setup.c

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/*
 *  S390 version
 *    Copyright IBM Corp. 1999, 2012
 *    Author(s): Hartmut Penner ([email protected]),
 *               Martin Schwidefsky ([email protected])
 *
 *  Derived from "arch/i386/kernel/setup.c"
 *    Copyright (C) 1995, Linus Torvalds
 */

/*
 * This file handles the architecture-dependent parts of initialization
 */

#define KMSG_COMPONENT "setup"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/tty.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/bootmem.h>
#include <linux/root_dev.h>
#include <linux/console.h>
#include <linux/kernel_stat.h>
#include <linux/device.h>
#include <linux/notifier.h>
#include <linux/pfn.h>
#include <linux/ctype.h>
#include <linux/reboot.h>
#include <linux/topology.h>
#include <linux/ftrace.h>
#include <linux/kexec.h>
#include <linux/crash_dump.h>
#include <linux/memory.h>
#include <linux/compat.h>

#include <asm/ipl.h>
#include <asm/uaccess.h>
#include <asm/facility.h>
#include <asm/smp.h>
#include <asm/mmu_context.h>
#include <asm/cpcmd.h>
#include <asm/lowcore.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/sections.h>
#include <asm/ebcdic.h>
#include <asm/kvm_virtio.h>
#include <asm/diag.h>
#include <asm/os_info.h>
#include <asm/sclp.h>
#include "entry.h"

long psw_kernel_bits    = PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_ASC_PRIMARY |
              PSW_MASK_EA | PSW_MASK_BA;
long psw_user_bits  = PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT |
              PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_MCHECK |
              PSW_MASK_PSTATE | PSW_ASC_HOME;

/*
 * User copy operations.
 */
struct uaccess_ops uaccess;
EXPORT_SYMBOL(uaccess);

/*
 * Machine setup..
 */
unsigned int console_mode = 0;
EXPORT_SYMBOL(console_mode);

unsigned int console_devno = -1;
EXPORT_SYMBOL(console_devno);

unsigned int console_irq = -1;
EXPORT_SYMBOL(console_irq);

unsigned long elf_hwcap = 0;
char elf_platform[ELF_PLATFORM_SIZE];

struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];

int __initdata memory_end_set;
unsigned long __initdata memory_end;

unsigned long VMALLOC_START;
EXPORT_SYMBOL(VMALLOC_START);

unsigned long VMALLOC_END;
EXPORT_SYMBOL(VMALLOC_END);

struct page *vmemmap;
EXPORT_SYMBOL(vmemmap);

#ifdef CONFIG_64BIT
unsigned long MODULES_VADDR;
unsigned long MODULES_END;
#endif

/* An array with a pointer to the lowcore of every CPU. */
struct _lowcore *lowcore_ptr[NR_CPUS];
EXPORT_SYMBOL(lowcore_ptr);

/*
 * This is set up by the setup-routine at boot-time
 * for S390 need to find out, what we have to setup
 * using address 0x10400 ...
 */

#include <asm/setup.h>

/*
 * condev= and conmode= setup parameter.
 */

static int __init condev_setup(char *str)
{
    int vdev;

    vdev = simple_strtoul(str, &str, 0);
    if (vdev >= 0 && vdev < 65536) {
        console_devno = vdev;
        console_irq = -1;
    }
    return 1;
}

__setup("condev=", condev_setup);

static void __init set_preferred_console(void)
{
    if (MACHINE_IS_KVM) {
        if (sclp_has_vt220())
            add_preferred_console("ttyS", 1, NULL);
        else if (sclp_has_linemode())
            add_preferred_console("ttyS", 0, NULL);
        else
            add_preferred_console("hvc", 0, NULL);
    } else if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
        add_preferred_console("ttyS", 0, NULL);
    else if (CONSOLE_IS_3270)
        add_preferred_console("tty3270", 0, NULL);
}

static int __init conmode_setup(char *str)
{
#if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
    if (strncmp(str, "hwc", 4) == 0 || strncmp(str, "sclp", 5) == 0)
                SET_CONSOLE_SCLP;
#endif
#if defined(CONFIG_TN3215_CONSOLE)
    if (strncmp(str, "3215", 5) == 0)
        SET_CONSOLE_3215;
#endif
#if defined(CONFIG_TN3270_CONSOLE)
    if (strncmp(str, "3270", 5) == 0)
        SET_CONSOLE_3270;
#endif
    set_preferred_console();
        return 1;
}

__setup("conmode=", conmode_setup);

static void __init conmode_default(void)
{
    char query_buffer[1024];
    char *ptr;

        if (MACHINE_IS_VM) {
        cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
        console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
        ptr = strstr(query_buffer, "SUBCHANNEL =");
        console_irq = simple_strtoul(ptr + 13, NULL, 16);
        cpcmd("QUERY TERM", query_buffer, 1024, NULL);
        ptr = strstr(query_buffer, "CONMODE");
        /*
         * Set the conmode to 3215 so that the device recognition 
         * will set the cu_type of the console to 3215. If the
         * conmode is 3270 and we don't set it back then both
         * 3215 and the 3270 driver will try to access the console
         * device (3215 as console and 3270 as normal tty).
         */
        cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
        if (ptr == NULL) {
#if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
            SET_CONSOLE_SCLP;
#endif
            return;
        }
        if (strncmp(ptr + 8, "3270", 4) == 0) {
#if defined(CONFIG_TN3270_CONSOLE)
            SET_CONSOLE_3270;
#elif defined(CONFIG_TN3215_CONSOLE)
            SET_CONSOLE_3215;
#elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
            SET_CONSOLE_SCLP;
#endif
        } else if (strncmp(ptr + 8, "3215", 4) == 0) {
#if defined(CONFIG_TN3215_CONSOLE)
            SET_CONSOLE_3215;
#elif defined(CONFIG_TN3270_CONSOLE)
            SET_CONSOLE_3270;
#elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
            SET_CONSOLE_SCLP;
#endif
        }
    } else {
#if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
        SET_CONSOLE_SCLP;
#endif
    }
}

#ifdef CONFIG_ZFCPDUMP
static void __init setup_zfcpdump(unsigned int console_devno)
{
    static char str[41];

    if (ipl_info.type != IPL_TYPE_FCP_DUMP)
        return;
    if (OLDMEM_BASE)
        return;
    if (console_devno != -1)
        sprintf(str, " cio_ignore=all,!0.0.%04x,!0.0.%04x",
            ipl_info.data.fcp.dev_id.devno, console_devno);
    else
        sprintf(str, " cio_ignore=all,!0.0.%04x",
            ipl_info.data.fcp.dev_id.devno);
    strcat(boot_command_line, str);
    console_loglevel = 2;
}
#else
static inline void setup_zfcpdump(unsigned int console_devno) {}
#endif /* CONFIG_ZFCPDUMP */

 /*
 * Reboot, halt and power_off stubs. They just call _machine_restart,
 * _machine_halt or _machine_power_off. 
 */

void machine_restart(char *command)
{
    if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
        /*
         * Only unblank the console if we are called in enabled
         * context or a bust_spinlocks cleared the way for us.
         */
        console_unblank();
    _machine_restart(command);
}

void machine_halt(void)
{
    if (!in_interrupt() || oops_in_progress)
        /*
         * Only unblank the console if we are called in enabled
         * context or a bust_spinlocks cleared the way for us.
         */
        console_unblank();
    _machine_halt();
}

void machine_power_off(void)
{
    if (!in_interrupt() || oops_in_progress)
        /*
         * Only unblank the console if we are called in enabled
         * context or a bust_spinlocks cleared the way for us.
         */
        console_unblank();
    _machine_power_off();
}

/*
 * Dummy power off function.
 */
void (*pm_power_off)(void) = machine_power_off;

static int __init early_parse_mem(char *p)
{
    memory_end = memparse(p, &p);
    memory_end_set = 1;
    return 0;
}
early_param("mem", early_parse_mem);

static int __init parse_vmalloc(char *arg)
{
    if (!arg)
        return -EINVAL;
    VMALLOC_END = (memparse(arg, &arg) + PAGE_SIZE - 1) & PAGE_MASK;
    return 0;
}
early_param("vmalloc", parse_vmalloc);

unsigned int s390_user_mode = PRIMARY_SPACE_MODE;
EXPORT_SYMBOL_GPL(s390_user_mode);

static void __init set_user_mode_primary(void)
{
    psw_kernel_bits = (psw_kernel_bits & ~PSW_MASK_ASC) | PSW_ASC_HOME;
    psw_user_bits = (psw_user_bits & ~PSW_MASK_ASC) | PSW_ASC_PRIMARY;
#ifdef CONFIG_COMPAT
    psw32_user_bits =
        (psw32_user_bits & ~PSW32_MASK_ASC) | PSW32_ASC_PRIMARY;
#endif
    uaccess = MACHINE_HAS_MVCOS ? uaccess_mvcos_switch : uaccess_pt;
}

static int __init early_parse_user_mode(char *p)
{
    if (p && strcmp(p, "primary") == 0)
        s390_user_mode = PRIMARY_SPACE_MODE;
    else if (!p || strcmp(p, "home") == 0)
        s390_user_mode = HOME_SPACE_MODE;
    else
        return 1;
    return 0;
}
early_param("user_mode", early_parse_user_mode);

static void __init setup_addressing_mode(void)
{
    if (s390_user_mode != PRIMARY_SPACE_MODE)
        return;
    set_user_mode_primary();
    if (MACHINE_HAS_MVCOS)
        pr_info("Address spaces switched, mvcos available\n");
    else
        pr_info("Address spaces switched, mvcos not available\n");
}

void *restart_stack __attribute__((__section__(".data")));

static void __init setup_lowcore(void)
{
    struct _lowcore *lc;

    /*
     * Setup lowcore for boot cpu
     */
    BUILD_BUG_ON(sizeof(struct _lowcore) != LC_PAGES * 4096);
    lc = __alloc_bootmem_low(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
    lc->restart_psw.mask = psw_kernel_bits;
    lc->restart_psw.addr =
        PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
    lc->external_new_psw.mask = psw_kernel_bits |
        PSW_MASK_DAT | PSW_MASK_MCHECK;
    lc->external_new_psw.addr =
        PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
    lc->svc_new_psw.mask = psw_kernel_bits |
        PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
    lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
    lc->program_new_psw.mask = psw_kernel_bits |
        PSW_MASK_DAT | PSW_MASK_MCHECK;
    lc->program_new_psw.addr =
        PSW_ADDR_AMODE | (unsigned long) pgm_check_handler;
    lc->mcck_new_psw.mask = psw_kernel_bits;
    lc->mcck_new_psw.addr =
        PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
    lc->io_new_psw.mask = psw_kernel_bits |
        PSW_MASK_DAT | PSW_MASK_MCHECK;
    lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
    lc->clock_comparator = -1ULL;
    lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
    lc->async_stack = (unsigned long)
        __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
    lc->panic_stack = (unsigned long)
        __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
    lc->current_task = (unsigned long) init_thread_union.thread_info.task;
    lc->thread_info = (unsigned long) &init_thread_union;
    lc->machine_flags = S390_lowcore.machine_flags;
    lc->stfl_fac_list = S390_lowcore.stfl_fac_list;
    memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
           MAX_FACILITY_BIT/8);
#ifndef CONFIG_64BIT
    if (MACHINE_HAS_IEEE) {
        lc->extended_save_area_addr = (__u32)
            __alloc_bootmem_low(PAGE_SIZE, PAGE_SIZE, 0);
        /* enable extended save area */
        __ctl_set_bit(14, 29);
    }
#else
    lc->vdso_per_cpu_data = (unsigned long) &lc->paste[0];
#endif
    lc->sync_enter_timer = S390_lowcore.sync_enter_timer;
    lc->async_enter_timer = S390_lowcore.async_enter_timer;
    lc->exit_timer = S390_lowcore.exit_timer;
    lc->user_timer = S390_lowcore.user_timer;
    lc->system_timer = S390_lowcore.system_timer;
    lc->steal_timer = S390_lowcore.steal_timer;
    lc->last_update_timer = S390_lowcore.last_update_timer;
    lc->last_update_clock = S390_lowcore.last_update_clock;
    lc->ftrace_func = S390_lowcore.ftrace_func;

    restart_stack = __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0);
    restart_stack += ASYNC_SIZE;

    /*
     * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
     * restart data to the absolute zero lowcore. This is necesary if
     * PSW restart is done on an offline CPU that has lowcore zero.
     */
    lc->restart_stack = (unsigned long) restart_stack;
    lc->restart_fn = (unsigned long) do_restart;
    lc->restart_data = 0;
    lc->restart_source = -1UL;

    /* Setup absolute zero lowcore */
    mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);
    mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);
    mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);
    mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);
    mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);

    set_prefix((u32)(unsigned long) lc);
    lowcore_ptr[0] = lc;
}

static struct resource code_resource = {
    .name  = "Kernel code",
    .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
};

static struct resource data_resource = {
    .name = "Kernel data",
    .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
};

static struct resource bss_resource = {
    .name = "Kernel bss",
    .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
};

static struct resource __initdata *standard_resources[] = {
    &code_resource,
    &data_resource,
    &bss_resource,
};

static void __init setup_resources(void)
{
    struct resource *res, *std_res, *sub_res;
    int i, j;

    code_resource.start = (unsigned long) &_text;
    code_resource.end = (unsigned long) &_etext - 1;
    data_resource.start = (unsigned long) &_etext;
    data_resource.end = (unsigned long) &_edata - 1;
    bss_resource.start = (unsigned long) &__bss_start;
    bss_resource.end = (unsigned long) &__bss_stop - 1;

    for (i = 0; i < MEMORY_CHUNKS; i++) {
        if (!memory_chunk[i].size)
            continue;
        if (memory_chunk[i].type == CHUNK_OLDMEM ||
            memory_chunk[i].type == CHUNK_CRASHK)
            continue;
        res = alloc_bootmem_low(sizeof(*res));
        res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
        switch (memory_chunk[i].type) {
        case CHUNK_READ_WRITE:
        case CHUNK_CRASHK:
            res->name = "System RAM";
            break;
        case CHUNK_READ_ONLY:
            res->name = "System ROM";
            res->flags |= IORESOURCE_READONLY;
            break;
        default:
            res->name = "reserved";
        }
        res->start = memory_chunk[i].addr;
        res->end = res->start + memory_chunk[i].size - 1;
        request_resource(&iomem_resource, res);

        for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
            std_res = standard_resources[j];
            if (std_res->start < res->start ||
                std_res->start > res->end)
                continue;
            if (std_res->end > res->end) {
                sub_res = alloc_bootmem_low(sizeof(*sub_res));
                *sub_res = *std_res;
                sub_res->end = res->end;
                std_res->start = res->end + 1;
                request_resource(res, sub_res);
            } else {
                request_resource(res, std_res);
            }
        }
    }
}

unsigned long real_memory_size;
EXPORT_SYMBOL_GPL(real_memory_size);

static void __init setup_memory_end(void)
{
    unsigned long vmax, vmalloc_size, tmp;
    int i;


#ifdef CONFIG_ZFCPDUMP
    if (ipl_info.type == IPL_TYPE_FCP_DUMP && !OLDMEM_BASE) {
        memory_end = ZFCPDUMP_HSA_SIZE;
        memory_end_set = 1;
    }
#endif
    real_memory_size = 0;
    memory_end &= PAGE_MASK;

    /*
     * Make sure all chunks are MAX_ORDER aligned so we don't need the
     * extra checks that HOLES_IN_ZONE would require.
     */
    for (i = 0; i < MEMORY_CHUNKS; i++) {
        unsigned long start, end;
        struct mem_chunk *chunk;
        unsigned long align;

        chunk = &memory_chunk[i];
        align = 1UL << (MAX_ORDER + PAGE_SHIFT - 1);
        start = (chunk->addr + align - 1) & ~(align - 1);
        end = (chunk->addr + chunk->size) & ~(align - 1);
        if (start >= end)
            memset(chunk, 0, sizeof(*chunk));
        else {
            chunk->addr = start;
            chunk->size = end - start;
        }
        real_memory_size = max(real_memory_size,
                       chunk->addr + chunk->size);
    }

    /* Choose kernel address space layout: 2, 3, or 4 levels. */
#ifdef CONFIG_64BIT
    vmalloc_size = VMALLOC_END ?: (128UL << 30) - MODULES_LEN;
    tmp = (memory_end ?: real_memory_size) / PAGE_SIZE;
    tmp = tmp * (sizeof(struct page) + PAGE_SIZE) + vmalloc_size;
    if (tmp <= (1UL << 42))
        vmax = 1UL << 42;   /* 3-level kernel page table */
    else
        vmax = 1UL << 53;   /* 4-level kernel page table */
    /* module area is at the end of the kernel address space. */
    MODULES_END = vmax;
    MODULES_VADDR = MODULES_END - MODULES_LEN;
    VMALLOC_END = MODULES_VADDR;
#else
    vmalloc_size = VMALLOC_END ?: 96UL << 20;
    vmax = 1UL << 31;       /* 2-level kernel page table */
    /* vmalloc area is at the end of the kernel address space. */
    VMALLOC_END = vmax;
#endif
    VMALLOC_START = vmax - vmalloc_size;

    /* Split remaining virtual space between 1:1 mapping & vmemmap array */
    tmp = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
    tmp = VMALLOC_START - tmp * sizeof(struct page);
    tmp &= ~((vmax >> 11) - 1); /* align to page table level */
    tmp = min(tmp, 1UL << MAX_PHYSMEM_BITS);
    vmemmap = (struct page *) tmp;

    /* Take care that memory_end is set and <= vmemmap */
    memory_end = min(memory_end ?: real_memory_size, tmp);

    /* Fixup memory chunk array to fit into 0..memory_end */
    for (i = 0; i < MEMORY_CHUNKS; i++) {
        struct mem_chunk *chunk = &memory_chunk[i];

        if (chunk->addr >= memory_end) {
            memset(chunk, 0, sizeof(*chunk));
            continue;
        }
        if (chunk->addr + chunk->size > memory_end)
            chunk->size = memory_end - chunk->addr;
    }
}

static void __init setup_vmcoreinfo(void)
{
    mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
}

#ifdef CONFIG_CRASH_DUMP

/*
 * Find suitable location for crashkernel memory
 */
static unsigned long __init find_crash_base(unsigned long crash_size,
                        char **msg)
{
    unsigned long crash_base;
    struct mem_chunk *chunk;
    int i;

    if (memory_chunk[0].size < crash_size) {
        *msg = "first memory chunk must be at least crashkernel size";
        return 0;
    }
    if (OLDMEM_BASE && crash_size == OLDMEM_SIZE)
        return OLDMEM_BASE;

    for (i = MEMORY_CHUNKS - 1; i >= 0; i--) {
        chunk = &memory_chunk[i];
        if (chunk->size == 0)
            continue;
        if (chunk->type != CHUNK_READ_WRITE)
            continue;
        if (chunk->size < crash_size)
            continue;
        crash_base = (chunk->addr + chunk->size) - crash_size;
        if (crash_base < crash_size)
            continue;
        if (crash_base < ZFCPDUMP_HSA_SIZE_MAX)
            continue;
        if (crash_base < (unsigned long) INITRD_START + INITRD_SIZE)
            continue;
        return crash_base;
    }
    *msg = "no suitable area found";
    return 0;
}

/*
 * Check if crash_base and crash_size is valid
 */
static int __init verify_crash_base(unsigned long crash_base,
                    unsigned long crash_size,
                    char **msg)
{
    struct mem_chunk *chunk;
    int i;

    /*
     * Because we do the swap to zero, we must have at least 'crash_size'
     * bytes free space before crash_base
     */
    if (crash_size > crash_base) {
        *msg = "crashkernel offset must be greater than size";
        return -EINVAL;
    }

    /* First memory chunk must be at least crash_size */
    if (memory_chunk[0].size < crash_size) {
        *msg = "first memory chunk must be at least crashkernel size";
        return -EINVAL;
    }
    /* Check if we fit into the respective memory chunk */
    for (i = 0; i < MEMORY_CHUNKS; i++) {
        chunk = &memory_chunk[i];
        if (chunk->size == 0)
            continue;
        if (crash_base < chunk->addr)
            continue;
        if (crash_base >= chunk->addr + chunk->size)
            continue;
        /* we have found the memory chunk */
        if (crash_base + crash_size > chunk->addr + chunk->size) {
            *msg = "selected memory chunk is too small for "
                "crashkernel memory";
            return -EINVAL;
        }
        return 0;
    }
    *msg = "invalid memory range specified";
    return -EINVAL;
}

/*
 * Reserve kdump memory by creating a memory hole in the mem_chunk array
 */
static void __init reserve_kdump_bootmem(unsigned long addr, unsigned long size,
                     int type)
{
    create_mem_hole(memory_chunk, addr, size, type);
}

/*
 * When kdump is enabled, we have to ensure that no memory from
 * the area [0 - crashkernel memory size] and
 * [crashk_res.start - crashk_res.end] is set offline.
 */
static int kdump_mem_notifier(struct notifier_block *nb,
                  unsigned long action, void *data)
{
    struct memory_notify *arg = data;

    if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
        return NOTIFY_BAD;
    if (arg->start_pfn > PFN_DOWN(crashk_res.end))
        return NOTIFY_OK;
    if (arg->start_pfn + arg->nr_pages - 1 < PFN_DOWN(crashk_res.start))
        return NOTIFY_OK;
    return NOTIFY_BAD;
}

static struct notifier_block kdump_mem_nb = {
    .notifier_call = kdump_mem_notifier,
};

#endif

/*
 * Make sure that oldmem, where the dump is stored, is protected
 */
static void reserve_oldmem(void)
{
#ifdef CONFIG_CRASH_DUMP
    if (!OLDMEM_BASE)
        return;

    reserve_kdump_bootmem(OLDMEM_BASE, OLDMEM_SIZE, CHUNK_OLDMEM);
    reserve_kdump_bootmem(OLDMEM_SIZE, memory_end - OLDMEM_SIZE,
                  CHUNK_OLDMEM);
    if (OLDMEM_BASE + OLDMEM_SIZE == real_memory_size)
        saved_max_pfn = PFN_DOWN(OLDMEM_BASE) - 1;
    else
        saved_max_pfn = PFN_DOWN(real_memory_size) - 1;
#endif
}

/*
 * Reserve memory for kdump kernel to be loaded with kexec
 */
static void __init reserve_crashkernel(void)
{
#ifdef CONFIG_CRASH_DUMP
    unsigned long long crash_base, crash_size;
    char *msg = NULL;
    int rc;

    rc = parse_crashkernel(boot_command_line, memory_end, &crash_size,
                   &crash_base);
    if (rc || crash_size == 0)
        return;
    crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
    crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
    if (register_memory_notifier(&kdump_mem_nb))
        return;
    if (!crash_base)
        crash_base = find_crash_base(crash_size, &msg);
    if (!crash_base) {
        pr_info("crashkernel reservation failed: %s\n", msg);
        unregister_memory_notifier(&kdump_mem_nb);
        return;
    }
    if (verify_crash_base(crash_base, crash_size, &msg)) {
        pr_info("crashkernel reservation failed: %s\n", msg);
        unregister_memory_notifier(&kdump_mem_nb);
        return;
    }
    if (!OLDMEM_BASE && MACHINE_IS_VM)
        diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
    crashk_res.start = crash_base;
    crashk_res.end = crash_base + crash_size - 1;
    insert_resource(&iomem_resource, &crashk_res);
    reserve_kdump_bootmem(crash_base, crash_size, CHUNK_CRASHK);
    pr_info("Reserving %lluMB of memory at %lluMB "
        "for crashkernel (System RAM: %luMB)\n",
        crash_size >> 20, crash_base >> 20, memory_end >> 20);
    os_info_crashkernel_add(crash_base, crash_size);
#endif
}

static void __init init_storage_keys(unsigned long start, unsigned long end)
{
    unsigned long boundary, function, size;

    while (start < end) {
        if (MACHINE_HAS_EDAT2) {
            /* set storage keys for a 2GB frame */
            function = 0x22000 | PAGE_DEFAULT_KEY;
            size = 1UL << 31;
            boundary = (start + size) & ~(size - 1);
            if (boundary <= end) {
                do {
                    start = pfmf(function, start);
                } while (start < boundary);
                continue;
            }
        }
        if (MACHINE_HAS_EDAT1) {
            /* set storage keys for a 1MB frame */
            function = 0x21000 | PAGE_DEFAULT_KEY;
            size = 1UL << 20;
            boundary = (start + size) & ~(size - 1);
            if (boundary <= end) {
                do {
                    start = pfmf(function, start);
                } while (start < boundary);
                continue;
            }
        }
        page_set_storage_key(start, PAGE_DEFAULT_KEY, 0);
        start += PAGE_SIZE;
    }
}

static void __init setup_memory(void)
{
        unsigned long bootmap_size;
    unsigned long start_pfn, end_pfn;
    int i;

    /*
     * partially used pages are not usable - thus
     * we are rounding upwards:
     */
    start_pfn = PFN_UP(__pa(&_end));
    end_pfn = max_pfn = PFN_DOWN(memory_end);

#ifdef CONFIG_BLK_DEV_INITRD
    /*
     * Move the initrd in case the bitmap of the bootmem allocater
     * would overwrite it.
     */

    if (INITRD_START && INITRD_SIZE) {
        unsigned long bmap_size;
        unsigned long start;

        bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
        bmap_size = PFN_PHYS(bmap_size);

        if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
            start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;

#ifdef CONFIG_CRASH_DUMP
            if (OLDMEM_BASE) {
                /* Move initrd behind kdump oldmem */
                if (start + INITRD_SIZE > OLDMEM_BASE &&
                    start < OLDMEM_BASE + OLDMEM_SIZE)
                    start = OLDMEM_BASE + OLDMEM_SIZE;
            }
#endif
            if (start + INITRD_SIZE > memory_end) {
                pr_err("initrd extends beyond end of "
                       "memory (0x%08lx > 0x%08lx) "
                       "disabling initrd\n",
                       start + INITRD_SIZE, memory_end);
                INITRD_START = INITRD_SIZE = 0;
            } else {
                pr_info("Moving initrd (0x%08lx -> "
                    "0x%08lx, size: %ld)\n",
                    INITRD_START, start, INITRD_SIZE);
                memmove((void *) start, (void *) INITRD_START,
                    INITRD_SIZE);
                INITRD_START = start;
            }
        }
    }
#endif

    /*
     * Initialize the boot-time allocator
     */
    bootmap_size = init_bootmem(start_pfn, end_pfn);

    /*
     * Register RAM areas with the bootmem allocator.
     */

    for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
        unsigned long start_chunk, end_chunk, pfn;

        if (memory_chunk[i].type != CHUNK_READ_WRITE &&
            memory_chunk[i].type != CHUNK_CRASHK)
            continue;
        start_chunk = PFN_DOWN(memory_chunk[i].addr);
        end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
        end_chunk = min(end_chunk, end_pfn);
        if (start_chunk >= end_chunk)
            continue;
        memblock_add_node(PFN_PHYS(start_chunk),
                  PFN_PHYS(end_chunk - start_chunk), 0);
        pfn = max(start_chunk, start_pfn);
        init_storage_keys(PFN_PHYS(pfn), PFN_PHYS(end_chunk));
    }

    psw_set_key(PAGE_DEFAULT_KEY);

    free_bootmem_with_active_regions(0, max_pfn);

    /*
     * Reserve memory used for lowcore/command line/kernel image.
     */
    reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
    reserve_bootmem((unsigned long)_stext,
            PFN_PHYS(start_pfn) - (unsigned long)_stext,
            BOOTMEM_DEFAULT);
    /*
     * Reserve the bootmem bitmap itself as well. We do this in two
     * steps (first step was init_bootmem()) because this catches
     * the (very unlikely) case of us accidentally initializing the
     * bootmem allocator with an invalid RAM area.
     */
    reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
            BOOTMEM_DEFAULT);

#ifdef CONFIG_CRASH_DUMP
    if (crashk_res.start)
        reserve_bootmem(crashk_res.start,
                crashk_res.end - crashk_res.start + 1,
                BOOTMEM_DEFAULT);
    if (is_kdump_kernel())
        reserve_bootmem(elfcorehdr_addr - OLDMEM_BASE,
                PAGE_ALIGN(elfcorehdr_size), BOOTMEM_DEFAULT);
#endif
#ifdef CONFIG_BLK_DEV_INITRD
    if (INITRD_START && INITRD_SIZE) {
        if (INITRD_START + INITRD_SIZE <= memory_end) {
            reserve_bootmem(INITRD_START, INITRD_SIZE,
                    BOOTMEM_DEFAULT);
            initrd_start = INITRD_START;
            initrd_end = initrd_start + INITRD_SIZE;
        } else {
            pr_err("initrd extends beyond end of "
                   "memory (0x%08lx > 0x%08lx) "
                   "disabling initrd\n",
                   initrd_start + INITRD_SIZE, memory_end);
            initrd_start = initrd_end = 0;
        }
    }
#endif
}

/*
 * Setup hardware capabilities.
 */
static void __init setup_hwcaps(void)
{
    static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
    struct cpuid cpu_id;
    int i;

    /*
     * The store facility list bits numbers as found in the principles
     * of operation are numbered with bit 1UL<<31 as number 0 to
     * bit 1UL<<0 as number 31.
     *   Bit 0: instructions named N3, "backported" to esa-mode
     *   Bit 2: z/Architecture mode is active
     *   Bit 7: the store-facility-list-extended facility is installed
     *   Bit 17: the message-security assist is installed
     *   Bit 19: the long-displacement facility is installed
     *   Bit 21: the extended-immediate facility is installed
     *   Bit 22: extended-translation facility 3 is installed
     *   Bit 30: extended-translation facility 3 enhancement facility
     * These get translated to:
     *   HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
     *   HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
     *   HWCAP_S390_LDISP bit 4, HWCAP_S390_EIMM bit 5 and
     *   HWCAP_S390_ETF3EH bit 8 (22 && 30).
     */
    for (i = 0; i < 6; i++)
        if (test_facility(stfl_bits[i]))
            elf_hwcap |= 1UL << i;

    if (test_facility(22) && test_facility(30))
        elf_hwcap |= HWCAP_S390_ETF3EH;

    /*
     * Check for additional facilities with store-facility-list-extended.
     * stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
     * and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
     * as stored by stfl, bits 32-xxx contain additional facilities.
     * How many facility words are stored depends on the number of
     * doublewords passed to the instruction. The additional facilities
     * are:
     *   Bit 42: decimal floating point facility is installed
     *   Bit 44: perform floating point operation facility is installed
     * translated to:
     *   HWCAP_S390_DFP bit 6 (42 && 44).
     */
    if ((elf_hwcap & (1UL << 2)) && test_facility(42) && test_facility(44))
        elf_hwcap |= HWCAP_S390_DFP;

    /*
     * Huge page support HWCAP_S390_HPAGE is bit 7.
     */
    if (MACHINE_HAS_HPAGE)
        elf_hwcap |= HWCAP_S390_HPAGE;

#if defined(CONFIG_64BIT)
    /*
     * 64-bit register support for 31-bit processes
     * HWCAP_S390_HIGH_GPRS is bit 9.
     */
    elf_hwcap |= HWCAP_S390_HIGH_GPRS;

    /*
     * Transactional execution support HWCAP_S390_TE is bit 10.
     */
    if (test_facility(50) && test_facility(73))
        elf_hwcap |= HWCAP_S390_TE;
#endif

    get_cpu_id(&cpu_id);
    switch (cpu_id.machine) {
    case 0x9672:
#if !defined(CONFIG_64BIT)
    default:    /* Use "g5" as default for 31 bit kernels. */
#endif
        strcpy(elf_platform, "g5");
        break;
    case 0x2064:
    case 0x2066:
#if defined(CONFIG_64BIT)
    default:    /* Use "z900" as default for 64 bit kernels. */
#endif
        strcpy(elf_platform, "z900");
        break;
    case 0x2084:
    case 0x2086:
        strcpy(elf_platform, "z990");
        break;
    case 0x2094:
    case 0x2096:
        strcpy(elf_platform, "z9-109");
        break;
    case 0x2097:
    case 0x2098:
        strcpy(elf_platform, "z10");
        break;
    case 0x2817:
    case 0x2818:
        strcpy(elf_platform, "z196");
        break;
    }
}

/*
 * Setup function called from init/main.c just after the banner
 * was printed.
 */

void __init setup_arch(char **cmdline_p)
{
        /*
         * print what head.S has found out about the machine
         */
#ifndef CONFIG_64BIT
    if (MACHINE_IS_VM)
        pr_info("Linux is running as a z/VM "
            "guest operating system in 31-bit mode\n");
    else if (MACHINE_IS_LPAR)
        pr_info("Linux is running natively in 31-bit mode\n");
    if (MACHINE_HAS_IEEE)
        pr_info("The hardware system has IEEE compatible "
            "floating point units\n");
    else
        pr_info("The hardware system has no IEEE compatible "
            "floating point units\n");
#else /* CONFIG_64BIT */
    if (MACHINE_IS_VM)
        pr_info("Linux is running as a z/VM "
            "guest operating system in 64-bit mode\n");
    else if (MACHINE_IS_KVM)
        pr_info("Linux is running under KVM in 64-bit mode\n");
    else if (MACHINE_IS_LPAR)
        pr_info("Linux is running natively in 64-bit mode\n");
#endif /* CONFIG_64BIT */

    /* Have one command line that is parsed and saved in /proc/cmdline */
    /* boot_command_line has been already set up in early.c */
    *cmdline_p = boot_command_line;

        ROOT_DEV = Root_RAM0;

    init_mm.start_code = PAGE_OFFSET;
    init_mm.end_code = (unsigned long) &_etext;
    init_mm.end_data = (unsigned long) &_edata;
    init_mm.brk = (unsigned long) &_end;

    if (MACHINE_HAS_MVCOS)
        memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
    else
        memcpy(&uaccess, &uaccess_std, sizeof(uaccess));

    parse_early_param();

    os_info_init();
    setup_ipl();
    setup_memory_end();
    setup_addressing_mode();
    reserve_oldmem();
    reserve_crashkernel();
    setup_memory();
    setup_resources();
    setup_vmcoreinfo();
    setup_lowcore();

        cpu_init();
    s390_init_cpu_topology();

    /*
     * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
     */
    setup_hwcaps();

    /*
     * Create kernel page tables and switch to virtual addressing.
     */
        paging_init();

        /* Setup default console */
    conmode_default();
    set_preferred_console();

    /* Setup zfcpdump support */
    setup_zfcpdump(console_devno);
}