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 <asm/cio.h> 17 #include <asm/setup.h> 18 #include <asm/pgtable.h> 19 #include <asm/pgalloc.h> 20 #include <asm/smp.h> 21 #include <asm/reset.h> 22 #include <asm/ipl.h> 23 #include <asm/diag.h> 24 #include <asm/asm-offsets.h> 25 #include <asm/os_info.h> 26 27 typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long); 28 29 extern const unsigned char relocate_kernel[]; 30 extern const unsigned long long relocate_kernel_len; 31 32 #ifdef CONFIG_CRASH_DUMP 33 34 void *fill_cpu_elf_notes(void *ptr, struct save_area *sa); 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 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 #endif 72 73 /* 74 * Start kdump: We expect here that a store status has been done on our CPU 75 */ 76 static void __do_machine_kdump(void *image) 77 { 78 #ifdef CONFIG_CRASH_DUMP 79 int (*start_kdump)(int) = (void *)((struct kimage *) image)->start; 80 81 setup_regs(); 82 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA); 83 start_kdump(1); 84 #endif 85 } 86 87 /* 88 * Check if kdump checksums are valid: We call purgatory with parameter "0" 89 */ 90 static int kdump_csum_valid(struct kimage *image) 91 { 92 #ifdef CONFIG_CRASH_DUMP 93 int (*start_kdump)(int) = (void *)image->start; 94 int rc; 95 96 __arch_local_irq_stnsm(0xfb); /* disable DAT */ 97 rc = start_kdump(0); 98 __arch_local_irq_stosm(0x04); /* enable DAT */ 99 return rc ? 0 : -EINVAL; 100 #else 101 return -EINVAL; 102 #endif 103 } 104 105 /* 106 * Map or unmap crashkernel memory 107 */ 108 static void crash_map_pages(int enable) 109 { 110 unsigned long size = resource_size(&crashk_res); 111 112 BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN || 113 size % KEXEC_CRASH_MEM_ALIGN); 114 if (enable) 115 vmem_add_mapping(crashk_res.start, size); 116 else { 117 vmem_remove_mapping(crashk_res.start, size); 118 if (size) 119 os_info_crashkernel_add(crashk_res.start, size); 120 else 121 os_info_crashkernel_add(0, 0); 122 } 123 } 124 125 /* 126 * Map crashkernel memory 127 */ 128 void crash_map_reserved_pages(void) 129 { 130 crash_map_pages(1); 131 } 132 133 /* 134 * Unmap crashkernel memory 135 */ 136 void crash_unmap_reserved_pages(void) 137 { 138 crash_map_pages(0); 139 } 140 141 /* 142 * Give back memory to hypervisor before new kdump is loaded 143 */ 144 static int machine_kexec_prepare_kdump(void) 145 { 146 #ifdef CONFIG_CRASH_DUMP 147 if (MACHINE_IS_VM) 148 diag10_range(PFN_DOWN(crashk_res.start), 149 PFN_DOWN(crashk_res.end - crashk_res.start + 1)); 150 return 0; 151 #else 152 return -EINVAL; 153 #endif 154 } 155 156 int machine_kexec_prepare(struct kimage *image) 157 { 158 void *reboot_code_buffer; 159 160 /* Can't replace kernel image since it is read-only. */ 161 if (ipl_flags & IPL_NSS_VALID) 162 return -ENOSYS; 163 164 if (image->type == KEXEC_TYPE_CRASH) 165 return machine_kexec_prepare_kdump(); 166 167 /* We don't support anything but the default image type for now. */ 168 if (image->type != KEXEC_TYPE_DEFAULT) 169 return -EINVAL; 170 171 /* Get the destination where the assembler code should be copied to.*/ 172 reboot_code_buffer = (void *) page_to_phys(image->control_code_page); 173 174 /* Then copy it */ 175 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len); 176 return 0; 177 } 178 179 void machine_kexec_cleanup(struct kimage *image) 180 { 181 } 182 183 void arch_crash_save_vmcoreinfo(void) 184 { 185 VMCOREINFO_SYMBOL(lowcore_ptr); 186 VMCOREINFO_SYMBOL(high_memory); 187 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS); 188 } 189 190 void machine_shutdown(void) 191 { 192 } 193 194 /* 195 * Do normal kexec 196 */ 197 static void __do_machine_kexec(void *data) 198 { 199 relocate_kernel_t data_mover; 200 struct kimage *image = data; 201 202 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page); 203 204 /* Call the moving routine */ 205 (*data_mover)(&image->head, image->start); 206 } 207 208 /* 209 * Reset system and call either kdump or normal kexec 210 */ 211 static void __machine_kexec(void *data) 212 { 213 struct kimage *image = data; 214 215 __arch_local_irq_stosm(0x04); /* enable DAT */ 216 pfault_fini(); 217 tracing_off(); 218 debug_locks_off(); 219 if (image->type == KEXEC_TYPE_CRASH) { 220 lgr_info_log(); 221 s390_reset_system(__do_machine_kdump, data); 222 } else { 223 s390_reset_system(__do_machine_kexec, data); 224 } 225 disabled_wait((unsigned long) __builtin_return_address(0)); 226 } 227 228 /* 229 * Do either kdump or normal kexec. In case of kdump we first ask 230 * purgatory, if kdump checksums are valid. 231 */ 232 void machine_kexec(struct kimage *image) 233 { 234 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image)) 235 return; 236 tracer_disable(); 237 smp_send_stop(); 238 smp_call_ipl_cpu(__machine_kexec, image); 239 } 240