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