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f8d8977a3d
Convert tod_clock_base to union tod_clock. This simplifies quite a bit
of code and also fixes a bug in read_persistent_clock64();
void read_persistent_clock64(struct timespec64 *ts)
{
__u64 delta;
delta = initial_leap_seconds + TOD_UNIX_EPOCH;
get_tod_clock_ext(clk);
*(__u64 *) &clk[1] -= delta;
if (*(__u64 *) &clk[1] > delta)
clk[0]--;
ext_to_timespec64(clk, ts);
}
Assume &clk[1] == 3 and delta == 2; then after the substraction the if
condition becomes true and the epoch part of the clock is decremented
by one because of an assumed overflow, even though there is none.
Fix this by using 128 bit arithmetics and let the compiler do the
right thing:
void read_persistent_clock64(struct timespec64 *ts)
{
union tod_clock clk;
u64 delta;
delta = initial_leap_seconds + TOD_UNIX_EPOCH;
store_tod_clock_ext(&clk);
clk.eitod -= delta;
ext_to_timespec64(&clk, ts);
}
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
314 lines
8.0 KiB
C
314 lines
8.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright IBM Corp. 2007, 2009
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* Author(s): Hongjie Yang <hongjie@us.ibm.com>,
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* Heiko Carstens <heiko.carstens@de.ibm.com>
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*/
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#define KMSG_COMPONENT "setup"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/compiler.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/ctype.h>
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#include <linux/lockdep.h>
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#include <linux/extable.h>
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#include <linux/pfn.h>
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#include <linux/uaccess.h>
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#include <linux/kernel.h>
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#include <asm/diag.h>
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#include <asm/ebcdic.h>
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#include <asm/ipl.h>
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#include <asm/lowcore.h>
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#include <asm/processor.h>
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#include <asm/sections.h>
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#include <asm/setup.h>
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#include <asm/sysinfo.h>
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#include <asm/cpcmd.h>
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#include <asm/sclp.h>
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#include <asm/facility.h>
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#include <asm/boot_data.h>
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#include <asm/switch_to.h>
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#include "entry.h"
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static void __init reset_tod_clock(void)
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{
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union tod_clock clk;
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if (store_tod_clock_ext_cc(&clk) == 0)
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return;
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/* TOD clock not running. Set the clock to Unix Epoch. */
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if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
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disabled_wait();
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memset(&tod_clock_base, 0, sizeof(tod_clock_base));
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tod_clock_base.tod = TOD_UNIX_EPOCH;
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S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
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}
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/*
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* Initialize storage key for kernel pages
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*/
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static noinline __init void init_kernel_storage_key(void)
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{
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#if PAGE_DEFAULT_KEY
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unsigned long end_pfn, init_pfn;
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end_pfn = PFN_UP(__pa(_end));
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for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
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page_set_storage_key(init_pfn << PAGE_SHIFT,
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PAGE_DEFAULT_KEY, 0);
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#endif
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}
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static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
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static noinline __init void detect_machine_type(void)
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{
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struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
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/* Check current-configuration-level */
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if (stsi(NULL, 0, 0, 0) <= 2) {
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S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
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return;
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}
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/* Get virtual-machine cpu information. */
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if (stsi(vmms, 3, 2, 2) || !vmms->count)
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return;
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/* Detect known hypervisors */
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if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
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S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
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else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
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S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
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}
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/* Remove leading, trailing and double whitespace. */
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static inline void strim_all(char *str)
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{
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char *s;
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s = strim(str);
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if (s != str)
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memmove(str, s, strlen(s));
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while (*str) {
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if (!isspace(*str++))
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continue;
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if (isspace(*str)) {
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s = skip_spaces(str);
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memmove(str, s, strlen(s) + 1);
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}
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}
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}
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static noinline __init void setup_arch_string(void)
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{
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struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
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struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
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char mstr[80], hvstr[17];
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if (stsi(mach, 1, 1, 1))
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return;
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EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
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EBCASC(mach->type, sizeof(mach->type));
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EBCASC(mach->model, sizeof(mach->model));
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EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
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sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
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mach->manufacturer, mach->type,
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mach->model, mach->model_capacity);
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strim_all(mstr);
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if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
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EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
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sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
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strim_all(hvstr);
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} else {
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sprintf(hvstr, "%s",
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MACHINE_IS_LPAR ? "LPAR" :
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MACHINE_IS_VM ? "z/VM" :
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MACHINE_IS_KVM ? "KVM" : "unknown");
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}
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dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
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}
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static __init void setup_topology(void)
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{
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int max_mnest;
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if (!test_facility(11))
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return;
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S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
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for (max_mnest = 6; max_mnest > 1; max_mnest--) {
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if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
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break;
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}
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topology_max_mnest = max_mnest;
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}
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static void early_pgm_check_handler(void)
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{
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const struct exception_table_entry *fixup;
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unsigned long cr0, cr0_new;
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unsigned long addr;
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addr = S390_lowcore.program_old_psw.addr;
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fixup = s390_search_extables(addr);
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if (!fixup)
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disabled_wait();
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/* Disable low address protection before storing into lowcore. */
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__ctl_store(cr0, 0, 0);
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cr0_new = cr0 & ~(1UL << 28);
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__ctl_load(cr0_new, 0, 0);
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S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
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__ctl_load(cr0, 0, 0);
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}
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static noinline __init void setup_lowcore_early(void)
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{
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psw_t psw;
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psw.addr = (unsigned long)s390_base_pgm_handler;
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psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
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if (IS_ENABLED(CONFIG_KASAN))
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psw.mask |= PSW_MASK_DAT;
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S390_lowcore.program_new_psw = psw;
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s390_base_pgm_handler_fn = early_pgm_check_handler;
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S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
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}
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static noinline __init void setup_facility_list(void)
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{
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memcpy(S390_lowcore.alt_stfle_fac_list,
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S390_lowcore.stfle_fac_list,
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sizeof(S390_lowcore.alt_stfle_fac_list));
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if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
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__clear_facility(82, S390_lowcore.alt_stfle_fac_list);
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}
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static __init void detect_diag9c(void)
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{
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unsigned int cpu_address;
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int rc;
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cpu_address = stap();
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diag_stat_inc(DIAG_STAT_X09C);
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asm volatile(
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" diag %2,0,0x9c\n"
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"0: la %0,0\n"
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"1:\n"
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EX_TABLE(0b,1b)
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: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
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if (!rc)
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S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
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}
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static __init void detect_machine_facilities(void)
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{
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if (test_facility(8)) {
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S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
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__ctl_set_bit(0, 23);
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}
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if (test_facility(78))
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S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
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if (test_facility(3))
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S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
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if (test_facility(50) && test_facility(73)) {
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S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
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__ctl_set_bit(0, 55);
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}
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if (test_facility(51))
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S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
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if (test_facility(129)) {
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S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
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__ctl_set_bit(0, 17);
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}
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if (test_facility(130) && !noexec_disabled) {
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S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
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__ctl_set_bit(0, 20);
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}
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if (test_facility(133))
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S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
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if (test_facility(139) && (tod_clock_base.tod >> 63)) {
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/* Enabled signed clock comparator comparisons */
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S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
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clock_comparator_max = -1ULL >> 1;
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__ctl_set_bit(0, 53);
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}
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}
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static inline void save_vector_registers(void)
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{
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#ifdef CONFIG_CRASH_DUMP
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if (test_facility(129))
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save_vx_regs(boot_cpu_vector_save_area);
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#endif
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}
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static inline void setup_control_registers(void)
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{
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unsigned long reg;
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__ctl_store(reg, 0, 0);
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reg |= CR0_LOW_ADDRESS_PROTECTION;
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reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
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reg |= CR0_EXTERNAL_CALL_SUBMASK;
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__ctl_load(reg, 0, 0);
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}
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static inline void setup_access_registers(void)
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{
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unsigned int acrs[NUM_ACRS] = { 0 };
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restore_access_regs(acrs);
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}
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static int __init disable_vector_extension(char *str)
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{
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S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
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__ctl_clear_bit(0, 17);
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return 0;
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}
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early_param("novx", disable_vector_extension);
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char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
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static void __init setup_boot_command_line(void)
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{
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/* copy arch command line */
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strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE);
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}
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static void __init check_image_bootable(void)
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{
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if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING)))
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return;
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sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
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sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
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sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
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disabled_wait();
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}
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void __init startup_init(void)
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{
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reset_tod_clock();
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check_image_bootable();
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time_early_init();
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init_kernel_storage_key();
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lockdep_off();
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setup_lowcore_early();
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setup_facility_list();
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detect_machine_type();
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setup_arch_string();
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setup_boot_command_line();
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detect_diag9c();
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detect_machine_facilities();
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save_vector_registers();
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setup_topology();
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sclp_early_detect();
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setup_control_registers();
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setup_access_registers();
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lockdep_on();
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}
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