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 /* 52 * Do what every setup is needed on image and the 53 * reboot code buffer to allow us to avoid allocations 54 * later. 55 */ 56 int machine_kexec_prepare(struct kimage *image) 57 { 58 if (ppc_md.machine_kexec_prepare) 59 return ppc_md.machine_kexec_prepare(image); 60 else 61 return default_machine_kexec_prepare(image); 62 } 63 64 void machine_kexec_cleanup(struct kimage *image) 65 { 66 } 67 68 void arch_crash_save_vmcoreinfo(void) 69 { 70 71 #ifdef CONFIG_NEED_MULTIPLE_NODES 72 VMCOREINFO_SYMBOL(node_data); 73 VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); 74 #endif 75 #ifndef CONFIG_NEED_MULTIPLE_NODES 76 VMCOREINFO_SYMBOL(contig_page_data); 77 #endif 78 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP) 79 VMCOREINFO_SYMBOL(vmemmap_list); 80 VMCOREINFO_SYMBOL(mmu_vmemmap_psize); 81 VMCOREINFO_SYMBOL(mmu_psize_defs); 82 VMCOREINFO_STRUCT_SIZE(vmemmap_backing); 83 VMCOREINFO_OFFSET(vmemmap_backing, list); 84 VMCOREINFO_OFFSET(vmemmap_backing, phys); 85 VMCOREINFO_OFFSET(vmemmap_backing, virt_addr); 86 VMCOREINFO_STRUCT_SIZE(mmu_psize_def); 87 VMCOREINFO_OFFSET(mmu_psize_def, shift); 88 #endif 89 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); 90 } 91 92 /* 93 * Do not allocate memory (or fail in any way) in machine_kexec(). 94 * We are past the point of no return, committed to rebooting now. 95 */ 96 void machine_kexec(struct kimage *image) 97 { 98 int save_ftrace_enabled; 99 100 save_ftrace_enabled = __ftrace_enabled_save(); 101 this_cpu_disable_ftrace(); 102 103 if (ppc_md.machine_kexec) 104 ppc_md.machine_kexec(image); 105 else 106 default_machine_kexec(image); 107 108 this_cpu_enable_ftrace(); 109 __ftrace_enabled_restore(save_ftrace_enabled); 110 111 /* Fall back to normal restart if we're still alive. */ 112 machine_restart(NULL); 113 for(;;); 114 } 115 116 void __init reserve_crashkernel(void) 117 { 118 unsigned long long crash_size, crash_base, total_mem_sz; 119 int ret; 120 121 total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size(); 122 /* use common parsing */ 123 ret = parse_crashkernel(boot_command_line, total_mem_sz, 124 &crash_size, &crash_base); 125 if (ret == 0 && crash_size > 0) { 126 crashk_res.start = crash_base; 127 crashk_res.end = crash_base + crash_size - 1; 128 } 129 130 if (crashk_res.end == crashk_res.start) { 131 crashk_res.start = crashk_res.end = 0; 132 return; 133 } 134 135 /* We might have got these values via the command line or the 136 * device tree, either way sanitise them now. */ 137 138 crash_size = resource_size(&crashk_res); 139 140 #ifndef CONFIG_NONSTATIC_KERNEL 141 if (crashk_res.start != KDUMP_KERNELBASE) 142 printk("Crash kernel location must be 0x%x\n", 143 KDUMP_KERNELBASE); 144 145 crashk_res.start = KDUMP_KERNELBASE; 146 #else 147 if (!crashk_res.start) { 148 #ifdef CONFIG_PPC64 149 /* 150 * On 64bit we split the RMO in half but cap it at half of 151 * a small SLB (128MB) since the crash kernel needs to place 152 * itself and some stacks to be in the first segment. 153 */ 154 crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2)); 155 #else 156 crashk_res.start = KDUMP_KERNELBASE; 157 #endif 158 } 159 160 crash_base = PAGE_ALIGN(crashk_res.start); 161 if (crash_base != crashk_res.start) { 162 printk("Crash kernel base must be aligned to 0x%lx\n", 163 PAGE_SIZE); 164 crashk_res.start = crash_base; 165 } 166 167 #endif 168 crash_size = PAGE_ALIGN(crash_size); 169 crashk_res.end = crashk_res.start + crash_size - 1; 170 171 /* The crash region must not overlap the current kernel */ 172 if (overlaps_crashkernel(__pa(_stext), _end - _stext)) { 173 printk(KERN_WARNING 174 "Crash kernel can not overlap current kernel\n"); 175 crashk_res.start = crashk_res.end = 0; 176 return; 177 } 178 179 /* Crash kernel trumps memory limit */ 180 if (memory_limit && memory_limit <= crashk_res.end) { 181 memory_limit = crashk_res.end + 1; 182 total_mem_sz = memory_limit; 183 printk("Adjusted memory limit for crashkernel, now 0x%llx\n", 184 memory_limit); 185 } 186 187 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB " 188 "for crashkernel (System RAM: %ldMB)\n", 189 (unsigned long)(crash_size >> 20), 190 (unsigned long)(crashk_res.start >> 20), 191 (unsigned long)(total_mem_sz >> 20)); 192 193 if (!memblock_is_region_memory(crashk_res.start, crash_size) || 194 memblock_reserve(crashk_res.start, crash_size)) { 195 pr_err("Failed to reserve memory for crashkernel!\n"); 196 crashk_res.start = crashk_res.end = 0; 197 return; 198 } 199 } 200 201 int overlaps_crashkernel(unsigned long start, unsigned long size) 202 { 203 return (start + size) > crashk_res.start && start <= crashk_res.end; 204 } 205 206 /* Values we need to export to the second kernel via the device tree. */ 207 static phys_addr_t kernel_end; 208 static phys_addr_t crashk_base; 209 static phys_addr_t crashk_size; 210 static unsigned long long mem_limit; 211 212 static struct property kernel_end_prop = { 213 .name = "linux,kernel-end", 214 .length = sizeof(phys_addr_t), 215 .value = &kernel_end, 216 }; 217 218 static struct property crashk_base_prop = { 219 .name = "linux,crashkernel-base", 220 .length = sizeof(phys_addr_t), 221 .value = &crashk_base 222 }; 223 224 static struct property crashk_size_prop = { 225 .name = "linux,crashkernel-size", 226 .length = sizeof(phys_addr_t), 227 .value = &crashk_size, 228 }; 229 230 static struct property memory_limit_prop = { 231 .name = "linux,memory-limit", 232 .length = sizeof(unsigned long long), 233 .value = &mem_limit, 234 }; 235 236 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG) 237 238 static void __init export_crashk_values(struct device_node *node) 239 { 240 /* There might be existing crash kernel properties, but we can't 241 * be sure what's in them, so remove them. */ 242 of_remove_property(node, of_find_property(node, 243 "linux,crashkernel-base", NULL)); 244 of_remove_property(node, of_find_property(node, 245 "linux,crashkernel-size", NULL)); 246 247 if (crashk_res.start != 0) { 248 crashk_base = cpu_to_be_ulong(crashk_res.start), 249 of_add_property(node, &crashk_base_prop); 250 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res)); 251 of_add_property(node, &crashk_size_prop); 252 } 253 254 /* 255 * memory_limit is required by the kexec-tools to limit the 256 * crash regions to the actual memory used. 257 */ 258 mem_limit = cpu_to_be_ulong(memory_limit); 259 of_update_property(node, &memory_limit_prop); 260 } 261 262 static int __init kexec_setup(void) 263 { 264 struct device_node *node; 265 266 node = of_find_node_by_path("/chosen"); 267 if (!node) 268 return -ENOENT; 269 270 /* remove any stale properties so ours can be found */ 271 of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL)); 272 273 /* information needed by userspace when using default_machine_kexec */ 274 kernel_end = cpu_to_be_ulong(__pa(_end)); 275 of_add_property(node, &kernel_end_prop); 276 277 export_crashk_values(node); 278 279 of_node_put(node); 280 return 0; 281 } 282 late_initcall(kexec_setup); 283