arch/mips/kernel/machine_kexec.c

   1 /*
   2  * machine_kexec.c for kexec
   3  * Created by <nschichan@corp.free.fr> on Thu Oct 12 15:15:06 2006
   4  *
   5  * This source code is licensed under the GNU General Public License,
   6  * Version 2.  See the file COPYING for more details.
   7  */
   8 #include <linux/compiler.h>
   9 #include <linux/kexec.h>
  10 #include <linux/mm.h>
  11 #include <linux/delay.h>
  12 #include <linux/libfdt.h>
  13
  14 #include <asm/cacheflush.h>
  15 #include <asm/page.h>
  16
  17 extern const unsigned char relocate_new_kernel[];
  18 extern const size_t relocate_new_kernel_size;
  19
  20 extern unsigned long kexec_start_address;
  21 extern unsigned long kexec_indirection_page;
  22
  23 static unsigned long reboot_code_buffer;
  24
  25 #ifdef CONFIG_SMP
  26 static void (*relocated_kexec_smp_wait)(void *);
  27
  28 atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
  29 void (*_crash_smp_send_stop)(void) = NULL;
  30 #endif
  31
  32 void (*_machine_kexec_shutdown)(void) = NULL;
  33 void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL;
  34
  35 static void kexec_image_info(const struct kimage *kimage)
  36 {
  37         unsigned long i;
  38
  39         pr_debug("kexec kimage info:\n");
  40         pr_debug("  type:        %d\n", kimage->type);
  41         pr_debug("  start:       %lx\n", kimage->start);
  42         pr_debug("  head:        %lx\n", kimage->head);
  43         pr_debug("  nr_segments: %lu\n", kimage->nr_segments);
  44
  45         for (i = 0; i < kimage->nr_segments; i++) {
  46                 pr_debug("    segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
  47                         i,
  48                         kimage->segment[i].mem,
  49                         kimage->segment[i].mem + kimage->segment[i].memsz,
  50                         (unsigned long)kimage->segment[i].memsz,
  51                         (unsigned long)kimage->segment[i].memsz /  PAGE_SIZE);
  52         }
  53 }
  54
  55 #ifdef CONFIG_UHI_BOOT
  56
  57 static int uhi_machine_kexec_prepare(struct kimage *kimage)
  58 {
  59         int i;
  60
  61         /*
  62          * In case DTB file is not passed to the new kernel, a flat device
  63          * tree will be created by kexec tool. It holds modified command
  64          * line for the new kernel.
  65          */
  66         for (i = 0; i < kimage->nr_segments; i++) {
  67                 struct fdt_header fdt;
  68
  69                 if (kimage->segment[i].memsz <= sizeof(fdt))
  70                         continue;
  71
  72                 if (copy_from_user(&fdt, kimage->segment[i].buf, sizeof(fdt)))
  73                         continue;
  74
  75                 if (fdt_check_header(&fdt))
  76                         continue;
  77
  78                 kexec_args[0] = -2;
  79                 kexec_args[1] = (unsigned long)
  80                         phys_to_virt((unsigned long)kimage->segment[i].mem);
  81                 break;
  82         }
  83
  84         return 0;
  85 }
  86
  87 int (*_machine_kexec_prepare)(struct kimage *) = uhi_machine_kexec_prepare;
  88
  89 #else
  90
  91 int (*_machine_kexec_prepare)(struct kimage *) = NULL;
  92
  93 #endif /* CONFIG_UHI_BOOT */
  94
  95 int
  96 machine_kexec_prepare(struct kimage *kimage)
  97 {
  98 #ifdef CONFIG_SMP
  99         if (!kexec_nonboot_cpu_func())
 100                 return -EINVAL;
 101 #endif
 102
 103         kexec_image_info(kimage);
 104
 105         if (_machine_kexec_prepare)
 106                 return _machine_kexec_prepare(kimage);
 107
 108         return 0;
 109 }
 110
 111 void
 112 machine_kexec_cleanup(struct kimage *kimage)
 113 {
 114 }
 115
 116 #ifdef CONFIG_SMP
 117 static void kexec_shutdown_secondary(void *param)
 118 {
 119         int cpu = smp_processor_id();
 120
 121         if (!cpu_online(cpu))
 122                 return;
 123
 124         /* We won't be sent IPIs any more. */
 125         set_cpu_online(cpu, false);
 126
 127         local_irq_disable();
 128         while (!atomic_read(&kexec_ready_to_reboot))
 129                 cpu_relax();
 130
 131         kexec_reboot();
 132
 133         /* NOTREACHED */
 134 }
 135 #endif
 136
 137 void
 138 machine_shutdown(void)
 139 {
 140         if (_machine_kexec_shutdown)
 141                 _machine_kexec_shutdown();
 142
 143 #ifdef CONFIG_SMP
 144         smp_call_function(kexec_shutdown_secondary, NULL, 0);
 145
 146         while (num_online_cpus() > 1) {
 147                 cpu_relax();
 148                 mdelay(1);
 149         }
 150 #endif
 151 }
 152
 153 void
 154 machine_crash_shutdown(struct pt_regs *regs)
 155 {
 156         if (_machine_crash_shutdown)
 157                 _machine_crash_shutdown(regs);
 158         else
 159                 default_machine_crash_shutdown(regs);
 160 }
 161
 162 #ifdef CONFIG_SMP
 163 void kexec_nonboot_cpu_jump(void)
 164 {
 165         local_flush_icache_range((unsigned long)relocated_kexec_smp_wait,
 166                                  reboot_code_buffer + relocate_new_kernel_size);
 167
 168         relocated_kexec_smp_wait(NULL);
 169 }
 170 #endif
 171
 172 void kexec_reboot(void)
 173 {
 174         void (*do_kexec)(void) __noreturn;
 175
 176         /*
 177          * We know we were online, and there will be no incoming IPIs at
 178          * this point. Mark online again before rebooting so that the crash
 179          * analysis tool will see us correctly.
 180          */
 181         set_cpu_online(smp_processor_id(), true);
 182
 183         /* Ensure remote CPUs observe that we're online before rebooting. */
 184         smp_mb__after_atomic();
 185
 186 #ifdef CONFIG_SMP
 187         if (smp_processor_id() > 0) {
 188                 /*
 189                  * Instead of cpu_relax() or wait, this is needed for kexec
 190                  * smp reboot. Kdump usually doesn't require an smp new
 191                  * kernel, but kexec may do.
 192                  */
 193                 kexec_nonboot_cpu();
 194
 195                 /* NOTREACHED */
 196         }
 197 #endif
 198
 199         /*
 200          * Make sure we get correct instructions written by the
 201          * machine_kexec() CPU.
 202          */
 203         local_flush_icache_range(reboot_code_buffer,
 204                                  reboot_code_buffer + relocate_new_kernel_size);
 205
 206         do_kexec = (void *)reboot_code_buffer;
 207         do_kexec();
 208 }
 209
 210 void
 211 machine_kexec(struct kimage *image)
 212 {
 213         unsigned long entry;
 214         unsigned long *ptr;
 215
 216         reboot_code_buffer =
 217           (unsigned long)page_address(image->control_code_page);
 218
 219         kexec_start_address =
 220                 (unsigned long) phys_to_virt(image->start);
 221
 222         if (image->type == KEXEC_TYPE_DEFAULT) {
 223                 kexec_indirection_page =
 224                         (unsigned long) phys_to_virt(image->head & PAGE_MASK);
 225         } else {
 226                 kexec_indirection_page = (unsigned long)&image->head;
 227         }
 228
 229         memcpy((void*)reboot_code_buffer, relocate_new_kernel,
 230                relocate_new_kernel_size);
 231
 232         /*
 233          * The generic kexec code builds a page list with physical
 234          * addresses. they are directly accessible through KSEG0 (or
 235          * CKSEG0 or XPHYS if on 64bit system), hence the
 236          * phys_to_virt() call.
 237          */
 238         for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
 239              ptr = (entry & IND_INDIRECTION) ?
 240                phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
 241                 if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
 242                     *ptr & IND_DESTINATION)
 243                         *ptr = (unsigned long) phys_to_virt(*ptr);
 244         }
 245
 246         /* Mark offline BEFORE disabling local irq. */
 247         set_cpu_online(smp_processor_id(), false);
 248
 249         /*
 250          * we do not want to be bothered.
 251          */
 252         local_irq_disable();
 253
 254         printk("Will call new kernel at %08lx\n", image->start);
 255         printk("Bye ...\n");
 256         /* Make reboot code buffer available to the boot CPU. */
 257         __flush_cache_all();
 258 #ifdef CONFIG_SMP
 259         /* All secondary cpus now may jump to kexec_wait cycle */
 260         relocated_kexec_smp_wait = reboot_code_buffer +
 261                 (void *)(kexec_smp_wait - relocate_new_kernel);
 262         smp_wmb();
 263         atomic_set(&kexec_ready_to_reboot, 1);
 264 #endif
 265         kexec_reboot();
 266 }