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 #include <asm/setup.h> 23 #include <asm/firmware.h> 24 25 void machine_kexec_mask_interrupts(void) { 26 unsigned int i; 27 struct irq_desc *desc; 28 29 for_each_irq_desc(i, desc) { 30 struct irq_chip *chip; 31 32 chip = irq_desc_get_chip(desc); 33 if (!chip) 34 continue; 35 36 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) 37 chip->irq_eoi(&desc->irq_data); 38 39 if (chip->irq_mask) 40 chip->irq_mask(&desc->irq_data); 41 42 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) 43 chip->irq_disable(&desc->irq_data); 44 } 45 } 46 47 void machine_crash_shutdown(struct pt_regs *regs) 48 { 49 default_machine_crash_shutdown(regs); 50 } 51 52 void machine_kexec_cleanup(struct kimage *image) 53 { 54 } 55 56 void arch_crash_save_vmcoreinfo(void) 57 { 58 59 #ifdef CONFIG_NUMA 60 VMCOREINFO_SYMBOL(node_data); 61 VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); 62 #endif 63 #ifndef CONFIG_NUMA 64 VMCOREINFO_SYMBOL(contig_page_data); 65 #endif 66 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP) 67 VMCOREINFO_SYMBOL(vmemmap_list); 68 VMCOREINFO_SYMBOL(mmu_vmemmap_psize); 69 VMCOREINFO_SYMBOL(mmu_psize_defs); 70 VMCOREINFO_STRUCT_SIZE(vmemmap_backing); 71 VMCOREINFO_OFFSET(vmemmap_backing, list); 72 VMCOREINFO_OFFSET(vmemmap_backing, phys); 73 VMCOREINFO_OFFSET(vmemmap_backing, virt_addr); 74 VMCOREINFO_STRUCT_SIZE(mmu_psize_def); 75 VMCOREINFO_OFFSET(mmu_psize_def, shift); 76 #endif 77 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); 78 } 79 80 /* 81 * Do not allocate memory (or fail in any way) in machine_kexec(). 82 * We are past the point of no return, committed to rebooting now. 83 */ 84 void machine_kexec(struct kimage *image) 85 { 86 int save_ftrace_enabled; 87 88 save_ftrace_enabled = __ftrace_enabled_save(); 89 this_cpu_disable_ftrace(); 90 91 if (ppc_md.machine_kexec) 92 ppc_md.machine_kexec(image); 93 else 94 default_machine_kexec(image); 95 96 this_cpu_enable_ftrace(); 97 __ftrace_enabled_restore(save_ftrace_enabled); 98 99 /* Fall back to normal restart if we're still alive. */ 100 machine_restart(NULL); 101 for(;;); 102 } 103 104 void __init reserve_crashkernel(void) 105 { 106 unsigned long long crash_size, crash_base, total_mem_sz; 107 int ret; 108 109 total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size(); 110 /* use common parsing */ 111 ret = parse_crashkernel(boot_command_line, total_mem_sz, 112 &crash_size, &crash_base); 113 if (ret == 0 && crash_size > 0) { 114 crashk_res.start = crash_base; 115 crashk_res.end = crash_base + crash_size - 1; 116 } 117 118 if (crashk_res.end == crashk_res.start) { 119 crashk_res.start = crashk_res.end = 0; 120 return; 121 } 122 123 /* We might have got these values via the command line or the 124 * device tree, either way sanitise them now. */ 125 126 crash_size = resource_size(&crashk_res); 127 128 #ifndef CONFIG_NONSTATIC_KERNEL 129 if (crashk_res.start != KDUMP_KERNELBASE) 130 printk("Crash kernel location must be 0x%x\n", 131 KDUMP_KERNELBASE); 132 133 crashk_res.start = KDUMP_KERNELBASE; 134 #else 135 if (!crashk_res.start) { 136 #ifdef CONFIG_PPC64 137 /* 138 * On the LPAR platform place the crash kernel to mid of 139 * RMA size (max. of 512MB) to ensure the crash kernel 140 * gets enough space to place itself and some stack to be 141 * in the first segment. At the same time normal kernel 142 * also get enough space to allocate memory for essential 143 * system resource in the first segment. Keep the crash 144 * kernel starts at 128MB offset on other platforms. 145 */ 146 if (firmware_has_feature(FW_FEATURE_LPAR)) 147 crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_512M); 148 else 149 crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_128M); 150 #else 151 crashk_res.start = KDUMP_KERNELBASE; 152 #endif 153 } 154 155 crash_base = PAGE_ALIGN(crashk_res.start); 156 if (crash_base != crashk_res.start) { 157 printk("Crash kernel base must be aligned to 0x%lx\n", 158 PAGE_SIZE); 159 crashk_res.start = crash_base; 160 } 161 162 #endif 163 crash_size = PAGE_ALIGN(crash_size); 164 crashk_res.end = crashk_res.start + crash_size - 1; 165 166 /* The crash region must not overlap the current kernel */ 167 if (overlaps_crashkernel(__pa(_stext), _end - _stext)) { 168 printk(KERN_WARNING 169 "Crash kernel can not overlap current kernel\n"); 170 crashk_res.start = crashk_res.end = 0; 171 return; 172 } 173 174 /* Crash kernel trumps memory limit */ 175 if (memory_limit && memory_limit <= crashk_res.end) { 176 memory_limit = crashk_res.end + 1; 177 total_mem_sz = memory_limit; 178 printk("Adjusted memory limit for crashkernel, now 0x%llx\n", 179 memory_limit); 180 } 181 182 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB " 183 "for crashkernel (System RAM: %ldMB)\n", 184 (unsigned long)(crash_size >> 20), 185 (unsigned long)(crashk_res.start >> 20), 186 (unsigned long)(total_mem_sz >> 20)); 187 188 if (!memblock_is_region_memory(crashk_res.start, crash_size) || 189 memblock_reserve(crashk_res.start, crash_size)) { 190 pr_err("Failed to reserve memory for crashkernel!\n"); 191 crashk_res.start = crashk_res.end = 0; 192 return; 193 } 194 } 195 196 int __init overlaps_crashkernel(unsigned long start, unsigned long size) 197 { 198 return (start + size) > crashk_res.start && start <= crashk_res.end; 199 } 200 201 /* Values we need to export to the second kernel via the device tree. */ 202 static phys_addr_t kernel_end; 203 static phys_addr_t crashk_base; 204 static phys_addr_t crashk_size; 205 static unsigned long long mem_limit; 206 207 static struct property kernel_end_prop = { 208 .name = "linux,kernel-end", 209 .length = sizeof(phys_addr_t), 210 .value = &kernel_end, 211 }; 212 213 static struct property crashk_base_prop = { 214 .name = "linux,crashkernel-base", 215 .length = sizeof(phys_addr_t), 216 .value = &crashk_base 217 }; 218 219 static struct property crashk_size_prop = { 220 .name = "linux,crashkernel-size", 221 .length = sizeof(phys_addr_t), 222 .value = &crashk_size, 223 }; 224 225 static struct property memory_limit_prop = { 226 .name = "linux,memory-limit", 227 .length = sizeof(unsigned long long), 228 .value = &mem_limit, 229 }; 230 231 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG) 232 233 static void __init export_crashk_values(struct device_node *node) 234 { 235 /* There might be existing crash kernel properties, but we can't 236 * be sure what's in them, so remove them. */ 237 of_remove_property(node, of_find_property(node, 238 "linux,crashkernel-base", NULL)); 239 of_remove_property(node, of_find_property(node, 240 "linux,crashkernel-size", NULL)); 241 242 if (crashk_res.start != 0) { 243 crashk_base = cpu_to_be_ulong(crashk_res.start), 244 of_add_property(node, &crashk_base_prop); 245 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res)); 246 of_add_property(node, &crashk_size_prop); 247 } 248 249 /* 250 * memory_limit is required by the kexec-tools to limit the 251 * crash regions to the actual memory used. 252 */ 253 mem_limit = cpu_to_be_ulong(memory_limit); 254 of_update_property(node, &memory_limit_prop); 255 } 256 257 static int __init kexec_setup(void) 258 { 259 struct device_node *node; 260 261 node = of_find_node_by_path("/chosen"); 262 if (!node) 263 return -ENOENT; 264 265 /* remove any stale properties so ours can be found */ 266 of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL)); 267 268 /* information needed by userspace when using default_machine_kexec */ 269 kernel_end = cpu_to_be_ulong(__pa(_end)); 270 of_add_property(node, &kernel_end_prop); 271 272 export_crashk_values(node); 273 274 of_node_put(node); 275 return 0; 276 } 277 late_initcall(kexec_setup); 278