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         struct irq_desc *desc;
  27
  28         for_each_irq_desc(i, desc) {
  29                 struct irq_chip *chip;
  30
  31                 chip = irq_desc_get_chip(desc);
  32                 if (!chip)
  33                         continue;
  34
  35                 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
  36                         chip->irq_eoi(&desc->irq_data);
  37
  38                 if (chip->irq_mask)
  39                         chip->irq_mask(&desc->irq_data);
  40
  41                 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
  42                         chip->irq_disable(&desc->irq_data);
  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         if (ppc_md.machine_kexec)
  91                 ppc_md.machine_kexec(image);
  92         else
  93                 default_machine_kexec(image);
  94
  95         __ftrace_enabled_restore(save_ftrace_enabled);
  96
  97         /* Fall back to normal restart if we're still alive. */
  98         machine_restart(NULL);
  99         for(;;);
 100 }
 101
 102 void __init reserve_crashkernel(void)
 103 {
 104         unsigned long long crash_size, crash_base;
 105         int ret;
 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 = resource_size(&crashk_res);
 124
 125 #ifndef CONFIG_NONSTATIC_KERNEL
 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 #ifdef CONFIG_PPC64
 134                 /*
 135                  * On 64bit we split the RMO in half but cap it at half of
 136                  * a small SLB (128MB) since the crash kernel needs to place
 137                  * itself and some stacks to be in the first segment.
 138                  */
 139                 crashk_res.start = min(0x80000000ULL, (ppc64_rma_size / 2));
 140 #else
 141                 crashk_res.start = KDUMP_KERNELBASE;
 142 #endif
 143         }
 144
 145         crash_base = PAGE_ALIGN(crashk_res.start);
 146         if (crash_base != crashk_res.start) {
 147                 printk("Crash kernel base must be aligned to 0x%lx\n",
 148                                 PAGE_SIZE);
 149                 crashk_res.start = crash_base;
 150         }
 151
 152 #endif
 153         crash_size = PAGE_ALIGN(crash_size);
 154         crashk_res.end = crashk_res.start + crash_size - 1;
 155
 156         /* The crash region must not overlap the current kernel */
 157         if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
 158                 printk(KERN_WARNING
 159                         "Crash kernel can not overlap current kernel\n");
 160                 crashk_res.start = crashk_res.end = 0;
 161                 return;
 162         }
 163
 164         /* Crash kernel trumps memory limit */
 165         if (memory_limit && memory_limit <= crashk_res.end) {
 166                 memory_limit = crashk_res.end + 1;
 167                 printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
 168                        memory_limit);
 169         }
 170
 171         printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 172                         "for crashkernel (System RAM: %ldMB)\n",
 173                         (unsigned long)(crash_size >> 20),
 174                         (unsigned long)(crashk_res.start >> 20),
 175                         (unsigned long)(memblock_phys_mem_size() >> 20));
 176
 177         memblock_reserve(crashk_res.start, crash_size);
 178 }
 179
 180 int overlaps_crashkernel(unsigned long start, unsigned long size)
 181 {
 182         return (start + size) > crashk_res.start && start <= crashk_res.end;
 183 }
 184
 185 /* Values we need to export to the second kernel via the device tree. */
 186 static phys_addr_t kernel_end;
 187 static phys_addr_t crashk_size;
 188
 189 static struct property kernel_end_prop = {
 190         .name = "linux,kernel-end",
 191         .length = sizeof(phys_addr_t),
 192         .value = &kernel_end,
 193 };
 194
 195 static struct property crashk_base_prop = {
 196         .name = "linux,crashkernel-base",
 197         .length = sizeof(phys_addr_t),
 198         .value = &crashk_res.start,
 199 };
 200
 201 static struct property crashk_size_prop = {
 202         .name = "linux,crashkernel-size",
 203         .length = sizeof(phys_addr_t),
 204         .value = &crashk_size,
 205 };
 206
 207 static struct property memory_limit_prop = {
 208         .name = "linux,memory-limit",
 209         .length = sizeof(unsigned long long),
 210         .value = &memory_limit,
 211 };
 212
 213 static void __init export_crashk_values(struct device_node *node)
 214 {
 215         struct property *prop;
 216
 217         /* There might be existing crash kernel properties, but we can't
 218          * be sure what's in them, so remove them. */
 219         prop = of_find_property(node, "linux,crashkernel-base", NULL);
 220         if (prop)
 221                 of_remove_property(node, prop);
 222
 223         prop = of_find_property(node, "linux,crashkernel-size", NULL);
 224         if (prop)
 225                 of_remove_property(node, prop);
 226
 227         if (crashk_res.start != 0) {
 228                 of_add_property(node, &crashk_base_prop);
 229                 crashk_size = resource_size(&crashk_res);
 230                 of_add_property(node, &crashk_size_prop);
 231         }
 232
 233         /*
 234          * memory_limit is required by the kexec-tools to limit the
 235          * crash regions to the actual memory used.
 236          */
 237         of_update_property(node, &memory_limit_prop);
 238 }
 239
 240 static int __init kexec_setup(void)
 241 {
 242         struct device_node *node;
 243         struct property *prop;
 244
 245         node = of_find_node_by_path("/chosen");
 246         if (!node)
 247                 return -ENOENT;
 248
 249         /* remove any stale properties so ours can be found */
 250         prop = of_find_property(node, kernel_end_prop.name, NULL);
 251         if (prop)
 252                 of_remove_property(node, prop);
 253
 254         /* information needed by userspace when using default_machine_kexec */
 255         kernel_end = __pa(_end);
 256         of_add_property(node, &kernel_end_prop);
 257
 258         export_crashk_values(node);
 259
 260         of_node_put(node);
 261         return 0;
 262 }
 263 late_initcall(kexec_setup);