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/cacheflush.h> 28 #include <asm/os_info.h> 29 #include <asm/switch_to.h> 30 31 typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long); 32 33 extern const unsigned char relocate_kernel[]; 34 extern const unsigned long long relocate_kernel_len; 35 36 #ifdef CONFIG_CRASH_DUMP 37 38 /* 39 * PM notifier callback for kdump 40 */ machine_kdump_pm_cb(struct notifier_block * nb,unsigned long action,void * ptr)41 static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action, 42 void *ptr) 43 { 44 switch (action) { 45 case PM_SUSPEND_PREPARE: 46 case PM_HIBERNATION_PREPARE: 47 if (kexec_crash_image) 48 arch_kexec_unprotect_crashkres(); 49 break; 50 case PM_POST_SUSPEND: 51 case PM_POST_HIBERNATION: 52 if (kexec_crash_image) 53 arch_kexec_protect_crashkres(); 54 break; 55 default: 56 return NOTIFY_DONE; 57 } 58 return NOTIFY_OK; 59 } 60 machine_kdump_pm_init(void)61 static int __init machine_kdump_pm_init(void) 62 { 63 pm_notifier(machine_kdump_pm_cb, 0); 64 return 0; 65 } 66 arch_initcall(machine_kdump_pm_init); 67 68 /* 69 * Reset the system, copy boot CPU registers to absolute zero, 70 * and jump to the kdump image 71 */ __do_machine_kdump(void * image)72 static void __do_machine_kdump(void *image) 73 { 74 int (*start_kdump)(int); 75 unsigned long prefix; 76 77 /* store_status() saved the prefix register to lowcore */ 78 prefix = (unsigned long) S390_lowcore.prefixreg_save_area; 79 80 /* Now do the reset */ 81 s390_reset_system(); 82 83 /* 84 * Copy dump CPU store status info to absolute zero. 85 * This need to be done *after* s390_reset_system set the 86 * prefix register of this CPU to zero 87 */ 88 memcpy((void *) __LC_FPREGS_SAVE_AREA, 89 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512); 90 91 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA); 92 start_kdump = (void *)((struct kimage *) image)->start; 93 start_kdump(1); 94 95 /* Die if start_kdump returns */ 96 disabled_wait((unsigned long) __builtin_return_address(0)); 97 } 98 99 /* 100 * Start kdump: create a LGR log entry, store status of all CPUs and 101 * branch to __do_machine_kdump. 102 */ __machine_kdump(void * image)103 static noinline void __machine_kdump(void *image) 104 { 105 int this_cpu, cpu; 106 107 lgr_info_log(); 108 /* Get status of the other CPUs */ 109 this_cpu = smp_find_processor_id(stap()); 110 for_each_online_cpu(cpu) { 111 if (cpu == this_cpu) 112 continue; 113 if (smp_store_status(cpu)) 114 continue; 115 } 116 /* Store status of the boot CPU */ 117 if (MACHINE_HAS_VX) 118 save_vx_regs((void *) &S390_lowcore.vector_save_area); 119 /* 120 * To create a good backchain for this CPU in the dump store_status 121 * is passed the address of a function. The address is saved into 122 * the PSW save area of the boot CPU and the function is invoked as 123 * a tail call of store_status. The backchain in the dump will look 124 * like this: 125 * restart_int_handler -> __machine_kexec -> __do_machine_kdump 126 * The call to store_status() will not return. 127 */ 128 store_status(__do_machine_kdump, image); 129 } 130 #endif 131 132 /* 133 * Check if kdump checksums are valid: We call purgatory with parameter "0" 134 */ kdump_csum_valid(struct kimage * image)135 static int kdump_csum_valid(struct kimage *image) 136 { 137 #ifdef CONFIG_CRASH_DUMP 138 int (*start_kdump)(int) = (void *)image->start; 139 int rc; 140 141 __arch_local_irq_stnsm(0xfb); /* disable DAT */ 142 rc = start_kdump(0); 143 __arch_local_irq_stosm(0x04); /* enable DAT */ 144 return rc ? 0 : -EINVAL; 145 #else 146 return -EINVAL; 147 #endif 148 } 149 150 #ifdef CONFIG_CRASH_DUMP 151 crash_free_reserved_phys_range(unsigned long begin,unsigned long end)152 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end) 153 { 154 unsigned long addr, size; 155 156 for (addr = begin; addr < end; addr += PAGE_SIZE) 157 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT)); 158 size = begin - crashk_res.start; 159 if (size) 160 os_info_crashkernel_add(crashk_res.start, size); 161 else 162 os_info_crashkernel_add(0, 0); 163 } 164 crash_protect_pages(int protect)165 static void crash_protect_pages(int protect) 166 { 167 unsigned long size; 168 169 if (!crashk_res.end) 170 return; 171 size = resource_size(&crashk_res); 172 if (protect) 173 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT); 174 else 175 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT); 176 } 177 arch_kexec_protect_crashkres(void)178 void arch_kexec_protect_crashkres(void) 179 { 180 crash_protect_pages(1); 181 } 182 arch_kexec_unprotect_crashkres(void)183 void arch_kexec_unprotect_crashkres(void) 184 { 185 crash_protect_pages(0); 186 } 187 188 #endif 189 190 /* 191 * Give back memory to hypervisor before new kdump is loaded 192 */ machine_kexec_prepare_kdump(void)193 static int machine_kexec_prepare_kdump(void) 194 { 195 #ifdef CONFIG_CRASH_DUMP 196 if (MACHINE_IS_VM) 197 diag10_range(PFN_DOWN(crashk_res.start), 198 PFN_DOWN(crashk_res.end - crashk_res.start + 1)); 199 return 0; 200 #else 201 return -EINVAL; 202 #endif 203 } 204 machine_kexec_prepare(struct kimage * image)205 int machine_kexec_prepare(struct kimage *image) 206 { 207 void *reboot_code_buffer; 208 209 /* Can't replace kernel image since it is read-only. */ 210 if (ipl_flags & IPL_NSS_VALID) 211 return -EOPNOTSUPP; 212 213 if (image->type == KEXEC_TYPE_CRASH) 214 return machine_kexec_prepare_kdump(); 215 216 /* We don't support anything but the default image type for now. */ 217 if (image->type != KEXEC_TYPE_DEFAULT) 218 return -EINVAL; 219 220 /* Get the destination where the assembler code should be copied to.*/ 221 reboot_code_buffer = (void *) page_to_phys(image->control_code_page); 222 223 /* Then copy it */ 224 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len); 225 return 0; 226 } 227 machine_kexec_cleanup(struct kimage * image)228 void machine_kexec_cleanup(struct kimage *image) 229 { 230 } 231 arch_crash_save_vmcoreinfo(void)232 void arch_crash_save_vmcoreinfo(void) 233 { 234 VMCOREINFO_SYMBOL(lowcore_ptr); 235 VMCOREINFO_SYMBOL(high_memory); 236 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS); 237 } 238 machine_shutdown(void)239 void machine_shutdown(void) 240 { 241 } 242 machine_crash_shutdown(struct pt_regs * regs)243 void machine_crash_shutdown(struct pt_regs *regs) 244 { 245 } 246 247 /* 248 * Do normal kexec 249 */ __do_machine_kexec(void * data)250 static void __do_machine_kexec(void *data) 251 { 252 relocate_kernel_t data_mover; 253 struct kimage *image = data; 254 255 s390_reset_system(); 256 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page); 257 258 /* Call the moving routine */ 259 (*data_mover)(&image->head, image->start); 260 261 /* Die if kexec returns */ 262 disabled_wait((unsigned long) __builtin_return_address(0)); 263 } 264 265 /* 266 * Reset system and call either kdump or normal kexec 267 */ __machine_kexec(void * data)268 static void __machine_kexec(void *data) 269 { 270 __arch_local_irq_stosm(0x04); /* enable DAT */ 271 pfault_fini(); 272 tracing_off(); 273 debug_locks_off(); 274 #ifdef CONFIG_CRASH_DUMP 275 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH) 276 __machine_kdump(data); 277 #endif 278 __do_machine_kexec(data); 279 } 280 281 /* 282 * Do either kdump or normal kexec. In case of kdump we first ask 283 * purgatory, if kdump checksums are valid. 284 */ machine_kexec(struct kimage * image)285 void machine_kexec(struct kimage *image) 286 { 287 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image)) 288 return; 289 tracer_disable(); 290 smp_send_stop(); 291 smp_call_ipl_cpu(__machine_kexec, image); 292 } 293