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linux/arch/x86_64/kernel/machine_kexec.c

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/*
* machine_kexec.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 <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] = __pa(control_page);
page_list[VA_CONTROL_PAGE] = (unsigned long)relocate_kernel;
[PATCH] x86: __pa and __pa_symbol address space separation Currently __pa_symbol is for use with symbols in the kernel address map and __pa is for use with pointers into the physical memory map. But the code is implemented so you can usually interchange the two. __pa which is much more common can be implemented much more cheaply if it is it doesn't have to worry about any other kernel address spaces. This is especially true with a relocatable kernel as __pa_symbol needs to peform an extra variable read to resolve the address. There is a third macro that is added for the vsyscall data __pa_vsymbol for finding the physical addesses of vsyscall pages. Most of this patch is simply sorting through the references to __pa or __pa_symbol and using the proper one. A little of it is continuing to use a physical address when we have it instead of recalculating it several times. swapper_pgd is now NULL. leave_mm now uses init_mm.pgd and init_mm.pgd is initialized at boot (instead of compile time) to the physmem virtual mapping of init_level4_pgd. The physical address changed. Except for the for EMPTY_ZERO page all of the remaining references to __pa_symbol appear to be during kernel initialization. So this should reduce the cost of __pa in the common case, even on a relocated kernel. As this is technically a semantic change we need to be on the lookout for anything I missed. But it works for me (tm). 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>
2007-05-02 10:27:07 -07:00
page_list[PA_PGD] = __pa_symbol(&kexec_pgd);
page_list[VA_PGD] = (unsigned long)kexec_pgd;
[PATCH] x86: __pa and __pa_symbol address space separation Currently __pa_symbol is for use with symbols in the kernel address map and __pa is for use with pointers into the physical memory map. But the code is implemented so you can usually interchange the two. __pa which is much more common can be implemented much more cheaply if it is it doesn't have to worry about any other kernel address spaces. This is especially true with a relocatable kernel as __pa_symbol needs to peform an extra variable read to resolve the address. There is a third macro that is added for the vsyscall data __pa_vsymbol for finding the physical addesses of vsyscall pages. Most of this patch is simply sorting through the references to __pa or __pa_symbol and using the proper one. A little of it is continuing to use a physical address when we have it instead of recalculating it several times. swapper_pgd is now NULL. leave_mm now uses init_mm.pgd and init_mm.pgd is initialized at boot (instead of compile time) to the physmem virtual mapping of init_level4_pgd. The physical address changed. Except for the for EMPTY_ZERO page all of the remaining references to __pa_symbol appear to be during kernel initialization. So this should reduce the cost of __pa in the common case, even on a relocated kernel. As this is technically a semantic change we need to be on the lookout for anything I missed. But it works for me (tm). 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>
2007-05-02 10:27:07 -07:00
page_list[PA_PUD_0] = __pa_symbol(&kexec_pud0);
page_list[VA_PUD_0] = (unsigned long)kexec_pud0;
[PATCH] x86: __pa and __pa_symbol address space separation Currently __pa_symbol is for use with symbols in the kernel address map and __pa is for use with pointers into the physical memory map. But the code is implemented so you can usually interchange the two. __pa which is much more common can be implemented much more cheaply if it is it doesn't have to worry about any other kernel address spaces. This is especially true with a relocatable kernel as __pa_symbol needs to peform an extra variable read to resolve the address. There is a third macro that is added for the vsyscall data __pa_vsymbol for finding the physical addesses of vsyscall pages. Most of this patch is simply sorting through the references to __pa or __pa_symbol and using the proper one. A little of it is continuing to use a physical address when we have it instead of recalculating it several times. swapper_pgd is now NULL. leave_mm now uses init_mm.pgd and init_mm.pgd is initialized at boot (instead of compile time) to the physmem virtual mapping of init_level4_pgd. The physical address changed. Except for the for EMPTY_ZERO page all of the remaining references to __pa_symbol appear to be during kernel initialization. So this should reduce the cost of __pa in the common case, even on a relocated kernel. As this is technically a semantic change we need to be on the lookout for anything I missed. But it works for me (tm). 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>
2007-05-02 10:27:07 -07:00
page_list[PA_PMD_0] = __pa_symbol(&kexec_pmd0);
page_list[VA_PMD_0] = (unsigned long)kexec_pmd0;
[PATCH] x86: __pa and __pa_symbol address space separation Currently __pa_symbol is for use with symbols in the kernel address map and __pa is for use with pointers into the physical memory map. But the code is implemented so you can usually interchange the two. __pa which is much more common can be implemented much more cheaply if it is it doesn't have to worry about any other kernel address spaces. This is especially true with a relocatable kernel as __pa_symbol needs to peform an extra variable read to resolve the address. There is a third macro that is added for the vsyscall data __pa_vsymbol for finding the physical addesses of vsyscall pages. Most of this patch is simply sorting through the references to __pa or __pa_symbol and using the proper one. A little of it is continuing to use a physical address when we have it instead of recalculating it several times. swapper_pgd is now NULL. leave_mm now uses init_mm.pgd and init_mm.pgd is initialized at boot (instead of compile time) to the physmem virtual mapping of init_level4_pgd. The physical address changed. Except for the for EMPTY_ZERO page all of the remaining references to __pa_symbol appear to be during kernel initialization. So this should reduce the cost of __pa in the common case, even on a relocated kernel. As this is technically a semantic change we need to be on the lookout for anything I missed. But it works for me (tm). 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>
2007-05-02 10:27:07 -07:00
page_list[PA_PTE_0] = __pa_symbol(&kexec_pte0);
page_list[VA_PTE_0] = (unsigned long)kexec_pte0;
[PATCH] x86: __pa and __pa_symbol address space separation Currently __pa_symbol is for use with symbols in the kernel address map and __pa is for use with pointers into the physical memory map. But the code is implemented so you can usually interchange the two. __pa which is much more common can be implemented much more cheaply if it is it doesn't have to worry about any other kernel address spaces. This is especially true with a relocatable kernel as __pa_symbol needs to peform an extra variable read to resolve the address. There is a third macro that is added for the vsyscall data __pa_vsymbol for finding the physical addesses of vsyscall pages. Most of this patch is simply sorting through the references to __pa or __pa_symbol and using the proper one. A little of it is continuing to use a physical address when we have it instead of recalculating it several times. swapper_pgd is now NULL. leave_mm now uses init_mm.pgd and init_mm.pgd is initialized at boot (instead of compile time) to the physmem virtual mapping of init_level4_pgd. The physical address changed. Except for the for EMPTY_ZERO page all of the remaining references to __pa_symbol appear to be during kernel initialization. So this should reduce the cost of __pa in the common case, even on a relocated kernel. As this is technically a semantic change we need to be on the lookout for anything I missed. But it works for me (tm). 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>
2007-05-02 10:27:07 -07:00
page_list[PA_PUD_1] = __pa_symbol(&kexec_pud1);
page_list[VA_PUD_1] = (unsigned long)kexec_pud1;
[PATCH] x86: __pa and __pa_symbol address space separation Currently __pa_symbol is for use with symbols in the kernel address map and __pa is for use with pointers into the physical memory map. But the code is implemented so you can usually interchange the two. __pa which is much more common can be implemented much more cheaply if it is it doesn't have to worry about any other kernel address spaces. This is especially true with a relocatable kernel as __pa_symbol needs to peform an extra variable read to resolve the address. There is a third macro that is added for the vsyscall data __pa_vsymbol for finding the physical addesses of vsyscall pages. Most of this patch is simply sorting through the references to __pa or __pa_symbol and using the proper one. A little of it is continuing to use a physical address when we have it instead of recalculating it several times. swapper_pgd is now NULL. leave_mm now uses init_mm.pgd and init_mm.pgd is initialized at boot (instead of compile time) to the physmem virtual mapping of init_level4_pgd. The physical address changed. Except for the for EMPTY_ZERO page all of the remaining references to __pa_symbol appear to be during kernel initialization. So this should reduce the cost of __pa in the common case, even on a relocated kernel. As this is technically a semantic change we need to be on the lookout for anything I missed. But it works for me (tm). 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>
2007-05-02 10:27:07 -07:00
page_list[PA_PMD_1] = __pa_symbol(&kexec_pmd1);
page_list[VA_PMD_1] = (unsigned long)kexec_pmd1;
[PATCH] x86: __pa and __pa_symbol address space separation Currently __pa_symbol is for use with symbols in the kernel address map and __pa is for use with pointers into the physical memory map. But the code is implemented so you can usually interchange the two. __pa which is much more common can be implemented much more cheaply if it is it doesn't have to worry about any other kernel address spaces. This is especially true with a relocatable kernel as __pa_symbol needs to peform an extra variable read to resolve the address. There is a third macro that is added for the vsyscall data __pa_vsymbol for finding the physical addesses of vsyscall pages. Most of this patch is simply sorting through the references to __pa or __pa_symbol and using the proper one. A little of it is continuing to use a physical address when we have it instead of recalculating it several times. swapper_pgd is now NULL. leave_mm now uses init_mm.pgd and init_mm.pgd is initialized at boot (instead of compile time) to the physmem virtual mapping of init_level4_pgd. The physical address changed. Except for the for EMPTY_ZERO page all of the remaining references to __pa_symbol appear to be during kernel initialization. So this should reduce the cost of __pa in the common case, even on a relocated kernel. As this is technically a semantic change we need to be on the lookout for anything I missed. But it works for me (tm). 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>
2007-05-02 10:27:07 -07:00
page_list[PA_PTE_1] = __pa_symbol(&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);
}
/* crashkernel=size@addr specifies the location to reserve for
* a crash kernel. By reserving this memory we guarantee
* that linux never set's it up as a DMA target.
* Useful for holding code to do something appropriate
* after a kernel panic.
*/
static int __init setup_crashkernel(char *arg)
{
unsigned long size, base;
char *p;
if (!arg)
return -EINVAL;
size = memparse(arg, &p);
if (arg == p)
return -EINVAL;
if (*p == '@') {
base = memparse(p+1, &p);
/* FIXME: Do I want a sanity check to validate the
* memory range? Yes you do, but it's too early for
* e820 -AK */
crashk_res.start = base;
crashk_res.end = base + size - 1;
}
return 0;
}
early_param("crashkernel", setup_crashkernel);