zephyr/arch/arc/core/fault_s.S

233 lines
5.9 KiB
ArmAsm

/*
* Copyright (c) 2014 Wind River Systems, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file
* @brief Fault handlers for ARCv2
*
* Fault handlers for ARCv2 processors.
*/
#define _ASMLANGUAGE
#include <toolchain.h>
#include <sections.h>
#include <arch/cpu.h>
#include "swap_macros.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)
SECTION_VAR(BSS, saved_stack_pointer)
.word 0
#if CONFIG_RGF_NUM_BANKS == 1
GDATA(_exception_stack)
SECTION_VAR(NOINIT, _exception_stack)
.space 512
/* note: QUARK_SE_C1000_SS can't afford 512B */
#else
GDATA(_firq_stack)
#endif
#if CONFIG_NUM_IRQ_PRIO_LEVELS == 1
#error "NUM_IRQ_PRIO_LEVELS==1 is not supported."
/* The code below sets bit 1 in AUX_IRQ_ACT and thus requires
* priority 0 and 1 at a minimum. Supporting only 1 priority
* requires a change to this file but also changes to make
* FIRQ optional.
*/
#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)
#ifndef CONFIG_IRQ_OFFLOAD
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_trap)
#endif
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)
/*
* Before invoking exception handler, the kernel switches to an exception
* stack, to save the faulting thread's registers.
* The exception is fatal and all the kernel can do is just print
* a diagnostic message and halt.
*/
#ifdef CONFIG_ARC_STACK_CHECKING
push_s r2
/* disable stack checking */
lr r2, [_ARC_V2_STATUS32]
bclr r2, r2, _ARC_V2_STATUS32_SC_BIT
kflag r2
pop_s r2
#endif
st sp, [saved_stack_pointer]
#if CONFIG_RGF_NUM_BANKS == 1
mov_s sp, _exception_stack
add sp, sp, 512
#else
mov_s sp, _firq_stack
add sp, sp, CONFIG_FIRQ_STACK_SIZE
#endif
/* save caller saved registers */
_create_irq_stack_frame
lr r0,[_ARC_V2_ERSTATUS]
st_s r0, [sp, __tISF_status32_OFFSET]
lr r0,[_ARC_V2_ERET]
st_s r0, [sp, __tISF_pc_OFFSET] /* eret into pc */
jl _Fault
/* if _Fault returns, restore the registers */
_pop_irq_stack_frame
/* now restore the stack */
ld sp,[saved_stack_pointer]
rtie
#ifdef CONFIG_IRQ_OFFLOAD
GTEXT(_irq_do_offload);
SECTION_SUBSEC_FUNC(TEXT,__fault,__ev_trap)
/*
* Before invoking exception handler, the kernel switches to an exception
* stack to save the faulting thread's registers.
* The exception is fatal and all the kernel can do is just print
* a diagnostic message and halt.
*/
#ifdef CONFIG_ARC_STACK_CHECKING
push_s r2
/* disable stack checking */
lr r2, [_ARC_V2_STATUS32]
bclr r2, r2, _ARC_V2_STATUS32_SC_BIT
kflag r2
pop_s r2
#endif
/* save caller saved registers */
_create_irq_stack_frame
lr r0,[_ARC_V2_ERSTATUS]
st_s r0, [sp, __tISF_status32_OFFSET]
lr r0,[_ARC_V2_ERET]
st_s r0, [sp, __tISF_pc_OFFSET] /* eret into pc */
jl _irq_do_offload
mov_s r1, _nanokernel
ld_s r2, [r1, __tNANO_current_OFFSET]
#if CONFIG_NUM_IRQ_PRIO_LEVELS > 1
/* check if we're a nested interrupt: if so, let the
* interrupted interrupt handle the reschedule
*/
lr r3, [_ARC_V2_AUX_IRQ_ACT]
/* the OS on ARCv2 always runs in kernel mode, so assume bit31 [U] in
* AUX_IRQ_ACT is always 0: if the contents of AUX_IRQ_ACT is 0, it
* means trap was taken from outside an interrupt handler.
* But if it was inside, let that handler do the swap.
*/
breq r3, 0, _trap_check_for_swap
_trap_return:
_pop_irq_stack_frame
rtie
#endif
.balign 4
_trap_check_for_swap:
/* coop thread ? do not schedule */
ld_s r0, [r2, __tTCS_prio_OFFSET]
brlt r0, 0, _trap_return
/* scheduler locked ? do not schedule */
ld_s r0, [r2, __tTCS_sched_locked_OFFSET]
brgt r0, 0, _trap_return
/* check if the current thread needs to be rescheduled */
push_s r2
push_s r1
push_s blink
jl _is_next_thread_current
pop_s blink
pop_s r1
pop_s r2
brne r0, 0, _trap_return
_save_callee_saved_regs
st _CAUSE_RIRQ, [r2, __tTCS_relinquish_cause_OFFSET]
/* note: Ok to use _CAUSE_RIRQ since everything is saved */
/*
* Save needed registers to callee saved ones. It is faster than
* pushing registers to stack. It is possible to do since program has
* just saved them and the calling routine will save them in turn
* if it uses them.
*/
mov_s r13, blink
mov_s r14, r0
mov_s r15, r1
jl _get_next_ready_thread
mov_s r2, r0
mov_s r1, r15
mov_s r0, r14
mov_s blink, r13
st_s r2, [r1, __tNANO_current_OFFSET]
/* clear AE bit to forget this was an exception */
lr r3, [_ARC_V2_STATUS32]
and r3,r3,(~_ARC_V2_STATUS32_AE)
kflag r3
/* pretend lowest priority interrupt happened to use common handler */
lr r3, [_ARC_V2_AUX_IRQ_ACT]
or r3,r3,(1<<(CONFIG_NUM_IRQ_PRIO_LEVELS-1)) /* use lowest */
sr r3, [_ARC_V2_AUX_IRQ_ACT]
/* Assumption: r2 has current thread */
b _rirq_common_interrupt_swap
#endif /* CONFIG_IRQ_OFFLOAD */