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
  27         for_each_irq(i) {
  28                 struct irq_desc *desc = irq_to_desc(i);
  29                 struct irq_chip *chip;
  30
  31                 if (!desc)
  32                         continue;
  33
  34                 chip = irq_desc_get_chip(desc);
  35                 if (!chip)
  36                         continue;
  37
  38                 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
  39                         chip->irq_eoi(&desc->irq_data);
  40
  41                 if (chip->irq_mask)
  42                         chip->irq_mask(&desc->irq_data);
  43
  44                 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
  45                         chip->irq_disable(&desc->irq_data);
  46         }
  47 }
  48
  49 void machine_crash_shutdown(struct pt_regs *regs)
  50 {
  51         default_machine_crash_shutdown(regs);
  52 }
  53
  54 /*
  55  * Do what every setup is needed on image and the
  56  * reboot code buffer to allow us to avoid allocations
  57  * later.
  58  */
  59 int machine_kexec_prepare(struct kimage *image)
  60 {
  61         if (ppc_md.machine_kexec_prepare)
  62                 return ppc_md.machine_kexec_prepare(image);
  63         else
  64                 return default_machine_kexec_prepare(image);
  65 }
  66
  67 void machine_kexec_cleanup(struct kimage *image)
  68 {
  69 }
  70
  71 void arch_crash_save_vmcoreinfo(void)
  72 {
  73
  74 #ifdef CONFIG_NEED_MULTIPLE_NODES
  75         VMCOREINFO_SYMBOL(node_data);
  76         VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
  77 #endif
  78 #ifndef CONFIG_NEED_MULTIPLE_NODES
  79         VMCOREINFO_SYMBOL(contig_page_data);
  80 #endif
  81 }
  82
  83 /*
  84  * Do not allocate memory (or fail in any way) in machine_kexec().
  85  * We are past the point of no return, committed to rebooting now.
  86  */
  87 void machine_kexec(struct kimage *image)
  88 {
  89         int save_ftrace_enabled;
  90
  91         save_ftrace_enabled = __ftrace_enabled_save();
  92
  93         if (ppc_md.machine_kexec)
  94                 ppc_md.machine_kexec(image);
  95         else
  96                 default_machine_kexec(image);
  97
  98         __ftrace_enabled_restore(save_ftrace_enabled);
  99
 100         /* Fall back to normal restart if we're still alive. */
 101         machine_restart(NULL);
 102         for(;;);
 103 }
 104
 105 void __init reserve_crashkernel(void)
 106 {
 107         unsigned long long crash_size, crash_base;
 108         int ret;
 109
 110         /* this is necessary because of memblock_phys_mem_size() */
 111         memblock_analyze();
 112
 113         /* use common parsing */
 114         ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 115                         &crash_size, &crash_base);
 116         if (ret == 0 && crash_size > 0) {
 117                 crashk_res.start = crash_base;
 118                 crashk_res.end = crash_base + crash_size - 1;
 119         }
 120
 121         if (crashk_res.end == crashk_res.start) {
 122                 crashk_res.start = crashk_res.end = 0;
 123                 return;
 124         }
 125
 126         /* We might have got these values via the command line or the
 127          * device tree, either way sanitise them now. */
 128
 129         crash_size = resource_size(&crashk_res);
 130
 131 #ifndef CONFIG_RELOCATABLE
 132         if (crashk_res.start != KDUMP_KERNELBASE)
 133                 printk("Crash kernel location must be 0x%x\n",
 134                                 KDUMP_KERNELBASE);
 135
 136         crashk_res.start = KDUMP_KERNELBASE;
 137 #else
 138         if (!crashk_res.start) {
 139 #ifdef CONFIG_PPC64
 140                 /*
 141                  * On 64bit we split the RMO in half but cap it at half of
 142                  * a small SLB (128MB) since the crash kernel needs to place
 143                  * itself and some stacks to be in the first segment.
 144                  */
 145                 crashk_res.start = min(0x80000000ULL, (ppc64_rma_size / 2));
 146 #else
 147                 crashk_res.start = KDUMP_KERNELBASE;
 148 #endif
 149         }
 150
 151         crash_base = PAGE_ALIGN(crashk_res.start);
 152         if (crash_base != crashk_res.start) {
 153                 printk("Crash kernel base must be aligned to 0x%lx\n",
 154                                 PAGE_SIZE);
 155                 crashk_res.start = crash_base;
 156         }
 157
 158 #endif
 159         crash_size = PAGE_ALIGN(crash_size);
 160         crashk_res.end = crashk_res.start + crash_size - 1;
 161
 162         /* The crash region must not overlap the current kernel */
 163         if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
 164                 printk(KERN_WARNING
 165                         "Crash kernel can not overlap current kernel\n");
 166                 crashk_res.start = crashk_res.end = 0;
 167                 return;
 168         }
 169
 170         /* Crash kernel trumps memory limit */
 171         if (memory_limit && memory_limit <= crashk_res.end) {
 172                 memory_limit = crashk_res.end + 1;
 173                 printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
 174                        (unsigned long long)memory_limit);
 175         }
 176
 177         printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 178                         "for crashkernel (System RAM: %ldMB)\n",
 179                         (unsigned long)(crash_size >> 20),
 180                         (unsigned long)(crashk_res.start >> 20),
 181                         (unsigned long)(memblock_phys_mem_size() >> 20));
 182
 183         memblock_reserve(crashk_res.start, crash_size);
 184 }
 185
 186 int overlaps_crashkernel(unsigned long start, unsigned long size)
 187 {
 188         return (start + size) > crashk_res.start && start <= crashk_res.end;
 189 }
 190
 191 /* Values we need to export to the second kernel via the device tree. */
 192 static phys_addr_t kernel_end;
 193 static phys_addr_t crashk_size;
 194
 195 static struct property kernel_end_prop = {
 196         .name = "linux,kernel-end",
 197         .length = sizeof(phys_addr_t),
 198         .value = &kernel_end,
 199 };
 200
 201 static struct property crashk_base_prop = {
 202         .name = "linux,crashkernel-base",
 203         .length = sizeof(phys_addr_t),
 204         .value = &crashk_res.start,
 205 };
 206
 207 static struct property crashk_size_prop = {
 208         .name = "linux,crashkernel-size",
 209         .length = sizeof(phys_addr_t),
 210         .value = &crashk_size,
 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                 prom_remove_property(node, prop);
 222
 223         prop = of_find_property(node, "linux,crashkernel-size", NULL);
 224         if (prop)
 225                 prom_remove_property(node, prop);
 226
 227         if (crashk_res.start != 0) {
 228                 prom_add_property(node, &crashk_base_prop);
 229                 crashk_size = resource_size(&crashk_res);
 230                 prom_add_property(node, &crashk_size_prop);
 231         }
 232 }
 233
 234 static int __init kexec_setup(void)
 235 {
 236         struct device_node *node;
 237         struct property *prop;
 238
 239         node = of_find_node_by_path("/chosen");
 240         if (!node)
 241                 return -ENOENT;
 242
 243         /* remove any stale properties so ours can be found */
 244         prop = of_find_property(node, kernel_end_prop.name, NULL);
 245         if (prop)
 246                 prom_remove_property(node, prop);
 247
 248         /* information needed by userspace when using default_machine_kexec */
 249         kernel_end = __pa(_end);
 250         prom_add_property(node, &kernel_end_prop);
 251
 252         export_crashk_values(node);
 253
 254         of_node_put(node);
 255         return 0;
 256 }
 257 late_initcall(kexec_setup);