LXR linux/arch/powerpc/kernel/machine

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Code to handle transition of Linux booting another kernel.
   4 *
   5 * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
   6 * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
   7 * Copyright (C) 2005 IBM Corporation.
   8 */
   9
  10#include <linux/kexec.h>
  11#include <linux/reboot.h>
  12#include <linux/threads.h>
  13#include <linux/memblock.h>
  14#include <linux/of.h>
  15#include <linux/irq.h>
  16#include <linux/ftrace.h>
  17
  18#include <asm/kdump.h>
  19#include <asm/machdep.h>
  20#include <asm/pgalloc.h>
  21#include <asm/prom.h>
  22#include <asm/sections.h>
  23
  24void 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
  46void 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 */
  56int 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
  64void machine_kexec_cleanup(struct kimage *image)
  65{
  66}
  67
  68void 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#if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
  79        VMCOREINFO_SYMBOL(vmemmap_list);
  80        VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
  81        VMCOREINFO_SYMBOL(mmu_psize_defs);
  82        VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
  83        VMCOREINFO_OFFSET(vmemmap_backing, list);
  84        VMCOREINFO_OFFSET(vmemmap_backing, phys);
  85        VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
  86        VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
  87        VMCOREINFO_OFFSET(mmu_psize_def, shift);
  88#endif
  89}
  90
  91/*
  92 * Do not allocate memory (or fail in any way) in machine_kexec().
  93 * We are past the point of no return, committed to rebooting now.
  94 */
  95void machine_kexec(struct kimage *image)
  96{
  97        int save_ftrace_enabled;
  98
  99        save_ftrace_enabled = __ftrace_enabled_save();
 100        this_cpu_disable_ftrace();
 101
 102        if (ppc_md.machine_kexec)
 103                ppc_md.machine_kexec(image);
 104        else
 105                default_machine_kexec(image);
 106
 107        this_cpu_enable_ftrace();
 108        __ftrace_enabled_restore(save_ftrace_enabled);
 109
 110        /* Fall back to normal restart if we're still alive. */
 111        machine_restart(NULL);
 112        for(;;);
 113}
 114
 115void __init reserve_crashkernel(void)
 116{
 117        unsigned long long crash_size, crash_base;
 118        int ret;
 119
 120        /* use common parsing */
 121        ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 122                        &crash_size, &crash_base);
 123        if (ret == 0 && crash_size > 0) {
 124                crashk_res.start = crash_base;
 125                crashk_res.end = crash_base + crash_size - 1;
 126        }
 127
 128        if (crashk_res.end == crashk_res.start) {
 129                crashk_res.start = crashk_res.end = 0;
 130                return;
 131        }
 132
 133        /* We might have got these values via the command line or the
 134         * device tree, either way sanitise them now. */
 135
 136        crash_size = resource_size(&crashk_res);
 137
 138#ifndef CONFIG_NONSTATIC_KERNEL
 139        if (crashk_res.start != KDUMP_KERNELBASE)
 140                printk("Crash kernel location must be 0x%x\n",
 141                                KDUMP_KERNELBASE);
 142
 143        crashk_res.start = KDUMP_KERNELBASE;
 144#else
 145        if (!crashk_res.start) {
 146#ifdef CONFIG_PPC64
 147                /*
 148                 * On 64bit we split the RMO in half but cap it at half of
 149                 * a small SLB (128MB) since the crash kernel needs to place
 150                 * itself and some stacks to be in the first segment.
 151                 */
 152                crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
 153#else
 154                crashk_res.start = KDUMP_KERNELBASE;
 155#endif
 156        }
 157
 158        crash_base = PAGE_ALIGN(crashk_res.start);
 159        if (crash_base != crashk_res.start) {
 160                printk("Crash kernel base must be aligned to 0x%lx\n",
 161                                PAGE_SIZE);
 162                crashk_res.start = crash_base;
 163        }
 164
 165#endif
 166        crash_size = PAGE_ALIGN(crash_size);
 167        crashk_res.end = crashk_res.start + crash_size - 1;
 168
 169        /* The crash region must not overlap the current kernel */
 170        if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
 171                printk(KERN_WARNING
 172                        "Crash kernel can not overlap current kernel\n");
 173                crashk_res.start = crashk_res.end = 0;
 174                return;
 175        }
 176
 177        /* Crash kernel trumps memory limit */
 178        if (memory_limit && memory_limit <= crashk_res.end) {
 179                memory_limit = crashk_res.end + 1;
 180                printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
 181                       memory_limit);
 182        }
 183
 184        printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
 185                        "for crashkernel (System RAM: %ldMB)\n",
 186                        (unsigned long)(crash_size >> 20),
 187                        (unsigned long)(crashk_res.start >> 20),
 188                        (unsigned long)(memblock_phys_mem_size() >> 20));
 189
 190        if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
 191            memblock_reserve(crashk_res.start, crash_size)) {
 192                pr_err("Failed to reserve memory for crashkernel!\n");
 193                crashk_res.start = crashk_res.end = 0;
 194                return;
 195        }
 196}
 197
 198int overlaps_crashkernel(unsigned long start, unsigned long size)
 199{
 200        return (start + size) > crashk_res.start && start <= crashk_res.end;
 201}
 202
 203/* Values we need to export to the second kernel via the device tree. */
 204static phys_addr_t kernel_end;
 205static phys_addr_t crashk_base;
 206static phys_addr_t crashk_size;
 207static unsigned long long mem_limit;
 208
 209static struct property kernel_end_prop = {
 210        .name = "linux,kernel-end",
 211        .length = sizeof(phys_addr_t),
 212        .value = &kernel_end,
 213};
 214
 215static struct property crashk_base_prop = {
 216        .name = "linux,crashkernel-base",
 217        .length = sizeof(phys_addr_t),
 218        .value = &crashk_base
 219};
 220
 221static struct property crashk_size_prop = {
 222        .name = "linux,crashkernel-size",
 223        .length = sizeof(phys_addr_t),
 224        .value = &crashk_size,
 225};
 226
 227static struct property memory_limit_prop = {
 228        .name = "linux,memory-limit",
 229        .length = sizeof(unsigned long long),
 230        .value = &mem_limit,
 231};
 232
 233#define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG)
 234
 235static void __init export_crashk_values(struct device_node *node)
 236{
 237        /* There might be existing crash kernel properties, but we can't
 238         * be sure what's in them, so remove them. */
 239        of_remove_property(node, of_find_property(node,
 240                                "linux,crashkernel-base", NULL));
 241        of_remove_property(node, of_find_property(node,
 242                                "linux,crashkernel-size", NULL));
 243
 244        if (crashk_res.start != 0) {
 245                crashk_base = cpu_to_be_ulong(crashk_res.start),
 246                of_add_property(node, &crashk_base_prop);
 247                crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
 248                of_add_property(node, &crashk_size_prop);
 249        }
 250
 251        /*
 252         * memory_limit is required by the kexec-tools to limit the
 253         * crash regions to the actual memory used.
 254         */
 255        mem_limit = cpu_to_be_ulong(memory_limit);
 256        of_update_property(node, &memory_limit_prop);
 257}
 258
 259static int __init kexec_setup(void)
 260{
 261        struct device_node *node;
 262
 263        node = of_find_node_by_path("/chosen");
 264        if (!node)
 265                return -ENOENT;
 266
 267        /* remove any stale properties so ours can be found */
 268        of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL));
 269
 270        /* information needed by userspace when using default_machine_kexec */
 271        kernel_end = cpu_to_be_ulong(__pa(_end));
 272        of_add_property(node, &kernel_end_prop);
 273
 274        export_crashk_values(node);
 275
 276        of_node_put(node);
 277        return 0;
 278}
 279late_initcall(kexec_setup);
 280