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, unsigned long reboot_code_buffer,
  25         unsigned long start_address) ATTRIB_NORET;
  26
  27 const extern unsigned char relocate_new_kernel[];
  28 const extern unsigned int relocate_new_kernel_size;
  29
  30 void machine_shutdown(void)
  31 {
  32         if (ppc_md.machine_shutdown) {
  33                 ppc_md.machine_shutdown();
  34         }
  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 /*
  45  * Do what every setup is needed on image and the
  46  * reboot code buffer to allow us to avoid allocations
  47  * later.
  48  */
  49 int machine_kexec_prepare(struct kimage *image)
  50 {
  51         if (ppc_md.machine_kexec_prepare) {
  52                 return ppc_md.machine_kexec_prepare(image);
  53         }
  54         /*
  55          * Fail if platform doesn't provide its own machine_kexec_prepare
  56          * implementation.
  57          */
  58         return -ENOSYS;
  59 }
  60
  61 void machine_kexec_cleanup(struct kimage *image)
  62 {
  63         if (ppc_md.machine_kexec_cleanup) {
  64                 ppc_md.machine_kexec_cleanup(image);
  65         }
  66 }
  67
  68 /*
  69  * Do not allocate memory (or fail in any way) in machine_kexec().
  70  * We are past the point of no return, committed to rebooting now.
  71  */
  72 NORET_TYPE void machine_kexec(struct kimage *image)
  73 {
  74         if (ppc_md.machine_kexec) {
  75                 ppc_md.machine_kexec(image);
  76         } else {
  77                 /*
  78                  * Fall back to normal restart if platform doesn't provide
  79                  * its own kexec function, and user insist to kexec...
  80                  */
  81                 machine_restart(NULL);
  82         }
  83         for(;;);
  84 }
  85
  86
  87 /*
  88  * This is a generic machine_kexec function suitable at least for
  89  * non-OpenFirmware embedded platforms.
  90  * It merely copies the image relocation code to the control page and
  91  * jumps to it.
  92  * A platform specific function may just call this one.
  93  */
  94 void machine_kexec_simple(struct kimage *image)
  95 {
  96         unsigned long page_list;
  97         unsigned long reboot_code_buffer, reboot_code_buffer_phys;
  98         relocate_new_kernel_t rnk;
  99
 100         /* Interrupts aren't acceptable while we reboot */
 101         local_irq_disable();
 102
 103         page_list = image->head;
 104
 105         /* we need both effective and real address here */
 106         reboot_code_buffer =
 107                 (unsigned long)page_address(image->control_code_page);
 108         reboot_code_buffer_phys = virt_to_phys((void *)reboot_code_buffer);
 109
 110         /* copy our kernel relocation code to the control code page */
 111         memcpy((void *)reboot_code_buffer,
 112                 relocate_new_kernel, relocate_new_kernel_size);
 113
 114         flush_icache_range(reboot_code_buffer,
 115                 reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
 116         printk(KERN_INFO "Bye!\n");
 117
 118         /* now call it */
 119         rnk = (relocate_new_kernel_t) reboot_code_buffer;
 120         (*rnk)(page_list, reboot_code_buffer_phys, image->start);
 121 }
 122