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#
# Copyright (c) 2005 Ondrej Palkovsky
# 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.
#
#define IREGISTER_SPACE 72
#define IOFFSET_RAX 0x0
#define IOFFSET_RCX 0x8
#define IOFFSET_RDX 0x10
#define IOFFSET_RSI 0x18
#define IOFFSET_RDI 0x20
#define IOFFSET_R8 0x28
#define IOFFSET_R9 0x30
#define IOFFSET_R10 0x38
#define IOFFSET_R11 0x40
# 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
#include <arch/pm.h>
#include <arch/mm/page.h>
.text
.global interrupt_handlers
.global syscall_entry
.global panic_printf
panic_printf:
movq $halt, (%rsp)
jmp printf
.global cpuid
.global has_cpuid
.global get_cycle
.global read_efer_flag
.global set_efer_flag
.global memsetb
.global memsetw
.global memcpy
.global memcpy_from_uspace
.global memcpy_to_uspace
.global memcpy_from_uspace_failover_address
.global memcpy_to_uspace_failover_address
# Wrapper for generic memsetb
memsetb:
jmp _memsetb
# Wrapper for generic memsetw
memsetw:
jmp _memsetw
#define MEMCPY_DST %rdi
#define MEMCPY_SRC %rsi
#define MEMCPY_SIZE %rdx
/**
* Copy memory from/to 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 Destination address.
* @param MEMCPY_SRC Source address.
* @param MEMCPY_SIZE Number of bytes to copy.
*
* @retrun MEMCPY_DST on success, 0 on failure.
*/
memcpy:
memcpy_from_uspace:
memcpy_to_uspace:
movq MEMCPY_DST, %rax
movq MEMCPY_SIZE, %rcx
shrq $3, %rcx /* size / 8 */
rep movsq /* copy as much as possible word by word */
movq MEMCPY_SIZE, %rcx
andq $7, %rcx /* size % 8 */
jz 0f
rep movsb /* copy the rest byte by byte */
0:
ret /* return MEMCPY_SRC, success */
memcpy_from_uspace_failover_address:
memcpy_to_uspace_failover_address:
xorq %rax, %rax /* return 0, failure */
ret
## Determine CPUID support
#
# Return 0 in EAX if CPUID is not support, 1 if supported.
#
has_cpuid:
pushfq # store flags
popq %rax # read flags
movq %rax,%rdx # copy flags
btcl $21,%edx # swap the ID bit
pushq %rdx
popfq # propagate the change into flags
pushfq
popq %rdx # read flags
andl $(1<<21),%eax # interested only in ID bit
andl $(1<<21),%edx
xorl %edx,%eax # 0 if not supported, 1 if supported
ret
cpuid:
movq %rbx, %r10 # we have to preserve rbx across function calls
movl %edi,%eax # load the command into %eax
cpuid
movl %eax,0(%rsi)
movl %ebx,4(%rsi)
movl %ecx,8(%rsi)
movl %edx,12(%rsi)
movq %r10, %rbx
ret
get_cycle:
xorq %rax,%rax
rdtsc
ret
set_efer_flag:
movq $0xc0000080, %rcx
rdmsr
btsl %edi, %eax
wrmsr
ret
read_efer_flag:
movq $0xc0000080, %rcx
rdmsr
ret
# Push all volatile general purpose registers on stack
.macro save_all_gpr
movq %rax, IOFFSET_RAX(%rsp)
movq %rcx, IOFFSET_RCX(%rsp)
movq %rdx, IOFFSET_RDX(%rsp)
movq %rsi, IOFFSET_RSI(%rsp)
movq %rdi, IOFFSET_RDI(%rsp)
movq %r8, IOFFSET_R8(%rsp)
movq %r9, IOFFSET_R9(%rsp)
movq %r10, IOFFSET_R10(%rsp)
movq %r11, IOFFSET_R11(%rsp)
.endm
.macro restore_all_gpr
movq IOFFSET_RAX(%rsp), %rax
movq IOFFSET_RCX(%rsp), %rcx
movq IOFFSET_RDX(%rsp), %rdx
movq IOFFSET_RSI(%rsp), %rsi
movq IOFFSET_RDI(%rsp), %rdi
movq IOFFSET_R8(%rsp), %r8
movq IOFFSET_R9(%rsp), %r9
movq IOFFSET_R10(%rsp), %r10
movq IOFFSET_R11(%rsp), %r11
.endm
#define INTERRUPT_ALIGN 128
## Declare interrupt handlers
#
# Declare interrupt handlers for n interrupt
# vectors starting at vector i.
#
# The handlers call exc_dispatch().
#
.macro handler i n
/*
* Choose between version with error code and version without error
* code. Both versions have to be of the same size. amd64 assembly is,
* however, a little bit tricky. For instance, subq $0x80, %rsp and
* subq $0x78, %rsp can result in two instructions with different
* op-code lengths.
* Therefore we align the interrupt handlers.
*/
.iflt \i-32
.if (1 << \i) & ERROR_WORD_INTERRUPT_LIST
/*
* Version with error word.
*/
subq $IREGISTER_SPACE, %rsp
.else
/*
* Version without error word,
*/
subq $(IREGISTER_SPACE+8), %rsp
.endif
.else
/*
* Version without error word,
*/
subq $(IREGISTER_SPACE+8), %rsp
.endif
save_all_gpr
cld
movq $(\i), %rdi # %rdi - first parameter
movq %rsp, %rsi # %rsi - pointer to istate
call exc_dispatch # exc_dispatch(i, istate)
restore_all_gpr
# $8 = Skip error word
addq $(IREGISTER_SPACE+8), %rsp
iretq
.align INTERRUPT_ALIGN
.if (\n-\i)-1
handler "(\i+1)",\n
.endif
.endm
.align INTERRUPT_ALIGN
interrupt_handlers:
h_start:
handler 0 IDT_ITEMS
h_end:
## Low-level syscall handler
#
# Registers on entry:
#
# @param rcx Userspace return address.
# @param r11 Userspace RLFAGS.
#
# @param rax Syscall number.
# @param rdi 1st syscall argument.
# @param rsi 2nd syscall argument.
# @param rdx 3rd syscall argument.
# @param r10 4th syscall argument. Used instead of RCX because the
# SYSCALL instruction clobbers it.
# @param r8 5th syscall argument.
# @param r9 6th syscall argument.
#
# @return Return value is in rax.
#
syscall_entry:
swapgs # Switch to hidden gs
#
# %gs:0 Scratch space for this thread's user RSP
# %gs:8 Address to be used as this thread's kernel RSP
#
movq %rsp, %gs:0 # Save this thread's user RSP
movq %gs:8, %rsp # Set this thread's kernel RSP
swapgs # Switch back to remain consistent
sti
pushq %rcx
pushq %r11
movq %r10, %rcx # Copy the 4th argument where it is expected
pushq %rax
call syscall_handler
addq $8, %rsp
popq %r11
popq %rcx
cli
swapgs
movq %gs:0, %rsp # Restore the user RSP
swapgs
sysretq
.data
.global interrupt_handler_size
interrupt_handler_size: .quad (h_end-h_start)/IDT_ITEMS