// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright IBM Corp. 2007, 2018
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*/
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/*
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* Early setup functions which may not rely on an initialized bss
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* section. The last thing that is supposed to happen here is
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* initialization of the bss section.
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*/
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#include <linux/processor.h>
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#include <linux/string.h>
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#include <asm/sections.h>
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#include <asm/lowcore.h>
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#include <asm/setup.h>
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#include <asm/timex.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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u64 time;
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if (store_tod_clock(&time) == 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) != 0 || store_tod_clock(&time) != 0)
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disabled_wait(0);
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memset(tod_clock_base, 0, 16);
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*(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
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S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
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}
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static void __init rescue_initrd(void)
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{
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unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
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/*
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* Just like in case of IPL from VM reader we make sure there is a
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* gap of 4MB between end of kernel and start of initrd.
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* That way we can also be sure that saving an NSS will succeed,
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* which however only requires different segments.
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*/
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if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
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return;
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if (!INITRD_START || !INITRD_SIZE)
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return;
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if (INITRD_START >= min_initrd_addr)
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return;
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memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
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INITRD_START = min_initrd_addr;
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}
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static void __init clear_bss_section(void)
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{
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memset(__bss_start, 0, __bss_stop - __bss_start);
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}
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void __init startup_init_nobss(void)
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{
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reset_tod_clock();
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rescue_initrd();
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clear_bss_section();
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}
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