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 <linux/lmb.h>
  16 #include <asm/machdep.h>
  17 #include <asm/prom.h>
  18
  19 void machine_crash_shutdown(struct pt_regs *regs)
  20 {
  21         if (ppc_md.machine_crash_shutdown)
  22                 ppc_md.machine_crash_shutdown(regs);
  23 }
  24
  25 /*
  26  * Do what every setup is needed on image and the
  27  * reboot code buffer to allow us to avoid allocations
  28  * later.
  29  */
  30 int machine_kexec_prepare(struct kimage *image)
  31 {
  32         if (ppc_md.machine_kexec_prepare)
  33                 return ppc_md.machine_kexec_prepare(image);
  34         /*
  35          * Fail if platform doesn't provide its own machine_kexec_prepare
  36          * implementation.
  37          */
  38         return -ENOSYS;
  39 }
  40
  41 void machine_kexec_cleanup(struct kimage *image)
  42 {
  43         if (ppc_md.machine_kexec_cleanup)
  44                 ppc_md.machine_kexec_cleanup(image);
  45 }
  46
  47 /*
  48  * Do not allocate memory (or fail in any way) in machine_kexec().
  49  * We are past the point of no return, committed to rebooting now.
  50  */
  51 NORET_TYPE void machine_kexec(struct kimage *image)
  52 {
  53         if (ppc_md.machine_kexec)
  54                 ppc_md.machine_kexec(image);
  55         else {
  56                 /*
  57                  * Fall back to normal restart if platform doesn't provide
  58                  * its own kexec function, and user insist to kexec...
  59                  */
  60                 machine_restart(NULL);
  61         }
  62         for(;;);
  63 }
  64
  65 void __init reserve_crashkernel(void)
  66 {
  67         unsigned long long crash_size, crash_base;
  68         int ret;
  69
  70         /* this is necessary because of lmb_phys_mem_size() */
  71         lmb_analyze();
  72
  73         /* use common parsing */
  74         ret = parse_crashkernel(boot_command_line, lmb_phys_mem_size(),
  75                         &crash_size, &crash_base);
  76         if (ret == 0 && crash_size > 0) {
  77                 crashk_res.start = crash_base;
  78                 crashk_res.end = crash_base + crash_size - 1;
  79         }
  80
  81         if (crashk_res.end == crashk_res.start) {
  82                 crashk_res.start = crashk_res.end = 0;
  83                 return;
  84         }
  85
  86         /* We might have got these values via the command line or the
  87          * device tree, either way sanitise them now. */
  88
  89         crash_size = crashk_res.end - crashk_res.start + 1;
  90
  91         if (crashk_res.start != KDUMP_KERNELBASE)
  92                 printk("Crash kernel location must be 0x%x\n",
  93                                 KDUMP_KERNELBASE);
  94
  95         crashk_res.start = KDUMP_KERNELBASE;
  96         crash_size = PAGE_ALIGN(crash_size);
  97         crashk_res.end = crashk_res.start + crash_size - 1;
  98
  99         /* Crash kernel trumps memory limit */
 100         if (memory_limit && memory_limit <= crashk_res.end) {
 101                 memory_limit = crashk_res.end + 1;
 102                 printk("Adjusted memory limit for crashkernel, now 0x%lx\n",
 103                                 memory_limit);
 104         }
 105
 106         printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 107                         "for crashkernel (System RAM: %ldMB)\n",
 108                         (unsigned long)(crash_size >> 20),
 109                         (unsigned long)(crashk_res.start >> 20),
 110                         (unsigned long)(lmb_phys_mem_size() >> 20));
 111
 112         lmb_reserve(crashk_res.start, crash_size);
 113 }
 114
 115 int overlaps_crashkernel(unsigned long start, unsigned long size)
 116 {
 117         return (start + size) > crashk_res.start && start <= crashk_res.end;
 118 }