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