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