| /* |
| * Copyright (c) 2014 Wind River Systems, Inc. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| /** |
| * @file |
| * @brief Fault handlers for ARCv2 |
| * |
| * Fault handlers for ARCv2 processors. |
| */ |
| |
| #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) |
| |
| .balign 4 |
| 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 |
| |
| /* |
| * @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, ___isf_t_status32_OFFSET] |
| lr r0,[_ARC_V2_ERET] |
| st_s r0, [sp, ___isf_t_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, ___isf_t_status32_OFFSET] |
| lr r0,[_ARC_V2_ERET] |
| st_s r0, [sp, ___isf_t_pc_OFFSET] /* eret into pc */ |
| |
| jl _irq_do_offload |
| |
| mov_s r1, _kernel |
| ld_s r2, [r1, _kernel_offset_to_current] |
| /* 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 |
| |
| .balign 4 |
| _trap_check_for_swap: |
| /* |
| * Non-preemptible thread ? Do not schedule (see explanation of |
| * preempt field in kernel_struct.h). |
| */ |
| ldh_s r0, [r2, _thread_offset_to_preempt] |
| brhs r0, _NON_PREEMPT_THRESHOLD, _trap_return |
| |
| /* check if the current thread needs to be rescheduled */ |
| ld_s r0, [r1, _kernel_offset_to_ready_q_cache] |
| breq r0, r2, _trap_return |
| |
| _save_callee_saved_regs |
| |
| st _CAUSE_RIRQ, [r2, _thread_offset_to_relinquish_cause] |
| /* note: Ok to use _CAUSE_RIRQ since everything is saved */ |
| |
| ld_s r2, [r1, _kernel_offset_to_ready_q_cache] |
| st_s r2, [r1, _kernel_offset_to_current] |
| |
| /* 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 */ |