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/prom.h> 22 #include <asm/sections.h> 23 24 void machine_kexec_mask_interrupts(void) { 25 unsigned int i; 26 struct irq_desc *desc; 27 28 for_each_irq_desc(i, desc) { 29 struct irq_chip *chip; 30 31 chip = irq_desc_get_chip(desc); 32 if (!chip) 33 continue; 34 35 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) 36 chip->irq_eoi(&desc->irq_data); 37 38 if (chip->irq_mask) 39 chip->irq_mask(&desc->irq_data); 40 41 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) 42 chip->irq_disable(&desc->irq_data); 43 } 44 } 45 46 void machine_crash_shutdown(struct pt_regs *regs) 47 { 48 default_machine_crash_shutdown(regs); 49 } 50 51 void machine_kexec_cleanup(struct kimage *image) 52 { 53 } 54 55 void arch_crash_save_vmcoreinfo(void) 56 { 57 58 #ifdef CONFIG_NUMA 59 VMCOREINFO_SYMBOL(node_data); 60 VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); 61 #endif 62 #ifndef CONFIG_NUMA 63 VMCOREINFO_SYMBOL(contig_page_data); 64 #endif 65 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP) 66 VMCOREINFO_SYMBOL(vmemmap_list); 67 VMCOREINFO_SYMBOL(mmu_vmemmap_psize); 68 VMCOREINFO_SYMBOL(mmu_psize_defs); 69 VMCOREINFO_STRUCT_SIZE(vmemmap_backing); 70 VMCOREINFO_OFFSET(vmemmap_backing, list); 71 VMCOREINFO_OFFSET(vmemmap_backing, phys); 72 VMCOREINFO_OFFSET(vmemmap_backing, virt_addr); 73 VMCOREINFO_STRUCT_SIZE(mmu_psize_def); 74 VMCOREINFO_OFFSET(mmu_psize_def, shift); 75 #endif 76 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); 77 } 78 79 /* 80 * Do not allocate memory (or fail in any way) in machine_kexec(). 81 * We are past the point of no return, committed to rebooting now. 82 */ 83 void machine_kexec(struct kimage *image) 84 { 85 int save_ftrace_enabled; 86 87 save_ftrace_enabled = __ftrace_enabled_save(); 88 this_cpu_disable_ftrace(); 89 90 if (ppc_md.machine_kexec) 91 ppc_md.machine_kexec(image); 92 else 93 default_machine_kexec(image); 94 95 this_cpu_enable_ftrace(); 96 __ftrace_enabled_restore(save_ftrace_enabled); 97 98 /* Fall back to normal restart if we're still alive. */ 99 machine_restart(NULL); 100 for(;;); 101 } 102 103 void __init reserve_crashkernel(void) 104 { 105 unsigned long long crash_size, crash_base, total_mem_sz; 106 int ret; 107 108 total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size(); 109 /* use common parsing */ 110 ret = parse_crashkernel(boot_command_line, total_mem_sz, 111 &crash_size, &crash_base); 112 if (ret == 0 && crash_size > 0) { 113 crashk_res.start = crash_base; 114 crashk_res.end = crash_base + crash_size - 1; 115 } 116 117 if (crashk_res.end == crashk_res.start) { 118 crashk_res.start = crashk_res.end = 0; 119 return; 120 } 121 122 /* We might have got these values via the command line or the 123 * device tree, either way sanitise them now. */ 124 125 crash_size = resource_size(&crashk_res); 126 127 #ifndef CONFIG_NONSTATIC_KERNEL 128 if (crashk_res.start != KDUMP_KERNELBASE) 129 printk("Crash kernel location must be 0x%x\n", 130 KDUMP_KERNELBASE); 131 132 crashk_res.start = KDUMP_KERNELBASE; 133 #else 134 if (!crashk_res.start) { 135 #ifdef CONFIG_PPC64 136 /* 137 * On the LPAR platform place the crash kernel to mid of 138 * RMA size (512MB or more) to ensure the crash kernel 139 * gets enough space to place itself and some stack to be 140 * in the first segment. At the same time normal kernel 141 * also get enough space to allocate memory for essential 142 * system resource in the first segment. Keep the crash 143 * kernel starts at 128MB offset on other platforms. 144 */ 145 if (firmware_has_feature(FW_FEATURE_LPAR)) 146 crashk_res.start = ppc64_rma_size / 2; 147 else 148 crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2)); 149 #else 150 crashk_res.start = KDUMP_KERNELBASE; 151 #endif 152 } 153 154 crash_base = PAGE_ALIGN(crashk_res.start); 155 if (crash_base != crashk_res.start) { 156 printk("Crash kernel base must be aligned to 0x%lx\n", 157 PAGE_SIZE); 158 crashk_res.start = crash_base; 159 } 160 161 #endif 162 crash_size = PAGE_ALIGN(crash_size); 163 crashk_res.end = crashk_res.start + crash_size - 1; 164 165 /* The crash region must not overlap the current kernel */ 166 if (overlaps_crashkernel(__pa(_stext), _end - _stext)) { 167 printk(KERN_WARNING 168 "Crash kernel can not overlap current kernel\n"); 169 crashk_res.start = crashk_res.end = 0; 170 return; 171 } 172 173 /* Crash kernel trumps memory limit */ 174 if (memory_limit && memory_limit <= crashk_res.end) { 175 memory_limit = crashk_res.end + 1; 176 total_mem_sz = memory_limit; 177 printk("Adjusted memory limit for crashkernel, now 0x%llx\n", 178 memory_limit); 179 } 180 181 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB " 182 "for crashkernel (System RAM: %ldMB)\n", 183 (unsigned long)(crash_size >> 20), 184 (unsigned long)(crashk_res.start >> 20), 185 (unsigned long)(total_mem_sz >> 20)); 186 187 if (!memblock_is_region_memory(crashk_res.start, crash_size) || 188 memblock_reserve(crashk_res.start, crash_size)) { 189 pr_err("Failed to reserve memory for crashkernel!\n"); 190 crashk_res.start = crashk_res.end = 0; 191 return; 192 } 193 } 194 195 int __init overlaps_crashkernel(unsigned long start, unsigned long size) 196 { 197 return (start + size) > crashk_res.start && start <= crashk_res.end; 198 } 199 200 /* Values we need to export to the second kernel via the device tree. */ 201 static phys_addr_t kernel_end; 202 static phys_addr_t crashk_base; 203 static phys_addr_t crashk_size; 204 static unsigned long long mem_limit; 205 206 static struct property kernel_end_prop = { 207 .name = "linux,kernel-end", 208 .length = sizeof(phys_addr_t), 209 .value = &kernel_end, 210 }; 211 212 static struct property crashk_base_prop = { 213 .name = "linux,crashkernel-base", 214 .length = sizeof(phys_addr_t), 215 .value = &crashk_base 216 }; 217 218 static struct property crashk_size_prop = { 219 .name = "linux,crashkernel-size", 220 .length = sizeof(phys_addr_t), 221 .value = &crashk_size, 222 }; 223 224 static struct property memory_limit_prop = { 225 .name = "linux,memory-limit", 226 .length = sizeof(unsigned long long), 227 .value = &mem_limit, 228 }; 229 230 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG) 231 232 static void __init export_crashk_values(struct device_node *node) 233 { 234 /* There might be existing crash kernel properties, but we can't 235 * be sure what's in them, so remove them. */ 236 of_remove_property(node, of_find_property(node, 237 "linux,crashkernel-base", NULL)); 238 of_remove_property(node, of_find_property(node, 239 "linux,crashkernel-size", NULL)); 240 241 if (crashk_res.start != 0) { 242 crashk_base = cpu_to_be_ulong(crashk_res.start), 243 of_add_property(node, &crashk_base_prop); 244 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res)); 245 of_add_property(node, &crashk_size_prop); 246 } 247 248 /* 249 * memory_limit is required by the kexec-tools to limit the 250 * crash regions to the actual memory used. 251 */ 252 mem_limit = cpu_to_be_ulong(memory_limit); 253 of_update_property(node, &memory_limit_prop); 254 } 255 256 static int __init kexec_setup(void) 257 { 258 struct device_node *node; 259 260 node = of_find_node_by_path("/chosen"); 261 if (!node) 262 return -ENOENT; 263 264 /* remove any stale properties so ours can be found */ 265 of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL)); 266 267 /* information needed by userspace when using default_machine_kexec */ 268 kernel_end = cpu_to_be_ulong(__pa(_end)); 269 of_add_property(node, &kernel_end_prop); 270 271 export_crashk_values(node); 272 273 of_node_put(node); 274 return 0; 275 } 276 late_initcall(kexec_setup); 277