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