cfd243d4af
With the rewrite of the SMP trampoline and the early page allocator there is nothing that needs identity mapped pages, once we start executing C code. So add zap_identity_mappings into head64.c and remove zap_low_mappings() from much later in the code. The functions are subtly different thus the name change. This also kills boot_level4_pgt which was from an earlier attempt to move the identity mappings as early as possible, and is now no longer needed. Essentially I have replaced boot_level4_pgt with trampoline_level4_pgt in trampoline.S Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de>
87 lines
2.0 KiB
C
87 lines
2.0 KiB
C
/*
|
|
* linux/arch/x86_64/kernel/head64.c -- prepare to run common code
|
|
*
|
|
* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/linkage.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/string.h>
|
|
#include <linux/percpu.h>
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/proto.h>
|
|
#include <asm/smp.h>
|
|
#include <asm/bootsetup.h>
|
|
#include <asm/setup.h>
|
|
#include <asm/desc.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/sections.h>
|
|
|
|
static void __init zap_identity_mappings(void)
|
|
{
|
|
pgd_t *pgd = pgd_offset_k(0UL);
|
|
pgd_clear(pgd);
|
|
__flush_tlb();
|
|
}
|
|
|
|
/* Don't add a printk in there. printk relies on the PDA which is not initialized
|
|
yet. */
|
|
static void __init clear_bss(void)
|
|
{
|
|
memset(__bss_start, 0,
|
|
(unsigned long) __bss_stop - (unsigned long) __bss_start);
|
|
}
|
|
|
|
#define NEW_CL_POINTER 0x228 /* Relative to real mode data */
|
|
#define OLD_CL_MAGIC_ADDR 0x20
|
|
#define OLD_CL_MAGIC 0xA33F
|
|
#define OLD_CL_OFFSET 0x22
|
|
|
|
static void __init copy_bootdata(char *real_mode_data)
|
|
{
|
|
unsigned long new_data;
|
|
char * command_line;
|
|
|
|
memcpy(x86_boot_params, real_mode_data, BOOT_PARAM_SIZE);
|
|
new_data = *(u32 *) (x86_boot_params + NEW_CL_POINTER);
|
|
if (!new_data) {
|
|
if (OLD_CL_MAGIC != *(u16 *)(real_mode_data + OLD_CL_MAGIC_ADDR)) {
|
|
return;
|
|
}
|
|
new_data = __pa(real_mode_data) + *(u16 *)(real_mode_data + OLD_CL_OFFSET);
|
|
}
|
|
command_line = __va(new_data);
|
|
memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
|
|
}
|
|
|
|
void __init x86_64_start_kernel(char * real_mode_data)
|
|
{
|
|
int i;
|
|
|
|
/* clear bss before set_intr_gate with early_idt_handler */
|
|
clear_bss();
|
|
|
|
/* Make NULL pointers segfault */
|
|
zap_identity_mappings();
|
|
|
|
for (i = 0; i < IDT_ENTRIES; i++)
|
|
set_intr_gate(i, early_idt_handler);
|
|
asm volatile("lidt %0" :: "m" (idt_descr));
|
|
|
|
early_printk("Kernel alive\n");
|
|
|
|
for (i = 0; i < NR_CPUS; i++)
|
|
cpu_pda(i) = &boot_cpu_pda[i];
|
|
|
|
pda_init(0);
|
|
copy_bootdata(__va(real_mode_data));
|
|
#ifdef CONFIG_SMP
|
|
cpu_set(0, cpu_online_map);
|
|
#endif
|
|
start_kernel();
|
|
}
|