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/elf.h> 25 #include <asm/asm-offsets.h> 26 #include <asm/os_info.h> 27 28 typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long); 29 30 extern const unsigned char relocate_kernel[]; 31 extern const unsigned long long relocate_kernel_len; 32 33 #ifdef CONFIG_CRASH_DUMP 34 35 /* 36 * Create ELF notes for one CPU 37 */ 38 static void add_elf_notes(int cpu) 39 { 40 struct save_area *sa = (void *) 4608 + store_prefix(); 41 void *ptr; 42 43 memcpy((void *) (4608UL + sa->pref_reg), sa, sizeof(*sa)); 44 ptr = (u64 *) per_cpu_ptr(crash_notes, cpu); 45 ptr = fill_cpu_elf_notes(ptr, sa); 46 memset(ptr, 0, sizeof(struct elf_note)); 47 } 48 49 /* 50 * Initialize CPU ELF notes 51 */ 52 void setup_regs(void) 53 { 54 unsigned long sa = S390_lowcore.prefixreg_save_area + SAVE_AREA_BASE; 55 int cpu, this_cpu; 56 57 this_cpu = smp_find_processor_id(stap()); 58 add_elf_notes(this_cpu); 59 for_each_online_cpu(cpu) { 60 if (cpu == this_cpu) 61 continue; 62 if (smp_store_status(cpu)) 63 continue; 64 add_elf_notes(cpu); 65 } 66 /* Copy dump CPU store status info to absolute zero */ 67 memcpy((void *) SAVE_AREA_BASE, (void *) sa, sizeof(struct save_area)); 68 } 69 70 #endif 71 72 /* 73 * Start kdump: We expect here that a store status has been done on our CPU 74 */ 75 static void __do_machine_kdump(void *image) 76 { 77 #ifdef CONFIG_CRASH_DUMP 78 int (*start_kdump)(int) = (void *)((struct kimage *) image)->start; 79 80 setup_regs(); 81 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA); 82 start_kdump(1); 83 #endif 84 } 85 86 /* 87 * Check if kdump checksums are valid: We call purgatory with parameter "0" 88 */ 89 static int kdump_csum_valid(struct kimage *image) 90 { 91 #ifdef CONFIG_CRASH_DUMP 92 int (*start_kdump)(int) = (void *)image->start; 93 int rc; 94 95 __arch_local_irq_stnsm(0xfb); /* disable DAT */ 96 rc = start_kdump(0); 97 __arch_local_irq_stosm(0x04); /* enable DAT */ 98 return rc ? 0 : -EINVAL; 99 #else 100 return -EINVAL; 101 #endif 102 } 103 104 /* 105 * Map or unmap crashkernel memory 106 */ 107 static void crash_map_pages(int enable) 108 { 109 unsigned long size = resource_size(&crashk_res); 110 111 BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN || 112 size % KEXEC_CRASH_MEM_ALIGN); 113 if (enable) 114 vmem_add_mapping(crashk_res.start, size); 115 else { 116 vmem_remove_mapping(crashk_res.start, size); 117 if (size) 118 os_info_crashkernel_add(crashk_res.start, size); 119 else 120 os_info_crashkernel_add(0, 0); 121 } 122 } 123 124 /* 125 * Map crashkernel memory 126 */ 127 void crash_map_reserved_pages(void) 128 { 129 crash_map_pages(1); 130 } 131 132 /* 133 * Unmap crashkernel memory 134 */ 135 void crash_unmap_reserved_pages(void) 136 { 137 crash_map_pages(0); 138 } 139 140 /* 141 * Give back memory to hypervisor before new kdump is loaded 142 */ 143 static int machine_kexec_prepare_kdump(void) 144 { 145 #ifdef CONFIG_CRASH_DUMP 146 if (MACHINE_IS_VM) 147 diag10_range(PFN_DOWN(crashk_res.start), 148 PFN_DOWN(crashk_res.end - crashk_res.start + 1)); 149 return 0; 150 #else 151 return -EINVAL; 152 #endif 153 } 154 155 int machine_kexec_prepare(struct kimage *image) 156 { 157 void *reboot_code_buffer; 158 159 /* Can't replace kernel image since it is read-only. */ 160 if (ipl_flags & IPL_NSS_VALID) 161 return -EOPNOTSUPP; 162 163 if (image->type == KEXEC_TYPE_CRASH) 164 return machine_kexec_prepare_kdump(); 165 166 /* We don't support anything but the default image type for now. */ 167 if (image->type != KEXEC_TYPE_DEFAULT) 168 return -EINVAL; 169 170 /* Get the destination where the assembler code should be copied to.*/ 171 reboot_code_buffer = (void *) page_to_phys(image->control_code_page); 172 173 /* Then copy it */ 174 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len); 175 return 0; 176 } 177 178 void machine_kexec_cleanup(struct kimage *image) 179 { 180 } 181 182 void arch_crash_save_vmcoreinfo(void) 183 { 184 VMCOREINFO_SYMBOL(lowcore_ptr); 185 VMCOREINFO_SYMBOL(high_memory); 186 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS); 187 } 188 189 void machine_shutdown(void) 190 { 191 } 192 193 void machine_crash_shutdown(struct pt_regs *regs) 194 { 195 } 196 197 /* 198 * Do normal kexec 199 */ 200 static void __do_machine_kexec(void *data) 201 { 202 relocate_kernel_t data_mover; 203 struct kimage *image = data; 204 205 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page); 206 207 /* Call the moving routine */ 208 (*data_mover)(&image->head, image->start); 209 } 210 211 /* 212 * Reset system and call either kdump or normal kexec 213 */ 214 static void __machine_kexec(void *data) 215 { 216 struct kimage *image = data; 217 218 __arch_local_irq_stosm(0x04); /* enable DAT */ 219 pfault_fini(); 220 tracing_off(); 221 debug_locks_off(); 222 if (image->type == KEXEC_TYPE_CRASH) { 223 lgr_info_log(); 224 s390_reset_system(__do_machine_kdump, data); 225 } else { 226 s390_reset_system(__do_machine_kexec, data); 227 } 228 disabled_wait((unsigned long) __builtin_return_address(0)); 229 } 230 231 /* 232 * Do either kdump or normal kexec. In case of kdump we first ask 233 * purgatory, if kdump checksums are valid. 234 */ 235 void machine_kexec(struct kimage *image) 236 { 237 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image)) 238 return; 239 tracer_disable(); 240 smp_send_stop(); 241 smp_call_ipl_cpu(__machine_kexec, image); 242 } 243