machine_kexec.c

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/*
 * machine_kexec.c - handle transition of Linux booting another kernel
 * Copyright (C) 2002-2003 Eric Biederman  <[email protected]>
 *
 * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
 * LANDISK/sh4 supported by kogiidena
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 */
#include <linux/mm.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/numa.h>
#include <linux/ftrace.h>
#include <linux/suspend.h>
#include <linux/memblock.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/mmu_context.h>
#include <asm/io.h>
#include <asm/cacheflush.h>
#include <asm/sh_bios.h>
#include <asm/reboot.h>

typedef void (*relocate_new_kernel_t)(unsigned long indirection_page,
                      unsigned long reboot_code_buffer,
                      unsigned long start_address);

extern const unsigned char relocate_new_kernel[];
extern const unsigned int relocate_new_kernel_size;
extern void *vbr_base;

void native_machine_crash_shutdown(struct pt_regs *regs)
{
    /* Nothing to do for UP, but definitely broken for SMP.. */
}

/*
 * Do what every setup is needed on image and the
 * reboot code buffer to allow us to avoid allocations
 * later.
 */
int machine_kexec_prepare(struct kimage *image)
{
    return 0;
}

void machine_kexec_cleanup(struct kimage *image)
{
}

static void kexec_info(struct kimage *image)
{
        int i;
    printk("kexec information\n");
    for (i = 0; i < image->nr_segments; i++) {
            printk("  segment[%d]: 0x%08x - 0x%08x (0x%08x)\n",
               i,
               (unsigned int)image->segment[i].mem,
               (unsigned int)image->segment[i].mem +
                     image->segment[i].memsz,
               (unsigned int)image->segment[i].memsz);
    }
    printk("  start     : 0x%08x\n\n", (unsigned int)image->start);
}

/*
 * Do not allocate memory (or fail in any way) in machine_kexec().
 * We are past the point of no return, committed to rebooting now.
 */
void machine_kexec(struct kimage *image)
{
    unsigned long page_list;
    unsigned long reboot_code_buffer;
    relocate_new_kernel_t rnk;
    unsigned long entry;
    unsigned long *ptr;
    int save_ftrace_enabled;

    /*
     * Nicked from the mips version of machine_kexec():
     * The generic kexec code builds a page list with physical
     * addresses. Use phys_to_virt() to convert them to virtual.
     */
    for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
         ptr = (entry & IND_INDIRECTION) ?
           phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
        if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
            *ptr & IND_DESTINATION)
            *ptr = (unsigned long) phys_to_virt(*ptr);
    }

#ifdef CONFIG_KEXEC_JUMP
    if (image->preserve_context)
        save_processor_state();
#endif

    save_ftrace_enabled = __ftrace_enabled_save();

    /* Interrupts aren't acceptable while we reboot */
    local_irq_disable();

    page_list = image->head;

    /* we need both effective and real address here */
    reboot_code_buffer =
            (unsigned long)page_address(image->control_code_page);

    /* copy our kernel relocation code to the control code page */
    memcpy((void *)reboot_code_buffer, relocate_new_kernel,
                        relocate_new_kernel_size);

    kexec_info(image);
    flush_cache_all();

    sh_bios_vbr_reload();

    /* now call it */
    rnk = (relocate_new_kernel_t) reboot_code_buffer;
    (*rnk)(page_list, reboot_code_buffer,
           (unsigned long)phys_to_virt(image->start));

#ifdef CONFIG_KEXEC_JUMP
    asm volatile("ldc %0, vbr" : : "r" (&vbr_base) : "memory");

    if (image->preserve_context)
        restore_processor_state();

    /* Convert page list back to physical addresses, what a mess. */
    for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
         ptr = (*ptr & IND_INDIRECTION) ?
           phys_to_virt(*ptr & PAGE_MASK) : ptr + 1) {
        if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
            *ptr & IND_DESTINATION)
            *ptr = virt_to_phys(*ptr);
    }
#endif

    __ftrace_enabled_restore(save_ftrace_enabled);
}

void arch_crash_save_vmcoreinfo(void)
{
#ifdef CONFIG_NUMA
    VMCOREINFO_SYMBOL(node_data);
    VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
#endif
#ifdef CONFIG_X2TLB
    VMCOREINFO_CONFIG(X2TLB);
#endif
}

void __init reserve_crashkernel(void)
{
    unsigned long long crash_size, crash_base;
    int ret;

    ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
            &crash_size, &crash_base);
    if (ret == 0 && crash_size > 0) {
        crashk_res.start = crash_base;
        crashk_res.end = crash_base + crash_size - 1;
    }

    if (crashk_res.end == crashk_res.start)
        goto disable;

    crash_size = PAGE_ALIGN(resource_size(&crashk_res));
    if (!crashk_res.start) {
        unsigned long max = memblock_end_of_DRAM() - memory_limit;
        crashk_res.start = __memblock_alloc_base(crash_size, PAGE_SIZE, max);
        if (!crashk_res.start) {
            pr_err("crashkernel allocation failed\n");
            goto disable;
        }
    } else {
        ret = memblock_reserve(crashk_res.start, crash_size);
        if (unlikely(ret < 0)) {
            pr_err("crashkernel reservation failed - "
                   "memory is in use\n");
            goto disable;
        }
    }

    crashk_res.end = crashk_res.start + crash_size - 1;

    /*
     * Crash kernel trumps memory limit
     */
    if ((memblock_end_of_DRAM() - memory_limit) <= crashk_res.end) {
        memory_limit = 0;
        pr_info("Disabled memory limit for crashkernel\n");
    }

    pr_info("Reserving %ldMB of memory at 0x%08lx "
        "for crashkernel (System RAM: %ldMB)\n",
        (unsigned long)(crash_size >> 20),
        (unsigned long)(crashk_res.start),
        (unsigned long)(memblock_phys_mem_size() >> 20));

    return;

disable:
    crashk_res.start = crashk_res.end = 0;
}