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/os_info.h> 28 #include <asm/switch_to.h> 29 30 typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long); 31 32 extern const unsigned char relocate_kernel[]; 33 extern const unsigned long long relocate_kernel_len; 34 35 #ifdef CONFIG_CRASH_DUMP 36 37 /* 38 * Create ELF notes for one CPU 39 */ 40 static void add_elf_notes(int cpu) 41 { 42 struct save_area *sa = (void *) 4608 + store_prefix(); 43 void *ptr; 44 45 memcpy((void *) (4608UL + sa->pref_reg), sa, sizeof(*sa)); 46 ptr = (u64 *) per_cpu_ptr(crash_notes, cpu); 47 ptr = fill_cpu_elf_notes(ptr, sa, NULL); 48 memset(ptr, 0, sizeof(struct elf_note)); 49 } 50 51 /* 52 * Initialize CPU ELF notes 53 */ 54 static void setup_regs(void) 55 { 56 unsigned long sa = S390_lowcore.prefixreg_save_area + SAVE_AREA_BASE; 57 struct _lowcore *lc; 58 int cpu, this_cpu; 59 60 /* Get lowcore pointer from store status of this CPU (absolute zero) */ 61 lc = (struct _lowcore *)(unsigned long)S390_lowcore.prefixreg_save_area; 62 this_cpu = smp_find_processor_id(stap()); 63 add_elf_notes(this_cpu); 64 for_each_online_cpu(cpu) { 65 if (cpu == this_cpu) 66 continue; 67 if (smp_store_status(cpu)) 68 continue; 69 add_elf_notes(cpu); 70 } 71 if (MACHINE_HAS_VX) 72 save_vx_regs_safe((void *) lc->vector_save_area_addr); 73 /* Copy dump CPU store status info to absolute zero */ 74 memcpy((void *) SAVE_AREA_BASE, (void *) sa, sizeof(struct save_area)); 75 } 76 77 /* 78 * PM notifier callback for kdump 79 */ 80 static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action, 81 void *ptr) 82 { 83 switch (action) { 84 case PM_SUSPEND_PREPARE: 85 case PM_HIBERNATION_PREPARE: 86 if (crashk_res.start) 87 crash_map_reserved_pages(); 88 break; 89 case PM_POST_SUSPEND: 90 case PM_POST_HIBERNATION: 91 if (crashk_res.start) 92 crash_unmap_reserved_pages(); 93 break; 94 default: 95 return NOTIFY_DONE; 96 } 97 return NOTIFY_OK; 98 } 99 100 static int __init machine_kdump_pm_init(void) 101 { 102 pm_notifier(machine_kdump_pm_cb, 0); 103 return 0; 104 } 105 arch_initcall(machine_kdump_pm_init); 106 107 /* 108 * Start kdump: We expect here that a store status has been done on our CPU 109 */ 110 static void __do_machine_kdump(void *image) 111 { 112 int (*start_kdump)(int) = (void *)((struct kimage *) image)->start; 113 114 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA); 115 start_kdump(1); 116 } 117 #endif 118 119 /* 120 * Check if kdump checksums are valid: We call purgatory with parameter "0" 121 */ 122 static int kdump_csum_valid(struct kimage *image) 123 { 124 #ifdef CONFIG_CRASH_DUMP 125 int (*start_kdump)(int) = (void *)image->start; 126 int rc; 127 128 __arch_local_irq_stnsm(0xfb); /* disable DAT */ 129 rc = start_kdump(0); 130 __arch_local_irq_stosm(0x04); /* enable DAT */ 131 return rc ? 0 : -EINVAL; 132 #else 133 return -EINVAL; 134 #endif 135 } 136 137 /* 138 * Map or unmap crashkernel memory 139 */ 140 static void crash_map_pages(int enable) 141 { 142 unsigned long size = resource_size(&crashk_res); 143 144 BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN || 145 size % KEXEC_CRASH_MEM_ALIGN); 146 if (enable) 147 vmem_add_mapping(crashk_res.start, size); 148 else { 149 vmem_remove_mapping(crashk_res.start, size); 150 if (size) 151 os_info_crashkernel_add(crashk_res.start, size); 152 else 153 os_info_crashkernel_add(0, 0); 154 } 155 } 156 157 /* 158 * Map crashkernel memory 159 */ 160 void crash_map_reserved_pages(void) 161 { 162 crash_map_pages(1); 163 } 164 165 /* 166 * Unmap crashkernel memory 167 */ 168 void crash_unmap_reserved_pages(void) 169 { 170 crash_map_pages(0); 171 } 172 173 /* 174 * Give back memory to hypervisor before new kdump is loaded 175 */ 176 static int machine_kexec_prepare_kdump(void) 177 { 178 #ifdef CONFIG_CRASH_DUMP 179 if (MACHINE_IS_VM) 180 diag10_range(PFN_DOWN(crashk_res.start), 181 PFN_DOWN(crashk_res.end - crashk_res.start + 1)); 182 return 0; 183 #else 184 return -EINVAL; 185 #endif 186 } 187 188 int machine_kexec_prepare(struct kimage *image) 189 { 190 void *reboot_code_buffer; 191 192 /* Can't replace kernel image since it is read-only. */ 193 if (ipl_flags & IPL_NSS_VALID) 194 return -EOPNOTSUPP; 195 196 if (image->type == KEXEC_TYPE_CRASH) 197 return machine_kexec_prepare_kdump(); 198 199 /* We don't support anything but the default image type for now. */ 200 if (image->type != KEXEC_TYPE_DEFAULT) 201 return -EINVAL; 202 203 /* Get the destination where the assembler code should be copied to.*/ 204 reboot_code_buffer = (void *) page_to_phys(image->control_code_page); 205 206 /* Then copy it */ 207 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len); 208 return 0; 209 } 210 211 void machine_kexec_cleanup(struct kimage *image) 212 { 213 } 214 215 void arch_crash_save_vmcoreinfo(void) 216 { 217 VMCOREINFO_SYMBOL(lowcore_ptr); 218 VMCOREINFO_SYMBOL(high_memory); 219 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS); 220 } 221 222 void machine_shutdown(void) 223 { 224 } 225 226 void machine_crash_shutdown(struct pt_regs *regs) 227 { 228 } 229 230 /* 231 * Do normal kexec 232 */ 233 static void __do_machine_kexec(void *data) 234 { 235 relocate_kernel_t data_mover; 236 struct kimage *image = data; 237 238 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page); 239 240 /* Call the moving routine */ 241 (*data_mover)(&image->head, image->start); 242 } 243 244 /* 245 * Reset system and call either kdump or normal kexec 246 */ 247 static void __machine_kexec(void *data) 248 { 249 __arch_local_irq_stosm(0x04); /* enable DAT */ 250 pfault_fini(); 251 tracing_off(); 252 debug_locks_off(); 253 #ifdef CONFIG_CRASH_DUMP 254 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH) { 255 256 lgr_info_log(); 257 s390_reset_system(setup_regs, __do_machine_kdump, data); 258 } else 259 #endif 260 s390_reset_system(NULL, __do_machine_kexec, data); 261 disabled_wait((unsigned long) __builtin_return_address(0)); 262 } 263 264 /* 265 * Do either kdump or normal kexec. In case of kdump we first ask 266 * purgatory, if kdump checksums are valid. 267 */ 268 void machine_kexec(struct kimage *image) 269 { 270 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image)) 271 return; 272 tracer_disable(); 273 smp_send_stop(); 274 smp_call_ipl_cpu(__machine_kexec, image); 275 } 276