4 *
  5 * Author(s): Rolf Adelsberger,
  6 *	      Heiko Carstens <heiko.carstens@de.ibm.com>
  7 *	      Michael Holzheu <holzheu@linux.vnet.ibm.com>
  8 */
  9
 10#include <linux/device.h>
 11#include <linux/mm.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 <asm/cio.h>
 18#include <asm/setup.h>
 
 
 19#include <asm/smp.h>
 
 20#include <asm/ipl.h>
 21#include <asm/diag.h>
 22#include <asm/elf.h>
 23#include <asm/asm-offsets.h>
 24#include <asm/cacheflush.h>
 25#include <asm/os_info.h>
 26#include <asm/set_memory.h>
 27#include <asm/stacktrace.h>
 28#include <asm/switch_to.h>
 29#include <asm/nmi.h>
 30
 31typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
 32
 33extern const unsigned char relocate_kernel[];
 34extern const unsigned long long relocate_kernel_len;
 35
 36#ifdef CONFIG_CRASH_DUMP
 37
 38/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 39 * Reset the system, copy boot CPU registers to absolute zero,
 40 * and jump to the kdump image
 41 */
 42static void __do_machine_kdump(void *image)
 43{
 44	int (*start_kdump)(int);
 45	unsigned long prefix;
 46
 47	/* store_status() saved the prefix register to lowcore */
 48	prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
 49
 50	/* Now do the reset  */
 51	s390_reset_system();
 52
 53	/*
 54	 * Copy dump CPU store status info to absolute zero.
 55	 * This need to be done *after* s390_reset_system set the
 56	 * prefix register of this CPU to zero
 57	 */
 58	memcpy((void *) __LC_FPREGS_SAVE_AREA,
 59	       (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
 60
 61	__load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
 62	start_kdump = (void *)((struct kimage *) image)->start;
 63	start_kdump(1);
 64
 65	/* Die if start_kdump returns */
 66	disabled_wait();
 67}
 68
 69/*
 70 * Start kdump: create a LGR log entry, store status of all CPUs and
 71 * branch to __do_machine_kdump.
 72 */
 73static noinline void __machine_kdump(void *image)
 74{
 75	struct mcesa *mcesa;
 76	union ctlreg2 cr2_old, cr2_new;
 77	int this_cpu, cpu;
 78
 79	lgr_info_log();
 80	/* Get status of the other CPUs */
 81	this_cpu = smp_find_processor_id(stap());
 82	for_each_online_cpu(cpu) {
 83		if (cpu == this_cpu)
 84			continue;
 85		if (smp_store_status(cpu))
 86			continue;
 87	}
 88	/* Store status of the boot CPU */
 89	mcesa = (struct mcesa *)(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
 90	if (MACHINE_HAS_VX)
 91		save_vx_regs((__vector128 *) mcesa->vector_save_area);
 92	if (MACHINE_HAS_GS) {
 93		__ctl_store(cr2_old.val, 2, 2);
 94		cr2_new = cr2_old;
 95		cr2_new.gse = 1;
 96		__ctl_load(cr2_new.val, 2, 2);
 97		save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
 98		__ctl_load(cr2_old.val, 2, 2);
 99	}
100	/*
101	 * To create a good backchain for this CPU in the dump store_status
102	 * is passed the address of a function. The address is saved into
103	 * the PSW save area of the boot CPU and the function is invoked as
104	 * a tail call of store_status. The backchain in the dump will look
105	 * like this:
106	 *   restart_int_handler ->  __machine_kexec -> __do_machine_kdump
107	 * The call to store_status() will not return.
108	 */
109	store_status(__do_machine_kdump, image);
110}
 
111
112static unsigned long do_start_kdump(unsigned long addr)
 
 
 
113{
114	struct kimage *image = (struct kimage *) addr;
115	int (*start_kdump)(int) = (void *)image->start;
116	int rc;
117
118	__arch_local_irq_stnsm(0xfb); /* disable DAT */
119	rc = start_kdump(0);
120	__arch_local_irq_stosm(0x04); /* enable DAT */
121	return rc;
122}
123
124#endif /* CONFIG_CRASH_DUMP */
125
126/*
127 * Check if kdump checksums are valid: We call purgatory with parameter "0"
128 */
129static bool kdump_csum_valid(struct kimage *image)
130{
131#ifdef CONFIG_CRASH_DUMP
132	int rc;
133
134	preempt_disable();
135	rc = call_on_stack(1, S390_lowcore.nodat_stack, unsigned long, do_start_kdump,
136			   unsigned long, (unsigned long)image);
137	preempt_enable();
138	return rc == 0;
139#else
140	return false;
141#endif
142}
143
144#ifdef CONFIG_CRASH_DUMP
145
146void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
147{
148	unsigned long addr, size;
149
150	for (addr = begin; addr < end; addr += PAGE_SIZE)
151		free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
152	size = begin - crashk_res.start;
153	if (size)
154		os_info_crashkernel_add(crashk_res.start, size);
155	else
156		os_info_crashkernel_add(0, 0);
157}
158
159static void crash_protect_pages(int protect)
160{
161	unsigned long size;
162
163	if (!crashk_res.end)
164		return;
165	size = resource_size(&crashk_res);
166	if (protect)
167		set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
168	else
169		set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
170}
171
172void arch_kexec_protect_crashkres(void)
173{
174	crash_protect_pages(1);
175}
176
177void arch_kexec_unprotect_crashkres(void)
178{
179	crash_protect_pages(0);
180}
181
182#endif
183
184/*
185 * Give back memory to hypervisor before new kdump is loaded
186 */
187static int machine_kexec_prepare_kdump(void)
188{
189#ifdef CONFIG_CRASH_DUMP
190	if (MACHINE_IS_VM)
191		diag10_range(PFN_DOWN(crashk_res.start),
192			     PFN_DOWN(crashk_res.end - crashk_res.start + 1));
193	return 0;
194#else
195	return -EINVAL;
196#endif
197}
198
199int machine_kexec_prepare(struct kimage *image)
200{
201	void *reboot_code_buffer;
202
 
 
 
 
203	if (image->type == KEXEC_TYPE_CRASH)
204		return machine_kexec_prepare_kdump();
205
206	/* We don't support anything but the default image type for now. */
207	if (image->type != KEXEC_TYPE_DEFAULT)
208		return -EINVAL;
209
210	/* Get the destination where the assembler code should be copied to.*/
211	reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
212
213	/* Then copy it */
214	memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
215	return 0;
216}
217
218void machine_kexec_cleanup(struct kimage *image)
219{
220}
221
222void arch_crash_save_vmcoreinfo(void)
223{
224	VMCOREINFO_SYMBOL(lowcore_ptr);
225	VMCOREINFO_SYMBOL(high_memory);
226	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
227	vmcoreinfo_append_str("SDMA=%lx\n", __sdma);
228	vmcoreinfo_append_str("EDMA=%lx\n", __edma);
229	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
230	mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
231}
232
233void machine_shutdown(void)
234{
235}
236
237void machine_crash_shutdown(struct pt_regs *regs)
238{
239	set_os_info_reipl_block();
240}
241
242/*
243 * Do normal kexec
244 */
245static void __do_machine_kexec(void *data)
246{
247	relocate_kernel_t data_mover;
248	struct kimage *image = data;
249
250	s390_reset_system();
251	data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
252
253	__arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
254	/* Call the moving routine */
255	(*data_mover)(&image->head, image->start);
256
257	/* Die if kexec returns */
258	disabled_wait();
259}
260
261/*
262 * Reset system and call either kdump or normal kexec
263 */
264static void __machine_kexec(void *data)
265{
 
266	pfault_fini();
267	tracing_off();
268	debug_locks_off();
269#ifdef CONFIG_CRASH_DUMP
270	if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
271		__machine_kdump(data);
272#endif
273	__do_machine_kexec(data);
274}
275
276/*
277 * Do either kdump or normal kexec. In case of kdump we first ask
278 * purgatory, if kdump checksums are valid.
279 */
280void machine_kexec(struct kimage *image)
281{
282	if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
283		return;
284	tracer_disable();
285	smp_send_stop();
286	smp_call_ipl_cpu(__machine_kexec, image);
287}