1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright IBM Corp. 2005, 2011
5 * Author(s): Rolf Adelsberger,
6 * Michael Holzheu <holzheu@linux.vnet.ibm.com>
9 #include <linux/device.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>
17 #include <asm/setup.h>
22 #include <asm/asm-offsets.h>
23 #include <asm/cacheflush.h>
24 #include <asm/abs_lowcore.h>
25 #include <asm/os_info.h>
26 #include <asm/set_memory.h>
27 #include <asm/stacktrace.h>
28 #include <asm/switch_to.h>
32 typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long,
35 extern const unsigned char relocate_kernel[];
36 extern const unsigned long long relocate_kernel_len;
38 #ifdef CONFIG_CRASH_DUMP
41 * Reset the system, copy boot CPU registers to absolute zero,
42 * and jump to the kdump image
44 static void __do_machine_kdump(void *image)
46 int (*start_kdump)(int);
49 /* store_status() saved the prefix register to lowcore */
50 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
52 /* Now do the reset */
56 * Copy dump CPU store status info to absolute zero.
57 * This need to be done *after* s390_reset_system set the
58 * prefix register of this CPU to zero
60 memcpy(absolute_pointer(__LC_FPREGS_SAVE_AREA),
61 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
63 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
64 start_kdump = (void *)((struct kimage *) image)->start;
67 /* Die if start_kdump returns */
72 * Start kdump: create a LGR log entry, store status of all CPUs and
73 * branch to __do_machine_kdump.
75 static noinline void __machine_kdump(void *image)
78 union ctlreg2 cr2_old, cr2_new;
82 /* Get status of the other CPUs */
83 this_cpu = smp_find_processor_id(stap());
84 for_each_online_cpu(cpu) {
87 if (smp_store_status(cpu))
90 /* Store status of the boot CPU */
91 mcesa = __va(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
93 save_vx_regs((__vector128 *) mcesa->vector_save_area);
95 __ctl_store(cr2_old.val, 2, 2);
98 __ctl_load(cr2_new.val, 2, 2);
99 save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
100 __ctl_load(cr2_old.val, 2, 2);
103 * To create a good backchain for this CPU in the dump store_status
104 * is passed the address of a function. The address is saved into
105 * the PSW save area of the boot CPU and the function is invoked as
106 * a tail call of store_status. The backchain in the dump will look
108 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
109 * The call to store_status() will not return.
111 store_status(__do_machine_kdump, image);
114 static unsigned long do_start_kdump(unsigned long addr)
116 struct kimage *image = (struct kimage *) addr;
117 int (*start_kdump)(int) = (void *)image->start;
120 __arch_local_irq_stnsm(0xfb); /* disable DAT */
122 __arch_local_irq_stosm(0x04); /* enable DAT */
126 #endif /* CONFIG_CRASH_DUMP */
129 * Check if kdump checksums are valid: We call purgatory with parameter "0"
131 static bool kdump_csum_valid(struct kimage *image)
133 #ifdef CONFIG_CRASH_DUMP
137 rc = call_on_stack(1, S390_lowcore.nodat_stack, unsigned long, do_start_kdump,
138 unsigned long, (unsigned long)image);
146 #ifdef CONFIG_CRASH_DUMP
148 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
150 unsigned long addr, size;
152 for (addr = begin; addr < end; addr += PAGE_SIZE)
153 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
154 size = begin - crashk_res.start;
156 os_info_crashkernel_add(crashk_res.start, size);
158 os_info_crashkernel_add(0, 0);
161 static void crash_protect_pages(int protect)
167 size = resource_size(&crashk_res);
169 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
171 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
174 void arch_kexec_protect_crashkres(void)
176 crash_protect_pages(1);
179 void arch_kexec_unprotect_crashkres(void)
181 crash_protect_pages(0);
187 * Give back memory to hypervisor before new kdump is loaded
189 static int machine_kexec_prepare_kdump(void)
191 #ifdef CONFIG_CRASH_DUMP
193 diag10_range(PFN_DOWN(crashk_res.start),
194 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
201 int machine_kexec_prepare(struct kimage *image)
203 void *reboot_code_buffer;
205 if (image->type == KEXEC_TYPE_CRASH)
206 return machine_kexec_prepare_kdump();
208 /* We don't support anything but the default image type for now. */
209 if (image->type != KEXEC_TYPE_DEFAULT)
212 /* Get the destination where the assembler code should be copied to.*/
213 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
216 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
220 void machine_kexec_cleanup(struct kimage *image)
224 void arch_crash_save_vmcoreinfo(void)
226 struct lowcore *abs_lc;
229 VMCOREINFO_SYMBOL(lowcore_ptr);
230 VMCOREINFO_SYMBOL(high_memory);
231 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
232 vmcoreinfo_append_str("SAMODE31=%lx\n", __samode31);
233 vmcoreinfo_append_str("EAMODE31=%lx\n", __eamode31);
234 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
235 abs_lc = get_abs_lowcore(&flags);
236 abs_lc->vmcore_info = paddr_vmcoreinfo_note();
237 put_abs_lowcore(abs_lc, flags);
240 void machine_shutdown(void)
244 void machine_crash_shutdown(struct pt_regs *regs)
246 set_os_info_reipl_block();
252 static void __do_machine_kexec(void *data)
254 unsigned long diag308_subcode;
255 relocate_kernel_t data_mover;
256 struct kimage *image = data;
259 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
261 __arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
262 /* Call the moving routine */
263 diag308_subcode = DIAG308_CLEAR_RESET;
265 diag308_subcode |= DIAG308_FLAG_EI;
266 (*data_mover)(&image->head, image->start, diag308_subcode);
268 /* Die if kexec returns */
273 * Reset system and call either kdump or normal kexec
275 static void __machine_kexec(void *data)
280 #ifdef CONFIG_CRASH_DUMP
281 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
282 __machine_kdump(data);
284 __do_machine_kexec(data);
288 * Do either kdump or normal kexec. In case of kdump we first ask
289 * purgatory, if kdump checksums are valid.
291 void machine_kexec(struct kimage *image)
293 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
297 smp_call_ipl_cpu(__machine_kexec, image);