zephyr/arch/arc/core/fault_s.S

237 lines
6.3 KiB
ArmAsm

/*
* Copyright (c) 2014 Wind River Systems, Inc.
* Copyright (c) 2018 Synopsys.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Fault handlers for ARCv2
*
* Fault handlers for ARCv2 processors.
*/
#include <zephyr/toolchain.h>
#include <zephyr/linker/sections.h>
#include <zephyr/arch/cpu.h>
#include <swap_macros.h>
#include <zephyr/syscall.h>
#include <zephyr/arch/arc/asm-compat/assembler.h>
GTEXT(_Fault)
GTEXT(__reset)
GTEXT(__memory_error)
GTEXT(__instruction_error)
GTEXT(__ev_machine_check)
GTEXT(__ev_tlb_miss_i)
GTEXT(__ev_tlb_miss_d)
GTEXT(__ev_prot_v)
GTEXT(__ev_privilege_v)
GTEXT(__ev_swi)
GTEXT(__ev_trap)
GTEXT(__ev_extension)
GTEXT(__ev_div_zero)
GTEXT(__ev_dc_error)
GTEXT(__ev_maligned)
.macro _save_exc_regs_into_stack
#ifdef CONFIG_ARC_HAS_SECURE
/* ERSEC_STAT is IOW/RAZ in normal mode */
lr r0,[_ARC_V2_ERSEC_STAT]
st_s r0, [sp, ___isf_t_sec_stat_OFFSET]
#endif
LRR r0, [_ARC_V2_ERET]
STR r0, sp, ___isf_t_pc_OFFSET
LRR r0, [_ARC_V2_ERSTATUS]
STR r0, sp, ___isf_t_status32_OFFSET
.endm
/*
* The exception handling will use top part of interrupt stack to
* get smaller memory footprint, because exception is not frequent.
* To reduce the impact on interrupt handling, especially nested interrupt
* the top part of interrupt stack cannot be too large, so add a check
* here
*/
#if CONFIG_ARC_EXCEPTION_STACK_SIZE > (CONFIG_ISR_STACK_SIZE >> 1)
#error "interrupt stack size is too small"
#endif
/*
* @brief Fault handler installed in the fault and reserved vectors
*/
SECTION_SUBSEC_FUNC(TEXT,__fault,__memory_error)
SECTION_SUBSEC_FUNC(TEXT,__fault,__instruction_error)
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_machine_check)
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_tlb_miss_i)
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_tlb_miss_d)
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_prot_v)
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_privilege_v)
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_swi)
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_extension)
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_div_zero)
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_dc_error)
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_maligned)
_exc_entry:
/*
* re-use the top part of interrupt stack as exception
* stack. If this top part is used by interrupt handling,
* and exception is raised, then here it's guaranteed that
* exception handling has necessary stack to use
*/
MOVR ilink, sp
_get_curr_cpu_irq_stack sp
SUBR sp, sp, (CONFIG_ISR_STACK_SIZE - CONFIG_ARC_EXCEPTION_STACK_SIZE)
/*
* save caller saved registers
* this stack frame is set up in exception stack,
* not in the original sp (thread stack or interrupt stack).
* Because the exception may be raised by stack checking or
* mpu protect violation related to stack. If this stack frame
* is setup in original sp, double exception may be raised during
* _create_irq_stack_frame, which is unrecoverable.
*/
_create_irq_stack_frame
_save_exc_regs_into_stack
/* sp is parameter of _Fault */
MOVR r0, sp
/* ilink is the thread's original sp */
MOVR r1, ilink
jl _Fault
_exc_return:
/* the exception cause must be fixed in exception handler when exception returns
* directly, or exception will be repeated.
*
* If thread switch is raised in exception handler, the context of old thread will
* not be saved, i.e., it cannot be recovered, because we don't know where the
* exception comes out, thread context?irq_context?nest irq context?
*/
_get_next_switch_handle
BREQR r0, 0, _exc_return_from_exc
/* Save old thread into switch handle which is required by z_sched_switch_spin which
* will be called during old thread abort.
*/
STR r2, r2, ___thread_t_switch_handle_OFFSET
MOVR r2, r0
#ifdef CONFIG_ARC_SECURE_FIRMWARE
/*
* sync up the ERSEC_STAT.ERM and SEC_STAT.IRM.
* use a fake interrupt return to simulate an exception turn.
* ERM and IRM record which mode the cpu should return, 1: secure
* 0: normal
*/
lr r3,[_ARC_V2_ERSEC_STAT]
btst r3, 31
bset.nz r3, r3, _ARC_V2_SEC_STAT_IRM_BIT
bclr.z r3, r3, _ARC_V2_SEC_STAT_IRM_BIT
sflag r3
#endif
/* clear AE bit to forget this was an exception, and go to
* register bank0 (if exception is raised in firq with 2 reg
* banks, then we may be bank1)
*/
#if defined(CONFIG_ARC_FIRQ) && CONFIG_RGF_NUM_BANKS != 1
/* save r2 in ilink because of the possible following reg
* bank switch
*/
mov ilink, r2
#endif
LRR r3, [_ARC_V2_STATUS32]
ANDR r3, r3, (~(_ARC_V2_STATUS32_AE | _ARC_V2_STATUS32_RB(7)))
kflag r3
/* pretend lowest priority interrupt happened to use common handler
* if exception is raised in irq, i.e., _ARC_V2_AUX_IRQ_ACT !=0,
* ignore irq handling, we cannot return to irq handling which may
* raise exception again. The ignored interrupts will be re-triggered
* if not cleared, or re-triggered by interrupt sources, or just missed
*/
#ifdef CONFIG_ARC_SECURE_FIRMWARE
mov_s r3, (1 << (ARC_N_IRQ_START_LEVEL - 1))
#else
MOVR r3, (1 << (CONFIG_NUM_IRQ_PRIO_LEVELS - 1))
#endif
#ifdef CONFIG_ARC_NORMAL_FIRMWARE
push_s r2
mov_s r0, _ARC_V2_AUX_IRQ_ACT
mov_s r1, r3
mov_s r6, ARC_S_CALL_AUX_WRITE
sjli SJLI_CALL_ARC_SECURE
pop_s r2
#else
SRR r3, [_ARC_V2_AUX_IRQ_ACT]
#endif
#if defined(CONFIG_ARC_FIRQ) && CONFIG_RGF_NUM_BANKS != 1
mov r2, ilink
#endif
/* Assumption: r2 has next thread */
b _rirq_newthread_switch
_exc_return_from_exc:
/* exception handler may change return address.
* reload it
*/
LDR r0, sp, ___isf_t_pc_OFFSET
SRR r0, [_ARC_V2_ERET]
_pop_irq_stack_frame
MOVR sp, ilink
rtie
/* separated entry for trap which may be used by irq_offload, USERPSACE */
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_trap)
/* get the id of trap_s */
LRR ilink, [_ARC_V2_ECR]
ANDR ilink, ilink, 0x3f
#ifdef CONFIG_USERSPACE
cmp ilink, _TRAP_S_CALL_SYSTEM_CALL
bne _do_non_syscall_trap
/* do sys_call */
mov ilink, K_SYSCALL_LIMIT
cmp r6, ilink
blo valid_syscall_id
mov_s r0, r6
mov_s r6, K_SYSCALL_BAD
valid_syscall_id:
/* create a sys call frame
* caller regs (r0 - 12) are saved in _create_irq_stack_frame
* ok to use them later
*/
_create_irq_stack_frame
_save_exc_regs_into_stack
/* exc return and do sys call in kernel mode,
* so need to clear U bit, r0 is already loaded
* with ERSTATUS in _save_exc_regs_into_stack
*/
bclr r0, r0, _ARC_V2_STATUS32_U_BIT
sr r0, [_ARC_V2_ERSTATUS]
mov_s r0, _arc_do_syscall
sr r0, [_ARC_V2_ERET]
rtie
_do_non_syscall_trap:
#endif /* CONFIG_USERSPACE */
b _exc_entry