arch/mips/kernel/machine_kexec.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * machine_kexec.c for kexec
   4  * Created by <nschichan@corp.free.fr> on Thu Oct 12 15:15:06 2006
   5  */
   6 #include <linux/compiler.h>
   7 #include <linux/kexec.h>
   8 #include <linux/mm.h>
   9 #include <linux/delay.h>
  10 #include <linux/libfdt.h>
  11 #include <linux/reboot.h>
  12
  13 #include <asm/cacheflush.h>
  14 #include <asm/page.h>
  15
  16 extern const unsigned char relocate_new_kernel[];
  17 extern const size_t relocate_new_kernel_size;
  18
  19 extern unsigned long kexec_start_address;
  20 extern unsigned long kexec_indirection_page;
  21
  22 static unsigned long reboot_code_buffer;
  23
  24 #ifdef CONFIG_SMP
  25 static void (*relocated_kexec_smp_wait)(void *);
  26
  27 atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
  28 void (*_crash_smp_send_stop)(void) = NULL;
  29 #endif
  30
  31 void (*_machine_kexec_shutdown)(void) = NULL;
  32 void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL;
  33
  34 static void kexec_image_info(const struct kimage *kimage)
  35 {
  36         unsigned long i;
  37
  38         pr_debug("kexec kimage info:\n");
  39         pr_debug("  type:        %d\n", kimage->type);
  40         pr_debug("  start:       %lx\n", kimage->start);
  41         pr_debug("  head:        %lx\n", kimage->head);
  42         pr_debug("  nr_segments: %lu\n", kimage->nr_segments);
  43
  44         for (i = 0; i < kimage->nr_segments; i++) {
  45                 pr_debug("    segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
  46                         i,
  47                         kimage->segment[i].mem,
  48                         kimage->segment[i].mem + kimage->segment[i].memsz,
  49                         (unsigned long)kimage->segment[i].memsz,
  50                         (unsigned long)kimage->segment[i].memsz /  PAGE_SIZE);
  51         }
  52 }
  53
  54 #ifdef CONFIG_UHI_BOOT
  55
  56 static int uhi_machine_kexec_prepare(struct kimage *kimage)
  57 {
  58         int i;
  59
  60         /*
  61          * In case DTB file is not passed to the new kernel, a flat device
  62          * tree will be created by kexec tool. It holds modified command
  63          * line for the new kernel.
  64          */
  65         for (i = 0; i < kimage->nr_segments; i++) {
  66                 struct fdt_header fdt;
  67
  68                 if (kimage->segment[i].memsz <= sizeof(fdt))
  69                         continue;
  70
  71                 if (copy_from_user(&fdt, kimage->segment[i].buf, sizeof(fdt)))
  72                         continue;
  73
  74                 if (fdt_check_header(&fdt))
  75                         continue;
  76
  77                 kexec_args[0] = -2;
  78                 kexec_args[1] = (unsigned long)
  79                         phys_to_virt((unsigned long)kimage->segment[i].mem);
  80                 break;
  81         }
  82
  83         return 0;
  84 }
  85
  86 int (*_machine_kexec_prepare)(struct kimage *) = uhi_machine_kexec_prepare;
  87
  88 #else
  89
  90 int (*_machine_kexec_prepare)(struct kimage *) = NULL;
  91
  92 #endif /* CONFIG_UHI_BOOT */
  93
  94 int
  95 machine_kexec_prepare(struct kimage *kimage)
  96 {
  97 #ifdef CONFIG_SMP
  98         if (!kexec_nonboot_cpu_func())
  99                 return -EINVAL;
 100 #endif
 101
 102         kexec_image_info(kimage);
 103
 104         if (_machine_kexec_prepare)
 105                 return _machine_kexec_prepare(kimage);
 106
 107         return 0;
 108 }
 109
 110 void
 111 machine_kexec_cleanup(struct kimage *kimage)
 112 {
 113 }
 114
 115 #ifdef CONFIG_SMP
 116 static void kexec_shutdown_secondary(void *param)
 117 {
 118         int cpu = smp_processor_id();
 119
 120         if (!cpu_online(cpu))
 121                 return;
 122
 123         /* We won't be sent IPIs any more. */
 124         set_cpu_online(cpu, false);
 125
 126         local_irq_disable();
 127         while (!atomic_read(&kexec_ready_to_reboot))
 128                 cpu_relax();
 129
 130         kexec_reboot();
 131
 132         /* NOTREACHED */
 133 }
 134 #endif
 135
 136 void
 137 machine_shutdown(void)
 138 {
 139         if (_machine_kexec_shutdown)
 140                 _machine_kexec_shutdown();
 141
 142 #ifdef CONFIG_SMP
 143         smp_call_function(kexec_shutdown_secondary, NULL, 0);
 144
 145         while (num_online_cpus() > 1) {
 146                 cpu_relax();
 147                 mdelay(1);
 148         }
 149 #endif
 150 }
 151
 152 void
 153 machine_crash_shutdown(struct pt_regs *regs)
 154 {
 155         if (_machine_crash_shutdown)
 156                 _machine_crash_shutdown(regs);
 157         else
 158                 default_machine_crash_shutdown(regs);
 159 }
 160
 161 #ifdef CONFIG_SMP
 162 void kexec_nonboot_cpu_jump(void)
 163 {
 164         local_flush_icache_range((unsigned long)relocated_kexec_smp_wait,
 165                                  reboot_code_buffer + relocate_new_kernel_size);
 166
 167         relocated_kexec_smp_wait(NULL);
 168 }
 169 #endif
 170
 171 void kexec_reboot(void)
 172 {
 173         void (*do_kexec)(void) __noreturn;
 174
 175         /*
 176          * We know we were online, and there will be no incoming IPIs at
 177          * this point. Mark online again before rebooting so that the crash
 178          * analysis tool will see us correctly.
 179          */
 180         set_cpu_online(smp_processor_id(), true);
 181
 182         /* Ensure remote CPUs observe that we're online before rebooting. */
 183         smp_mb__after_atomic();
 184
 185 #ifdef CONFIG_SMP
 186         if (smp_processor_id() > 0) {
 187                 /*
 188                  * Instead of cpu_relax() or wait, this is needed for kexec
 189                  * smp reboot. Kdump usually doesn't require an smp new
 190                  * kernel, but kexec may do.
 191                  */
 192                 kexec_nonboot_cpu();
 193
 194                 /* NOTREACHED */
 195         }
 196 #endif
 197
 198         /*
 199          * Make sure we get correct instructions written by the
 200          * machine_kexec() CPU.
 201          */
 202         local_flush_icache_range(reboot_code_buffer,
 203                                  reboot_code_buffer + relocate_new_kernel_size);
 204
 205         do_kexec = (void *)reboot_code_buffer;
 206         do_kexec();
 207 }
 208
 209 void
 210 machine_kexec(struct kimage *image)
 211 {
 212         unsigned long entry;
 213         unsigned long *ptr;
 214
 215         reboot_code_buffer =
 216           (unsigned long)page_address(image->control_code_page);
 217
 218         kexec_start_address =
 219                 (unsigned long) phys_to_virt(image->start);
 220
 221         if (image->type == KEXEC_TYPE_DEFAULT) {
 222                 kexec_indirection_page =
 223                         (unsigned long) phys_to_virt(image->head & PAGE_MASK);
 224         } else {
 225                 kexec_indirection_page = (unsigned long)&image->head;
 226         }
 227
 228         memcpy((void*)reboot_code_buffer, relocate_new_kernel,
 229                relocate_new_kernel_size);
 230
 231         /*
 232          * The generic kexec code builds a page list with physical
 233          * addresses. they are directly accessible through KSEG0 (or
 234          * CKSEG0 or XPHYS if on 64bit system), hence the
 235          * phys_to_virt() call.
 236          */
 237         for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
 238              ptr = (entry & IND_INDIRECTION) ?
 239                phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
 240                 if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
 241                     *ptr & IND_DESTINATION)
 242                         *ptr = (unsigned long) phys_to_virt(*ptr);
 243         }
 244
 245         /* Mark offline BEFORE disabling local irq. */
 246         set_cpu_online(smp_processor_id(), false);
 247
 248         /*
 249          * we do not want to be bothered.
 250          */
 251         local_irq_disable();
 252
 253         printk("Will call new kernel at %08lx\n", image->start);
 254         printk("Bye ...\n");
 255         /* Make reboot code buffer available to the boot CPU. */
 256         __flush_cache_all();
 257 #ifdef CONFIG_SMP
 258         /* All secondary cpus now may jump to kexec_wait cycle */
 259         relocated_kexec_smp_wait = reboot_code_buffer +
 260                 (void *)(kexec_smp_wait - relocate_new_kernel);
 261         smp_wmb();
 262         atomic_set(&kexec_ready_to_reboot, 1);
 263 #endif
 264         kexec_reboot();
 265 }