/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup RTEMSScoreCPUAArch64
*
* @brief Implementation of _CPU_Context_validate
*
* This file implements _CPU_Context_validate for use in spcontext01.
*/
/*
* Copyright (C) 2020 On-Line Applications Research Corporation (OAR)
* Written by Kinsey Moore <kinsey.moore@oarcorp.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/asm.h>
#include <rtems/score/cpu.h>
#include <rtems/score/basedefs.h>
/*
* This register size applies to X (integer) registers as well as the D (lower
* half floating point) registers. It does not apply to V (full size floating
* point) registers or W (lower half integer) registers.
*/
#define AARCH64_REGISTER_SIZE 8
/* According to the AAPCS64, X19-X28 are callee-saved registers */
#define FRAME_OFFSET_X19 0x00
#define FRAME_OFFSET_X20 0x08
#define FRAME_OFFSET_X21 0x10
#define FRAME_OFFSET_X22 0x18
#define FRAME_OFFSET_X23 0x20
#define FRAME_OFFSET_X24 0x28
#define FRAME_OFFSET_X25 0x30
#define FRAME_OFFSET_X26 0x38
#define FRAME_OFFSET_X27 0x40
#define FRAME_OFFSET_X28 0x48
#define FRAME_OFFSET_LR 0x50
#ifdef AARCH64_MULTILIB_VFP
/*
* According to the AAPCS64, V8-V15 are callee-saved registers, but only the
* bottom 8 bytes are required to be saved which correspond to D8-D15.
*/
#define FRAME_OFFSET_D8 0x58
#define FRAME_OFFSET_D9 0x60
#define FRAME_OFFSET_D10 0x68
#define FRAME_OFFSET_D11 0x70
#define FRAME_OFFSET_D12 0x78
#define FRAME_OFFSET_D13 0x80
#define FRAME_OFFSET_D14 0x88
#define FRAME_OFFSET_D15 0x90
/*
* Force 16 byte alignment of the frame size to avoid stack pointer alignment
* exceptions.
*/
#define FRAME_SIZE RTEMS_ALIGN_UP( FRAME_OFFSET_D15 + AARCH64_REGISTER_SIZE, 16 )
#else
#define FRAME_SIZE RTEMS_ALIGN_UP( FRAME_OFFSET_LR + AARCH64_REGISTER_SIZE, 16 )
#endif
.section .text
FUNCTION_ENTRY(_CPU_Context_validate)
/* Save */
sub sp, sp, #FRAME_SIZE
str x19, [sp, #FRAME_OFFSET_X19]
str x20, [sp, #FRAME_OFFSET_X20]
str x21, [sp, #FRAME_OFFSET_X21]
str x22, [sp, #FRAME_OFFSET_X22]
str x23, [sp, #FRAME_OFFSET_X23]
str x24, [sp, #FRAME_OFFSET_X24]
str x25, [sp, #FRAME_OFFSET_X25]
str x26, [sp, #FRAME_OFFSET_X26]
str x27, [sp, #FRAME_OFFSET_X27]
str x28, [sp, #FRAME_OFFSET_X28]
str lr, [sp, #FRAME_OFFSET_LR]
#ifdef AARCH64_MULTILIB_VFP
str d8, [sp, #FRAME_OFFSET_D8]
str d9, [sp, #FRAME_OFFSET_D9]
str d10, [sp, #FRAME_OFFSET_D10]
str d11, [sp, #FRAME_OFFSET_D11]
str d12, [sp, #FRAME_OFFSET_D12]
str d13, [sp, #FRAME_OFFSET_D13]
str d14, [sp, #FRAME_OFFSET_D14]
str d15, [sp, #FRAME_OFFSET_D15]
#endif
/* Fill */
/* R1 is used for temporary values */
mov x1, x0
/* R2 contains the stack pointer */
mov x2, sp
.macro fill_register reg
add x1, x1, #1
mov \reg, x1
.endm
#ifdef AARCH64_MULTILIB_VFP
/* X3 contains the FPSR */
mrs x3, FPSR
ldr x4, =0xf000001f
bic x3, x3, x4
and x4, x4, x0
orr x3, x3, x4
msr FPSR, x3
#else
fill_register x3
#endif
fill_register x4
fill_register x5
fill_register x6
fill_register x7
fill_register x8
fill_register x9
fill_register x10
fill_register x11
fill_register x12
fill_register x13
fill_register x14
fill_register x15
fill_register x16
fill_register x17
fill_register x18
fill_register x19
fill_register x20
fill_register x21
fill_register x22
fill_register x23
fill_register x24
fill_register x25
fill_register x26
fill_register x27
fill_register x28
fill_register x29
fill_register lr
#ifdef AARCH64_MULTILIB_VFP
.macro fill_vfp_register regnum
add x1, x1, #1
fmov d\regnum\(), x1
fmov v\regnum\().D[1], x1
.endm
fill_vfp_register 0
fill_vfp_register 1
fill_vfp_register 2
fill_vfp_register 3
fill_vfp_register 4
fill_vfp_register 5
fill_vfp_register 6
fill_vfp_register 7
fill_vfp_register 8
fill_vfp_register 9
fill_vfp_register 10
fill_vfp_register 11
fill_vfp_register 12
fill_vfp_register 13
fill_vfp_register 14
fill_vfp_register 15
fill_vfp_register 16
fill_vfp_register 17
fill_vfp_register 18
fill_vfp_register 19
fill_vfp_register 20
fill_vfp_register 21
fill_vfp_register 22
fill_vfp_register 23
fill_vfp_register 24
fill_vfp_register 25
fill_vfp_register 26
fill_vfp_register 27
fill_vfp_register 28
fill_vfp_register 29
fill_vfp_register 30
fill_vfp_register 31
#endif /* AARCH64_MULTILIB_VFP */
/* Check */
check:
.macro check_register reg
add x1, x1, #1
cmp \reg, x1
bne restore
.endm
mov x1, sp
cmp x2, x1
bne restore
mov x1, x0
#ifndef AARCH64_MULTILIB_VFP
check_register x3
#endif
check_register x4
check_register x5
check_register x6
check_register x7
check_register x8
check_register x9
check_register x10
check_register x11
check_register x12
check_register x13
check_register x14
check_register x15
check_register x16
check_register x17
check_register x18
check_register x19
check_register x20
check_register x21
check_register x22
check_register x23
check_register x24
check_register x25
check_register x26
check_register x27
check_register x28
check_register x29
check_register lr
#ifdef AARCH64_MULTILIB_VFP
b check_vfp
#endif
b check
/* Restore */
restore:
ldr x19, [sp, #FRAME_OFFSET_X19]
ldr x20, [sp, #FRAME_OFFSET_X20]
ldr x21, [sp, #FRAME_OFFSET_X21]
ldr x22, [sp, #FRAME_OFFSET_X22]
ldr x23, [sp, #FRAME_OFFSET_X23]
ldr x24, [sp, #FRAME_OFFSET_X24]
ldr x25, [sp, #FRAME_OFFSET_X25]
ldr x26, [sp, #FRAME_OFFSET_X26]
ldr x27, [sp, #FRAME_OFFSET_X27]
ldr x28, [sp, #FRAME_OFFSET_X28]
ldr lr, [sp, #FRAME_OFFSET_LR]
#ifdef AARCH64_MULTILIB_VFP
ldr d8, [sp, #FRAME_OFFSET_D8]
ldr d9, [sp, #FRAME_OFFSET_D9]
ldr d10, [sp, #FRAME_OFFSET_D10]
ldr d11, [sp, #FRAME_OFFSET_D11]
ldr d12, [sp, #FRAME_OFFSET_D12]
ldr d13, [sp, #FRAME_OFFSET_D13]
ldr d14, [sp, #FRAME_OFFSET_D14]
ldr d15, [sp, #FRAME_OFFSET_D15]
#endif
add sp, sp, #FRAME_SIZE
ret
FUNCTION_END(_CPU_Context_validate)
#ifdef AARCH64_MULTILIB_VFP
check_vfp:
.macro check_vfp_register regnum
add x1, x1, #1
fmov x4, d\regnum
fmov x5, v\regnum\().D[1]
cmp x5, x4
bne 1f
cmp x1, x4
bne 1f
b 2f
1:
b restore
2:
.endm
mrs x4, FPSR
cmp x4, x3
bne restore
check_vfp_register 0
check_vfp_register 1
check_vfp_register 2
check_vfp_register 3
check_vfp_register 4
check_vfp_register 5
check_vfp_register 6
check_vfp_register 7
check_vfp_register 8
check_vfp_register 9
check_vfp_register 10
check_vfp_register 11
check_vfp_register 12
check_vfp_register 13
check_vfp_register 14
check_vfp_register 15
check_vfp_register 16
check_vfp_register 17
check_vfp_register 18
check_vfp_register 19
check_vfp_register 20
check_vfp_register 21
check_vfp_register 22
check_vfp_register 23
check_vfp_register 24
check_vfp_register 25
check_vfp_register 26
check_vfp_register 27
check_vfp_register 28
check_vfp_register 29
check_vfp_register 30
check_vfp_register 31
/* Restore x4 and x5 */
mov x1, x0
fill_register x4
fill_register x5
b check
#endif /* AARCH64_MULTILIB_VFP */
