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 void __init reserve_crashkernel(void)
  65 {
  66         unsigned long long crash_size, crash_base;
  67         int ret;
  68
  69         /* this is necessary because of lmb_phys_mem_size() */
  70         lmb_analyze();
  71
  72         /* use common parsing */
  73         ret = parse_crashkernel(boot_command_line, lmb_phys_mem_size(),
  74                         &crash_size, &crash_base);
  75         if (ret == 0 && crash_size > 0) {
  76                 if (crash_base == 0)
  77                         crash_base = KDUMP_KERNELBASE;
  78                 crashk_res.start = crash_base;
  79         } else {
  80                 /* handle the device tree */
  81                 crash_size = crashk_res.end - crashk_res.start + 1;
  82         }
  83
  84         if (crash_size == 0)
  85                 return;
  86
  87         /* We might have got these values via the command line or the
  88          * device tree, either way sanitise them now. */
  89
  90         if (crashk_res.start != KDUMP_KERNELBASE)
  91                 printk("Crash kernel location must be 0x%x\n",
  92                                 KDUMP_KERNELBASE);
  93
  94         crashk_res.start = KDUMP_KERNELBASE;
  95         crash_size = PAGE_ALIGN(crash_size);
  96         crashk_res.end = crashk_res.start + crash_size - 1;
  97
  98         /* Crash kernel trumps memory limit */
  99         if (memory_limit && memory_limit <= crashk_res.end) {
 100                 memory_limit = crashk_res.end + 1;
 101                 printk("Adjusted memory limit for crashkernel, now 0x%lx\n",
 102                                 memory_limit);
 103         }
 104
 105         printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 106                         "for crashkernel (System RAM: %ldMB)\n",
 107                         (unsigned long)(crash_size >> 20),
 108                         (unsigned long)(crashk_res.start >> 20),
 109                         (unsigned long)(lmb_phys_mem_size() >> 20));
 110
 111         lmb_reserve(crashk_res.start, crash_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 }