rt-thread/libcpu/risc-v/nuclei/interrupt_gcc.S

219 lines
5.7 KiB
ArmAsm

/*
* Copyright (c) 2019-Present Nuclei Limited. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2020/03/26 hqfang First Nuclei RISC-V porting implementation
*/
#include "riscv_encoding.h"
.section .text.entry
.align 8
/**
* \brief Global interrupt disabled
* \details
* This function disable global interrupt.
* \remarks
* - All the interrupt requests will be ignored by CPU.
*/
.macro DISABLE_MIE
csrc CSR_MSTATUS, MSTATUS_MIE
.endm
/**
* \brief Macro for context save
* \details
* This macro save ABI defined caller saved registers in the stack.
* \remarks
* - This Macro could use to save context when you enter to interrupt
* or exception
*/
/* Save caller registers */
.macro SAVE_CONTEXT
csrrw sp, CSR_MSCRATCHCSWL, sp
/* Allocate stack space for context saving */
#ifndef __riscv_32e
addi sp, sp, -20*REGBYTES
#else
addi sp, sp, -14*REGBYTES
#endif /* __riscv_32e */
STORE x1, 0*REGBYTES(sp)
STORE x4, 1*REGBYTES(sp)
STORE x5, 2*REGBYTES(sp)
STORE x6, 3*REGBYTES(sp)
STORE x7, 4*REGBYTES(sp)
STORE x10, 5*REGBYTES(sp)
STORE x11, 6*REGBYTES(sp)
STORE x12, 7*REGBYTES(sp)
STORE x13, 8*REGBYTES(sp)
STORE x14, 9*REGBYTES(sp)
STORE x15, 10*REGBYTES(sp)
#ifndef __riscv_32e
STORE x16, 14*REGBYTES(sp)
STORE x17, 15*REGBYTES(sp)
STORE x28, 16*REGBYTES(sp)
STORE x29, 17*REGBYTES(sp)
STORE x30, 18*REGBYTES(sp)
STORE x31, 19*REGBYTES(sp)
#endif /* __riscv_32e */
.endm
/**
* \brief Macro for restore caller registers
* \details
* This macro restore ABI defined caller saved registers from stack.
* \remarks
* - You could use this macro to restore context before you want return
* from interrupt or exeception
*/
/* Restore caller registers */
.macro RESTORE_CONTEXT
LOAD x1, 0*REGBYTES(sp)
LOAD x4, 1*REGBYTES(sp)
LOAD x5, 2*REGBYTES(sp)
LOAD x6, 3*REGBYTES(sp)
LOAD x7, 4*REGBYTES(sp)
LOAD x10, 5*REGBYTES(sp)
LOAD x11, 6*REGBYTES(sp)
LOAD x12, 7*REGBYTES(sp)
LOAD x13, 8*REGBYTES(sp)
LOAD x14, 9*REGBYTES(sp)
LOAD x15, 10*REGBYTES(sp)
#ifndef __riscv_32e
LOAD x16, 14*REGBYTES(sp)
LOAD x17, 15*REGBYTES(sp)
LOAD x28, 16*REGBYTES(sp)
LOAD x29, 17*REGBYTES(sp)
LOAD x30, 18*REGBYTES(sp)
LOAD x31, 19*REGBYTES(sp)
/* De-allocate the stack space */
addi sp, sp, 20*REGBYTES
#else
/* De-allocate the stack space */
addi sp, sp, 14*REGBYTES
#endif /* __riscv_32e */
csrrw sp, CSR_MSCRATCHCSWL, sp
.endm
/**
* \brief Macro for save necessary CSRs to stack
* \details
* This macro store MCAUSE, MEPC, MSUBM to stack.
*/
.macro SAVE_CSR_CONTEXT
/* Store CSR mcause to stack using pushmcause */
csrrwi x0, CSR_PUSHMCAUSE, 11
/* Store CSR mepc to stack using pushmepc */
csrrwi x0, CSR_PUSHMEPC, 12
/* Store CSR msub to stack using pushmsub */
csrrwi x0, CSR_PUSHMSUBM, 13
.endm
/**
* \brief Macro for restore necessary CSRs from stack
* \details
* This macro restore MSUBM, MEPC, MCAUSE from stack.
*/
.macro RESTORE_CSR_CONTEXT
LOAD x5, 13*REGBYTES(sp)
csrw CSR_MSUBM, x5
LOAD x5, 12*REGBYTES(sp)
csrw CSR_MEPC, x5
LOAD x5, 11*REGBYTES(sp)
csrw CSR_MCAUSE, x5
.endm
/**
* \brief Exception/NMI Entry
* \details
* This function provide common entry functions for exception/nmi.
* \remarks
* This function provide a default exception/nmi entry.
* ABI defined caller save register and some CSR registers
* to be saved before enter interrupt handler and be restored before return.
*/
.section .text.trap
/* In CLIC mode, the exeception entry must be 64bytes aligned */
.align 6
.global exc_entry
exc_entry:
/* Save the caller saving registers (context) */
SAVE_CONTEXT
/* Save the necessary CSR registers */
SAVE_CSR_CONTEXT
/*
* Set the exception handler function arguments
* argument 1: mcause value
* argument 2: current stack point(SP) value
*/
csrr a0, mcause
mv a1, sp
/*
* TODO: Call the exception handler function
* By default, the function template is provided in
* system_Device.c, you can adjust it as you want
*/
call core_exception_handler
/* Restore the necessary CSR registers */
RESTORE_CSR_CONTEXT
/* Restore the caller saving registers (context) */
RESTORE_CONTEXT
/* Return to regular code */
mret
/**
* \brief Non-Vector Interrupt Entry
* \details
* This function provide common entry functions for handling
* non-vector interrupts
* \remarks
* This function provide a default non-vector interrupt entry.
* ABI defined caller save register and some CSR registers need
* to be saved before enter interrupt handler and be restored before return.
*/
.section .text.irq
/* In CLIC mode, the interrupt entry must be 4bytes aligned */
.align 2
.global irq_entry
/* This label will be set to MTVT2 register */
irq_entry:
/* Save the caller saving registers (context) */
SAVE_CONTEXT
/* Save the necessary CSR registers */
SAVE_CSR_CONTEXT
/* This special CSR read/write operation, which is actually
* claim the CLIC to find its pending highest ID, if the ID
* is not 0, then automatically enable the mstatus.MIE, and
* jump to its vector-entry-label, and update the link register
*/
csrrw ra, CSR_JALMNXTI, ra
/* Critical section with interrupts disabled */
DISABLE_MIE
/* Restore the necessary CSR registers */
RESTORE_CSR_CONTEXT
/* Restore the caller saving registers (context) */
RESTORE_CONTEXT
/* Return to regular code */
mret
/* Default Handler for Exceptions / Interrupts */
.global default_intexc_handler
Undef_Handler:
default_intexc_handler:
1:
j 1b