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