Commit 7ba78799 authored by Pavel Machek's avatar Pavel Machek Committed by Linus Torvalds

[PATCH] acpi_wakeup.S: simplify logic

This simplifies logic in acpi_wakeup.S by putting code and data into
same segment. Plus it kills off-by-3 bug and uses constant instead of
hardcoded value.
parent 8bbde7ed
.text
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/page.h>
# Do we need to deal with A20?
#
# wakeup_code runs in real mode, and at unknown address (determined at run-time).
# Therefore it must only use relative jumps/calls.
#
# Do we need to deal with A20? It is okay: ACPI specs says A20 must be enabled
#
# If physical address of wakeup_code is 0x12345, BIOS should call us with
# cs = 0x1234, eip = 0x05
#
ALIGN
wakeup_start:
.align 4096
ENTRY(wakeup_start)
wakeup_code:
wakeup_code_start = .
.code16
......@@ -14,49 +23,70 @@ wakeup_code:
movw $0xb800, %ax
movw %ax,%fs
movw $0x0e00 + 'L', %fs:(0x10)
cli
cld
# setup data segment
movw %cs, %ax
addw $(wakeup_data - wakeup_code) >> 4, %ax
movw %ax, %ds
movw %ax, %ds # Make ds:0 point to wakeup_start
movw %ax, %ss
mov $(wakeup_stack - wakeup_data), %sp # Private stack is needed for ASUS board
movw $0x0e00 + 'S', %fs:(0x12)
mov wakeup_stack - wakeup_code, %sp # Private stack is needed for ASUS board
movw $0x0e00 + 'S', %fs:(0x12)
movl real_magic - wakeup_data, %eax
pushl $0 # Kill any dangerous flags
popfl
movl real_magic - wakeup_code, %eax
cmpl $0x12345678, %eax
jne bogus_real_magic
mov video_mode - wakeup_data, %ax
#if 1
lcall $0xc000,$3
#endif
#if 0
mov video_mode - wakeup_code, %ax
call mode_set
#endif
# set up page table
movl (real_save_cr3 - wakeup_data), %eax
#if 1
movl $swapper_pg_dir-__PAGE_OFFSET, %eax
#else
movl (real_save_cr3 - wakeup_data), %eax
#endif
movl %eax, %cr3
# make sure %cr4 is set correctly (features, etc)
movl (real_save_cr4 - wakeup_data), %eax
movl real_save_cr4 - wakeup_code, %eax
movl %eax, %cr4
movw $0xb800, %ax
movw %ax,%fs
movw $0x0e00 + 'i', %fs:(0x12)
# need a gdt
lgdt real_save_gdt - wakeup_data
lgdt real_save_gdt - wakeup_code
movl (real_save_cr0 - wakeup_data), %eax
movl real_save_cr0 - wakeup_code, %eax
movl %eax, %cr0
jmp 1f
1:
movw $0x0e00 + 'n', %fs:(0x14)
movl real_magic - wakeup_data, %eax
movl real_magic - wakeup_code, %eax
cmpl $0x12345678, %eax
jne bogus_real_magic
ljmpl $__KERNEL_CS,$wakeup_pmode_return
real_save_gdt: .word 0
.long 0
real_save_cr0: .long 0
real_save_cr3: .long 0
real_save_cr4: .long 0
real_magic: .long 0
video_mode: .long 0
bogus_real_magic:
movw $0x0e00 + 'B', %fs:(0x12)
jmp bogus_real_magic
......@@ -129,20 +159,12 @@ _setbad: jmp setbad
.code32
ALIGN
.org 0x300
wakeup_data:
.word 0
real_save_gdt: .word 0
.long 0
real_save_cr0: .long 0
real_save_cr3: .long 0
real_save_cr4: .long 0
real_magic: .long 0
video_mode: .long 0
.org 0x500
.org 0x2000
wakeup_stack:
wakeup_end:
.org 0x3000
ENTRY(wakeup_end)
.org 0x4000
wakeup_pmode_return:
movl $__KERNEL_DS, %eax
......@@ -205,7 +227,6 @@ bogus_magic2:
movw $0x0e00 + '2', %ds:(0xb8018)
jmp bogus_magic2
##
# acpi_copy_wakeup_routine
#
......@@ -228,7 +249,7 @@ ENTRY(acpi_copy_wakeup_routine)
movl %eax, %edi
leal wakeup_start, %esi
movl $(wakeup_end - wakeup_start) >> 2, %ecx
movl $(wakeup_end - wakeup_start + 3) >> 2, %ecx
rep ; movsl
......@@ -290,8 +311,8 @@ ENTRY(do_suspend_lowlevel)
ret
.p2align 4,,7
.L1432:
movl $104,%eax
movw %eax, %ds
movl $__KERNEL_DS,%eax
movw %ax, %ds
movl saved_context_esp, %esp
movl saved_context_ebp, %ebp
movl saved_context_eax, %eax
......@@ -310,5 +331,4 @@ saved_gdt: .long 0,0
saved_idt: .long 0,0
saved_ldt: .long 0
saved_tss: .long 0
saved_cr0: .long 0
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