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 * PM notifier callback for kdump 39 */ 40 static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action, 41 void *ptr) 42 { 43 switch (action) { 44 case PM_SUSPEND_PREPARE: 45 case PM_HIBERNATION_PREPARE: 46 if (crashk_res.start) 47 crash_map_reserved_pages(); 48 break; 49 case PM_POST_SUSPEND: 50 case PM_POST_HIBERNATION: 51 if (crashk_res.start) 52 crash_unmap_reserved_pages(); 53 break; 54 default: 55 return NOTIFY_DONE; 56 } 57 return NOTIFY_OK; 58 } 59 60 static int __init machine_kdump_pm_init(void) 61 { 62 pm_notifier(machine_kdump_pm_cb, 0); 63 return 0; 64 } 65 arch_initcall(machine_kdump_pm_init); 66 67 /* 68 * Reset the system, copy boot CPU registers to absolute zero, 69 * and jump to the kdump image 70 */ 71 static void __do_machine_kdump(void *image) 72 { 73 int (*start_kdump)(int); 74 unsigned long prefix; 75 76 /* store_status() saved the prefix register to lowcore */ 77 prefix = (unsigned long) S390_lowcore.prefixreg_save_area; 78 79 /* Now do the reset */ 80 s390_reset_system(); 81 82 /* 83 * Copy dump CPU store status info to absolute zero. 84 * This need to be done *after* s390_reset_system set the 85 * prefix register of this CPU to zero 86 */ 87 memcpy((void *) __LC_FPREGS_SAVE_AREA, 88 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512); 89 90 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA); 91 start_kdump = (void *)((struct kimage *) image)->start; 92 start_kdump(1); 93 94 /* Die if start_kdump returns */ 95 disabled_wait((unsigned long) __builtin_return_address(0)); 96 } 97 98 /* 99 * Start kdump: create a LGR log entry, store status of all CPUs and 100 * branch to __do_machine_kdump. 101 */ 102 static noinline void __machine_kdump(void *image) 103 { 104 int this_cpu, cpu; 105 106 lgr_info_log(); 107 /* Get status of the other CPUs */ 108 this_cpu = smp_find_processor_id(stap()); 109 for_each_online_cpu(cpu) { 110 if (cpu == this_cpu) 111 continue; 112 if (smp_store_status(cpu)) 113 continue; 114 } 115 /* Store status of the boot CPU */ 116 if (MACHINE_HAS_VX) 117 save_vx_regs((void *) &S390_lowcore.vector_save_area); 118 /* 119 * To create a good backchain for this CPU in the dump store_status 120 * is passed the address of a function. The address is saved into 121 * the PSW save area of the boot CPU and the function is invoked as 122 * a tail call of store_status. The backchain in the dump will look 123 * like this: 124 * restart_int_handler -> __machine_kexec -> __do_machine_kdump 125 * The call to store_status() will not return. 126 */ 127 store_status(__do_machine_kdump, image); 128 } 129 #endif 130 131 /* 132 * Check if kdump checksums are valid: We call purgatory with parameter "0" 133 */ 134 static int kdump_csum_valid(struct kimage *image) 135 { 136 #ifdef CONFIG_CRASH_DUMP 137 int (*start_kdump)(int) = (void *)image->start; 138 int rc; 139 140 __arch_local_irq_stnsm(0xfb); /* disable DAT */ 141 rc = start_kdump(0); 142 __arch_local_irq_stosm(0x04); /* enable DAT */ 143 return rc ? 0 : -EINVAL; 144 #else 145 return -EINVAL; 146 #endif 147 } 148 149 /* 150 * Map or unmap crashkernel memory 151 */ 152 static void crash_map_pages(int enable) 153 { 154 unsigned long size = resource_size(&crashk_res); 155 156 BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN || 157 size % KEXEC_CRASH_MEM_ALIGN); 158 if (enable) 159 vmem_add_mapping(crashk_res.start, size); 160 else { 161 vmem_remove_mapping(crashk_res.start, size); 162 if (size) 163 os_info_crashkernel_add(crashk_res.start, size); 164 else 165 os_info_crashkernel_add(0, 0); 166 } 167 } 168 169 /* 170 * Map crashkernel memory 171 */ 172 void crash_map_reserved_pages(void) 173 { 174 crash_map_pages(1); 175 } 176 177 /* 178 * Unmap crashkernel memory 179 */ 180 void crash_unmap_reserved_pages(void) 181 { 182 crash_map_pages(0); 183 } 184 185 /* 186 * Give back memory to hypervisor before new kdump is loaded 187 */ 188 static int machine_kexec_prepare_kdump(void) 189 { 190 #ifdef CONFIG_CRASH_DUMP 191 if (MACHINE_IS_VM) 192 diag10_range(PFN_DOWN(crashk_res.start), 193 PFN_DOWN(crashk_res.end - crashk_res.start + 1)); 194 return 0; 195 #else 196 return -EINVAL; 197 #endif 198 } 199 200 int machine_kexec_prepare(struct kimage *image) 201 { 202 void *reboot_code_buffer; 203 204 /* Can't replace kernel image since it is read-only. */ 205 if (ipl_flags & IPL_NSS_VALID) 206 return -EOPNOTSUPP; 207 208 if (image->type == KEXEC_TYPE_CRASH) 209 return machine_kexec_prepare_kdump(); 210 211 /* We don't support anything but the default image type for now. */ 212 if (image->type != KEXEC_TYPE_DEFAULT) 213 return -EINVAL; 214 215 /* Get the destination where the assembler code should be copied to.*/ 216 reboot_code_buffer = (void *) page_to_phys(image->control_code_page); 217 218 /* Then copy it */ 219 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len); 220 return 0; 221 } 222 223 void machine_kexec_cleanup(struct kimage *image) 224 { 225 } 226 227 void arch_crash_save_vmcoreinfo(void) 228 { 229 VMCOREINFO_SYMBOL(lowcore_ptr); 230 VMCOREINFO_SYMBOL(high_memory); 231 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS); 232 } 233 234 void machine_shutdown(void) 235 { 236 } 237 238 void machine_crash_shutdown(struct pt_regs *regs) 239 { 240 } 241 242 /* 243 * Do normal kexec 244 */ 245 static void __do_machine_kexec(void *data) 246 { 247 relocate_kernel_t data_mover; 248 struct kimage *image = data; 249 250 s390_reset_system(); 251 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page); 252 253 /* Call the moving routine */ 254 (*data_mover)(&image->head, image->start); 255 256 /* Die if kexec returns */ 257 disabled_wait((unsigned long) __builtin_return_address(0)); 258 } 259 260 /* 261 * Reset system and call either kdump or normal kexec 262 */ 263 static void __machine_kexec(void *data) 264 { 265 __arch_local_irq_stosm(0x04); /* enable DAT */ 266 pfault_fini(); 267 tracing_off(); 268 debug_locks_off(); 269 #ifdef CONFIG_CRASH_DUMP 270 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH) 271 __machine_kdump(data); 272 #endif 273 __do_machine_kexec(data); 274 } 275 276 /* 277 * Do either kdump or normal kexec. In case of kdump we first ask 278 * purgatory, if kdump checksums are valid. 279 */ 280 void machine_kexec(struct kimage *image) 281 { 282 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image)) 283 return; 284 tracer_disable(); 285 smp_send_stop(); 286 smp_call_ipl_cpu(__machine_kexec, image); 287 } 288