zephyr/arch/arm64/core/userspace.S

129 lines
2.2 KiB
ArmAsm

/*
* Copyright (c) 2020 Carlo Caione <ccaione@baylibre.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/toolchain.h>
#include <zephyr/linker/sections.h>
#include <offsets_short.h>
#include <zephyr/arch/cpu.h>
#include <zephyr/syscall.h>
#include <zephyr/arch/arm64/mm.h>
#include "macro_priv.inc"
_ASM_FILE_PROLOGUE
/*
* size_t arch_user_string_nlen(const char *s, size_t maxsize, int *err_arg)
*/
GTEXT(z_arm64_user_string_nlen_fault_start)
GTEXT(z_arm64_user_string_nlen_fault_end)
GTEXT(z_arm64_user_string_nlen_fixup)
GTEXT(arch_user_string_nlen)
SECTION_FUNC(TEXT, arch_user_string_nlen)
mov x3, x0
mov x0, #0
mov x4, #0
strlen_loop:
cmp x0, x1
beq strlen_done
z_arm64_user_string_nlen_fault_start:
ldrb w5, [x3, x0]
z_arm64_user_string_nlen_fault_end:
cbz x5, strlen_done
add x0, x0, #1
b strlen_loop
z_arm64_user_string_nlen_fixup:
mov x4, #-1
mov x0, #0
strlen_done:
str w4, [x2]
ret
/*
* int arch_buffer_validate(const void *addr, size_t size, int write)
*/
GTEXT(arch_buffer_validate)
SECTION_FUNC(TEXT, arch_buffer_validate)
add x1, x1, x0
mrs x3, DAIF
msr DAIFSET, #DAIFSET_IRQ_BIT
abv_loop:
cbnz w2, 1f
at S1E0R, x0
b 2f
1: at S1E0W, x0
2: orr x0, x0, #(MEM_DOMAIN_ALIGN_AND_SIZE - 1)
add x0, x0, #1
isb
mrs x4, PAR_EL1
tbnz x4, #0, abv_fail
cmp x0, x1
blo abv_loop
msr DAIF, x3
mov x0, #0
ret
abv_fail:
msr DAIF, x3
mov x0, #-1
ret
/*
* System call entry point.
*/
GTEXT(z_arm64_do_syscall)
SECTION_FUNC(TEXT, z_arm64_do_syscall)
/* Recover the syscall parameters from the ESF */
ldp x0, x1, [sp, ___esf_t_x0_x1_OFFSET]
ldp x2, x3, [sp, ___esf_t_x2_x3_OFFSET]
ldp x4, x5, [sp, ___esf_t_x4_x5_OFFSET]
/* Use the ESF as SSF */
mov x6, sp
/* Recover the syscall ID */
ldr x8, [sp, ___esf_t_x8_x9_OFFSET]
/* Check whether the ID is valid */
ldr x9, =K_SYSCALL_LIMIT
cmp x8, x9
blo valid_syscall_id
/* Save the bad ID for handler_bad_syscall() */
mov x0, x8
ldr x8, =K_SYSCALL_BAD
valid_syscall_id:
ldr x9, =_k_syscall_table
ldr x9, [x9, x8, lsl #3]
/* Jump into the syscall */
msr daifclr, #(DAIFSET_IRQ_BIT)
blr x9
msr daifset, #(DAIFSET_IRQ_BIT)
/* Save the return value into the ESF */
str x0, [sp, ___esf_t_x0_x1_OFFSET]
/* Return from exception */
b z_arm64_exit_exc