Commit d8e1baf1 authored by Vivek Goyal's avatar Vivek Goyal Committed by Andi Kleen

[PATCH] x86-64: 64bit ACPI wakeup trampoline

o Moved wakeup_level4_pgt into the wakeup routine so we can
  run the kernel above 4G.

o Now we first go to 64bit mode and continue to run from trampoline and
  then then start accessing kernel symbols and restore processor context.
  This enables us to resume even in relocatable kernel context when
  kernel might not be loaded at physical addr it has been compiled for.

o Removed the need for modifying any existing kernel page table.

o Increased the size of the wakeup routine to 8K. This is required as
  wake page tables are on trampoline itself and they got to be at 4K
  boundary, hence one page is not sufficient.
Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent 275f5517
......@@ -60,19 +60,6 @@ extern char wakeup_start, wakeup_end;
extern unsigned long acpi_copy_wakeup_routine(unsigned long);
static pgd_t low_ptr;
static void init_low_mapping(void)
{
pgd_t *slot0 = pgd_offset(current->mm, 0UL);
low_ptr = *slot0;
/* FIXME: We're playing with the current task's page tables here, which
* is potentially dangerous on SMP systems.
*/
set_pgd(slot0, *pgd_offset(current->mm, PAGE_OFFSET));
local_flush_tlb();
}
/**
* acpi_save_state_mem - save kernel state
*
......@@ -81,8 +68,6 @@ static void init_low_mapping(void)
*/
int acpi_save_state_mem(void)
{
init_low_mapping();
memcpy((void *)acpi_wakeup_address, &wakeup_start,
&wakeup_end - &wakeup_start);
acpi_copy_wakeup_routine(acpi_wakeup_address);
......@@ -95,8 +80,6 @@ int acpi_save_state_mem(void)
*/
void acpi_restore_state_mem(void)
{
set_pgd(pgd_offset(current->mm, 0UL), low_ptr);
local_flush_tlb();
}
/**
......@@ -109,10 +92,11 @@ void acpi_restore_state_mem(void)
*/
void __init acpi_reserve_bootmem(void)
{
acpi_wakeup_address = (unsigned long)alloc_bootmem_low(PAGE_SIZE);
if ((&wakeup_end - &wakeup_start) > PAGE_SIZE)
acpi_wakeup_address = (unsigned long)alloc_bootmem_low(PAGE_SIZE*2);
if ((&wakeup_end - &wakeup_start) > (PAGE_SIZE*2))
printk(KERN_CRIT
"ACPI: Wakeup code way too big, will crash on attempt to suspend\n");
"ACPI: Wakeup code way too big, will crash on attempt"
" to suspend\n");
}
static int __init acpi_sleep_setup(char *str)
......
.text
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/msr.h>
......@@ -62,12 +63,15 @@ wakeup_code:
movb $0xa2, %al ; outb %al, $0x80
lidt %ds:idt_48a - wakeup_code
xorl %eax, %eax
movw %ds, %ax # (Convert %ds:gdt to a linear ptr)
shll $4, %eax
addl $(gdta - wakeup_code), %eax
movl %eax, gdt_48a +2 - wakeup_code
mov %ds, %ax # Find 32bit wakeup_code addr
movzx %ax, %esi # (Convert %ds:gdt to a liner ptr)
shll $4, %esi
# Fix up the vectors
addl %esi, wakeup_32_vector - wakeup_code
addl %esi, wakeup_long64_vector - wakeup_code
addl %esi, gdt_48a + 2 - wakeup_code # Fixup the gdt pointer
lidtl %ds:idt_48a - wakeup_code
lgdtl %ds:gdt_48a - wakeup_code # load gdt with whatever is
# appropriate
......@@ -80,7 +84,7 @@ wakeup_code:
.balign 4
wakeup_32_vector:
.long wakeup_32 - __START_KERNEL_map
.long wakeup_32 - wakeup_code
.word __KERNEL32_CS, 0
.code32
......@@ -103,10 +107,6 @@ wakeup_32:
movl $__KERNEL_DS, %eax
movl %eax, %ds
movl saved_magic - __START_KERNEL_map, %eax
cmpl $0x9abcdef0, %eax
jne bogus_32_magic
movw $0x0e00 + 'i', %ds:(0xb8012)
movb $0xa8, %al ; outb %al, $0x80;
......@@ -120,7 +120,7 @@ wakeup_32:
movl %eax, %cr4
/* Setup early boot stage 4 level pagetables */
movl $(wakeup_level4_pgt - __START_KERNEL_map), %eax
leal (wakeup_level4_pgt - wakeup_code)(%esi), %eax
movl %eax, %cr3
/* Enable Long Mode */
......@@ -159,11 +159,11 @@ wakeup_32:
*/
/* Finally jump in 64bit mode */
ljmp *(wakeup_long64_vector - __START_KERNEL_map)
ljmp *(wakeup_long64_vector - wakeup_code)(%esi)
.balign 4
wakeup_long64_vector:
.long wakeup_long64 - __START_KERNEL_map
.long wakeup_long64 - wakeup_code
.word __KERNEL_CS, 0
.code64
......@@ -178,11 +178,16 @@ wakeup_long64:
* addresses where we're currently running on. We have to do that here
* because in 32bit we couldn't load a 64bit linear address.
*/
lgdt cpu_gdt_descr - __START_KERNEL_map
lgdt cpu_gdt_descr
movw $0x0e00 + 'n', %ds:(0xb8014)
movb $0xa9, %al ; outb %al, $0x80
movq saved_magic, %rax
movq $0x123456789abcdef0, %rdx
cmpq %rdx, %rax
jne bogus_64_magic
movw $0x0e00 + 'u', %ds:(0xb8016)
nop
......@@ -223,20 +228,21 @@ idt_48a:
gdt_48a:
.word 0x800 # gdt limit=2048,
# 256 GDT entries
.word 0, 0 # gdt base (filled in later)
.long gdta - wakeup_code # gdt base (relocated in later)
real_magic: .quad 0
video_mode: .quad 0
video_flags: .quad 0
.code16
bogus_real_magic:
movb $0xba,%al ; outb %al,$0x80
jmp bogus_real_magic
bogus_32_magic:
.code64
bogus_64_magic:
movb $0xb3,%al ; outb %al,$0x80
jmp bogus_32_magic
jmp bogus_64_magic
bogus_cpu:
movb $0xbc,%al ; outb %al,$0x80
......@@ -263,6 +269,7 @@ bogus_cpu:
#define VIDEO_FIRST_V7 0x0900
# Setting of user mode (AX=mode ID) => CF=success
.code16
mode_seta:
movw %ax, %bx
#if 0
......@@ -313,6 +320,13 @@ wakeup_stack_begin: # Stack grows down
.org 0xff0
wakeup_stack: # Just below end of page
.org 0x1000
ENTRY(wakeup_level4_pgt)
.quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE
.fill 510,8,0
/* (2^48-(2*1024*1024*1024))/(2^39) = 511 */
.quad level3_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE
ENTRY(wakeup_end)
##
......@@ -338,9 +352,10 @@ ENTRY(acpi_copy_wakeup_routine)
movq $0x123456789abcdef0, %rdx
movq %rdx, saved_magic
movl saved_magic - __START_KERNEL_map, %eax
cmpl $0x9abcdef0, %eax
jne bogus_32_magic
movq saved_magic, %rax
movq $0x123456789abcdef0, %rdx
cmpq %rdx, %rax
jne bogus_64_magic
# restore the regs we used
popq %rdx
......
......@@ -308,15 +308,6 @@ NEXT_PAGE(level2_kernel_pgt)
.data
#ifdef CONFIG_ACPI_SLEEP
.align PAGE_SIZE
ENTRY(wakeup_level4_pgt)
.quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE
.fill 510,8,0
/* (2^48-(2*1024*1024*1024))/(2^39) = 511 */
.quad level3_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE
#endif
#ifndef CONFIG_HOTPLUG_CPU
__INITDATA
#endif
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment