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/os_info.h>
25 #include <asm/set_memory.h>
26 #include <asm/stacktrace.h>
27 #include <asm/switch_to.h>
31 typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long,
34 extern const unsigned char relocate_kernel[];
35 extern const unsigned long long relocate_kernel_len;
37 #ifdef CONFIG_CRASH_DUMP
40 * Reset the system, copy boot CPU registers to absolute zero,
41 * and jump to the kdump image
43 static void __do_machine_kdump(void *image)
45 int (*start_kdump)(int);
48 /* store_status() saved the prefix register to lowcore */
49 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
51 /* Now do the reset */
55 * Copy dump CPU store status info to absolute zero.
56 * This need to be done *after* s390_reset_system set the
57 * prefix register of this CPU to zero
59 memcpy(absolute_pointer(__LC_FPREGS_SAVE_AREA),
60 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
62 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
63 start_kdump = (void *)((struct kimage *) image)->start;
66 /* Die if start_kdump returns */
71 * Start kdump: create a LGR log entry, store status of all CPUs and
72 * branch to __do_machine_kdump.
74 static noinline void __machine_kdump(void *image)
77 union ctlreg2 cr2_old, cr2_new;
81 /* Get status of the other CPUs */
82 this_cpu = smp_find_processor_id(stap());
83 for_each_online_cpu(cpu) {
86 if (smp_store_status(cpu))
89 /* Store status of the boot CPU */
90 mcesa = __va(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
92 save_vx_regs((__vector128 *) mcesa->vector_save_area);
94 __ctl_store(cr2_old.val, 2, 2);
97 __ctl_load(cr2_new.val, 2, 2);
98 save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
99 __ctl_load(cr2_old.val, 2, 2);
102 * To create a good backchain for this CPU in the dump store_status
103 * is passed the address of a function. The address is saved into
104 * the PSW save area of the boot CPU and the function is invoked as
105 * a tail call of store_status. The backchain in the dump will look
107 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
108 * The call to store_status() will not return.
110 store_status(__do_machine_kdump, image);
113 static unsigned long do_start_kdump(unsigned long addr)
115 struct kimage *image = (struct kimage *) addr;
116 int (*start_kdump)(int) = (void *)image->start;
119 __arch_local_irq_stnsm(0xfb); /* disable DAT */
121 __arch_local_irq_stosm(0x04); /* enable DAT */
125 #endif /* CONFIG_CRASH_DUMP */
128 * Check if kdump checksums are valid: We call purgatory with parameter "0"
130 static bool kdump_csum_valid(struct kimage *image)
132 #ifdef CONFIG_CRASH_DUMP
136 rc = call_on_stack(1, S390_lowcore.nodat_stack, unsigned long, do_start_kdump,
137 unsigned long, (unsigned long)image);
145 #ifdef CONFIG_CRASH_DUMP
147 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
149 unsigned long addr, size;
151 for (addr = begin; addr < end; addr += PAGE_SIZE)
152 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
153 size = begin - crashk_res.start;
155 os_info_crashkernel_add(crashk_res.start, size);
157 os_info_crashkernel_add(0, 0);
160 static void crash_protect_pages(int protect)
166 size = resource_size(&crashk_res);
168 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
170 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
173 void arch_kexec_protect_crashkres(void)
175 crash_protect_pages(1);
178 void arch_kexec_unprotect_crashkres(void)
180 crash_protect_pages(0);
186 * Give back memory to hypervisor before new kdump is loaded
188 static int machine_kexec_prepare_kdump(void)
190 #ifdef CONFIG_CRASH_DUMP
192 diag10_range(PFN_DOWN(crashk_res.start),
193 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
200 int machine_kexec_prepare(struct kimage *image)
202 void *reboot_code_buffer;
204 if (image->type == KEXEC_TYPE_CRASH)
205 return machine_kexec_prepare_kdump();
207 /* We don't support anything but the default image type for now. */
208 if (image->type != KEXEC_TYPE_DEFAULT)
211 /* Get the destination where the assembler code should be copied to.*/
212 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
215 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
219 void machine_kexec_cleanup(struct kimage *image)
223 void arch_crash_save_vmcoreinfo(void)
225 VMCOREINFO_SYMBOL(lowcore_ptr);
226 VMCOREINFO_SYMBOL(high_memory);
227 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
228 vmcoreinfo_append_str("SAMODE31=%lx\n", __samode31);
229 vmcoreinfo_append_str("EAMODE31=%lx\n", __eamode31);
230 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
231 put_abs_lowcore(vmcore_info, paddr_vmcoreinfo_note());
234 void machine_shutdown(void)
238 void machine_crash_shutdown(struct pt_regs *regs)
240 set_os_info_reipl_block();
246 static void __do_machine_kexec(void *data)
248 unsigned long diag308_subcode;
249 relocate_kernel_t data_mover;
250 struct kimage *image = data;
253 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
255 __arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
256 /* Call the moving routine */
257 diag308_subcode = DIAG308_CLEAR_RESET;
259 diag308_subcode |= DIAG308_FLAG_EI;
260 (*data_mover)(&image->head, image->start, diag308_subcode);
262 /* Die if kexec returns */
267 * Reset system and call either kdump or normal kexec
269 static void __machine_kexec(void *data)
274 #ifdef CONFIG_CRASH_DUMP
275 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
276 __machine_kdump(data);
278 __do_machine_kexec(data);
282 * Do either kdump or normal kexec. In case of kdump we first ask
283 * purgatory, if kdump checksums are valid.
285 void machine_kexec(struct kimage *image)
287 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
291 smp_call_ipl_cpu(__machine_kexec, image);