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|
/*
* handle transition of Linux booting another kernel
* Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/mm.h>
#include <linux/kexec.h>
#include <linux/string.h>
#include <linux/reboot.h>
#include <linux/numa.h>
#include <linux/ftrace.h>
#include <linux/io.h>
#include <linux/suspend.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
static int init_one_level2_page(struct kimage *image, pgd_t *pgd,
unsigned long addr)
{
pud_t *pud;
pmd_t *pmd;
struct page *page;
int result = -ENOMEM;
addr &= PMD_MASK;
pgd += pgd_index(addr);
if (!pgd_present(*pgd)) {
page = kimage_alloc_control_pages(image, 0);
if (!page)
goto out;
pud = (pud_t *)page_address(page);
memset(pud, 0, PAGE_SIZE);
set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
}
pud = pud_offset(pgd, addr);
if (!pud_present(*pud)) {
page = kimage_alloc_control_pages(image, 0);
if (!page)
goto out;
pmd = (pmd_t *)page_address(page);
memset(pmd, 0, PAGE_SIZE);
set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
}
pmd = pmd_offset(pud, addr);
if (!pmd_present(*pmd))
set_pmd(pmd, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
result = 0;
out:
return result;
}
static void init_level2_page(pmd_t *level2p, unsigned long addr)
{
unsigned long end_addr;
addr &= PAGE_MASK;
end_addr = addr + PUD_SIZE;
while (addr < end_addr) {
set_pmd(level2p++, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
addr += PMD_SIZE;
}
}
static int init_level3_page(struct kimage *image, pud_t *level3p,
unsigned long addr, unsigned long last_addr)
{
unsigned long end_addr;
int result;
result = 0;
addr &= PAGE_MASK;
end_addr = addr + PGDIR_SIZE;
while ((addr < last_addr) && (addr < end_addr)) {
struct page *page;
pmd_t *level2p;
page = kimage_alloc_control_pages(image, 0);
if (!page) {
result = -ENOMEM;
goto out;
}
level2p = (pmd_t *)page_address(page);
init_level2_page(level2p, addr);
set_pud(level3p++, __pud(__pa(level2p) | _KERNPG_TABLE));
addr += PUD_SIZE;
}
/* clear the unused entries */
while (addr < end_addr) {
pud_clear(level3p++);
addr += PUD_SIZE;
}
out:
return result;
}
static int init_level4_page(struct kimage *image, pgd_t *level4p,
unsigned long addr, unsigned long last_addr)
{
unsigned long end_addr;
int result;
result = 0;
addr &= PAGE_MASK;
end_addr = addr + (PTRS_PER_PGD * PGDIR_SIZE);
while ((addr < last_addr) && (addr < end_addr)) {
struct page *page;
pud_t *level3p;
page = kimage_alloc_control_pages(image, 0);
if (!page) {
result = -ENOMEM;
goto out;
}
level3p = (pud_t *)page_address(page);
result = init_level3_page(image, level3p, addr, last_addr);
if (result)
goto out;
set_pgd(level4p++, __pgd(__pa(level3p) | _KERNPG_TABLE));
addr += PGDIR_SIZE;
}
/* clear the unused entries */
while (addr < end_addr) {
pgd_clear(level4p++);
addr += PGDIR_SIZE;
}
out:
return result;
}
static void free_transition_pgtable(struct kimage *image)
{
free_page((unsigned long)image->arch.pud);
free_page((unsigned long)image->arch.pmd);
free_page((unsigned long)image->arch.pte);
}
static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
{
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
unsigned long vaddr, paddr;
int result = -ENOMEM;
vaddr = (unsigned long)relocate_kernel;
paddr = __pa(page_address(image->control_code_page)+PAGE_SIZE);
pgd += pgd_index(vaddr);
if (!pgd_present(*pgd)) {
pud = (pud_t *)get_zeroed_page(GFP_KERNEL);
if (!pud)
goto err;
image->arch.pud = pud;
set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
}
pud = pud_offset(pgd, vaddr);
if (!pud_present(*pud)) {
pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL);
if (!pmd)
goto err;
image->arch.pmd = pmd;
set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
}
pmd = pmd_offset(pud, vaddr);
if (!pmd_present(*pmd)) {
pte = (pte_t *)get_zeroed_page(GFP_KERNEL);
if (!pte)
goto err;
image->arch.pte = pte;
set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE));
}
pte = pte_offset_kernel(pmd, vaddr);
set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC));
return 0;
err:
free_transition_pgtable(image);
return result;
}
static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
{
pgd_t *level4p;
int result;
level4p = (pgd_t *)__va(start_pgtable);
result = init_level4_page(image, level4p, 0, max_pfn << PAGE_SHIFT);
if (result)
return result;
/*
* image->start may be outside 0 ~ max_pfn, for example when
* jump back to original kernel from kexeced kernel
*/
result = init_one_level2_page(image, level4p, image->start);
if (result)
return result;
return init_transition_pgtable(image, level4p);
}
static void set_idt(void *newidt, u16 limit)
{
struct desc_ptr curidt;
/* x86-64 supports unaliged loads & stores */
curidt.size = limit;
curidt.address = (unsigned long)newidt;
__asm__ __volatile__ (
"lidtq %0\n"
: : "m" (curidt)
);
};
static void set_gdt(void *newgdt, u16 limit)
{
struct desc_ptr curgdt;
/* x86-64 supports unaligned loads & stores */
curgdt.size = limit;
curgdt.address = (unsigned long)newgdt;
__asm__ __volatile__ (
"lgdtq %0\n"
: : "m" (curgdt)
);
};
static void load_segments(void)
{
__asm__ __volatile__ (
"\tmovl %0,%%ds\n"
"\tmovl %0,%%es\n"
"\tmovl %0,%%ss\n"
"\tmovl %0,%%fs\n"
"\tmovl %0,%%gs\n"
: : "a" (__KERNEL_DS) : "memory"
);
}
int machine_kexec_prepare(struct kimage *image)
{
unsigned long start_pgtable;
int result;
/* Calculate the offsets */
start_pgtable <
|