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 <linux/of.h>
  17 #include <asm/machdep.h>
  18 #include <asm/prom.h>
  19 #include <asm/sections.h>
  20
  21 void machine_crash_shutdown(struct pt_regs *regs)
  22 {
  23         if (ppc_md.machine_crash_shutdown)
  24                 ppc_md.machine_crash_shutdown(regs);
  25         else
  26                 default_machine_crash_shutdown(regs);
  27 }
  28
  29 /*
  30  * Do what every setup is needed on image and the
  31  * reboot code buffer to allow us to avoid allocations
  32  * later.
  33  */
  34 int machine_kexec_prepare(struct kimage *image)
  35 {
  36         if (ppc_md.machine_kexec_prepare)
  37                 return ppc_md.machine_kexec_prepare(image);
  38         else
  39                 return default_machine_kexec_prepare(image);
  40 }
  41
  42 void machine_kexec_cleanup(struct kimage *image)
  43 {
  44         if (ppc_md.machine_kexec_cleanup)
  45                 ppc_md.machine_kexec_cleanup(image);
  46 }
  47
  48 /*
  49  * Do not allocate memory (or fail in any way) in machine_kexec().
  50  * We are past the point of no return, committed to rebooting now.
  51  */
  52 void machine_kexec(struct kimage *image)
  53 {
  54         if (ppc_md.machine_kexec)
  55                 ppc_md.machine_kexec(image);
  56         else
  57                 default_machine_kexec(image);
  58
  59         /* Fall back to normal restart if we're still alive. */
  60         machine_restart(NULL);
  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                 crashk_res.start = crash_base;
  77                 crashk_res.end = crash_base + crash_size - 1;
  78         }
  79
  80         if (crashk_res.end == crashk_res.start) {
  81                 crashk_res.start = crashk_res.end = 0;
  82                 return;
  83         }
  84
  85         /* We might have got these values via the command line or the
  86          * device tree, either way sanitise them now. */
  87
  88         crash_size = crashk_res.end - crashk_res.start + 1;
  89
  90 #ifndef CONFIG_RELOCATABLE
  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 #else
  97         if (!crashk_res.start) {
  98                 /*
  99                  * unspecified address, choose a region of specified size
 100                  * can overlap with initrd (ignoring corruption when retained)
 101                  * ppc64 requires kernel and some stacks to be in first segemnt
 102                  */
 103                 crashk_res.start = KDUMP_KERNELBASE;
 104         }
 105
 106         crash_base = PAGE_ALIGN(crashk_res.start);
 107         if (crash_base != crashk_res.start) {
 108                 printk("Crash kernel base must be aligned to 0x%lx\n",
 109                                 PAGE_SIZE);
 110                 crashk_res.start = crash_base;
 111         }
 112
 113 #endif
 114         crash_size = PAGE_ALIGN(crash_size);
 115         crashk_res.end = crashk_res.start + crash_size - 1;
 116
 117         /* The crash region must not overlap the current kernel */
 118         if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
 119                 printk(KERN_WARNING
 120                         "Crash kernel can not overlap current kernel\n");
 121                 crashk_res.start = crashk_res.end = 0;
 122                 return;
 123         }
 124
 125         /* Crash kernel trumps memory limit */
 126         if (memory_limit && memory_limit <= crashk_res.end) {
 127                 memory_limit = crashk_res.end + 1;
 128                 printk("Adjusted memory limit for crashkernel, now 0x%lx\n",
 129                                 memory_limit);
 130         }
 131
 132         printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 133                         "for crashkernel (System RAM: %ldMB)\n",
 134                         (unsigned long)(crash_size >> 20),
 135                         (unsigned long)(crashk_res.start >> 20),
 136                         (unsigned long)(lmb_phys_mem_size() >> 20));
 137
 138         lmb_reserve(crashk_res.start, crash_size);
 139 }
 140
 141 int overlaps_crashkernel(unsigned long start, unsigned long size)
 142 {
 143         return (start + size) > crashk_res.start && start <= crashk_res.end;
 144 }
 145
 146 /* Values we need to export to the second kernel via the device tree. */
 147 static unsigned long kernel_end;
 148 static unsigned long crashk_size;
 149
 150 static struct property kernel_end_prop = {
 151         .name = "linux,kernel-end",
 152         .length = sizeof(unsigned long),
 153         .value = &kernel_end,
 154 };
 155
 156 static struct property crashk_base_prop = {
 157         .name = "linux,crashkernel-base",
 158         .length = sizeof(unsigned long),
 159         .value = &crashk_res.start,
 160 };
 161
 162 static struct property crashk_size_prop = {
 163         .name = "linux,crashkernel-size",
 164         .length = sizeof(unsigned long),
 165         .value = &crashk_size,
 166 };
 167
 168 static void __init export_crashk_values(struct device_node *node)
 169 {
 170         struct property *prop;
 171
 172         /* There might be existing crash kernel properties, but we can't
 173          * be sure what's in them, so remove them. */
 174         prop = of_find_property(node, "linux,crashkernel-base", NULL);
 175         if (prop)
 176                 prom_remove_property(node, prop);
 177
 178         prop = of_find_property(node, "linux,crashkernel-size", NULL);
 179         if (prop)
 180                 prom_remove_property(node, prop);
 181
 182         if (crashk_res.start != 0) {
 183                 prom_add_property(node, &crashk_base_prop);
 184                 crashk_size = crashk_res.end - crashk_res.start + 1;
 185                 prom_add_property(node, &crashk_size_prop);
 186         }
 187 }
 188
 189 static int __init kexec_setup(void)
 190 {
 191         struct device_node *node;
 192         struct property *prop;
 193
 194         node = of_find_node_by_path("/chosen");
 195         if (!node)
 196                 return -ENOENT;
 197
 198         /* remove any stale properties so ours can be found */
 199         prop = of_find_property(node, kernel_end_prop.name, NULL);
 200         if (prop)
 201                 prom_remove_property(node, prop);
 202
 203         /* information needed by userspace when using default_machine_kexec */
 204         kernel_end = __pa(_end);
 205         prom_add_property(node, &kernel_end_prop);
 206
 207         export_crashk_values(node);
 208
 209         of_node_put(node);
 210         return 0;
 211 }
 212 late_initcall(kexec_setup);