release/src-rt-6.x.4708/linux/linux-2.6.36/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/memblock.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 void arch_crash_save_vmcoreinfo(void)
  49 {
  50
  51 #ifdef CONFIG_NEED_MULTIPLE_NODES
  52         VMCOREINFO_SYMBOL(node_data);
  53         VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
  54 #endif
  55 #ifndef CONFIG_NEED_MULTIPLE_NODES
  56         VMCOREINFO_SYMBOL(contig_page_data);
  57 #endif
  58 }
  59
  60 /*
  61  * Do not allocate memory (or fail in any way) in machine_kexec().
  62  * We are past the point of no return, committed to rebooting now.
  63  */
  64 void machine_kexec(struct kimage *image)
  65 {
  66         if (ppc_md.machine_kexec)
  67                 ppc_md.machine_kexec(image);
  68         else
  69                 default_machine_kexec(image);
  70
  71         /* Fall back to normal restart if we're still alive. */
  72         machine_restart(NULL);
  73         for(;;);
  74 }
  75
  76 void __init reserve_crashkernel(void)
  77 {
  78         unsigned long long crash_size, crash_base;
  79         int ret;
  80
  81         /* this is necessary because of memblock_phys_mem_size() */
  82         memblock_analyze();
  83
  84         /* use common parsing */
  85         ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
  86                         &crash_size, &crash_base);
  87         if (ret == 0 && crash_size > 0) {
  88                 crashk_res.start = crash_base;
  89                 crashk_res.end = crash_base + crash_size - 1;
  90         }
  91
  92         if (crashk_res.end == crashk_res.start) {
  93                 crashk_res.start = crashk_res.end = 0;
  94                 return;
  95         }
  96
  97         /* We might have got these values via the command line or the
  98          * device tree, either way sanitise them now. */
  99
 100         crash_size = crashk_res.end - crashk_res.start + 1;
 101
 102 #ifndef CONFIG_RELOCATABLE
 103         if (crashk_res.start != KDUMP_KERNELBASE)
 104                 printk("Crash kernel location must be 0x%x\n",
 105                                 KDUMP_KERNELBASE);
 106
 107         crashk_res.start = KDUMP_KERNELBASE;
 108 #else
 109         if (!crashk_res.start) {
 110                 /*
 111                  * unspecified address, choose a region of specified size
 112                  * can overlap with initrd (ignoring corruption when retained)
 113                  * ppc64 requires kernel and some stacks to be in first segemnt
 114                  */
 115                 crashk_res.start = KDUMP_KERNELBASE;
 116         }
 117
 118         crash_base = PAGE_ALIGN(crashk_res.start);
 119         if (crash_base != crashk_res.start) {
 120                 printk("Crash kernel base must be aligned to 0x%lx\n",
 121                                 PAGE_SIZE);
 122                 crashk_res.start = crash_base;
 123         }
 124
 125 #endif
 126         crash_size = PAGE_ALIGN(crash_size);
 127         crashk_res.end = crashk_res.start + crash_size - 1;
 128
 129         /* The crash region must not overlap the current kernel */
 130         if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
 131                 printk(KERN_WARNING
 132                         "Crash kernel can not overlap current kernel\n");
 133                 crashk_res.start = crashk_res.end = 0;
 134                 return;
 135         }
 136
 137         /* Crash kernel trumps memory limit */
 138         if (memory_limit && memory_limit <= crashk_res.end) {
 139                 memory_limit = crashk_res.end + 1;
 140                 printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
 141                        (unsigned long long)memory_limit);
 142         }
 143
 144         printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 145                         "for crashkernel (System RAM: %ldMB)\n",
 146                         (unsigned long)(crash_size >> 20),
 147                         (unsigned long)(crashk_res.start >> 20),
 148                         (unsigned long)(memblock_phys_mem_size() >> 20));
 149
 150         memblock_reserve(crashk_res.start, crash_size);
 151 }
 152
 153 int overlaps_crashkernel(unsigned long start, unsigned long size)
 154 {
 155         return (start + size) > crashk_res.start && start <= crashk_res.end;
 156 }
 157
 158 /* Values we need to export to the second kernel via the device tree. */
 159 static phys_addr_t kernel_end;
 160 static phys_addr_t crashk_size;
 161
 162 static struct property kernel_end_prop = {
 163         .name = "linux,kernel-end",
 164         .length = sizeof(phys_addr_t),
 165         .value = &kernel_end,
 166 };
 167
 168 static struct property crashk_base_prop = {
 169         .name = "linux,crashkernel-base",
 170         .length = sizeof(phys_addr_t),
 171         .value = &crashk_res.start,
 172 };
 173
 174 static struct property crashk_size_prop = {
 175         .name = "linux,crashkernel-size",
 176         .length = sizeof(phys_addr_t),
 177         .value = &crashk_size,
 178 };
 179
 180 static void __init export_crashk_values(struct device_node *node)
 181 {
 182         struct property *prop;
 183
 184         /* There might be existing crash kernel properties, but we can't
 185          * be sure what's in them, so remove them. */
 186         prop = of_find_property(node, "linux,crashkernel-base", NULL);
 187         if (prop)
 188                 prom_remove_property(node, prop);
 189
 190         prop = of_find_property(node, "linux,crashkernel-size", NULL);
 191         if (prop)
 192                 prom_remove_property(node, prop);
 193
 194         if (crashk_res.start != 0) {
 195                 prom_add_property(node, &crashk_base_prop);
 196                 crashk_size = crashk_res.end - crashk_res.start + 1;
 197                 prom_add_property(node, &crashk_size_prop);
 198         }
 199 }
 200
 201 static int __init kexec_setup(void)
 202 {
 203         struct device_node *node;
 204         struct property *prop;
 205
 206         node = of_find_node_by_path("/chosen");
 207         if (!node)
 208                 return -ENOENT;
 209
 210         /* remove any stale properties so ours can be found */
 211         prop = of_find_property(node, kernel_end_prop.name, NULL);
 212         if (prop)
 213                 prom_remove_property(node, prop);
 214
 215         /* information needed by userspace when using default_machine_kexec */
 216         kernel_end = __pa(_end);
 217         prom_add_property(node, &kernel_end_prop);
 218
 219         export_crashk_values(node);
 220
 221         of_node_put(node);
 222         return 0;
 223 }
 224 late_initcall(kexec_setup);