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