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 VMCOREINFO_SYMBOL(cur_cpu_spec); 67 VMCOREINFO_OFFSET(cpu_spec, mmu_features); 68 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP) 69 VMCOREINFO_SYMBOL(vmemmap_list); 70 VMCOREINFO_SYMBOL(mmu_vmemmap_psize); 71 VMCOREINFO_SYMBOL(mmu_psize_defs); 72 VMCOREINFO_STRUCT_SIZE(vmemmap_backing); 73 VMCOREINFO_OFFSET(vmemmap_backing, list); 74 VMCOREINFO_OFFSET(vmemmap_backing, phys); 75 VMCOREINFO_OFFSET(vmemmap_backing, virt_addr); 76 VMCOREINFO_STRUCT_SIZE(mmu_psize_def); 77 VMCOREINFO_OFFSET(mmu_psize_def, shift); 78 #endif 79 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); 80 } 81 82 /* 83 * Do not allocate memory (or fail in any way) in machine_kexec(). 84 * We are past the point of no return, committed to rebooting now. 85 */ 86 void machine_kexec(struct kimage *image) 87 { 88 int save_ftrace_enabled; 89 90 save_ftrace_enabled = __ftrace_enabled_save(); 91 this_cpu_disable_ftrace(); 92 93 if (ppc_md.machine_kexec) 94 ppc_md.machine_kexec(image); 95 else 96 default_machine_kexec(image); 97 98 this_cpu_enable_ftrace(); 99 __ftrace_enabled_restore(save_ftrace_enabled); 100 101 /* Fall back to normal restart if we're still alive. */ 102 machine_restart(NULL); 103 for(;;); 104 } 105 106 void __init reserve_crashkernel(void) 107 { 108 unsigned long long crash_size, crash_base, total_mem_sz; 109 int ret; 110 111 total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size(); 112 /* use common parsing */ 113 ret = parse_crashkernel(boot_command_line, total_mem_sz, 114 &crash_size, &crash_base); 115 if (ret == 0 && crash_size > 0) { 116 crashk_res.start = crash_base; 117 crashk_res.end = crash_base + crash_size - 1; 118 } 119 120 if (crashk_res.end == crashk_res.start) { 121 crashk_res.start = crashk_res.end = 0; 122 return; 123 } 124 125 /* We might have got these values via the command line or the 126 * device tree, either way sanitise them now. */ 127 128 crash_size = resource_size(&crashk_res); 129 130 #ifndef CONFIG_NONSTATIC_KERNEL 131 if (crashk_res.start != KDUMP_KERNELBASE) 132 printk("Crash kernel location must be 0x%x\n", 133 KDUMP_KERNELBASE); 134 135 crashk_res.start = KDUMP_KERNELBASE; 136 #else 137 if (!crashk_res.start) { 138 #ifdef CONFIG_PPC64 139 /* 140 * On the LPAR platform place the crash kernel to mid of 141 * RMA size (max. of 512MB) to ensure the crash kernel 142 * gets enough space to place itself and some stack to be 143 * in the first segment. At the same time normal kernel 144 * also get enough space to allocate memory for essential 145 * system resource in the first segment. Keep the crash 146 * kernel starts at 128MB offset on other platforms. 147 */ 148 if (firmware_has_feature(FW_FEATURE_LPAR)) 149 crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_512M); 150 else 151 crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_128M); 152 #else 153 crashk_res.start = KDUMP_KERNELBASE; 154 #endif 155 } 156 157 crash_base = PAGE_ALIGN(crashk_res.start); 158 if (crash_base != crashk_res.start) { 159 printk("Crash kernel base must be aligned to 0x%lx\n", 160 PAGE_SIZE); 161 crashk_res.start = crash_base; 162 } 163 164 #endif 165 crash_size = PAGE_ALIGN(crash_size); 166 crashk_res.end = crashk_res.start + crash_size - 1; 167 168 /* The crash region must not overlap the current kernel */ 169 if (overlaps_crashkernel(__pa(_stext), _end - _stext)) { 170 printk(KERN_WARNING 171 "Crash kernel can not overlap current kernel\n"); 172 crashk_res.start = crashk_res.end = 0; 173 return; 174 } 175 176 /* Crash kernel trumps memory limit */ 177 if (memory_limit && memory_limit <= crashk_res.end) { 178 memory_limit = crashk_res.end + 1; 179 total_mem_sz = memory_limit; 180 printk("Adjusted memory limit for crashkernel, now 0x%llx\n", 181 memory_limit); 182 } 183 184 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB " 185 "for crashkernel (System RAM: %ldMB)\n", 186 (unsigned long)(crash_size >> 20), 187 (unsigned long)(crashk_res.start >> 20), 188 (unsigned long)(total_mem_sz >> 20)); 189 190 if (!memblock_is_region_memory(crashk_res.start, crash_size) || 191 memblock_reserve(crashk_res.start, crash_size)) { 192 pr_err("Failed to reserve memory for crashkernel!\n"); 193 crashk_res.start = crashk_res.end = 0; 194 return; 195 } 196 } 197 198 int __init overlaps_crashkernel(unsigned long start, unsigned long size) 199 { 200 return (start + size) > crashk_res.start && start <= crashk_res.end; 201 } 202 203 /* Values we need to export to the second kernel via the device tree. */ 204 static phys_addr_t kernel_end; 205 static phys_addr_t crashk_base; 206 static phys_addr_t crashk_size; 207 static unsigned long long mem_limit; 208 209 static struct property kernel_end_prop = { 210 .name = "linux,kernel-end", 211 .length = sizeof(phys_addr_t), 212 .value = &kernel_end, 213 }; 214 215 static struct property crashk_base_prop = { 216 .name = "linux,crashkernel-base", 217 .length = sizeof(phys_addr_t), 218 .value = &crashk_base 219 }; 220 221 static struct property crashk_size_prop = { 222 .name = "linux,crashkernel-size", 223 .length = sizeof(phys_addr_t), 224 .value = &crashk_size, 225 }; 226 227 static struct property memory_limit_prop = { 228 .name = "linux,memory-limit", 229 .length = sizeof(unsigned long long), 230 .value = &mem_limit, 231 }; 232 233 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG) 234 235 static void __init export_crashk_values(struct device_node *node) 236 { 237 /* There might be existing crash kernel properties, but we can't 238 * be sure what's in them, so remove them. */ 239 of_remove_property(node, of_find_property(node, 240 "linux,crashkernel-base", NULL)); 241 of_remove_property(node, of_find_property(node, 242 "linux,crashkernel-size", NULL)); 243 244 if (crashk_res.start != 0) { 245 crashk_base = cpu_to_be_ulong(crashk_res.start), 246 of_add_property(node, &crashk_base_prop); 247 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res)); 248 of_add_property(node, &crashk_size_prop); 249 } 250 251 /* 252 * memory_limit is required by the kexec-tools to limit the 253 * crash regions to the actual memory used. 254 */ 255 mem_limit = cpu_to_be_ulong(memory_limit); 256 of_update_property(node, &memory_limit_prop); 257 } 258 259 static int __init kexec_setup(void) 260 { 261 struct device_node *node; 262 263 node = of_find_node_by_path("/chosen"); 264 if (!node) 265 return -ENOENT; 266 267 /* remove any stale properties so ours can be found */ 268 of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL)); 269 270 /* information needed by userspace when using default_machine_kexec */ 271 kernel_end = cpu_to_be_ulong(__pa(_end)); 272 of_add_property(node, &kernel_end_prop); 273 274 export_crashk_values(node); 275 276 of_node_put(node); 277 return 0; 278 } 279 late_initcall(kexec_setup); 280