arch/powerpc/kexec/core.c

   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, total_mem_sz;
 119         int ret;
 120
 121         total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();
 122         /* use common parsing */
 123         ret = parse_crashkernel(boot_command_line, total_mem_sz,
 124                         &crash_size, &crash_base);
 125         if (ret == 0 && crash_size > 0) {
 126                 crashk_res.start = crash_base;
 127                 crashk_res.end = crash_base + crash_size - 1;
 128         }
 129
 130         if (crashk_res.end == crashk_res.start) {
 131                 crashk_res.start = crashk_res.end = 0;
 132                 return;
 133         }
 134
 135         /* We might have got these values via the command line or the
 136          * device tree, either way sanitise them now. */
 137
 138         crash_size = resource_size(&crashk_res);
 139
 140 #ifndef CONFIG_NONSTATIC_KERNEL
 141         if (crashk_res.start != KDUMP_KERNELBASE)
 142                 printk("Crash kernel location must be 0x%x\n",
 143                                 KDUMP_KERNELBASE);
 144
 145         crashk_res.start = KDUMP_KERNELBASE;
 146 #else
 147         if (!crashk_res.start) {
 148 #ifdef CONFIG_PPC64
 149                 /*
 150                  * On 64bit we split the RMO in half but cap it at half of
 151                  * a small SLB (128MB) since the crash kernel needs to place
 152                  * itself and some stacks to be in the first segment.
 153                  */
 154                 crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
 155 #else
 156                 crashk_res.start = KDUMP_KERNELBASE;
 157 #endif
 158         }
 159
 160         crash_base = PAGE_ALIGN(crashk_res.start);
 161         if (crash_base != crashk_res.start) {
 162                 printk("Crash kernel base must be aligned to 0x%lx\n",
 163                                 PAGE_SIZE);
 164                 crashk_res.start = crash_base;
 165         }
 166
 167 #endif
 168         crash_size = PAGE_ALIGN(crash_size);
 169         crashk_res.end = crashk_res.start + crash_size - 1;
 170
 171         /* The crash region must not overlap the current kernel */
 172         if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
 173                 printk(KERN_WARNING
 174                         "Crash kernel can not overlap current kernel\n");
 175                 crashk_res.start = crashk_res.end = 0;
 176                 return;
 177         }
 178
 179         /* Crash kernel trumps memory limit */
 180         if (memory_limit && memory_limit <= crashk_res.end) {
 181                 memory_limit = crashk_res.end + 1;
 182                 total_mem_sz = memory_limit;
 183                 printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
 184                        memory_limit);
 185         }
 186
 187         printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 188                         "for crashkernel (System RAM: %ldMB)\n",
 189                         (unsigned long)(crash_size >> 20),
 190                         (unsigned long)(crashk_res.start >> 20),
 191                         (unsigned long)(total_mem_sz >> 20));
 192
 193         if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
 194             memblock_reserve(crashk_res.start, crash_size)) {
 195                 pr_err("Failed to reserve memory for crashkernel!\n");
 196                 crashk_res.start = crashk_res.end = 0;
 197                 return;
 198         }
 199 }
 200
 201 int overlaps_crashkernel(unsigned long start, unsigned long size)
 202 {
 203         return (start + size) > crashk_res.start && start <= crashk_res.end;
 204 }
 205
 206 /* Values we need to export to the second kernel via the device tree. */
 207 static phys_addr_t kernel_end;
 208 static phys_addr_t crashk_base;
 209 static phys_addr_t crashk_size;
 210 static unsigned long long mem_limit;
 211
 212 static struct property kernel_end_prop = {
 213         .name = "linux,kernel-end",
 214         .length = sizeof(phys_addr_t),
 215         .value = &kernel_end,
 216 };
 217
 218 static struct property crashk_base_prop = {
 219         .name = "linux,crashkernel-base",
 220         .length = sizeof(phys_addr_t),
 221         .value = &crashk_base
 222 };
 223
 224 static struct property crashk_size_prop = {
 225         .name = "linux,crashkernel-size",
 226         .length = sizeof(phys_addr_t),
 227         .value = &crashk_size,
 228 };
 229
 230 static struct property memory_limit_prop = {
 231         .name = "linux,memory-limit",
 232         .length = sizeof(unsigned long long),
 233         .value = &mem_limit,
 234 };
 235
 236 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG)
 237
 238 static void __init export_crashk_values(struct device_node *node)
 239 {
 240         /* There might be existing crash kernel properties, but we can't
 241          * be sure what's in them, so remove them. */
 242         of_remove_property(node, of_find_property(node,
 243                                 "linux,crashkernel-base", NULL));
 244         of_remove_property(node, of_find_property(node,
 245                                 "linux,crashkernel-size", NULL));
 246
 247         if (crashk_res.start != 0) {
 248                 crashk_base = cpu_to_be_ulong(crashk_res.start),
 249                 of_add_property(node, &crashk_base_prop);
 250                 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
 251                 of_add_property(node, &crashk_size_prop);
 252         }
 253
 254         /*
 255          * memory_limit is required by the kexec-tools to limit the
 256          * crash regions to the actual memory used.
 257          */
 258         mem_limit = cpu_to_be_ulong(memory_limit);
 259         of_update_property(node, &memory_limit_prop);
 260 }
 261
 262 static int __init kexec_setup(void)
 263 {
 264         struct device_node *node;
 265
 266         node = of_find_node_by_path("/chosen");
 267         if (!node)
 268                 return -ENOENT;
 269
 270         /* remove any stale properties so ours can be found */
 271         of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL));
 272
 273         /* information needed by userspace when using default_machine_kexec */
 274         kernel_end = cpu_to_be_ulong(__pa(_end));
 275         of_add_property(node, &kernel_end_prop);
 276
 277         export_crashk_values(node);
 278
 279         of_node_put(node);
 280         return 0;
 281 }
 282 late_initcall(kexec_setup);