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RISCV Add FPU context save (#1250)

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* port: riscv: Split the number of registers and the size of the context

* port: riscv: Create some macros for the FPU context

* port: riscv: Add a couple of macros that store fpu context

* port: riscv: Update the stack init function to include the fpu context size

* port: riscv: Add a chip_specific_extensions file that includes the F extension

* Update dictionary to include some risc-v instructions

* port: riscv: Fix a few typos

* port: riscv: Apply @aggarg's sugestions
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Jonathan Cubides 2025-03-06 19:34:48 +01:00 • committed by GitHub
parent 742729ed29
commit 4d9cd906d3
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4 changed files with 287 additions and 123 deletions
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287
portable/GCC/RISC-V/portContext.h
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@ -29,6 +29,10 @@
#ifndef PORTCONTEXT_H
#define PORTCONTEXT_H
#ifndef configENABLE_FPU
#define configENABLE_FPU 0
#endif
#if __riscv_xlen == 64
#define portWORD_SIZE 8
#define store_x sd
@ -50,65 +54,199 @@
* notes at the top of portASM.S file. */
#ifdef __riscv_32e
#define portCONTEXT_SIZE ( 15 * portWORD_SIZE )
#define portCRITICAL_NESTING_OFFSET 13
#define portMSTATUS_OFFSET 14
#define portCRITICAL_NESTING_OFFSET 14
#else
#define portCONTEXT_SIZE ( 31 * portWORD_SIZE )
#define portCRITICAL_NESTING_OFFSET 29
#define portMSTATUS_OFFSET 30
#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_CONTEXT_SIZE ( portFPU_REG_SIZE * portFPU_REG_COUNT )
#else
#error configENABLE_FPU must not be set to 1 if the hardwar does not have FPU
#endif
#endif
/*-----------------------------------------------------------*/
.extern pxCurrentTCB
.extern xISRStackTop
.extern xCriticalNesting
.extern pxCriticalNesting
.extern xISRStackTop
.extern xCriticalNesting
.extern pxCriticalNesting
/*-----------------------------------------------------------*/
.macro portcontexSAVE_FPU_CONTEXT
addi sp, sp, -( portFPU_CONTEXT_SIZE )
/* Store the FPU registers. */
store_f f0, 2 * portWORD_SIZE( sp )
store_f f1, 3 * portWORD_SIZE( sp )
store_f f2, 4 * portWORD_SIZE( sp )
store_f f3, 5 * portWORD_SIZE( sp )
store_f f4, 6 * portWORD_SIZE( sp )
store_f f5, 7 * portWORD_SIZE( sp )
store_f f6, 8 * portWORD_SIZE( sp )
store_f f7, 9 * portWORD_SIZE( sp )
store_f f8, 10 * portWORD_SIZE( sp )
store_f f9, 11 * portWORD_SIZE( sp )
store_f f10, 12 * portWORD_SIZE( sp )
store_f f11, 13 * portWORD_SIZE( sp )
store_f f12, 14 * portWORD_SIZE( sp )
store_f f13, 15 * portWORD_SIZE( sp )
store_f f14, 16 * portWORD_SIZE( sp )
store_f f15, 17 * portWORD_SIZE( sp )
store_f f16, 18 * portWORD_SIZE( sp )
store_f f17, 19 * portWORD_SIZE( sp )
store_f f18, 20 * portWORD_SIZE( sp )
store_f f19, 21 * portWORD_SIZE( sp )
store_f f20, 22 * portWORD_SIZE( sp )
store_f f21, 23 * portWORD_SIZE( sp )
store_f f22, 24 * portWORD_SIZE( sp )
store_f f23, 25 * portWORD_SIZE( sp )
store_f f24, 26 * portWORD_SIZE( sp )
store_f f25, 27 * portWORD_SIZE( sp )
store_f f26, 28 * portWORD_SIZE( sp )
store_f f27, 29 * portWORD_SIZE( sp )
store_f f28, 30 * portWORD_SIZE( sp )
store_f f29, 31 * portWORD_SIZE( sp )
store_f f30, 32 * portWORD_SIZE( sp )
store_f f31, 33 * portWORD_SIZE( sp )
csrr t0, fcsr
store_x t0, 34 * portWORD_SIZE( sp )
.endm
/*-----------------------------------------------------------*/
.macro portcontextRESTORE_FPU_CONTEXT
/* Restore the FPU registers. */
load_f f0, 2 * portWORD_SIZE( sp )
load_f f1, 3 * portWORD_SIZE( sp )
load_f f2, 4 * portWORD_SIZE( sp )
load_f f3, 5 * portWORD_SIZE( sp )
load_f f4, 6 * portWORD_SIZE( sp )
load_f f5, 7 * portWORD_SIZE( sp )
load_f f6, 8 * portWORD_SIZE( sp )
load_f f7, 9 * portWORD_SIZE( sp )
load_f f8, 10 * portWORD_SIZE( sp )
load_f f9, 11 * portWORD_SIZE( sp )
load_f f10, 12 * portWORD_SIZE( sp )
load_f f11, 13 * portWORD_SIZE( sp )
load_f f12, 14 * portWORD_SIZE( sp )
load_f f13, 15 * portWORD_SIZE( sp )
load_f f14, 16 * portWORD_SIZE( sp )
load_f f15, 17 * portWORD_SIZE( sp )
load_f f16, 18 * portWORD_SIZE( sp )
load_f f17, 19 * portWORD_SIZE( sp )
load_f f18, 20 * portWORD_SIZE( sp )
load_f f19, 21 * portWORD_SIZE( sp )
load_f f20, 22 * portWORD_SIZE( sp )
load_f f21, 23 * portWORD_SIZE( sp )
load_f f22, 24 * portWORD_SIZE( sp )
load_f f23, 25 * portWORD_SIZE( sp )
load_f f24, 26 * portWORD_SIZE( sp )
load_f f25, 27 * portWORD_SIZE( sp )
load_f f26, 28 * portWORD_SIZE( sp )
load_f f27, 29 * portWORD_SIZE( sp )
load_f f28, 30 * portWORD_SIZE( sp )
load_f f29, 31 * portWORD_SIZE( sp )
load_f f30, 32 * portWORD_SIZE( sp )
load_f f31, 33 * portWORD_SIZE( sp )
load_x t0, 34 * portWORD_SIZE( sp )
csrw fcsr, t0
addi sp, sp, ( portFPU_CONTEXT_SIZE )
.endm
/*-----------------------------------------------------------*/
.macro portcontextSAVE_CONTEXT_INTERNAL
addi sp, sp, -portCONTEXT_SIZE
store_x x1, 1 * portWORD_SIZE( sp )
store_x x5, 2 * portWORD_SIZE( sp )
store_x x6, 3 * portWORD_SIZE( sp )
store_x x7, 4 * portWORD_SIZE( sp )
store_x x8, 5 * portWORD_SIZE( sp )
store_x x9, 6 * portWORD_SIZE( sp )
store_x x10, 7 * portWORD_SIZE( sp )
store_x x11, 8 * portWORD_SIZE( sp )
store_x x12, 9 * portWORD_SIZE( sp )
store_x x13, 10 * portWORD_SIZE( sp )
store_x x14, 11 * portWORD_SIZE( sp )
store_x x15, 12 * portWORD_SIZE( sp )
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, 13 * portWORD_SIZE( sp )
store_x x17, 14 * portWORD_SIZE( sp )
store_x x18, 15 * portWORD_SIZE( sp )
store_x x19, 16 * portWORD_SIZE( sp )
store_x x20, 17 * portWORD_SIZE( sp )
store_x x21, 18 * portWORD_SIZE( sp )
store_x x22, 19 * portWORD_SIZE( sp )
store_x x23, 20 * portWORD_SIZE( sp )
store_x x24, 21 * portWORD_SIZE( sp )
store_x x25, 22 * portWORD_SIZE( sp )
store_x x26, 23 * portWORD_SIZE( sp )
store_x x27, 24 * portWORD_SIZE( sp )
store_x x28, 25 * portWORD_SIZE( sp )
store_x x29, 26 * portWORD_SIZE( sp )
store_x x30, 27 * portWORD_SIZE( sp )
store_x x31, 28 * portWORD_SIZE( sp )
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. */
csrr t0, mstatus /* Required for MPIE bit. */
store_x t0, portMSTATUS_OFFSET * portWORD_SIZE( sp )
portcontexSAVE_FPU_CONTEXT
1:
#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, 2f
li t1, ~MSTATUS_FS_MASK
and t0, t0, t1
li t1, MSTATUS_FS_CLEAN
or t0, t0, t1
csrw mstatus, t0
2:
#endif
load_x t0, pxCurrentTCB /* Load pxCurrentTCB. */
store_x sp, 0 ( t0 ) /* Write sp to first TCB member. */
@ -142,46 +280,57 @@ load_x sp, 0 ( t1 ) /* Read sp from first TCB member. */
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
/* Load mstatus with the interrupt enable bits used by the task. */
load_x t0, portMSTATUS_OFFSET * portWORD_SIZE( sp )
csrw mstatus, t0 /* Required for MPIE bit. */
#if( configENABLE_FPU == 1 )
csrr t0, mstatus
srl t1, t0, MSTATUS_FS_OFFSET
andi t1, t1, 3
addi t2, x0, 3
bne t1, t2, 3f /* If FPU status is not dirty, do not restore FPU registers. */
portcontextRESTORE_FPU_CONTEXT
3:
#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, 1 * portWORD_SIZE( sp )
load_x x5, 2 * portWORD_SIZE( sp )
load_x x6, 3 * portWORD_SIZE( sp )
load_x x7, 4 * portWORD_SIZE( sp )
load_x x8, 5 * portWORD_SIZE( sp )
load_x x9, 6 * portWORD_SIZE( sp )
load_x x10, 7 * portWORD_SIZE( sp )
load_x x11, 8 * portWORD_SIZE( sp )
load_x x12, 9 * portWORD_SIZE( sp )
load_x x13, 10 * portWORD_SIZE( sp )
load_x x14, 11 * portWORD_SIZE( sp )
load_x x15, 12 * portWORD_SIZE( sp )
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, 13 * portWORD_SIZE( sp )
load_x x17, 14 * portWORD_SIZE( sp )
load_x x18, 15 * portWORD_SIZE( sp )
load_x x19, 16 * portWORD_SIZE( sp )
load_x x20, 17 * portWORD_SIZE( sp )
load_x x21, 18 * portWORD_SIZE( sp )
load_x x22, 19 * portWORD_SIZE( sp )
load_x x23, 20 * portWORD_SIZE( sp )
load_x x24, 21 * portWORD_SIZE( sp )
load_x x25, 22 * portWORD_SIZE( sp )
load_x x26, 23 * portWORD_SIZE( sp )
load_x x27, 24 * portWORD_SIZE( sp )
load_x x28, 25 * portWORD_SIZE( sp )
load_x x29, 26 * portWORD_SIZE( sp )
load_x x30, 27 * portWORD_SIZE( sp )
load_x x31, 28 * portWORD_SIZE( sp )
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