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/pgalloc.h>
  22 #include <asm/prom.h>
  23 #include <asm/sections.h>
  24
  25 void machine_kexec_mask_interrupts(void) {
  26         unsigned int i;
  27         struct irq_desc *desc;
  28
  29         for_each_irq_desc(i, desc) {
  30                 struct irq_chip *chip;
  31
  32                 chip = irq_desc_get_chip(desc);
  33                 if (!chip)
  34                         continue;
  35
  36                 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
  37                         chip->irq_eoi(&desc->irq_data);
  38
  39                 if (chip->irq_mask)
  40                         chip->irq_mask(&desc->irq_data);
  41
  42                 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
  43                         chip->irq_disable(&desc->irq_data);
  44         }
  45 }
  46
  47 void machine_crash_shutdown(struct pt_regs *regs)
  48 {
  49         default_machine_crash_shutdown(regs);
  50 }
  51
  52 /*
  53  * Do what every setup is needed on image and the
  54  * reboot code buffer to allow us to avoid allocations
  55  * later.
  56  */
  57 int machine_kexec_prepare(struct kimage *image)
  58 {
  59         if (ppc_md.machine_kexec_prepare)
  60                 return ppc_md.machine_kexec_prepare(image);
  61         else
  62                 return default_machine_kexec_prepare(image);
  63 }
  64
  65 void machine_kexec_cleanup(struct kimage *image)
  66 {
  67 }
  68
  69 void arch_crash_save_vmcoreinfo(void)
  70 {
  71
  72 #ifdef CONFIG_NEED_MULTIPLE_NODES
  73         VMCOREINFO_SYMBOL(node_data);
  74         VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
  75 #endif
  76 #ifndef CONFIG_NEED_MULTIPLE_NODES
  77         VMCOREINFO_SYMBOL(contig_page_data);
  78 #endif
  79 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
  80         VMCOREINFO_SYMBOL(vmemmap_list);
  81         VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
  82         VMCOREINFO_SYMBOL(mmu_psize_defs);
  83         VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
  84         VMCOREINFO_OFFSET(vmemmap_backing, list);
  85         VMCOREINFO_OFFSET(vmemmap_backing, phys);
  86         VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
  87         VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
  88         VMCOREINFO_OFFSET(mmu_psize_def, shift);
  89 #endif
  90 }
  91
  92 /*
  93  * Do not allocate memory (or fail in any way) in machine_kexec().
  94  * We are past the point of no return, committed to rebooting now.
  95  */
  96 void machine_kexec(struct kimage *image)
  97 {
  98         int save_ftrace_enabled;
  99
 100         save_ftrace_enabled = __ftrace_enabled_save();
 101
 102         if (ppc_md.machine_kexec)
 103                 ppc_md.machine_kexec(image);
 104         else
 105                 default_machine_kexec(image);
 106
 107         __ftrace_enabled_restore(save_ftrace_enabled);
 108
 109         /* Fall back to normal restart if we're still alive. */
 110         machine_restart(NULL);
 111         for(;;);
 112 }
 113
 114 void __init reserve_crashkernel(void)
 115 {
 116         unsigned long long crash_size, crash_base;
 117         int ret;
 118
 119         /* use common parsing */
 120         ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 121                         &crash_size, &crash_base);
 122         if (ret == 0 && crash_size > 0) {
 123                 crashk_res.start = crash_base;
 124                 crashk_res.end = crash_base + crash_size - 1;
 125         }
 126
 127         if (crashk_res.end == crashk_res.start) {
 128                 crashk_res.start = crashk_res.end = 0;
 129                 return;
 130         }
 131
 132         /* We might have got these values via the command line or the
 133          * device tree, either way sanitise them now. */
 134
 135         crash_size = resource_size(&crashk_res);
 136
 137 #ifndef CONFIG_NONSTATIC_KERNEL
 138         if (crashk_res.start != KDUMP_KERNELBASE)
 139                 printk("Crash kernel location must be 0x%x\n",
 140                                 KDUMP_KERNELBASE);
 141
 142         crashk_res.start = KDUMP_KERNELBASE;
 143 #else
 144         if (!crashk_res.start) {
 145 #ifdef CONFIG_PPC64
 146                 /*
 147                  * On 64bit we split the RMO in half but cap it at half of
 148                  * a small SLB (128MB) since the crash kernel needs to place
 149                  * itself and some stacks to be in the first segment.
 150                  */
 151                 crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
 152 #else
 153                 crashk_res.start = KDUMP_KERNELBASE;
 154 #endif
 155         }
 156
 157         crash_base = PAGE_ALIGN(crashk_res.start);
 158         if (crash_base != crashk_res.start) {
 159                 printk("Crash kernel base must be aligned to 0x%lx\n",
 160                                 PAGE_SIZE);
 161                 crashk_res.start = crash_base;
 162         }
 163
 164 #endif
 165         crash_size = PAGE_ALIGN(crash_size);
 166         crashk_res.end = crashk_res.start + crash_size - 1;
 167
 168         /* The crash region must not overlap the current kernel */
 169         if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
 170                 printk(KERN_WARNING
 171                         "Crash kernel can not overlap current kernel\n");
 172                 crashk_res.start = crashk_res.end = 0;
 173                 return;
 174         }
 175
 176         /* Crash kernel trumps memory limit */
 177         if (memory_limit && memory_limit <= crashk_res.end) {
 178                 memory_limit = crashk_res.end + 1;
 179                 printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
 180                        memory_limit);
 181         }
 182
 183         printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 184                         "for crashkernel (System RAM: %ldMB)\n",
 185                         (unsigned long)(crash_size >> 20),
 186                         (unsigned long)(crashk_res.start >> 20),
 187                         (unsigned long)(memblock_phys_mem_size() >> 20));
 188
 189         memblock_reserve(crashk_res.start, crash_size);
 190 }
 191
 192 int overlaps_crashkernel(unsigned long start, unsigned long size)
 193 {
 194         return (start + size) > crashk_res.start && start <= crashk_res.end;
 195 }
 196
 197 /* Values we need to export to the second kernel via the device tree. */
 198 static phys_addr_t kernel_end;
 199 static phys_addr_t crashk_base;
 200 static phys_addr_t crashk_size;
 201 static unsigned long long mem_limit;
 202
 203 static struct property kernel_end_prop = {
 204         .name = "linux,kernel-end",
 205         .length = sizeof(phys_addr_t),
 206         .value = &kernel_end,
 207 };
 208
 209 static struct property crashk_base_prop = {
 210         .name = "linux,crashkernel-base",
 211         .length = sizeof(phys_addr_t),
 212         .value = &crashk_base
 213 };
 214
 215 static struct property crashk_size_prop = {
 216         .name = "linux,crashkernel-size",
 217         .length = sizeof(phys_addr_t),
 218         .value = &crashk_size,
 219 };
 220
 221 static struct property memory_limit_prop = {
 222         .name = "linux,memory-limit",
 223         .length = sizeof(unsigned long long),
 224         .value = &mem_limit,
 225 };
 226
 227 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG)
 228
 229 static void __init export_crashk_values(struct device_node *node)
 230 {
 231         /* There might be existing crash kernel properties, but we can't
 232          * be sure what's in them, so remove them. */
 233         of_remove_property(node, of_find_property(node,
 234                                 "linux,crashkernel-base", NULL));
 235         of_remove_property(node, of_find_property(node,
 236                                 "linux,crashkernel-size", NULL));
 237
 238         if (crashk_res.start != 0) {
 239                 crashk_base = cpu_to_be_ulong(crashk_res.start),
 240                 of_add_property(node, &crashk_base_prop);
 241                 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
 242                 of_add_property(node, &crashk_size_prop);
 243         }
 244
 245         /*
 246          * memory_limit is required by the kexec-tools to limit the
 247          * crash regions to the actual memory used.
 248          */
 249         mem_limit = cpu_to_be_ulong(memory_limit);
 250         of_update_property(node, &memory_limit_prop);
 251 }
 252
 253 static int __init kexec_setup(void)
 254 {
 255         struct device_node *node;
 256
 257         node = of_find_node_by_path("/chosen");
 258         if (!node)
 259                 return -ENOENT;
 260
 261         /* remove any stale properties so ours can be found */
 262         of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL));
 263
 264         /* information needed by userspace when using default_machine_kexec */
 265         kernel_end = cpu_to_be_ulong(__pa(_end));
 266         of_add_property(node, &kernel_end_prop);
 267
 268         export_crashk_values(node);
 269
 270         of_node_put(node);
 271         return 0;
 272 }
 273 late_initcall(kexec_setup);