kernel-ark/arch/x86/kernel/machine_kexec_64.c
Ken'ichi Ohmichi 69243f9125 x86: Dump filtering supports x86_64 sparsemem
This patch adds the symbol "init_level4_pgt" to the vmcoreinfo data so
that makedumpfile (dump filtering command) supports x86_64 sparsemem 
kernel of linux-2.6.24.

makedumpfile creates a small dumpfile by excluding unnecessary pages for
the analysis. It checks attributes in page structures and distinguishes
necessary pages and unnecessary ones. To check them, makedumpfile gets
the vmcoreinfo data which has the minimum debugging information only for
dump filtering.

For older x86_64 kernel (linux-2.6.23 or before), makedumpfile translates
the virtual address of page structure into physical address by subtracting
PAGE_OFFSET from virtual address, but this translation isn't effective for
linux-2.6.24 sparsemem kernel, because its page structures are in virtual
memmap area. makedumpfile should translate their virtual address by 4-levels
paging and it needs the symbol "init_level4_pgt".

Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-27 20:57:43 +02:00

244 lines
6.0 KiB
C

/*
* 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 <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/io.h>
#define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
static u64 kexec_pgd[512] PAGE_ALIGNED;
static u64 kexec_pud0[512] PAGE_ALIGNED;
static u64 kexec_pmd0[512] PAGE_ALIGNED;
static u64 kexec_pte0[512] PAGE_ALIGNED;
static u64 kexec_pud1[512] PAGE_ALIGNED;
static u64 kexec_pmd1[512] PAGE_ALIGNED;
static u64 kexec_pte1[512] PAGE_ALIGNED;
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 int init_pgtable(struct kimage *image, unsigned long start_pgtable)
{
pgd_t *level4p;
level4p = (pgd_t *)__va(start_pgtable);
return init_level4_page(image, level4p, 0, end_pfn << PAGE_SHIFT);
}
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 = page_to_pfn(image->control_code_page) << PAGE_SHIFT;
/* Setup the identity mapped 64bit page table */
result = init_pgtable(image, start_pgtable);
if (result)
return result;
return 0;
}
void machine_kexec_cleanup(struct kimage *image)
{
return;
}
/*
* Do not allocate memory (or fail in any way) in machine_kexec().
* We are past the point of no return, committed to rebooting now.
*/
NORET_TYPE void machine_kexec(struct kimage *image)
{
unsigned long page_list[PAGES_NR];
void *control_page;
/* Interrupts aren't acceptable while we reboot */
local_irq_disable();
control_page = page_address(image->control_code_page) + PAGE_SIZE;
memcpy(control_page, relocate_kernel, PAGE_SIZE);
page_list[PA_CONTROL_PAGE] = virt_to_phys(control_page);
page_list[VA_CONTROL_PAGE] = (unsigned long)relocate_kernel;
page_list[PA_PGD] = virt_to_phys(&kexec_pgd);
page_list[VA_PGD] = (unsigned long)kexec_pgd;
page_list[PA_PUD_0] = virt_to_phys(&kexec_pud0);
page_list[VA_PUD_0] = (unsigned long)kexec_pud0;
page_list[PA_PMD_0] = virt_to_phys(&kexec_pmd0);
page_list[VA_PMD_0] = (unsigned long)kexec_pmd0;
page_list[PA_PTE_0] = virt_to_phys(&kexec_pte0);
page_list[VA_PTE_0] = (unsigned long)kexec_pte0;
page_list[PA_PUD_1] = virt_to_phys(&kexec_pud1);
page_list[VA_PUD_1] = (unsigned long)kexec_pud1;
page_list[PA_PMD_1] = virt_to_phys(&kexec_pmd1);
page_list[VA_PMD_1] = (unsigned long)kexec_pmd1;
page_list[PA_PTE_1] = virt_to_phys(&kexec_pte1);
page_list[VA_PTE_1] = (unsigned long)kexec_pte1;
page_list[PA_TABLE_PAGE] =
(unsigned long)__pa(page_address(image->control_code_page));
/* The segment registers are funny things, they have both a
* visible and an invisible part. Whenever the visible part is
* set to a specific selector, the invisible part is loaded
* with from a table in memory. At no other time is the
* descriptor table in memory accessed.
*
* I take advantage of this here by force loading the
* segments, before I zap the gdt with an invalid value.
*/
load_segments();
/* The gdt & idt are now invalid.
* If you want to load them you must set up your own idt & gdt.
*/
set_gdt(phys_to_virt(0),0);
set_idt(phys_to_virt(0),0);
/* now call it */
relocate_kernel((unsigned long)image->head, (unsigned long)page_list,
image->start);
}
void arch_crash_save_vmcoreinfo(void)
{
VMCOREINFO_SYMBOL(init_level4_pgt);
#ifdef CONFIG_ARCH_DISCONTIGMEM_ENABLE
VMCOREINFO_SYMBOL(node_data);
VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
#endif
}