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// 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}