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 #endif 107 108 /* 109 * Start kdump: We expect here that a store status has been done on our CPU 110 */ 111 static void __do_machine_kdump(void *image) 112 { 113 #ifdef CONFIG_CRASH_DUMP 114 int (*start_kdump)(int) = (void *)((struct kimage *) image)->start; 115 116 setup_regs(); 117 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA); 118 start_kdump(1); 119 #endif 120 } 121 122 /* 123 * Check if kdump checksums are valid: We call purgatory with parameter "0" 124 */ 125 static int kdump_csum_valid(struct kimage *image) 126 { 127 #ifdef CONFIG_CRASH_DUMP 128 int (*start_kdump)(int) = (void *)image->start; 129 int rc; 130 131 __arch_local_irq_stnsm(0xfb); /* disable DAT */ 132 rc = start_kdump(0); 133 __arch_local_irq_stosm(0x04); /* enable DAT */ 134 return rc ? 0 : -EINVAL; 135 #else 136 return -EINVAL; 137 #endif 138 } 139 140 /* 141 * Map or unmap crashkernel memory 142 */ 143 static void crash_map_pages(int enable) 144 { 145 unsigned long size = resource_size(&crashk_res); 146 147 BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN || 148 size % KEXEC_CRASH_MEM_ALIGN); 149 if (enable) 150 vmem_add_mapping(crashk_res.start, size); 151 else { 152 vmem_remove_mapping(crashk_res.start, size); 153 if (size) 154 os_info_crashkernel_add(crashk_res.start, size); 155 else 156 os_info_crashkernel_add(0, 0); 157 } 158 } 159 160 /* 161 * Map crashkernel memory 162 */ 163 void crash_map_reserved_pages(void) 164 { 165 crash_map_pages(1); 166 } 167 168 /* 169 * Unmap crashkernel memory 170 */ 171 void crash_unmap_reserved_pages(void) 172 { 173 crash_map_pages(0); 174 } 175 176 /* 177 * Give back memory to hypervisor before new kdump is loaded 178 */ 179 static int machine_kexec_prepare_kdump(void) 180 { 181 #ifdef CONFIG_CRASH_DUMP 182 if (MACHINE_IS_VM) 183 diag10_range(PFN_DOWN(crashk_res.start), 184 PFN_DOWN(crashk_res.end - crashk_res.start + 1)); 185 return 0; 186 #else 187 return -EINVAL; 188 #endif 189 } 190 191 int machine_kexec_prepare(struct kimage *image) 192 { 193 void *reboot_code_buffer; 194 195 /* Can't replace kernel image since it is read-only. */ 196 if (ipl_flags & IPL_NSS_VALID) 197 return -EOPNOTSUPP; 198 199 if (image->type == KEXEC_TYPE_CRASH) 200 return machine_kexec_prepare_kdump(); 201 202 /* We don't support anything but the default image type for now. */ 203 if (image->type != KEXEC_TYPE_DEFAULT) 204 return -EINVAL; 205 206 /* Get the destination where the assembler code should be copied to.*/ 207 reboot_code_buffer = (void *) page_to_phys(image->control_code_page); 208 209 /* Then copy it */ 210 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len); 211 return 0; 212 } 213 214 void machine_kexec_cleanup(struct kimage *image) 215 { 216 } 217 218 void arch_crash_save_vmcoreinfo(void) 219 { 220 VMCOREINFO_SYMBOL(lowcore_ptr); 221 VMCOREINFO_SYMBOL(high_memory); 222 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS); 223 } 224 225 void machine_shutdown(void) 226 { 227 } 228 229 void machine_crash_shutdown(struct pt_regs *regs) 230 { 231 } 232 233 /* 234 * Do normal kexec 235 */ 236 static void __do_machine_kexec(void *data) 237 { 238 relocate_kernel_t data_mover; 239 struct kimage *image = data; 240 241 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page); 242 243 /* Call the moving routine */ 244 (*data_mover)(&image->head, image->start); 245 } 246 247 /* 248 * Reset system and call either kdump or normal kexec 249 */ 250 static void __machine_kexec(void *data) 251 { 252 struct kimage *image = data; 253 254 __arch_local_irq_stosm(0x04); /* enable DAT */ 255 pfault_fini(); 256 tracing_off(); 257 debug_locks_off(); 258 if (image->type == KEXEC_TYPE_CRASH) { 259 lgr_info_log(); 260 s390_reset_system(__do_machine_kdump, data); 261 } else { 262 s390_reset_system(__do_machine_kexec, data); 263 } 264 disabled_wait((unsigned long) __builtin_return_address(0)); 265 } 266 267 /* 268 * Do either kdump or normal kexec. In case of kdump we first ask 269 * purgatory, if kdump checksums are valid. 270 */ 271 void machine_kexec(struct kimage *image) 272 { 273 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image)) 274 return; 275 tracer_disable(); 276 smp_send_stop(); 277 smp_call_ipl_cpu(__machine_kexec, image); 278 } 279