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 <linux/irq.h>
  18 #include <linux/ftrace.h>
  19
  20 #include <asm/machdep.h>
  21 #include <asm/prom.h>
  22 #include <asm/sections.h>
  23
  24 void machine_kexec_mask_interrupts(void) {
  25         unsigned int i;
  26
  27         for_each_irq(i) {
  28                 struct irq_desc *desc = irq_to_desc(i);
  29
  30                 if (!desc || !desc->chip)
  31                         continue;
  32
  33                 if (desc->chip->eoi &&
  34                     desc->status & IRQ_INPROGRESS)
  35                         desc->chip->eoi(i);
  36
  37                 if (desc->chip->mask)
  38                         desc->chip->mask(i);
  39
  40                 if (desc->chip->disable &&
  41                     !(desc->status & IRQ_DISABLED))
  42                         desc->chip->disable(i);
  43         }
  44 }
  45
  46 void machine_crash_shutdown(struct pt_regs *regs)
  47 {
  48         default_machine_crash_shutdown(regs);
  49 }
  50
  51 /*
  52  * Do what every setup is needed on image and the
  53  * reboot code buffer to allow us to avoid allocations
  54  * later.
  55  */
  56 int machine_kexec_prepare(struct kimage *image)
  57 {
  58         if (ppc_md.machine_kexec_prepare)
  59                 return ppc_md.machine_kexec_prepare(image);
  60         else
  61                 return default_machine_kexec_prepare(image);
  62 }
  63
  64 void machine_kexec_cleanup(struct kimage *image)
  65 {
  66 }
  67
  68 void arch_crash_save_vmcoreinfo(void)
  69 {
  70
  71 #ifdef CONFIG_NEED_MULTIPLE_NODES
  72         VMCOREINFO_SYMBOL(node_data);
  73         VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
  74 #endif
  75 #ifndef CONFIG_NEED_MULTIPLE_NODES
  76         VMCOREINFO_SYMBOL(contig_page_data);
  77 #endif
  78 }
  79
  80 /*
  81  * Do not allocate memory (or fail in any way) in machine_kexec().
  82  * We are past the point of no return, committed to rebooting now.
  83  */
  84 void machine_kexec(struct kimage *image)
  85 {
  86         int save_ftrace_enabled;
  87
  88         save_ftrace_enabled = __ftrace_enabled_save();
  89
  90         default_machine_kexec(image);
  91
  92         __ftrace_enabled_restore(save_ftrace_enabled);
  93
  94         /* Fall back to normal restart if we're still alive. */
  95         machine_restart(NULL);
  96         for(;;);
  97 }
  98
  99 void __init reserve_crashkernel(void)
 100 {
 101         unsigned long long crash_size, crash_base;
 102         int ret;
 103
 104         /* this is necessary because of memblock_phys_mem_size() */
 105         memblock_analyze();
 106
 107         /* use common parsing */
 108         ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 109                         &crash_size, &crash_base);
 110         if (ret == 0 && crash_size > 0) {
 111                 crashk_res.start = crash_base;
 112                 crashk_res.end = crash_base + crash_size - 1;
 113         }
 114
 115         if (crashk_res.end == crashk_res.start) {
 116                 crashk_res.start = crashk_res.end = 0;
 117                 return;
 118         }
 119
 120         /* We might have got these values via the command line or the
 121          * device tree, either way sanitise them now. */
 122
 123         crash_size = crashk_res.end - crashk_res.start + 1;
 124
 125 #ifndef CONFIG_RELOCATABLE
 126         if (crashk_res.start != KDUMP_KERNELBASE)
 127                 printk("Crash kernel location must be 0x%x\n",
 128                                 KDUMP_KERNELBASE);
 129
 130         crashk_res.start = KDUMP_KERNELBASE;
 131 #else
 132         if (!crashk_res.start) {
 133                 /*
 134                  * unspecified address, choose a region of specified size
 135                  * can overlap with initrd (ignoring corruption when retained)
 136                  * ppc64 requires kernel and some stacks to be in first segemnt
 137                  */
 138                 crashk_res.start = KDUMP_KERNELBASE;
 139         }
 140
 141         crash_base = PAGE_ALIGN(crashk_res.start);
 142         if (crash_base != crashk_res.start) {
 143                 printk("Crash kernel base must be aligned to 0x%lx\n",
 144                                 PAGE_SIZE);
 145                 crashk_res.start = crash_base;
 146         }
 147
 148 #endif
 149         crash_size = PAGE_ALIGN(crash_size);
 150         crashk_res.end = crashk_res.start + crash_size - 1;
 151
 152         /* The crash region must not overlap the current kernel */
 153         if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
 154                 printk(KERN_WARNING
 155                         "Crash kernel can not overlap current kernel\n");
 156                 crashk_res.start = crashk_res.end = 0;
 157                 return;
 158         }
 159
 160         /* Crash kernel trumps memory limit */
 161         if (memory_limit && memory_limit <= crashk_res.end) {
 162                 memory_limit = crashk_res.end + 1;
 163                 printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
 164                        (unsigned long long)memory_limit);
 165         }
 166
 167         printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 168                         "for crashkernel (System RAM: %ldMB)\n",
 169                         (unsigned long)(crash_size >> 20),
 170                         (unsigned long)(crashk_res.start >> 20),
 171                         (unsigned long)(memblock_phys_mem_size() >> 20));
 172
 173         memblock_reserve(crashk_res.start, crash_size);
 174 }
 175
 176 int overlaps_crashkernel(unsigned long start, unsigned long size)
 177 {
 178         return (start + size) > crashk_res.start && start <= crashk_res.end;
 179 }
 180
 181 /* Values we need to export to the second kernel via the device tree. */
 182 static phys_addr_t kernel_end;
 183 static phys_addr_t crashk_size;
 184
 185 static struct property kernel_end_prop = {
 186         .name = "linux,kernel-end",
 187         .length = sizeof(phys_addr_t),
 188         .value = &kernel_end,
 189 };
 190
 191 static struct property crashk_base_prop = {
 192         .name = "linux,crashkernel-base",
 193         .length = sizeof(phys_addr_t),
 194         .value = &crashk_res.start,
 195 };
 196
 197 static struct property crashk_size_prop = {
 198         .name = "linux,crashkernel-size",
 199         .length = sizeof(phys_addr_t),
 200         .value = &crashk_size,
 201 };
 202
 203 static void __init export_crashk_values(struct device_node *node)
 204 {
 205         struct property *prop;
 206
 207         /* There might be existing crash kernel properties, but we can't
 208          * be sure what's in them, so remove them. */
 209         prop = of_find_property(node, "linux,crashkernel-base", NULL);
 210         if (prop)
 211                 prom_remove_property(node, prop);
 212
 213         prop = of_find_property(node, "linux,crashkernel-size", NULL);
 214         if (prop)
 215                 prom_remove_property(node, prop);
 216
 217         if (crashk_res.start != 0) {
 218                 prom_add_property(node, &crashk_base_prop);
 219                 crashk_size = crashk_res.end - crashk_res.start + 1;
 220                 prom_add_property(node, &crashk_size_prop);
 221         }
 222 }
 223
 224 static int __init kexec_setup(void)
 225 {
 226         struct device_node *node;
 227         struct property *prop;
 228
 229         node = of_find_node_by_path("/chosen");
 230         if (!node)
 231                 return -ENOENT;
 232
 233         /* remove any stale properties so ours can be found */
 234         prop = of_find_property(node, kernel_end_prop.name, NULL);
 235         if (prop)
 236                 prom_remove_property(node, prop);
 237
 238         /* information needed by userspace when using default_machine_kexec */
 239         kernel_end = __pa(_end);
 240         prom_add_property(node, &kernel_end_prop);
 241
 242         export_crashk_values(node);
 243
 244         of_node_put(node);
 245         return 0;
 246 }
 247 late_initcall(kexec_setup);