1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Code to handle transition of Linux booting another kernel. 4 * 5 * Copyright (C) 2002-2003 Eric Biederman <ebiederm@xmission.com> 6 * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz 7 * Copyright (C) 2005 IBM Corporation. 8 */ 9 10 #include <linux/kexec.h> 11 #include <linux/reboot.h> 12 #include <linux/threads.h> 13 #include <linux/memblock.h> 14 #include <linux/of.h> 15 #include <linux/irq.h> 16 #include <linux/ftrace.h> 17 18 #include <asm/kdump.h> 19 #include <asm/machdep.h> 20 #include <asm/pgalloc.h> 21 #include <asm/sections.h> 22 23 void machine_kexec_mask_interrupts(void) { 24 unsigned int i; 25 struct irq_desc *desc; 26 27 for_each_irq_desc(i, desc) { 28 struct irq_chip *chip; 29 30 chip = irq_desc_get_chip(desc); 31 if (!chip) 32 continue; 33 34 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) 35 chip->irq_eoi(&desc->irq_data); 36 37 if (chip->irq_mask) 38 chip->irq_mask(&desc->irq_data); 39 40 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) 41 chip->irq_disable(&desc->irq_data); 42 } 43 } 44 45 void machine_crash_shutdown(struct pt_regs *regs) 46 { 47 default_machine_crash_shutdown(regs); 48 } 49 50 void machine_kexec_cleanup(struct kimage *image) 51 { 52 } 53 54 void arch_crash_save_vmcoreinfo(void) 55 { 56 57 #ifdef CONFIG_NUMA 58 VMCOREINFO_SYMBOL(node_data); 59 VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); 60 #endif 61 #ifndef CONFIG_NUMA 62 VMCOREINFO_SYMBOL(contig_page_data); 63 #endif 64 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP) 65 VMCOREINFO_SYMBOL(vmemmap_list); 66 VMCOREINFO_SYMBOL(mmu_vmemmap_psize); 67 VMCOREINFO_SYMBOL(mmu_psize_defs); 68 VMCOREINFO_STRUCT_SIZE(vmemmap_backing); 69 VMCOREINFO_OFFSET(vmemmap_backing, list); 70 VMCOREINFO_OFFSET(vmemmap_backing, phys); 71 VMCOREINFO_OFFSET(vmemmap_backing, virt_addr); 72 VMCOREINFO_STRUCT_SIZE(mmu_psize_def); 73 VMCOREINFO_OFFSET(mmu_psize_def, shift); 74 #endif 75 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); 76 } 77 78 /* 79 * Do not allocate memory (or fail in any way) in machine_kexec(). 80 * We are past the point of no return, committed to rebooting now. 81 */ 82 void machine_kexec(struct kimage *image) 83 { 84 int save_ftrace_enabled; 85 86 save_ftrace_enabled = __ftrace_enabled_save(); 87 this_cpu_disable_ftrace(); 88 89 if (ppc_md.machine_kexec) 90 ppc_md.machine_kexec(image); 91 else 92 default_machine_kexec(image); 93 94 this_cpu_enable_ftrace(); 95 __ftrace_enabled_restore(save_ftrace_enabled); 96 97 /* Fall back to normal restart if we're still alive. */ 98 machine_restart(NULL); 99 for(;;); 100 } 101 102 void __init reserve_crashkernel(void) 103 { 104 unsigned long long crash_size, crash_base, total_mem_sz; 105 int ret; 106 107 total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size(); 108 /* use common parsing */ 109 ret = parse_crashkernel(boot_command_line, total_mem_sz, 110 &crash_size, &crash_base); 111 if (ret == 0 && crash_size > 0) { 112 crashk_res.start = crash_base; 113 crashk_res.end = crash_base + crash_size - 1; 114 } 115 116 if (crashk_res.end == crashk_res.start) { 117 crashk_res.start = crashk_res.end = 0; 118 return; 119 } 120 121 /* We might have got these values via the command line or the 122 * device tree, either way sanitise them now. */ 123 124 crash_size = resource_size(&crashk_res); 125 126 #ifndef CONFIG_NONSTATIC_KERNEL 127 if (crashk_res.start != KDUMP_KERNELBASE) 128 printk("Crash kernel location must be 0x%x\n", 129 KDUMP_KERNELBASE); 130 131 crashk_res.start = KDUMP_KERNELBASE; 132 #else 133 if (!crashk_res.start) { 134 #ifdef CONFIG_PPC64 135 /* 136 * On the LPAR platform place the crash kernel to mid of 137 * RMA size (512MB or more) to ensure the crash kernel 138 * gets enough space to place itself and some stack to be 139 * in the first segment. At the same time normal kernel 140 * also get enough space to allocate memory for essential 141 * system resource in the first segment. Keep the crash 142 * kernel starts at 128MB offset on other platforms. 143 */ 144 if (firmware_has_feature(FW_FEATURE_LPAR)) 145 crashk_res.start = ppc64_rma_size / 2; 146 else 147 crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2)); 148 #else 149 crashk_res.start = KDUMP_KERNELBASE; 150 #endif 151 } 152 153 crash_base = PAGE_ALIGN(crashk_res.start); 154 if (crash_base != crashk_res.start) { 155 printk("Crash kernel base must be aligned to 0x%lx\n", 156 PAGE_SIZE); 157 crashk_res.start = crash_base; 158 } 159 160 #endif 161 crash_size = PAGE_ALIGN(crash_size); 162 crashk_res.end = crashk_res.start + crash_size - 1; 163 164 /* The crash region must not overlap the current kernel */ 165 if (overlaps_crashkernel(__pa(_stext), _end - _stext)) { 166 printk(KERN_WARNING 167 "Crash kernel can not overlap current kernel\n"); 168 crashk_res.start = crashk_res.end = 0; 169 return; 170 } 171 172 /* Crash kernel trumps memory limit */ 173 if (memory_limit && memory_limit <= crashk_res.end) { 174 memory_limit = crashk_res.end + 1; 175 total_mem_sz = memory_limit; 176 printk("Adjusted memory limit for crashkernel, now 0x%llx\n", 177 memory_limit); 178 } 179 180 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB " 181 "for crashkernel (System RAM: %ldMB)\n", 182 (unsigned long)(crash_size >> 20), 183 (unsigned long)(crashk_res.start >> 20), 184 (unsigned long)(total_mem_sz >> 20)); 185 186 if (!memblock_is_region_memory(crashk_res.start, crash_size) || 187 memblock_reserve(crashk_res.start, crash_size)) { 188 pr_err("Failed to reserve memory for crashkernel!\n"); 189 crashk_res.start = crashk_res.end = 0; 190 return; 191 } 192 } 193 194 int __init overlaps_crashkernel(unsigned long start, unsigned long size) 195 { 196 return (start + size) > crashk_res.start && start <= crashk_res.end; 197 } 198 199 /* Values we need to export to the second kernel via the device tree. */ 200 static phys_addr_t kernel_end; 201 static phys_addr_t crashk_base; 202 static phys_addr_t crashk_size; 203 static unsigned long long mem_limit; 204 205 static struct property kernel_end_prop = { 206 .name = "linux,kernel-end", 207 .length = sizeof(phys_addr_t), 208 .value = &kernel_end, 209 }; 210 211 static struct property crashk_base_prop = { 212 .name = "linux,crashkernel-base", 213 .length = sizeof(phys_addr_t), 214 .value = &crashk_base 215 }; 216 217 static struct property crashk_size_prop = { 218 .name = "linux,crashkernel-size", 219 .length = sizeof(phys_addr_t), 220 .value = &crashk_size, 221 }; 222 223 static struct property memory_limit_prop = { 224 .name = "linux,memory-limit", 225 .length = sizeof(unsigned long long), 226 .value = &mem_limit, 227 }; 228 229 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG) 230 231 static void __init export_crashk_values(struct device_node *node) 232 { 233 /* There might be existing crash kernel properties, but we can't 234 * be sure what's in them, so remove them. */ 235 of_remove_property(node, of_find_property(node, 236 "linux,crashkernel-base", NULL)); 237 of_remove_property(node, of_find_property(node, 238 "linux,crashkernel-size", NULL)); 239 240 if (crashk_res.start != 0) { 241 crashk_base = cpu_to_be_ulong(crashk_res.start), 242 of_add_property(node, &crashk_base_prop); 243 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res)); 244 of_add_property(node, &crashk_size_prop); 245 } 246 247 /* 248 * memory_limit is required by the kexec-tools to limit the 249 * crash regions to the actual memory used. 250 */ 251 mem_limit = cpu_to_be_ulong(memory_limit); 252 of_update_property(node, &memory_limit_prop); 253 } 254 255 static int __init kexec_setup(void) 256 { 257 struct device_node *node; 258 259 node = of_find_node_by_path("/chosen"); 260 if (!node) 261 return -ENOENT; 262 263 /* remove any stale properties so ours can be found */ 264 of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL)); 265 266 /* information needed by userspace when using default_machine_kexec */ 267 kernel_end = cpu_to_be_ulong(__pa(_end)); 268 of_add_property(node, &kernel_end_prop); 269 270 export_crashk_values(node); 271 272 of_node_put(node); 273 return 0; 274 } 275 late_initcall(kexec_setup); 276