1 /* 2 * arch/s390/kernel/machine_kexec.c 3 * 4 * Copyright IBM Corp. 2005,2011 5 * 6 * Author(s): Rolf Adelsberger, 7 * Heiko Carstens <heiko.carstens@de.ibm.com> 8 * Michael Holzheu <holzheu@linux.vnet.ibm.com> 9 */ 10 11 #include <linux/device.h> 12 #include <linux/mm.h> 13 #include <linux/kexec.h> 14 #include <linux/delay.h> 15 #include <linux/reboot.h> 16 #include <linux/ftrace.h> 17 #include <linux/debug_locks.h> 18 #include <asm/cio.h> 19 #include <asm/setup.h> 20 #include <asm/pgtable.h> 21 #include <asm/pgalloc.h> 22 #include <asm/smp.h> 23 #include <asm/reset.h> 24 #include <asm/ipl.h> 25 #include <asm/diag.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 void *fill_cpu_elf_notes(void *ptr, struct save_area *sa); 37 38 /* 39 * Create ELF notes for one CPU 40 */ 41 static void add_elf_notes(int cpu) 42 { 43 struct save_area *sa = (void *) 4608 + store_prefix(); 44 void *ptr; 45 46 memcpy((void *) (4608UL + sa->pref_reg), sa, sizeof(*sa)); 47 ptr = (u64 *) per_cpu_ptr(crash_notes, cpu); 48 ptr = fill_cpu_elf_notes(ptr, sa); 49 memset(ptr, 0, sizeof(struct elf_note)); 50 } 51 52 /* 53 * Initialize CPU ELF notes 54 */ 55 void setup_regs(void) 56 { 57 unsigned long sa = S390_lowcore.prefixreg_save_area + SAVE_AREA_BASE; 58 int cpu, this_cpu; 59 60 this_cpu = smp_find_processor_id(stap()); 61 add_elf_notes(this_cpu); 62 for_each_online_cpu(cpu) { 63 if (cpu == this_cpu) 64 continue; 65 if (smp_store_status(cpu)) 66 continue; 67 add_elf_notes(cpu); 68 } 69 /* Copy dump CPU store status info to absolute zero */ 70 memcpy((void *) SAVE_AREA_BASE, (void *) sa, sizeof(struct save_area)); 71 } 72 73 #endif 74 75 /* 76 * Start kdump: We expect here that a store status has been done on our CPU 77 */ 78 static void __do_machine_kdump(void *image) 79 { 80 #ifdef CONFIG_CRASH_DUMP 81 int (*start_kdump)(int) = (void *)((struct kimage *) image)->start; 82 83 setup_regs(); 84 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA); 85 start_kdump(1); 86 #endif 87 } 88 89 /* 90 * Check if kdump checksums are valid: We call purgatory with parameter "0" 91 */ 92 static int kdump_csum_valid(struct kimage *image) 93 { 94 #ifdef CONFIG_CRASH_DUMP 95 int (*start_kdump)(int) = (void *)image->start; 96 int rc; 97 98 __arch_local_irq_stnsm(0xfb); /* disable DAT */ 99 rc = start_kdump(0); 100 __arch_local_irq_stosm(0x04); /* enable DAT */ 101 return rc ? 0 : -EINVAL; 102 #else 103 return -EINVAL; 104 #endif 105 } 106 107 /* 108 * Map or unmap crashkernel memory 109 */ 110 static void crash_map_pages(int enable) 111 { 112 unsigned long size = resource_size(&crashk_res); 113 114 BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN || 115 size % KEXEC_CRASH_MEM_ALIGN); 116 if (enable) 117 vmem_add_mapping(crashk_res.start, size); 118 else { 119 vmem_remove_mapping(crashk_res.start, size); 120 if (size) 121 os_info_crashkernel_add(crashk_res.start, size); 122 else 123 os_info_crashkernel_add(0, 0); 124 } 125 } 126 127 /* 128 * Map crashkernel memory 129 */ 130 void crash_map_reserved_pages(void) 131 { 132 crash_map_pages(1); 133 } 134 135 /* 136 * Unmap crashkernel memory 137 */ 138 void crash_unmap_reserved_pages(void) 139 { 140 crash_map_pages(0); 141 } 142 143 /* 144 * Give back memory to hypervisor before new kdump is loaded 145 */ 146 static int machine_kexec_prepare_kdump(void) 147 { 148 #ifdef CONFIG_CRASH_DUMP 149 if (MACHINE_IS_VM) 150 diag10_range(PFN_DOWN(crashk_res.start), 151 PFN_DOWN(crashk_res.end - crashk_res.start + 1)); 152 return 0; 153 #else 154 return -EINVAL; 155 #endif 156 } 157 158 int machine_kexec_prepare(struct kimage *image) 159 { 160 void *reboot_code_buffer; 161 162 /* Can't replace kernel image since it is read-only. */ 163 if (ipl_flags & IPL_NSS_VALID) 164 return -ENOSYS; 165 166 if (image->type == KEXEC_TYPE_CRASH) 167 return machine_kexec_prepare_kdump(); 168 169 /* We don't support anything but the default image type for now. */ 170 if (image->type != KEXEC_TYPE_DEFAULT) 171 return -EINVAL; 172 173 /* Get the destination where the assembler code should be copied to.*/ 174 reboot_code_buffer = (void *) page_to_phys(image->control_code_page); 175 176 /* Then copy it */ 177 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len); 178 return 0; 179 } 180 181 void machine_kexec_cleanup(struct kimage *image) 182 { 183 } 184 185 void arch_crash_save_vmcoreinfo(void) 186 { 187 VMCOREINFO_SYMBOL(lowcore_ptr); 188 VMCOREINFO_SYMBOL(high_memory); 189 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS); 190 } 191 192 void machine_shutdown(void) 193 { 194 } 195 196 /* 197 * Do normal kexec 198 */ 199 static void __do_machine_kexec(void *data) 200 { 201 relocate_kernel_t data_mover; 202 struct kimage *image = data; 203 204 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page); 205 206 /* Call the moving routine */ 207 (*data_mover)(&image->head, image->start); 208 } 209 210 /* 211 * Reset system and call either kdump or normal kexec 212 */ 213 static void __machine_kexec(void *data) 214 { 215 struct kimage *image = data; 216 217 __arch_local_irq_stosm(0x04); /* enable DAT */ 218 pfault_fini(); 219 tracing_off(); 220 debug_locks_off(); 221 if (image->type == KEXEC_TYPE_CRASH) { 222 lgr_info_log(); 223 s390_reset_system(__do_machine_kdump, data); 224 } else { 225 s390_reset_system(__do_machine_kexec, data); 226 } 227 disabled_wait((unsigned long) __builtin_return_address(0)); 228 } 229 230 /* 231 * Do either kdump or normal kexec. In case of kdump we first ask 232 * purgatory, if kdump checksums are valid. 233 */ 234 void machine_kexec(struct kimage *image) 235 { 236 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image)) 237 return; 238 tracer_disable(); 239 smp_send_stop(); 240 smp_call_ipl_cpu(__machine_kexec, image); 241 } 242