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; 119 int ret; 120 121 /* use common parsing */ 122 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), 123 &crash_size, &crash_base); 124 if (ret == 0 && crash_size > 0) { 125 crashk_res.start = crash_base; 126 crashk_res.end = crash_base + crash_size - 1; 127 } 128 129 if (crashk_res.end == crashk_res.start) { 130 crashk_res.start = crashk_res.end = 0; 131 return; 132 } 133 134 /* We might have got these values via the command line or the 135 * device tree, either way sanitise them now. */ 136 137 crash_size = resource_size(&crashk_res); 138 139 #ifndef CONFIG_NONSTATIC_KERNEL 140 if (crashk_res.start != KDUMP_KERNELBASE) 141 printk("Crash kernel location must be 0x%x\n", 142 KDUMP_KERNELBASE); 143 144 crashk_res.start = KDUMP_KERNELBASE; 145 #else 146 if (!crashk_res.start) { 147 #ifdef CONFIG_PPC64 148 /* 149 * On 64bit we split the RMO in half but cap it at half of 150 * a small SLB (128MB) since the crash kernel needs to place 151 * itself and some stacks to be in the first segment. 152 */ 153 crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2)); 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 printk("Adjusted memory limit for crashkernel, now 0x%llx\n", 182 memory_limit); 183 } 184 185 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB " 186 "for crashkernel (System RAM: %ldMB)\n", 187 (unsigned long)(crash_size >> 20), 188 (unsigned long)(crashk_res.start >> 20), 189 (unsigned long)(memblock_phys_mem_size() >> 20)); 190 191 if (!memblock_is_region_memory(crashk_res.start, crash_size) || 192 memblock_reserve(crashk_res.start, crash_size)) { 193 pr_err("Failed to reserve memory for crashkernel!\n"); 194 crashk_res.start = crashk_res.end = 0; 195 return; 196 } 197 } 198 199 int overlaps_crashkernel(unsigned long start, unsigned long size) 200 { 201 return (start + size) > crashk_res.start && start <= crashk_res.end; 202 } 203 204 /* Values we need to export to the second kernel via the device tree. */ 205 static phys_addr_t kernel_end; 206 static phys_addr_t crashk_base; 207 static phys_addr_t crashk_size; 208 static unsigned long long mem_limit; 209 210 static struct property kernel_end_prop = { 211 .name = "linux,kernel-end", 212 .length = sizeof(phys_addr_t), 213 .value = &kernel_end, 214 }; 215 216 static struct property crashk_base_prop = { 217 .name = "linux,crashkernel-base", 218 .length = sizeof(phys_addr_t), 219 .value = &crashk_base 220 }; 221 222 static struct property crashk_size_prop = { 223 .name = "linux,crashkernel-size", 224 .length = sizeof(phys_addr_t), 225 .value = &crashk_size, 226 }; 227 228 static struct property memory_limit_prop = { 229 .name = "linux,memory-limit", 230 .length = sizeof(unsigned long long), 231 .value = &mem_limit, 232 }; 233 234 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG) 235 236 static void __init export_crashk_values(struct device_node *node) 237 { 238 /* There might be existing crash kernel properties, but we can't 239 * be sure what's in them, so remove them. */ 240 of_remove_property(node, of_find_property(node, 241 "linux,crashkernel-base", NULL)); 242 of_remove_property(node, of_find_property(node, 243 "linux,crashkernel-size", NULL)); 244 245 if (crashk_res.start != 0) { 246 crashk_base = cpu_to_be_ulong(crashk_res.start), 247 of_add_property(node, &crashk_base_prop); 248 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res)); 249 of_add_property(node, &crashk_size_prop); 250 } 251 252 /* 253 * memory_limit is required by the kexec-tools to limit the 254 * crash regions to the actual memory used. 255 */ 256 mem_limit = cpu_to_be_ulong(memory_limit); 257 of_update_property(node, &memory_limit_prop); 258 } 259 260 static int __init kexec_setup(void) 261 { 262 struct device_node *node; 263 264 node = of_find_node_by_path("/chosen"); 265 if (!node) 266 return -ENOENT; 267 268 /* remove any stale properties so ours can be found */ 269 of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL)); 270 271 /* information needed by userspace when using default_machine_kexec */ 272 kernel_end = cpu_to_be_ulong(__pa(_end)); 273 of_add_property(node, &kernel_end_prop); 274 275 export_crashk_values(node); 276 277 of_node_put(node); 278 return 0; 279 } 280 late_initcall(kexec_setup); 281