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/pfault.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/abs_lowcore.h>
 26#include <asm/os_info.h>
 27#include <asm/set_memory.h>
 28#include <asm/stacktrace.h>
 29#include <asm/switch_to.h>
 30#include <asm/nmi.h>
 31#include <asm/sclp.h>
 32
 33typedef void (*relocate_kernel_t)(unsigned long, unsigned long, unsigned long);
 34typedef int (*purgatory_t)(int);
 35
 36extern const unsigned char relocate_kernel[];
 37extern const unsigned long long relocate_kernel_len;
 38
 39#ifdef CONFIG_CRASH_DUMP
 40
 41/*
 42 * Reset the system, copy boot CPU registers to absolute zero,
 43 * and jump to the kdump image
 44 */
 45static void __do_machine_kdump(void *data)
 46{
 47	struct kimage *image = data;
 48	purgatory_t purgatory;
 49	unsigned long prefix;
 50
 51	purgatory = (purgatory_t)image->start;
 52
 53	/* store_status() saved the prefix register to lowcore */
 54	prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
 55
 56	/* Now do the reset  */
 57	s390_reset_system();
 58
 59	/*
 60	 * Copy dump CPU store status info to absolute zero.
 61	 * This need to be done *after* s390_reset_system set the
 62	 * prefix register of this CPU to zero
 63	 */
 64	memcpy(absolute_pointer(__LC_FPREGS_SAVE_AREA),
 65	       phys_to_virt(prefix + __LC_FPREGS_SAVE_AREA), 512);
 66
 67	call_nodat(1, int, purgatory, int, 1);
 
 
 68
 69	/* Die if kdump returns */
 70	disabled_wait();
 71}
 72
 73/*
 74 * Start kdump: create a LGR log entry, store status of all CPUs and
 75 * branch to __do_machine_kdump.
 76 */
 77static noinline void __machine_kdump(void *image)
 78{
 79	struct mcesa *mcesa;
 80	union ctlreg2 cr2_old, cr2_new;
 81	int this_cpu, cpu;
 82
 83	lgr_info_log();
 84	/* Get status of the other CPUs */
 85	this_cpu = smp_find_processor_id(stap());
 86	for_each_online_cpu(cpu) {
 87		if (cpu == this_cpu)
 88			continue;
 89		if (smp_store_status(cpu))
 90			continue;
 91	}
 92	/* Store status of the boot CPU */
 93	mcesa = __va(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
 94	if (cpu_has_vx())
 95		save_vx_regs((__vector128 *) mcesa->vector_save_area);
 96	if (MACHINE_HAS_GS) {
 97		local_ctl_store(2, &cr2_old.reg);
 98		cr2_new = cr2_old;
 99		cr2_new.gse = 1;
100		local_ctl_load(2, &cr2_new.reg);
101		save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
102		local_ctl_load(2, &cr2_old.reg);
103	}
104	/*
105	 * To create a good backchain for this CPU in the dump store_status
106	 * is passed the address of a function. The address is saved into
107	 * the PSW save area of the boot CPU and the function is invoked as
108	 * a tail call of store_status. The backchain in the dump will look
109	 * like this:
110	 *   restart_int_handler ->  __machine_kexec -> __do_machine_kdump
111	 * The call to store_status() will not return.
112	 */
113	store_status(__do_machine_kdump, image);
114}
115
 
 
 
 
 
 
 
 
 
 
 
 
116#endif /* CONFIG_CRASH_DUMP */
117
118/*
119 * Check if kdump checksums are valid: We call purgatory with parameter "0"
120 */
121static bool kdump_csum_valid(struct kimage *image)
122{
123#ifdef CONFIG_CRASH_DUMP
124	purgatory_t purgatory = (purgatory_t)image->start;
125	int rc;
126
127	rc = call_nodat(1, int, purgatory, int, 0);
 
 
128	return rc == 0;
129#else
130	return false;
131#endif
132}
133
134#ifdef CONFIG_CRASH_DUMP
135
136void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
137{
138	unsigned long addr, size;
139
140	for (addr = begin; addr < end; addr += PAGE_SIZE)
141		free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
142	size = begin - crashk_res.start;
143	if (size)
144		os_info_crashkernel_add(crashk_res.start, size);
145	else
146		os_info_crashkernel_add(0, 0);
147}
148
149static void crash_protect_pages(int protect)
150{
151	unsigned long size;
152
153	if (!crashk_res.end)
154		return;
155	size = resource_size(&crashk_res);
156	if (protect)
157		set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
158	else
159		set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
160}
161
162void arch_kexec_protect_crashkres(void)
163{
164	crash_protect_pages(1);
165}
166
167void arch_kexec_unprotect_crashkres(void)
168{
169	crash_protect_pages(0);
170}
171
172#endif
173
174/*
175 * Give back memory to hypervisor before new kdump is loaded
176 */
177static int machine_kexec_prepare_kdump(void)
178{
179#ifdef CONFIG_CRASH_DUMP
180	if (MACHINE_IS_VM)
181		diag10_range(PFN_DOWN(crashk_res.start),
182			     PFN_DOWN(crashk_res.end - crashk_res.start + 1));
183	return 0;
184#else
185	return -EINVAL;
186#endif
187}
188
189int machine_kexec_prepare(struct kimage *image)
190{
191	void *reboot_code_buffer;
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 = page_to_virt(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	struct lowcore *abs_lc;
215
216	VMCOREINFO_SYMBOL(lowcore_ptr);
217	VMCOREINFO_SYMBOL(high_memory);
218	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
219	vmcoreinfo_append_str("SAMODE31=%lx\n", (unsigned long)__samode31);
220	vmcoreinfo_append_str("EAMODE31=%lx\n", (unsigned long)__eamode31);
221	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
222	abs_lc = get_abs_lowcore();
223	abs_lc->vmcore_info = paddr_vmcoreinfo_note();
224	put_abs_lowcore(abs_lc);
225}
226
227void machine_shutdown(void)
228{
229}
230
231void machine_crash_shutdown(struct pt_regs *regs)
232{
233	set_os_info_reipl_block();
234}
235
236/*
237 * Do normal kexec
238 */
239static void __do_machine_kexec(void *data)
240{
241	unsigned long data_mover, entry, diag308_subcode;
242	struct kimage *image = data;
243
244	data_mover = page_to_phys(image->control_code_page);
245	entry = virt_to_phys(&image->head);
246	diag308_subcode = DIAG308_CLEAR_RESET;
247	if (sclp.has_iplcc)
248		diag308_subcode |= DIAG308_FLAG_EI;
249	s390_reset_system();
 
250
251	call_nodat(3, void, (relocate_kernel_t)data_mover,
252		   unsigned long, entry,
253		   unsigned long, image->start,
254		   unsigned long, diag308_subcode);
255
256	/* Die if kexec returns */
257	disabled_wait();
258}
259
260/*
261 * Reset system and call either kdump or normal kexec
262 */
263static void __machine_kexec(void *data)
264{
 
265	pfault_fini();
266	tracing_off();
267	debug_locks_off();
268#ifdef CONFIG_CRASH_DUMP
269	if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
270		__machine_kdump(data);
271#endif
272	__do_machine_kexec(data);
273}
274
275/*
276 * Do either kdump or normal kexec. In case of kdump we first ask
277 * purgatory, if kdump checksums are valid.
278 */
279void machine_kexec(struct kimage *image)
280{
281	if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
282		return;
283	tracer_disable();
284	smp_send_stop();
285	smp_call_ipl_cpu(__machine_kexec, image);
286}

  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(do_start_kdump, S390_lowcore.nodat_stack, 1, image);
136	preempt_enable();
137	return rc == 0;
138#else
139	return false;
140#endif
141}
142
143#ifdef CONFIG_CRASH_DUMP
144
145void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
146{
147	unsigned long addr, size;
148
149	for (addr = begin; addr < end; addr += PAGE_SIZE)
150		free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
151	size = begin - crashk_res.start;
152	if (size)
153		os_info_crashkernel_add(crashk_res.start, size);
154	else
155		os_info_crashkernel_add(0, 0);
156}
157
158static void crash_protect_pages(int protect)
159{
160	unsigned long size;
161
162	if (!crashk_res.end)
163		return;
164	size = resource_size(&crashk_res);
165	if (protect)
166		set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
167	else
168		set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
169}
170
171void arch_kexec_protect_crashkres(void)
172{
173	crash_protect_pages(1);
174}
175
176void arch_kexec_unprotect_crashkres(void)
177{
178	crash_protect_pages(0);
179}
180
181#endif
182
183/*
184 * Give back memory to hypervisor before new kdump is loaded
185 */
186static int machine_kexec_prepare_kdump(void)
187{
188#ifdef CONFIG_CRASH_DUMP
189	if (MACHINE_IS_VM)
190		diag10_range(PFN_DOWN(crashk_res.start),
191			     PFN_DOWN(crashk_res.end - crashk_res.start + 1));
192	return 0;
193#else
194	return -EINVAL;
195#endif
196}
197
198int machine_kexec_prepare(struct kimage *image)
199{
200	void *reboot_code_buffer;
201
202	if (image->type == KEXEC_TYPE_CRASH)
203		return machine_kexec_prepare_kdump();
204
205	/* We don't support anything but the default image type for now. */
206	if (image->type != KEXEC_TYPE_DEFAULT)
207		return -EINVAL;
208
209	/* Get the destination where the assembler code should be copied to.*/
210	reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
211
212	/* Then copy it */
213	memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
214	return 0;
215}
216
217void machine_kexec_cleanup(struct kimage *image)
218{
219}
220
221void arch_crash_save_vmcoreinfo(void)
222{
 
 
223	VMCOREINFO_SYMBOL(lowcore_ptr);
224	VMCOREINFO_SYMBOL(high_memory);
225	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
226	vmcoreinfo_append_str("SDMA=%lx\n", __sdma);
227	vmcoreinfo_append_str("EDMA=%lx\n", __edma);
228	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
229	mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
 
 
230}
231
232void machine_shutdown(void)
233{
234}
235
236void machine_crash_shutdown(struct pt_regs *regs)
237{
238	set_os_info_reipl_block();
239}
240
241/*
242 * Do normal kexec
243 */
244static void __do_machine_kexec(void *data)
245{
246	relocate_kernel_t data_mover;
247	struct kimage *image = data;
248
 
 
 
 
 
249	s390_reset_system();
250	data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
251
252	__arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
253	/* Call the moving routine */
254	(*data_mover)(&image->head, image->start);
 
255
256	/* Die if kexec returns */
257	disabled_wait();
258}
259
260/*
261 * Reset system and call either kdump or normal kexec
262 */
263static void __machine_kexec(void *data)
264{
265	__arch_local_irq_stosm(0x04); /* enable DAT */
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}