early.c

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/*
 *    Copyright IBM Corp. 2007, 2009
 *    Author(s): Hongjie Yang <[email protected]>,
 *       Heiko Carstens <[email protected]>
 */

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

#include <linux/compiler.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/ftrace.h>
#include <linux/lockdep.h>
#include <linux/module.h>
#include <linux/pfn.h>
#include <linux/uaccess.h>
#include <linux/kernel.h>
#include <asm/ebcdic.h>
#include <asm/ipl.h>
#include <asm/lowcore.h>
#include <asm/processor.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sysinfo.h>
#include <asm/cpcmd.h>
#include <asm/sclp.h>
#include <asm/facility.h>
#include "entry.h"

/*
 * Create a Kernel NSS if the SAVESYS= parameter is defined
 */
#define DEFSYS_CMD_SIZE     128
#define SAVESYS_CMD_SIZE    32

char kernel_nss_name[NSS_NAME_SIZE + 1];

static void __init setup_boot_command_line(void);

/*
 * Get the TOD clock running.
 */
static void __init reset_tod_clock(void)
{
    u64 time;

    if (store_clock(&time) == 0)
        return;
    /* TOD clock not running. Set the clock to Unix Epoch. */
    if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
        disabled_wait(0);

    sched_clock_base_cc = TOD_UNIX_EPOCH;
    S390_lowcore.last_update_clock = sched_clock_base_cc;
}

#ifdef CONFIG_SHARED_KERNEL
int __init savesys_ipl_nss(char *cmd, const int cmdlen);

asm(
    "   .section .init.text,\"ax\",@progbits\n"
    "   .align  4\n"
    "   .type   savesys_ipl_nss, @function\n"
    "savesys_ipl_nss:\n"
#ifdef CONFIG_64BIT
    "   stmg    6,15,48(15)\n"
    "   lgr 14,3\n"
    "   sam31\n"
    "   diag    2,14,0x8\n"
    "   sam64\n"
    "   lgr 2,14\n"
    "   lmg 6,15,48(15)\n"
#else
    "   stm 6,15,24(15)\n"
    "   lr  14,3\n"
    "   diag    2,14,0x8\n"
    "   lr  2,14\n"
    "   lm  6,15,24(15)\n"
#endif
    "   br  14\n"
    "   .size   savesys_ipl_nss, .-savesys_ipl_nss\n"
    "   .previous\n");

static __initdata char upper_command_line[COMMAND_LINE_SIZE];

static noinline __init void create_kernel_nss(void)
{
    unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
#ifdef CONFIG_BLK_DEV_INITRD
    unsigned int sinitrd_pfn, einitrd_pfn;
#endif
    int response;
    int hlen;
    size_t len;
    char *savesys_ptr;
    char defsys_cmd[DEFSYS_CMD_SIZE];
    char savesys_cmd[SAVESYS_CMD_SIZE];

    /* Do nothing if we are not running under VM */
    if (!MACHINE_IS_VM)
        return;

    /* Convert COMMAND_LINE to upper case */
    for (i = 0; i < strlen(boot_command_line); i++)
        upper_command_line[i] = toupper(boot_command_line[i]);

    savesys_ptr = strstr(upper_command_line, "SAVESYS=");

    if (!savesys_ptr)
        return;

    savesys_ptr += 8;    /* Point to the beginning of the NSS name */
    for (i = 0; i < NSS_NAME_SIZE; i++) {
        if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
            break;
        kernel_nss_name[i] = savesys_ptr[i];
    }

    stext_pfn = PFN_DOWN(__pa(&_stext));
    eshared_pfn = PFN_DOWN(__pa(&_eshared));
    end_pfn = PFN_UP(__pa(&_end));
    min_size = end_pfn << 2;

    hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
            "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
            kernel_nss_name, stext_pfn - 1, stext_pfn,
            eshared_pfn - 1, eshared_pfn, end_pfn);

#ifdef CONFIG_BLK_DEV_INITRD
    if (INITRD_START && INITRD_SIZE) {
        sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
        einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
        min_size = einitrd_pfn << 2;
        hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
                 " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
    }
#endif

    snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
         " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
    defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
    snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
         kernel_nss_name, kernel_nss_name);
    savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';

    __cpcmd(defsys_cmd, NULL, 0, &response);

    if (response != 0) {
        pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
            response);
        kernel_nss_name[0] = '\0';
        return;
    }

    len = strlen(savesys_cmd);
    ASCEBC(savesys_cmd, len);
    response = savesys_ipl_nss(savesys_cmd, len);

    /* On success: response is equal to the command size,
     *         max SAVESYS_CMD_SIZE
     * On error: response contains the numeric portion of cp error message.
     *       for SAVESYS it will be >= 263
     *       for missing privilege class, it will be 1
     */
    if (response > SAVESYS_CMD_SIZE || response == 1) {
        pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
            response);
        kernel_nss_name[0] = '\0';
        return;
    }

    /* re-initialize cputime accounting. */
    sched_clock_base_cc = get_clock();
    S390_lowcore.last_update_clock = sched_clock_base_cc;
    S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
    S390_lowcore.user_timer = 0;
    S390_lowcore.system_timer = 0;
    asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));

    /* re-setup boot command line with new ipl vm parms */
    ipl_update_parameters();
    setup_boot_command_line();

    ipl_flags = IPL_NSS_VALID;
}

#else /* CONFIG_SHARED_KERNEL */

static inline void create_kernel_nss(void) { }

#endif /* CONFIG_SHARED_KERNEL */

/*
 * Clear bss memory
 */
static noinline __init void clear_bss_section(void)
{
    memset(__bss_start, 0, __bss_stop - __bss_start);
}

/*
 * Initialize storage key for kernel pages
 */
static noinline __init void init_kernel_storage_key(void)
{
    unsigned long end_pfn, init_pfn;

    end_pfn = PFN_UP(__pa(&_end));

    for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
        page_set_storage_key(init_pfn << PAGE_SHIFT,
                     PAGE_DEFAULT_KEY, 0);
}

static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);

static noinline __init void detect_machine_type(void)
{
    struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;

    /* Check current-configuration-level */
    if (stsi(NULL, 0, 0, 0) <= 2) {
        S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
        return;
    }
    /* Get virtual-machine cpu information. */
    if (stsi(vmms, 3, 2, 2) || !vmms->count)
        return;

    /* Running under KVM? If not we assume z/VM */
    if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
        S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
    else
        S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
}

static __init void setup_topology(void)
{
#ifdef CONFIG_64BIT
    int max_mnest;

    if (!test_facility(11))
        return;
    S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
    for (max_mnest = 6; max_mnest > 1; max_mnest--) {
        if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
            break;
    }
    topology_max_mnest = max_mnest;
#endif
}

static void early_pgm_check_handler(void)
{
    const struct exception_table_entry *fixup;
    unsigned long addr;

    addr = S390_lowcore.program_old_psw.addr;
    fixup = search_exception_tables(addr & PSW_ADDR_INSN);
    if (!fixup)
        disabled_wait(0);
    S390_lowcore.program_old_psw.addr = extable_fixup(fixup)|PSW_ADDR_AMODE;
}

static noinline __init void setup_lowcore_early(void)
{
    psw_t psw;

    psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
    psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
    S390_lowcore.external_new_psw = psw;
    psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
    S390_lowcore.program_new_psw = psw;
    s390_base_pgm_handler_fn = early_pgm_check_handler;
}

static noinline __init void setup_facility_list(void)
{
    stfle(S390_lowcore.stfle_fac_list,
          ARRAY_SIZE(S390_lowcore.stfle_fac_list));
}

static __init void detect_mvpg(void)
{
#ifndef CONFIG_64BIT
    int rc;

    asm volatile(
        "   la  0,0\n"
        "   mvpg    %2,%2\n"
        "0: la  %0,0\n"
        "1:\n"
        EX_TABLE(0b,1b)
        : "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
    if (!rc)
        S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
#endif
}

static __init void detect_ieee(void)
{
#ifndef CONFIG_64BIT
    int rc, tmp;

    asm volatile(
        "   efpc    %1,0\n"
        "0: la  %0,0\n"
        "1:\n"
        EX_TABLE(0b,1b)
        : "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
    if (!rc)
        S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
#endif
}

static __init void detect_csp(void)
{
#ifndef CONFIG_64BIT
    int rc;

    asm volatile(
        "   la  0,0\n"
        "   la  1,0\n"
        "   la  2,4\n"
        "   csp 0,2\n"
        "0: la  %0,0\n"
        "1:\n"
        EX_TABLE(0b,1b)
        : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
    if (!rc)
        S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
#endif
}

static __init void detect_diag9c(void)
{
    unsigned int cpu_address;
    int rc;

    cpu_address = stap();
    asm volatile(
        "   diag    %2,0,0x9c\n"
        "0: la  %0,0\n"
        "1:\n"
        EX_TABLE(0b,1b)
        : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
    if (!rc)
        S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
}

static __init void detect_diag44(void)
{
#ifdef CONFIG_64BIT
    int rc;

    asm volatile(
        "   diag    0,0,0x44\n"
        "0: la  %0,0\n"
        "1:\n"
        EX_TABLE(0b,1b)
        : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
    if (!rc)
        S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
#endif
}

static __init void detect_machine_facilities(void)
{
#ifdef CONFIG_64BIT
    if (test_facility(8)) {
        S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
        __ctl_set_bit(0, 23);
    }
    if (test_facility(78))
        S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
    if (test_facility(3))
        S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
    if (test_facility(27))
        S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
    if (test_facility(40))
        S390_lowcore.machine_flags |= MACHINE_FLAG_SPP;
    if (test_facility(50) && test_facility(73))
        S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
    if (test_facility(66))
        S390_lowcore.machine_flags |= MACHINE_FLAG_RRBM;
#endif
}

static __init void rescue_initrd(void)
{
#ifdef CONFIG_BLK_DEV_INITRD
    unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
    /*
     * Just like in case of IPL from VM reader we make sure there is a
     * gap of 4MB between end of kernel and start of initrd.
     * That way we can also be sure that saving an NSS will succeed,
     * which however only requires different segments.
     */
    if (!INITRD_START || !INITRD_SIZE)
        return;
    if (INITRD_START >= min_initrd_addr)
        return;
    memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
    INITRD_START = min_initrd_addr;
#endif
}

/* Set up boot command line */
static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
{
    char *parm, *delim;
    size_t rc, len;

    len = strlen(boot_command_line);

    delim = boot_command_line + len;    /* '\0' character position */
    parm  = boot_command_line + len + 1;    /* append right after '\0' */

    rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
    if (rc) {
        if (*parm == '=')
            memmove(boot_command_line, parm + 1, rc);
        else
            *delim = ' ';       /* replace '\0' with space */
    }
}

static inline int has_ebcdic_char(const char *str)
{
    int i;

    for (i = 0; str[i]; i++)
        if (str[i] & 0x80)
            return 1;
    return 0;
}

static void __init setup_boot_command_line(void)
{
    COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
    /* convert arch command line to ascii if necessary */
    if (has_ebcdic_char(COMMAND_LINE))
        EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
    /* copy arch command line */
    strlcpy(boot_command_line, strstrip(COMMAND_LINE),
        ARCH_COMMAND_LINE_SIZE);

    /* append IPL PARM data to the boot command line */
    if (MACHINE_IS_VM)
        append_to_cmdline(append_ipl_vmparm);

    append_to_cmdline(append_ipl_scpdata);
}

/*
 * Save ipl parameters, clear bss memory, initialize storage keys
 * and create a kernel NSS at startup if the SAVESYS= parm is defined
 */
void __init startup_init(void)
{
    reset_tod_clock();
    ipl_save_parameters();
    rescue_initrd();
    clear_bss_section();
    init_kernel_storage_key();
    lockdep_init();
    lockdep_off();
    setup_lowcore_early();
    setup_facility_list();
    detect_machine_type();
    ipl_update_parameters();
    setup_boot_command_line();
    create_kernel_nss();
    detect_mvpg();
    detect_ieee();
    detect_csp();
    detect_diag9c();
    detect_diag44();
    detect_machine_facilities();
    setup_topology();
    sclp_facilities_detect();
    detect_memory_layout(memory_chunk);
#ifdef CONFIG_DYNAMIC_FTRACE
    S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
#endif
    lockdep_on();
}