mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-01 13:46:42 +07:00
25eff8d4cd
helps debugging problems in this rather murky area of code. Signed-off-by: Yinghai Lu <yinghai.lu@sun.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
128 lines
2.9 KiB
C
128 lines
2.9 KiB
C
/*
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* prepare to run common code
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*
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* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
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*/
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#include <linux/init.h>
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#include <linux/linkage.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/percpu.h>
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#include <linux/start_kernel.h>
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#include <asm/processor.h>
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#include <asm/proto.h>
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#include <asm/smp.h>
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#include <asm/setup.h>
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#include <asm/desc.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/sections.h>
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#include <asm/kdebug.h>
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#include <asm/e820.h>
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static void __init zap_identity_mappings(void)
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{
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pgd_t *pgd = pgd_offset_k(0UL);
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pgd_clear(pgd);
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__flush_tlb_all();
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}
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/* Don't add a printk in there. printk relies on the PDA which is not initialized
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yet. */
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static void __init clear_bss(void)
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{
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memset(__bss_start, 0,
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(unsigned long) __bss_stop - (unsigned long) __bss_start);
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}
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static void __init copy_bootdata(char *real_mode_data)
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{
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char * command_line;
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memcpy(&boot_params, real_mode_data, sizeof boot_params);
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if (boot_params.hdr.cmd_line_ptr) {
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command_line = __va(boot_params.hdr.cmd_line_ptr);
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memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
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}
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}
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#define EBDA_ADDR_POINTER 0x40E
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static __init void reserve_ebda(void)
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{
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unsigned ebda_addr, ebda_size;
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/*
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* there is a real-mode segmented pointer pointing to the
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* 4K EBDA area at 0x40E
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*/
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ebda_addr = *(unsigned short *)__va(EBDA_ADDR_POINTER);
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ebda_addr <<= 4;
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if (!ebda_addr)
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return;
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ebda_size = *(unsigned short *)__va(ebda_addr);
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/* Round EBDA up to pages */
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if (ebda_size == 0)
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ebda_size = 1;
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ebda_size <<= 10;
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ebda_size = round_up(ebda_size + (ebda_addr & ~PAGE_MASK), PAGE_SIZE);
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if (ebda_size > 64*1024)
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ebda_size = 64*1024;
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reserve_early(ebda_addr, ebda_addr + ebda_size, "EBDA");
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}
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void __init x86_64_start_kernel(char * real_mode_data)
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{
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int i;
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/* clear bss before set_intr_gate with early_idt_handler */
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clear_bss();
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/* Make NULL pointers segfault */
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zap_identity_mappings();
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for (i = 0; i < IDT_ENTRIES; i++) {
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#ifdef CONFIG_EARLY_PRINTK
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set_intr_gate(i, &early_idt_handlers[i]);
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#else
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set_intr_gate(i, early_idt_handler);
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#endif
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}
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load_idt((const struct desc_ptr *)&idt_descr);
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early_printk("Kernel alive\n");
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for (i = 0; i < NR_CPUS; i++)
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cpu_pda(i) = &boot_cpu_pda[i];
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pda_init(0);
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copy_bootdata(__va(real_mode_data));
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reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA BSS");
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/* Reserve INITRD */
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if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
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unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
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unsigned long ramdisk_size = boot_params.hdr.ramdisk_size;
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unsigned long ramdisk_end = ramdisk_image + ramdisk_size;
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reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
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}
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reserve_ebda();
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/*
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* At this point everything still needed from the boot loader
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* or BIOS or kernel text should be early reserved or marked not
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* RAM in e820. All other memory is free game.
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*/
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start_kernel();
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}
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