arch/ppc/kernel/machine_kexec.c

   1 /*
   2  * machine_kexec.c - handle transition of Linux booting another kernel
   3  * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
   4  *
   5  * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
   6  *
   7  * This source code is licensed under the GNU General Public License,
   8  * Version 2.  See the file COPYING for more details.
   9  */
  10
  11 #include <linux/mm.h>
  12 #include <linux/kexec.h>
  13 #include <linux/delay.h>
  14 #include <linux/reboot.h>
  15 #include <asm/pgtable.h>
  16 #include <asm/pgalloc.h>
  17 #include <asm/mmu_context.h>
  18 #include <asm/io.h>
  19 #include <asm/hw_irq.h>
  20 #include <asm/cacheflush.h>
  21 #include <asm/machdep.h>
  22
  23 typedef NORET_TYPE void (*relocate_new_kernel_t)(
  24                                 unsigned long indirection_page,
  25                                 unsigned long reboot_code_buffer,
  26                                 unsigned long start_address) ATTRIB_NORET;
  27
  28 extern const unsigned char relocate_new_kernel[];
  29 extern const unsigned int relocate_new_kernel_size;
  30
  31 void machine_shutdown(void)
  32 {
  33         if (ppc_md.machine_shutdown)
  34                 ppc_md.machine_shutdown();
  35 }
  36
  37 void machine_crash_shutdown(struct pt_regs *regs)
  38 {
  39         if (ppc_md.machine_crash_shutdown)
  40                 ppc_md.machine_crash_shutdown();
  41 }
  42
  43 /*
  44  * Do what every setup is needed on image and the
  45  * reboot code buffer to allow us to avoid allocations
  46  * later.
  47  */
  48 int machine_kexec_prepare(struct kimage *image)
  49 {
  50         if (ppc_md.machine_kexec_prepare)
  51                 return ppc_md.machine_kexec_prepare(image);
  52         /*
  53          * Fail if platform doesn't provide its own machine_kexec_prepare
  54          * implementation.
  55          */
  56         return -ENOSYS;
  57 }
  58
  59 void machine_kexec_cleanup(struct kimage *image)
  60 {
  61         if (ppc_md.machine_kexec_cleanup)
  62                 ppc_md.machine_kexec_cleanup(image);
  63 }
  64
  65 /*
  66  * Do not allocate memory (or fail in any way) in machine_kexec().
  67  * We are past the point of no return, committed to rebooting now.
  68  */
  69 NORET_TYPE void machine_kexec(struct kimage *image)
  70 {
  71         if (ppc_md.machine_kexec)
  72                 ppc_md.machine_kexec(image);
  73         else {
  74                 /*
  75                  * Fall back to normal restart if platform doesn't provide
  76                  * its own kexec function, and user insist to kexec...
  77                  */
  78                 machine_restart(NULL);
  79         }
  80         for(;;);
  81 }
  82
  83 /*
  84  * This is a generic machine_kexec function suitable at least for
  85  * non-OpenFirmware embedded platforms.
  86  * It merely copies the image relocation code to the control page and
  87  * jumps to it.
  88  * A platform specific function may just call this one.
  89  */
  90 void machine_kexec_simple(struct kimage *image)
  91 {
  92         unsigned long page_list;
  93         unsigned long reboot_code_buffer, reboot_code_buffer_phys;
  94         relocate_new_kernel_t rnk;
  95
  96         /* Interrupts aren't acceptable while we reboot */
  97         local_irq_disable();
  98
  99         page_list = image->head;
 100
 101         /* we need both effective and real address here */
 102         reboot_code_buffer =
 103                         (unsigned long)page_address(image->control_code_page);
 104         reboot_code_buffer_phys = virt_to_phys((void *)reboot_code_buffer);
 105
 106         /* copy our kernel relocation code to the control code page */
 107         memcpy((void *)reboot_code_buffer, relocate_new_kernel,
 108                                                 relocate_new_kernel_size);
 109
 110         flush_icache_range(reboot_code_buffer,
 111                                 reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
 112         printk(KERN_INFO "Bye!\n");
 113
 114         /* now call it */
 115         rnk = (relocate_new_kernel_t) reboot_code_buffer;
 116         (*rnk)(page_list, reboot_code_buffer_phys, image->start);
 117 }
 118