FreeRTOS-Kernel/portable/GCC/RISC-V/portContext.h
Jonathan Cubides 0030d609a4
Add support for Vector context save support on RISC-V (#1260)
port: riscv: Add vector context save support
2025-03-27 15:22:22 +05:30

469 lines
16 KiB
C

/*
* FreeRTOS Kernel <DEVELOPMENT BRANCH>
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
#ifndef PORTCONTEXT_H
#define PORTCONTEXT_H
#ifndef configENABLE_FPU
#define configENABLE_FPU 0
#endif
#ifndef configENABLE_VPU
#define configENABLE_VPU 0
#endif
#if __riscv_xlen == 64
#define portWORD_SIZE 8
#define store_x sd
#define load_x ld
#elif __riscv_xlen == 32
#define store_x sw
#define load_x lw
#define portWORD_SIZE 4
#else
#error Assembler did not define __riscv_xlen
#endif
#include "freertos_risc_v_chip_specific_extensions.h"
/* Only the standard core registers are stored by default. Any additional
* registers must be saved by the portasmSAVE_ADDITIONAL_REGISTERS and
* portasmRESTORE_ADDITIONAL_REGISTERS macros - which can be defined in a chip
* specific version of freertos_risc_v_chip_specific_extensions.h. See the
* notes at the top of portASM.S file. */
#ifdef __riscv_32e
#define portCONTEXT_SIZE ( 15 * portWORD_SIZE )
#define portCRITICAL_NESTING_OFFSET 14
#else
#define portCONTEXT_SIZE ( 31 * portWORD_SIZE )
#define portCRITICAL_NESTING_OFFSET 30
#endif
#if ( configENABLE_FPU == 1 )
/* Bit [14:13] in the mstatus encode the status of FPU state which is one of
* the following values:
* 1. Value: 0, Meaning: Off.
* 2. Value: 1, Meaning: Initial.
* 3. Value: 2, Meaning: Clean.
* 4. Value: 3, Meaning: Dirty.
*/
#define MSTATUS_FS_MASK 0x6000
#define MSTATUS_FS_INITIAL 0x2000
#define MSTATUS_FS_CLEAN 0x4000
#define MSTATUS_FS_DIRTY 0x6000
#define MSTATUS_FS_OFFSET 13
#ifdef __riscv_fdiv
#if __riscv_flen == 32
#define load_f flw
#define store_f fsw
#elif __riscv_flen == 64
#define load_f fld
#define store_f fsd
#else
#error Assembler did not define __riscv_flen
#endif
#define portFPU_REG_SIZE ( __riscv_flen / 8 )
#define portFPU_REG_COUNT 33 /* 32 Floating point registers plus one CSR. */
#define portFPU_REG_OFFSET( regIndex ) ( ( 2 * portWORD_SIZE ) + ( regIndex * portFPU_REG_SIZE ) )
#define portFPU_CONTEXT_SIZE ( portFPU_REG_SIZE * portFPU_REG_COUNT )
#else
#error configENABLE_FPU must not be set to 1 if the hardware does not have FPU
#endif
#endif
#if ( configENABLE_VPU == 1 )
/* Bit [10:9] in the mstatus encode the status of VPU state which is one of
* the following values:
* 1. Value: 0, Meaning: Off.
* 2. Value: 1, Meaning: Initial.
* 3. Value: 2, Meaning: Clean.
* 4. Value: 3, Meaning: Dirty.
*/
#define MSTATUS_VS_MASK 0x600
#define MSTATUS_VS_INITIAL 0x200
#define MSTATUS_VS_CLEAN 0x400
#define MSTATUS_VS_DIRTY 0x600
#define MSTATUS_VS_OFFSET 9
#ifndef __riscv_vector
#error configENABLE_VPU must not be set to 1 if the hardware does not have VPU
#endif
#endif
/*-----------------------------------------------------------*/
.extern pxCurrentTCB
.extern xISRStackTop
.extern xCriticalNesting
.extern pxCriticalNesting
/*-----------------------------------------------------------*/
.macro portcontexSAVE_FPU_CONTEXT
addi sp, sp, -( portFPU_CONTEXT_SIZE )
/* Store the FPU registers. */
store_f f0, portFPU_REG_OFFSET( 0 )( sp )
store_f f1, portFPU_REG_OFFSET( 1 )( sp )
store_f f2, portFPU_REG_OFFSET( 2 )( sp )
store_f f3, portFPU_REG_OFFSET( 3 )( sp )
store_f f4, portFPU_REG_OFFSET( 4 )( sp )
store_f f5, portFPU_REG_OFFSET( 5 )( sp )
store_f f6, portFPU_REG_OFFSET( 6 )( sp )
store_f f7, portFPU_REG_OFFSET( 7 )( sp )
store_f f8, portFPU_REG_OFFSET( 8 )( sp )
store_f f9, portFPU_REG_OFFSET( 9 )( sp )
store_f f10, portFPU_REG_OFFSET( 10 )( sp )
store_f f11, portFPU_REG_OFFSET( 11 )( sp )
store_f f12, portFPU_REG_OFFSET( 12 )( sp )
store_f f13, portFPU_REG_OFFSET( 13 )( sp )
store_f f14, portFPU_REG_OFFSET( 14 )( sp )
store_f f15, portFPU_REG_OFFSET( 15 )( sp )
store_f f16, portFPU_REG_OFFSET( 16 )( sp )
store_f f17, portFPU_REG_OFFSET( 17 )( sp )
store_f f18, portFPU_REG_OFFSET( 18 )( sp )
store_f f19, portFPU_REG_OFFSET( 19 )( sp )
store_f f20, portFPU_REG_OFFSET( 20 )( sp )
store_f f21, portFPU_REG_OFFSET( 21 )( sp )
store_f f22, portFPU_REG_OFFSET( 22 )( sp )
store_f f23, portFPU_REG_OFFSET( 23 )( sp )
store_f f24, portFPU_REG_OFFSET( 24 )( sp )
store_f f25, portFPU_REG_OFFSET( 25 )( sp )
store_f f26, portFPU_REG_OFFSET( 26 )( sp )
store_f f27, portFPU_REG_OFFSET( 27 )( sp )
store_f f28, portFPU_REG_OFFSET( 28 )( sp )
store_f f29, portFPU_REG_OFFSET( 29 )( sp )
store_f f30, portFPU_REG_OFFSET( 30 )( sp )
store_f f31, portFPU_REG_OFFSET( 31 )( sp )
csrr t0, fcsr
store_x t0, portFPU_REG_OFFSET( 32 )( sp )
.endm
/*-----------------------------------------------------------*/
.macro portcontextRESTORE_FPU_CONTEXT
/* Restore the FPU registers. */
load_f f0, portFPU_REG_OFFSET( 0 )( sp )
load_f f1, portFPU_REG_OFFSET( 1 )( sp )
load_f f2, portFPU_REG_OFFSET( 2 )( sp )
load_f f3, portFPU_REG_OFFSET( 3 )( sp )
load_f f4, portFPU_REG_OFFSET( 4 )( sp )
load_f f5, portFPU_REG_OFFSET( 5 )( sp )
load_f f6, portFPU_REG_OFFSET( 6 )( sp )
load_f f7, portFPU_REG_OFFSET( 7 )( sp )
load_f f8, portFPU_REG_OFFSET( 8 )( sp )
load_f f9, portFPU_REG_OFFSET( 9 )( sp )
load_f f10, portFPU_REG_OFFSET( 10 )( sp )
load_f f11, portFPU_REG_OFFSET( 11 )( sp )
load_f f12, portFPU_REG_OFFSET( 12 )( sp )
load_f f13, portFPU_REG_OFFSET( 13 )( sp )
load_f f14, portFPU_REG_OFFSET( 14 )( sp )
load_f f15, portFPU_REG_OFFSET( 15 )( sp )
load_f f16, portFPU_REG_OFFSET( 16 )( sp )
load_f f17, portFPU_REG_OFFSET( 17 )( sp )
load_f f18, portFPU_REG_OFFSET( 18 )( sp )
load_f f19, portFPU_REG_OFFSET( 19 )( sp )
load_f f20, portFPU_REG_OFFSET( 20 )( sp )
load_f f21, portFPU_REG_OFFSET( 21 )( sp )
load_f f22, portFPU_REG_OFFSET( 22 )( sp )
load_f f23, portFPU_REG_OFFSET( 23 )( sp )
load_f f24, portFPU_REG_OFFSET( 24 )( sp )
load_f f25, portFPU_REG_OFFSET( 25 )( sp )
load_f f26, portFPU_REG_OFFSET( 26 )( sp )
load_f f27, portFPU_REG_OFFSET( 27 )( sp )
load_f f28, portFPU_REG_OFFSET( 28 )( sp )
load_f f29, portFPU_REG_OFFSET( 29 )( sp )
load_f f30, portFPU_REG_OFFSET( 30 )( sp )
load_f f31, portFPU_REG_OFFSET( 31 )( sp )
load_x t0, portFPU_REG_OFFSET( 32 )( sp )
csrw fcsr, t0
addi sp, sp, ( portFPU_CONTEXT_SIZE )
.endm
/*-----------------------------------------------------------*/
.macro portcontexSAVE_VPU_CONTEXT
/* Un-reserve the space reserved for mstatus and epc. */
add sp, sp, ( 2 * portWORD_SIZE )
csrr t0, vlenb /* t0 = vlenb. vlenb is the length of each vector register in bytes. */
slli t0, t0, 3 /* t0 = vlenb * 8. t0 now contains the space required to store 8 vector registers. */
neg t0, t0
/* Store the vector registers in group of 8. */
add sp, sp, t0
vs8r.v v0, (sp) /* Store v0-v7. */
add sp, sp, t0
vs8r.v v8, (sp) /* Store v8-v15. */
add sp, sp, t0
vs8r.v v16, (sp) /* Store v16-v23. */
add sp, sp, t0
vs8r.v v24, (sp) /* Store v24-v31. */
/* Store the VPU CSRs. */
addi sp, sp, -( 4 * portWORD_SIZE )
csrr t0, vstart
store_x t0, 0 * portWORD_SIZE( sp )
csrr t0, vcsr
store_x t0, 1 * portWORD_SIZE( sp )
csrr t0, vl
store_x t0, 2 * portWORD_SIZE( sp )
csrr t0, vtype
store_x t0, 3 * portWORD_SIZE( sp )
/* Re-reserve the space for mstatus and epc. */
add sp, sp, -( 2 * portWORD_SIZE )
.endm
/*-----------------------------------------------------------*/
.macro portcontextRESTORE_VPU_CONTEXT
/* Un-reserve the space reserved for mstatus and epc. */
add sp, sp, ( 2 * portWORD_SIZE )
/* Restore the VPU CSRs. */
load_x t0, 0 * portWORD_SIZE( sp )
csrw vstart, t0
load_x t0, 1 * portWORD_SIZE( sp )
csrw vcsr, t0
load_x t0, 2 * portWORD_SIZE( sp )
load_x t1, 3 * portWORD_SIZE( sp )
vsetvl x0, t0, t1 /* vlen and vtype can only be updated by using vset*vl* instructions. */
addi sp, sp, ( 4 * portWORD_SIZE )
csrr t0, vlenb /* t0 = vlenb. vlenb is the length of each vector register in bytes. */
slli t0, t0, 3 /* t0 = vlenb * 8. t0 now contains the space required to store 8 vector registers. */
/* Restore the vector registers. */
vl8r.v v24, (sp)
add sp, sp, t0
vl8r.v v16, (sp)
add sp, sp, t0
vl8r.v v8, (sp)
add sp, sp, t0
vl8r.v v0, (sp)
add sp, sp, t0
/* Re-reserve the space for mstatus and epc. */
add sp, sp, -( 2 * portWORD_SIZE )
.endm
/*-----------------------------------------------------------*/
.macro portcontextSAVE_CONTEXT_INTERNAL
addi sp, sp, -portCONTEXT_SIZE
store_x x1, 2 * portWORD_SIZE( sp )
store_x x5, 3 * portWORD_SIZE( sp )
store_x x6, 4 * portWORD_SIZE( sp )
store_x x7, 5 * portWORD_SIZE( sp )
store_x x8, 6 * portWORD_SIZE( sp )
store_x x9, 7 * portWORD_SIZE( sp )
store_x x10, 8 * portWORD_SIZE( sp )
store_x x11, 9 * portWORD_SIZE( sp )
store_x x12, 10 * portWORD_SIZE( sp )
store_x x13, 11 * portWORD_SIZE( sp )
store_x x14, 12 * portWORD_SIZE( sp )
store_x x15, 13 * portWORD_SIZE( sp )
#ifndef __riscv_32e
store_x x16, 14 * portWORD_SIZE( sp )
store_x x17, 15 * portWORD_SIZE( sp )
store_x x18, 16 * portWORD_SIZE( sp )
store_x x19, 17 * portWORD_SIZE( sp )
store_x x20, 18 * portWORD_SIZE( sp )
store_x x21, 19 * portWORD_SIZE( sp )
store_x x22, 20 * portWORD_SIZE( sp )
store_x x23, 21 * portWORD_SIZE( sp )
store_x x24, 22 * portWORD_SIZE( sp )
store_x x25, 23 * portWORD_SIZE( sp )
store_x x26, 24 * portWORD_SIZE( sp )
store_x x27, 25 * portWORD_SIZE( sp )
store_x x28, 26 * portWORD_SIZE( sp )
store_x x29, 27 * portWORD_SIZE( sp )
store_x x30, 28 * portWORD_SIZE( sp )
store_x x31, 29 * portWORD_SIZE( sp )
#endif /* ifndef __riscv_32e */
load_x t0, xCriticalNesting /* Load the value of xCriticalNesting into t0. */
store_x t0, portCRITICAL_NESTING_OFFSET * portWORD_SIZE( sp ) /* Store the critical nesting value to the stack. */
#if( configENABLE_FPU == 1 )
csrr t0, mstatus
srl t1, t0, MSTATUS_FS_OFFSET
andi t1, t1, 3
addi t2, x0, 3
bne t1, t2, 1f /* If FPU status is not dirty, do not save FPU registers. */
portcontexSAVE_FPU_CONTEXT
1:
#endif
#if( configENABLE_VPU == 1 )
csrr t0, mstatus
srl t1, t0, MSTATUS_VS_OFFSET
andi t1, t1, 3
addi t2, x0, 3
bne t1, t2, 2f /* If VPU status is not dirty, do not save FPU registers. */
portcontexSAVE_VPU_CONTEXT
2:
#endif
portasmSAVE_ADDITIONAL_REGISTERS /* Defined in freertos_risc_v_chip_specific_extensions.h to save any registers unique to the RISC-V implementation. */
csrr t0, mstatus
store_x t0, 1 * portWORD_SIZE( sp )
#if( configENABLE_FPU == 1 )
/* Mark the FPU as clean, if it was dirty and we saved FPU registers. */
srl t1, t0, MSTATUS_FS_OFFSET
andi t1, t1, 3
addi t2, x0, 3
bne t1, t2, 3f
li t1, ~MSTATUS_FS_MASK
and t0, t0, t1
li t1, MSTATUS_FS_CLEAN
or t0, t0, t1
csrw mstatus, t0
3:
#endif
#if( configENABLE_VPU == 1 )
/* Mark the VPU as clean, if it was dirty and we saved VPU registers. */
srl t1, t0, MSTATUS_VS_OFFSET
andi t1, t1, 3
addi t2, x0, 3
bne t1, t2, 4f
li t1, ~MSTATUS_VS_MASK
and t0, t0, t1
li t1, MSTATUS_VS_CLEAN
or t0, t0, t1
csrw mstatus, t0
4:
#endif
load_x t0, pxCurrentTCB /* Load pxCurrentTCB. */
store_x sp, 0 ( t0 ) /* Write sp to first TCB member. */
.endm
/*-----------------------------------------------------------*/
.macro portcontextSAVE_EXCEPTION_CONTEXT
portcontextSAVE_CONTEXT_INTERNAL
csrr a0, mcause
csrr a1, mepc
addi a1, a1, 4 /* Synchronous so update exception return address to the instruction after the instruction that generated the exception. */
store_x a1, 0 ( sp ) /* Save updated exception return address. */
load_x sp, xISRStackTop /* Switch to ISR stack. */
.endm
/*-----------------------------------------------------------*/
.macro portcontextSAVE_INTERRUPT_CONTEXT
portcontextSAVE_CONTEXT_INTERNAL
csrr a0, mcause
csrr a1, mepc
store_x a1, 0 ( sp ) /* Asynchronous interrupt so save unmodified exception return address. */
load_x sp, xISRStackTop /* Switch to ISR stack. */
.endm
/*-----------------------------------------------------------*/
.macro portcontextRESTORE_CONTEXT
load_x t1, pxCurrentTCB /* Load pxCurrentTCB. */
load_x sp, 0 ( t1 ) /* Read sp from first TCB member. */
/* Load mepc with the address of the instruction in the task to run next. */
load_x t0, 0 ( sp )
csrw mepc, t0
/* Restore mstatus register. */
load_x t0, 1 * portWORD_SIZE( sp )
csrw mstatus, t0
/* Defined in freertos_risc_v_chip_specific_extensions.h to restore any registers unique to the RISC-V implementation. */
portasmRESTORE_ADDITIONAL_REGISTERS
#if( configENABLE_VPU == 1 )
csrr t0, mstatus
srl t1, t0, MSTATUS_VS_OFFSET
andi t1, t1, 3
addi t2, x0, 3
bne t1, t2, 5f /* If VPU status is not dirty, do not restore VPU registers. */
portcontextRESTORE_VPU_CONTEXT
5:
#endif /* ifdef portasmSTORE_VPU_CONTEXT */
#if( configENABLE_FPU == 1 )
csrr t0, mstatus
srl t1, t0, MSTATUS_FS_OFFSET
andi t1, t1, 3
addi t2, x0, 3
bne t1, t2, 6f /* If FPU status is not dirty, do not restore FPU registers. */
portcontextRESTORE_FPU_CONTEXT
6:
#endif /* ifdef portasmSTORE_FPU_CONTEXT */
load_x t0, portCRITICAL_NESTING_OFFSET * portWORD_SIZE( sp ) /* Obtain xCriticalNesting value for this task from task's stack. */
load_x t1, pxCriticalNesting /* Load the address of xCriticalNesting into t1. */
store_x t0, 0 ( t1 ) /* Restore the critical nesting value for this task. */
load_x x1, 2 * portWORD_SIZE( sp )
load_x x5, 3 * portWORD_SIZE( sp )
load_x x6, 4 * portWORD_SIZE( sp )
load_x x7, 5 * portWORD_SIZE( sp )
load_x x8, 6 * portWORD_SIZE( sp )
load_x x9, 7 * portWORD_SIZE( sp )
load_x x10, 8 * portWORD_SIZE( sp )
load_x x11, 9 * portWORD_SIZE( sp )
load_x x12, 10 * portWORD_SIZE( sp )
load_x x13, 11 * portWORD_SIZE( sp )
load_x x14, 12 * portWORD_SIZE( sp )
load_x x15, 13 * portWORD_SIZE( sp )
#ifndef __riscv_32e
load_x x16, 14 * portWORD_SIZE( sp )
load_x x17, 15 * portWORD_SIZE( sp )
load_x x18, 16 * portWORD_SIZE( sp )
load_x x19, 17 * portWORD_SIZE( sp )
load_x x20, 18 * portWORD_SIZE( sp )
load_x x21, 19 * portWORD_SIZE( sp )
load_x x22, 20 * portWORD_SIZE( sp )
load_x x23, 21 * portWORD_SIZE( sp )
load_x x24, 22 * portWORD_SIZE( sp )
load_x x25, 23 * portWORD_SIZE( sp )
load_x x26, 24 * portWORD_SIZE( sp )
load_x x27, 25 * portWORD_SIZE( sp )
load_x x28, 26 * portWORD_SIZE( sp )
load_x x29, 27 * portWORD_SIZE( sp )
load_x x30, 28 * portWORD_SIZE( sp )
load_x x31, 29 * portWORD_SIZE( sp )
#endif /* ifndef __riscv_32e */
addi sp, sp, portCONTEXT_SIZE
mret
.endm
/*-----------------------------------------------------------*/
#endif /* PORTCONTEXT_H */