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#
# Copyright (c) 2001-2004 Jakub Jermar
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# - The name of the author may not be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
## very low and hardware-level functions
# Mask for interrupts 0 - 31 (bits 0 - 31) where 0 means that int has no error word
# and 1 means interrupt with error word
#define ERROR_WORD_INTERRUPT_LIST 0x00027D00
.text
.global paging_on
.global enable_l_apic_in_msr
.global interrupt_handlers
.global memcpy
.global memcpy_from_uspace
.global memcpy_from_uspace_failover_address
.global memcpy_to_uspace
.global memcpy_to_uspace_failover_address
#define MEMCPY_DST 4
#define MEMCPY_SRC 8
#define MEMCPY_SIZE 12
/** Copy memory to/from userspace.
*
* This is almost conventional memcpy().
* The difference is that there is a failover part
* to where control is returned from a page fault
* if the page fault occurs during copy_from_uspace()
* or copy_to_uspace().
*
* @param MEMCPY_DST(%esp) Destination address.
* @param MEMCPY_SRC(%esp) Source address.
* @param MEMCPY_SIZE(%esp) Size.
*
* @return MEMCPY_SRC(%esp) on success and 0 on failure.
*/
memcpy:
memcpy_from_uspace:
memcpy_to_uspace:
movl %edi, %edx /* save %edi */
movl %esi, %eax /* save %esi */
movl MEMCPY_SIZE(%esp), %ecx
shrl $2, %ecx /* size / 4 */
movl MEMCPY_DST(%esp), %edi
movl MEMCPY_SRC(%esp), %esi
rep movsl /* copy as much as possible word by word */
movl MEMCPY_SIZE(%esp), %ecx
andl $3, %ecx /* size % 4 */
jz 0f
rep movsb /* copy the rest byte by byte */
0:
movl %edx, %edi
movl %eax, %esi
movl MEMCPY_SRC(%esp), %eax /* MEMCPY_SRC(%esp), success */
ret
/*
* We got here from as_page_fault() after the memory operations
* above had caused a page fault.
*/
memcpy_from_uspace_failover_address:
memcpy_to_uspace_failover_address:
movl %edx, %edi
movl %eax, %esi
xorl %eax, %eax /* return 0, failure */
ret
## Turn paging on
#
# Enable paging and write-back caching in CR0.
#
paging_on:
movl %cr0,%edx
orl $(1<<31),%edx # paging on
andl $~((1<<30)|(1<<29)),%edx # clear Cache Disable and not Write Though
movl %edx,%cr0
jmp 0f
0:
ret
## Enable local APIC
#
# Enable local APIC in MSR.
#
enable_l_apic_in_msr:
push %eax
movl $0x1b, %ecx
rdmsr
orl $(1<<11),%eax
orl $(0xfee00000),%eax
wrmsr
pop %eax
ret
# Clear nested flag
# overwrites %ecx
.macro CLEAR_NT_FLAG
pushfl
pop %ecx
and $0xffffbfff,%ecx
push %ecx
popfl
.endm
## Declare interrupt handlers
#
# Declare interrupt handlers for n interrupt
# vectors starting at vector i.
#
# The handlers setup data segment registers
# and call exc_dispatch().
#
#define INTERRUPT_ALIGN 64
.macro handler i n
.ifeq \i-0x30 # Syscall handler
push %ds
push %es
push %fs
push %gs
# Push arguments on stack
push %edi
push %esi
push %edx
push %ecx
push %eax
# we must fill the data segment registers
movw $16,%ax
movw %ax,%ds
movw %ax,%es
sti
call syscall_handler # syscall_handler(ax,cx,dx,si,di)
cli
addl $20, %esp # clean-up of parameters
pop %gs
pop %fs
pop %es
pop %ds
CLEAR_NT_FLAG
iret
.else
/*
* This macro distinguishes between two versions of ia32 exceptions.
* One version has error word and the other does not have it.
* The latter version fakes the error word on the stack so that the
* handlers and istate_t can be the same for both types.
*/
.iflt \i-32
.if (1 << \i) & ERROR_WORD_INTERRUPT_LIST
/*
* With error word, do nothing
*/
.else
/*
* Version without error word,
*/
subl $4, %esp
.endif
.else
/*
* Version without error word,
*/
subl $4, %esp
.endif
push %ds
push %es
push %fs
push %gs
#ifdef CONFIG_DEBUG_ALLREGS
push %ebx
push %ebp
push %edi
push %esi
#else
sub $16, %esp
#endif
push %edx
push %ecx
push %eax
# we must fill the data segment registers
movw $16,%ax
movw %ax,%ds
movw %ax,%es
pushl %esp # *istate
pushl $(\i) # intnum
call exc_dispatch # excdispatch(intnum, *istate)
addl $8,%esp # Clear arguments from stack
CLEAR_NT_FLAG # Modifies %ecx
pop %eax
pop %ecx
pop %edx
#ifdef CONFIG_DEBUG_ALLREGS
pop %esi
pop %edi
pop %ebp
pop %ebx
#else
add $16, %esp
#endif
pop %gs
pop %fs
pop %es
pop %ds
addl $4,%esp # Skip error word, no matter whether real or fake.
iret
.endif
.align INTERRUPT_ALIGN
.if (\n-\i)-1
handler "(\i+1)",\n
.endif
.endm
# keep in sync with pm.h !!!
IDT_ITEMS=64
.align INTERRUPT_ALIGN
interrupt_handlers:
h_start:
handler 0 IDT_ITEMS
h_end:
.data
.global interrupt_handler_size
interrupt_handler_size: .long (h_end-h_start)/IDT_ITEMS