release/src-rt-6.x/linux/linux-2.6/arch/powerpc/kernel/machine_kexec.c

   1 /*
   2  * Code to handle transition of Linux booting another kernel.
   3  *
   4  * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
   5  * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
   6  * Copyright (C) 2005 IBM Corporation.
   7  *
   8  * This source code is licensed under the GNU General Public License,
   9  * Version 2.  See the file COPYING for more details.
  10  */
  11
  12 #include <linux/kexec.h>
  13 #include <linux/reboot.h>
  14 #include <linux/threads.h>
  15 #include <asm/machdep.h>
  16 #include <asm/lmb.h>
  17
  18 void machine_crash_shutdown(struct pt_regs *regs)
  19 {
  20         if (ppc_md.machine_crash_shutdown)
  21                 ppc_md.machine_crash_shutdown(regs);
  22 }
  23
  24 /*
  25  * Do what every setup is needed on image and the
  26  * reboot code buffer to allow us to avoid allocations
  27  * later.
  28  */
  29 int machine_kexec_prepare(struct kimage *image)
  30 {
  31         if (ppc_md.machine_kexec_prepare)
  32                 return ppc_md.machine_kexec_prepare(image);
  33         /*
  34          * Fail if platform doesn't provide its own machine_kexec_prepare
  35          * implementation.
  36          */
  37         return -ENOSYS;
  38 }
  39
  40 void machine_kexec_cleanup(struct kimage *image)
  41 {
  42         if (ppc_md.machine_kexec_cleanup)
  43                 ppc_md.machine_kexec_cleanup(image);
  44 }
  45
  46 /*
  47  * Do not allocate memory (or fail in any way) in machine_kexec().
  48  * We are past the point of no return, committed to rebooting now.
  49  */
  50 NORET_TYPE void machine_kexec(struct kimage *image)
  51 {
  52         if (ppc_md.machine_kexec)
  53                 ppc_md.machine_kexec(image);
  54         else {
  55                 /*
  56                  * Fall back to normal restart if platform doesn't provide
  57                  * its own kexec function, and user insist to kexec...
  58                  */
  59                 machine_restart(NULL);
  60         }
  61         for(;;);
  62 }
  63
  64 static int __init early_parse_crashk(char *p)
  65 {
  66         unsigned long size;
  67
  68         if (!p)
  69                 return 1;
  70
  71         size = memparse(p, &p);
  72
  73         if (*p == '@')
  74                 crashk_res.start = memparse(p + 1, &p);
  75         else
  76                 crashk_res.start = KDUMP_KERNELBASE;
  77
  78         crashk_res.end = crashk_res.start + size - 1;
  79
  80         return 0;
  81 }
  82 early_param("crashkernel", early_parse_crashk);
  83
  84 void __init reserve_crashkernel(void)
  85 {
  86         unsigned long size;
  87
  88         if (crashk_res.start == 0)
  89                 return;
  90
  91         /* We might have got these values via the command line or the
  92          * device tree, either way sanitise them now. */
  93
  94         size = crashk_res.end - crashk_res.start + 1;
  95
  96         if (crashk_res.start != KDUMP_KERNELBASE)
  97                 printk("Crash kernel location must be 0x%x\n",
  98                                 KDUMP_KERNELBASE);
  99
 100         crashk_res.start = KDUMP_KERNELBASE;
 101         size = PAGE_ALIGN(size);
 102         crashk_res.end = crashk_res.start + size - 1;
 103
 104         /* Crash kernel trumps memory limit */
 105         if (memory_limit && memory_limit <= crashk_res.end) {
 106                 memory_limit = crashk_res.end + 1;
 107                 printk("Adjusted memory limit for crashkernel, now 0x%lx\n",
 108                                 memory_limit);
 109         }
 110
 111         lmb_reserve(crashk_res.start, size);
 112 }
 113
 114 int overlaps_crashkernel(unsigned long start, unsigned long size)
 115 {
 116         return (start + size) > crashk_res.start && start <= crashk_res.end;
 117 }