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_SYMBOL(cur_cpu_spec); 78 VMCOREINFO_OFFSET(cpu_spec, cpu_features); 79 VMCOREINFO_OFFSET(cpu_spec, mmu_features); 80 vmcoreinfo_append_str("NUMBER(RADIX_MMU)=%d\n", early_radix_enabled()); 81 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); 82 } 83 84 /* 85 * Do not allocate memory (or fail in any way) in machine_kexec(). 86 * We are past the point of no return, committed to rebooting now. 87 */ 88 void machine_kexec(struct kimage *image) 89 { 90 int save_ftrace_enabled; 91 92 save_ftrace_enabled = __ftrace_enabled_save(); 93 this_cpu_disable_ftrace(); 94 95 if (ppc_md.machine_kexec) 96 ppc_md.machine_kexec(image); 97 else 98 default_machine_kexec(image); 99 100 this_cpu_enable_ftrace(); 101 __ftrace_enabled_restore(save_ftrace_enabled); 102 103 /* Fall back to normal restart if we're still alive. */ 104 machine_restart(NULL); 105 for(;;); 106 } 107 108 void __init reserve_crashkernel(void) 109 { 110 unsigned long long crash_size, crash_base, total_mem_sz; 111 int ret; 112 113 total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size(); 114 /* use common parsing */ 115 ret = parse_crashkernel(boot_command_line, total_mem_sz, 116 &crash_size, &crash_base, NULL, NULL); 117 if (ret == 0 && crash_size > 0) { 118 crashk_res.start = crash_base; 119 crashk_res.end = crash_base + crash_size - 1; 120 } 121 122 if (crashk_res.end == crashk_res.start) { 123 crashk_res.start = crashk_res.end = 0; 124 return; 125 } 126 127 /* We might have got these values via the command line or the 128 * device tree, either way sanitise them now. */ 129 130 crash_size = resource_size(&crashk_res); 131 132 #ifndef CONFIG_NONSTATIC_KERNEL 133 if (crashk_res.start != KDUMP_KERNELBASE) 134 printk("Crash kernel location must be 0x%x\n", 135 KDUMP_KERNELBASE); 136 137 crashk_res.start = KDUMP_KERNELBASE; 138 #else 139 if (!crashk_res.start) { 140 #ifdef CONFIG_PPC64 141 /* 142 * On the LPAR platform place the crash kernel to mid of 143 * RMA size (max. of 512MB) to ensure the crash kernel 144 * gets enough space to place itself and some stack to be 145 * in the first segment. At the same time normal kernel 146 * also get enough space to allocate memory for essential 147 * system resource in the first segment. Keep the crash 148 * kernel starts at 128MB offset on other platforms. 149 */ 150 if (firmware_has_feature(FW_FEATURE_LPAR)) 151 crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_512M); 152 else 153 crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_128M); 154 #else 155 crashk_res.start = KDUMP_KERNELBASE; 156 #endif 157 } 158 159 crash_base = PAGE_ALIGN(crashk_res.start); 160 if (crash_base != crashk_res.start) { 161 printk("Crash kernel base must be aligned to 0x%lx\n", 162 PAGE_SIZE); 163 crashk_res.start = crash_base; 164 } 165 166 #endif 167 crash_size = PAGE_ALIGN(crash_size); 168 crashk_res.end = crashk_res.start + crash_size - 1; 169 170 /* The crash region must not overlap the current kernel */ 171 if (overlaps_crashkernel(__pa(_stext), _end - _stext)) { 172 printk(KERN_WARNING 173 "Crash kernel can not overlap current kernel\n"); 174 crashk_res.start = crashk_res.end = 0; 175 return; 176 } 177 178 /* Crash kernel trumps memory limit */ 179 if (memory_limit && memory_limit <= crashk_res.end) { 180 memory_limit = crashk_res.end + 1; 181 total_mem_sz = memory_limit; 182 printk("Adjusted memory limit for crashkernel, now 0x%llx\n", 183 memory_limit); 184 } 185 186 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB " 187 "for crashkernel (System RAM: %ldMB)\n", 188 (unsigned long)(crash_size >> 20), 189 (unsigned long)(crashk_res.start >> 20), 190 (unsigned long)(total_mem_sz >> 20)); 191 192 if (!memblock_is_region_memory(crashk_res.start, crash_size) || 193 memblock_reserve(crashk_res.start, crash_size)) { 194 pr_err("Failed to reserve memory for crashkernel!\n"); 195 crashk_res.start = crashk_res.end = 0; 196 return; 197 } 198 } 199 200 int __init overlaps_crashkernel(unsigned long start, unsigned long size) 201 { 202 return (start + size) > crashk_res.start && start <= crashk_res.end; 203 } 204 205 /* Values we need to export to the second kernel via the device tree. */ 206 static phys_addr_t kernel_end; 207 static phys_addr_t crashk_base; 208 static phys_addr_t crashk_size; 209 static unsigned long long mem_limit; 210 211 static struct property kernel_end_prop = { 212 .name = "linux,kernel-end", 213 .length = sizeof(phys_addr_t), 214 .value = &kernel_end, 215 }; 216 217 static struct property crashk_base_prop = { 218 .name = "linux,crashkernel-base", 219 .length = sizeof(phys_addr_t), 220 .value = &crashk_base 221 }; 222 223 static struct property crashk_size_prop = { 224 .name = "linux,crashkernel-size", 225 .length = sizeof(phys_addr_t), 226 .value = &crashk_size, 227 }; 228 229 static struct property memory_limit_prop = { 230 .name = "linux,memory-limit", 231 .length = sizeof(unsigned long long), 232 .value = &mem_limit, 233 }; 234 235 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG) 236 237 static void __init export_crashk_values(struct device_node *node) 238 { 239 /* There might be existing crash kernel properties, but we can't 240 * be sure what's in them, so remove them. */ 241 of_remove_property(node, of_find_property(node, 242 "linux,crashkernel-base", NULL)); 243 of_remove_property(node, of_find_property(node, 244 "linux,crashkernel-size", NULL)); 245 246 if (crashk_res.start != 0) { 247 crashk_base = cpu_to_be_ulong(crashk_res.start), 248 of_add_property(node, &crashk_base_prop); 249 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res)); 250 of_add_property(node, &crashk_size_prop); 251 } 252 253 /* 254 * memory_limit is required by the kexec-tools to limit the 255 * crash regions to the actual memory used. 256 */ 257 mem_limit = cpu_to_be_ulong(memory_limit); 258 of_update_property(node, &memory_limit_prop); 259 } 260 261 static int __init kexec_setup(void) 262 { 263 struct device_node *node; 264 265 node = of_find_node_by_path("/chosen"); 266 if (!node) 267 return -ENOENT; 268 269 /* remove any stale properties so ours can be found */ 270 of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL)); 271 272 /* information needed by userspace when using default_machine_kexec */ 273 kernel_end = cpu_to_be_ulong(__pa(_end)); 274 of_add_property(node, &kernel_end_prop); 275 276 export_crashk_values(node); 277 278 of_node_put(node); 279 return 0; 280 } 281 late_initcall(kexec_setup); 282