machine_kexec.c revision bbc8e30f17077f83fdeeeca0cf70e0f179279282
1/* 2 * Code to handle transition of Linux booting another kernel. 3 * 4 * Copyright (C) 2002-2003 Eric Biederman <ebiederm@xmission.com> 5 * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz 6 * Copyright (C) 2005 IBM Corporation. 7 * 8 * This source code is licensed under the GNU General Public License, 9 * Version 2. See the file COPYING for more details. 10 */ 11 12#include <linux/kexec.h> 13#include <linux/reboot.h> 14#include <linux/threads.h> 15#include <linux/lmb.h> 16#include <linux/of.h> 17#include <asm/machdep.h> 18#include <asm/prom.h> 19#include <asm/sections.h> 20 21void machine_crash_shutdown(struct pt_regs *regs) 22{ 23 if (ppc_md.machine_crash_shutdown) 24 ppc_md.machine_crash_shutdown(regs); 25 else 26 default_machine_crash_shutdown(regs); 27} 28 29/* 30 * Do what every setup is needed on image and the 31 * reboot code buffer to allow us to avoid allocations 32 * later. 33 */ 34int machine_kexec_prepare(struct kimage *image) 35{ 36 if (ppc_md.machine_kexec_prepare) 37 return ppc_md.machine_kexec_prepare(image); 38 else 39 return default_machine_kexec_prepare(image); 40} 41 42void machine_kexec_cleanup(struct kimage *image) 43{ 44 if (ppc_md.machine_kexec_cleanup) 45 ppc_md.machine_kexec_cleanup(image); 46} 47 48/* 49 * Do not allocate memory (or fail in any way) in machine_kexec(). 50 * We are past the point of no return, committed to rebooting now. 51 */ 52void machine_kexec(struct kimage *image) 53{ 54 if (ppc_md.machine_kexec) 55 ppc_md.machine_kexec(image); 56 else 57 default_machine_kexec(image); 58 59 /* Fall back to normal restart if we're still alive. */ 60 machine_restart(NULL); 61 for(;;); 62} 63 64void __init reserve_crashkernel(void) 65{ 66 unsigned long long crash_size, crash_base; 67 int ret; 68 69 /* this is necessary because of lmb_phys_mem_size() */ 70 lmb_analyze(); 71 72 /* use common parsing */ 73 ret = parse_crashkernel(boot_command_line, lmb_phys_mem_size(), 74 &crash_size, &crash_base); 75 if (ret == 0 && crash_size > 0) { 76 crashk_res.start = crash_base; 77 crashk_res.end = crash_base + crash_size - 1; 78 } 79 80 if (crashk_res.end == crashk_res.start) { 81 crashk_res.start = crashk_res.end = 0; 82 return; 83 } 84 85 /* We might have got these values via the command line or the 86 * device tree, either way sanitise them now. */ 87 88 crash_size = crashk_res.end - crashk_res.start + 1; 89 90#ifndef CONFIG_RELOCATABLE 91 if (crashk_res.start != KDUMP_KERNELBASE) 92 printk("Crash kernel location must be 0x%x\n", 93 KDUMP_KERNELBASE); 94 95 crashk_res.start = KDUMP_KERNELBASE; 96#else 97 if (!crashk_res.start) { 98 /* 99 * unspecified address, choose a region of specified size 100 * can overlap with initrd (ignoring corruption when retained) 101 * ppc64 requires kernel and some stacks to be in first segemnt 102 */ 103 crashk_res.start = KDUMP_KERNELBASE; 104 } 105 106 crash_base = PAGE_ALIGN(crashk_res.start); 107 if (crash_base != crashk_res.start) { 108 printk("Crash kernel base must be aligned to 0x%lx\n", 109 PAGE_SIZE); 110 crashk_res.start = crash_base; 111 } 112 113#endif 114 crash_size = PAGE_ALIGN(crash_size); 115 crashk_res.end = crashk_res.start + crash_size - 1; 116 117 /* The crash region must not overlap the current kernel */ 118 if (overlaps_crashkernel(__pa(_stext), _end - _stext)) { 119 printk(KERN_WARNING 120 "Crash kernel can not overlap current kernel\n"); 121 crashk_res.start = crashk_res.end = 0; 122 return; 123 } 124 125 /* Crash kernel trumps memory limit */ 126 if (memory_limit && memory_limit <= crashk_res.end) { 127 memory_limit = crashk_res.end + 1; 128 printk("Adjusted memory limit for crashkernel, now 0x%llx\n", 129 (unsigned long long)memory_limit); 130 } 131 132 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB " 133 "for crashkernel (System RAM: %ldMB)\n", 134 (unsigned long)(crash_size >> 20), 135 (unsigned long)(crashk_res.start >> 20), 136 (unsigned long)(lmb_phys_mem_size() >> 20)); 137 138 lmb_reserve(crashk_res.start, crash_size); 139} 140 141int overlaps_crashkernel(unsigned long start, unsigned long size) 142{ 143 return (start + size) > crashk_res.start && start <= crashk_res.end; 144} 145 146/* Values we need to export to the second kernel via the device tree. */ 147static phys_addr_t kernel_end; 148static phys_addr_t crashk_size; 149 150static struct property kernel_end_prop = { 151 .name = "linux,kernel-end", 152 .length = sizeof(phys_addr_t), 153 .value = &kernel_end, 154}; 155 156static struct property crashk_base_prop = { 157 .name = "linux,crashkernel-base", 158 .length = sizeof(phys_addr_t), 159 .value = &crashk_res.start, 160}; 161 162static struct property crashk_size_prop = { 163 .name = "linux,crashkernel-size", 164 .length = sizeof(phys_addr_t), 165 .value = &crashk_size, 166}; 167 168static void __init export_crashk_values(struct device_node *node) 169{ 170 struct property *prop; 171 172 /* There might be existing crash kernel properties, but we can't 173 * be sure what's in them, so remove them. */ 174 prop = of_find_property(node, "linux,crashkernel-base", NULL); 175 if (prop) 176 prom_remove_property(node, prop); 177 178 prop = of_find_property(node, "linux,crashkernel-size", NULL); 179 if (prop) 180 prom_remove_property(node, prop); 181 182 if (crashk_res.start != 0) { 183 prom_add_property(node, &crashk_base_prop); 184 crashk_size = crashk_res.end - crashk_res.start + 1; 185 prom_add_property(node, &crashk_size_prop); 186 } 187} 188 189static int __init kexec_setup(void) 190{ 191 struct device_node *node; 192 struct property *prop; 193 194 node = of_find_node_by_path("/chosen"); 195 if (!node) 196 return -ENOENT; 197 198 /* remove any stale properties so ours can be found */ 199 prop = of_find_property(node, kernel_end_prop.name, NULL); 200 if (prop) 201 prom_remove_property(node, prop); 202 203 /* information needed by userspace when using default_machine_kexec */ 204 kernel_end = __pa(_end); 205 prom_add_property(node, &kernel_end_prop); 206 207 export_crashk_values(node); 208 209 of_node_put(node); 210 return 0; 211} 212late_initcall(kexec_setup); 213