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