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 const extern unsigned char relocate_new_kernel[];
  29 const extern unsigned int relocate_new_kernel_size;
  30
  31 /*
  32  * Provide a dummy crash_notes definition while crash dump arrives to ppc.
  33  * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
  34  */
  35 void *crash_notes = NULL;
  36
  37 void machine_shutdown(void)
  38 {
  39         if (ppc_md.machine_shutdown)
  40                 ppc_md.machine_shutdown();
  41 }
  42
  43 void machine_crash_shutdown(struct pt_regs *regs)
  44 {
  45         if (ppc_md.machine_crash_shutdown)
  46                 ppc_md.machine_crash_shutdown();
  47 }
  48
  49 /*
  50  * Do what every setup is needed on image and the
  51  * reboot code buffer to allow us to avoid allocations
  52  * later.
  53  */
  54 int machine_kexec_prepare(struct kimage *image)
  55 {
  56         if (ppc_md.machine_kexec_prepare)
  57                 return ppc_md.machine_kexec_prepare(image);
  58         /*
  59          * Fail if platform doesn't provide its own machine_kexec_prepare
  60          * implementation.
  61          */
  62         return -ENOSYS;
  63 }
  64
  65 void machine_kexec_cleanup(struct kimage *image)
  66 {
  67         if (ppc_md.machine_kexec_cleanup)
  68                 ppc_md.machine_kexec_cleanup(image);
  69 }
  70
  71 /*
  72  * Do not allocate memory (or fail in any way) in machine_kexec().
  73  * We are past the point of no return, committed to rebooting now.
  74  */
  75 NORET_TYPE void machine_kexec(struct kimage *image)
  76 {
  77         if (ppc_md.machine_kexec)
  78                 ppc_md.machine_kexec(image);
  79         else {
  80                 /*
  81                  * Fall back to normal restart if platform doesn't provide
  82                  * its own kexec function, and user insist to kexec...
  83                  */
  84                 machine_restart(NULL);
  85         }
  86         for(;;);
  87 }
  88
  89 /*
  90  * This is a generic machine_kexec function suitable at least for
  91  * non-OpenFirmware embedded platforms.
  92  * It merely copies the image relocation code to the control page and
  93  * jumps to it.
  94  * A platform specific function may just call this one.
  95  */
  96 void machine_kexec_simple(struct kimage *image)
  97 {
  98         unsigned long page_list;
  99         unsigned long reboot_code_buffer, reboot_code_buffer_phys;
 100         relocate_new_kernel_t rnk;
 101
 102         /* Interrupts aren't acceptable while we reboot */
 103         local_irq_disable();
 104
 105         page_list = image->head;
 106
 107         /* we need both effective and real address here */
 108         reboot_code_buffer =
 109                         (unsigned long)page_address(image->control_code_page);
 110         reboot_code_buffer_phys = virt_to_phys((void *)reboot_code_buffer);
 111
 112         /* copy our kernel relocation code to the control code page */
 113         memcpy((void *)reboot_code_buffer, relocate_new_kernel,
 114                                                 relocate_new_kernel_size);
 115
 116         flush_icache_range(reboot_code_buffer,
 117                                 reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
 118         printk(KERN_INFO "Bye!\n");
 119
 120         /* now call it */
 121         rnk = (relocate_new_kernel_t) reboot_code_buffer;
 122         (*rnk)(page_list, reboot_code_buffer_phys, image->start);
 123 }
 124