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Merge pull request #14868 from bergzand/pr/fe310/irq_trap_entry_optimize

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fe310: Merge and optimize trap_entry with irq_arch
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Alexandre Abadie 2020-08-28 15:04:14 +02:00 committed by GitHub
commit d369eff042
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2 changed files with 147 additions and 129 deletions
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114
cpu/fe310/intr.S
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@ -1,114 +0,0 @@
/*
* Copyright (C) 2017, 2019 JP Bonn, Ken Rabold
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
#include "vendor/encoding.h"
#include "context_frame.h"
.section .text.entry
.align 2
.global trap_entry
trap_entry:
/* Save registers to stack */
addi sp, sp, -CONTEXT_FRAME_SIZE
sw s0, s0_OFFSET(sp)
sw s1, s1_OFFSET(sp)
sw s2, s2_OFFSET(sp)
sw s3, s3_OFFSET(sp)
sw s4, s4_OFFSET(sp)
sw s5, s5_OFFSET(sp)
sw s6, s6_OFFSET(sp)
sw s7, s7_OFFSET(sp)
sw s8, s8_OFFSET(sp)
sw s9, s9_OFFSET(sp)
sw s10, s10_OFFSET(sp)
sw s11, s11_OFFSET(sp)
sw ra, ra_OFFSET(sp)
sw t0, t0_OFFSET(sp)
sw t1, t1_OFFSET(sp)
sw t2, t2_OFFSET(sp)
sw t3, t3_OFFSET(sp)
sw t4, t4_OFFSET(sp)
sw t5, t5_OFFSET(sp)
sw t6, t6_OFFSET(sp)
sw a0, a0_OFFSET(sp)
sw a1, a1_OFFSET(sp)
sw a2, a2_OFFSET(sp)
sw a3, a3_OFFSET(sp)
sw a4, a4_OFFSET(sp)
sw a5, a5_OFFSET(sp)
sw a6, a6_OFFSET(sp)
sw a7, a7_OFFSET(sp)
/* Get the interrupt cause, PC, and address */
csrr a0, mcause
csrr a1, mepc
csrr a2, mtval
/* Save return PC in stack frame */
sw a1, pc_OFFSET(sp)
/* Get the active thread (could be NULL) */
lw tp, sched_active_thread
beqz tp, null_thread
/* Save stack pointer of current thread */
sw sp, SP_OFFSET_IN_THREAD(tp)
null_thread:
/* Switch to ISR stack. Interrupts are not nested so use fixed
* starting address and just abandon stack when finished. */
la sp, _sp
/* Call handle_trap with MCAUSE and MEPC register value as args */
call handle_trap
/* Get the active thread (guaranteed to be non NULL) */
lw tp, sched_active_thread
/* Load the thread SP of scheduled thread */
lw sp, SP_OFFSET_IN_THREAD(tp)
/* Set return PC */
lw a1, pc_OFFSET(sp)
csrw mepc, a1
/* Restore registers from stack */
lw s0, s0_OFFSET(sp)
lw s1, s1_OFFSET(sp)
lw s2, s2_OFFSET(sp)
lw s3, s3_OFFSET(sp)
lw s4, s4_OFFSET(sp)
lw s5, s5_OFFSET(sp)
lw s6, s6_OFFSET(sp)
lw s7, s7_OFFSET(sp)
lw s8, s8_OFFSET(sp)
lw s9, s9_OFFSET(sp)
lw s10, s10_OFFSET(sp)
lw s11, s11_OFFSET(sp)
lw ra, ra_OFFSET(sp)
lw t0, t0_OFFSET(sp)
lw t1, t1_OFFSET(sp)
lw t2, t2_OFFSET(sp)
lw t3, t3_OFFSET(sp)
lw t4, t4_OFFSET(sp)
lw t5, t5_OFFSET(sp)
lw t6, t6_OFFSET(sp)
lw a0, a0_OFFSET(sp)
lw a1, a1_OFFSET(sp)
lw a2, a2_OFFSET(sp)
lw a3, a3_OFFSET(sp)
lw a4, a4_OFFSET(sp)
lw a5, a5_OFFSET(sp)
lw a6, a6_OFFSET(sp)
lw a7, a7_OFFSET(sp)
addi sp, sp, CONTEXT_FRAME_SIZE
mret

162
cpu/fe310/irq_arch.c
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@ -21,7 +21,9 @@
#include <assert.h> #include <assert.h>
#include <inttypes.h> #include <inttypes.h>
#include "macros/xtstr.h"
#include "cpu.h" #include "cpu.h"
#include "context_frame.h"
#include "irq.h" #include "irq.h"
#include "irq_arch.h" #include "irq_arch.h"
#include "panic.h" #include "panic.h"
@ -42,7 +44,7 @@ static external_isr_ptr_t _ext_isrs[PLIC_NUM_INTERRUPTS];
/** /**
* @brief ISR trap vector * @brief ISR trap vector
*/ */
void trap_entry(void); static void trap_entry(void);
/** /**
* @brief Timer ISR * @brief Timer ISR
@ -95,12 +97,8 @@ void external_isr(void)
/** /**
* @brief Global trap and interrupt handler * @brief Global trap and interrupt handler
*/ */
void handle_trap(unsigned int mcause, unsigned int mepc, unsigned int mtval) void handle_trap(uint32_t mcause)
{ {
#ifndef DEVELHELP
(void) mepc;
(void) mtval;
#endif
/* Tell RIOT to set sched_context_switch_request instead of /* Tell RIOT to set sched_context_switch_request instead of
* calling thread_yield(). */ * calling thread_yield(). */
fe310_in_isr = 1; fe310_in_isr = 1;
@ -135,19 +133,153 @@ void handle_trap(unsigned int mcause, unsigned int mepc, unsigned int mtval)
else { else {
#ifdef DEVELHELP #ifdef DEVELHELP
printf("Unhandled trap:\n"); printf("Unhandled trap:\n");
printf(" mcause: 0x%08x\n", mcause); printf(" mcause: 0x%"PRIx32"\n", mcause);
printf(" mepc: 0x%08x\n", mepc); printf(" mepc: 0x%"PRIx32"\n", read_csr(mepc));
printf(" mtval: 0x%08x\n", mtval); printf(" mtval: 0x%"PRIx32"\n", read_csr(mtval));
#endif #endif
/* Unknown trap */ /* Unknown trap */
core_panic(PANIC_GENERAL_ERROR, "Unhandled trap"); core_panic(PANIC_GENERAL_ERROR, "Unhandled trap");
} }
/* Check if context change was requested */
if (sched_context_switch_request) {
sched_run();
}
/* ISR done - no more changes to thread states */ /* ISR done - no more changes to thread states */
fe310_in_isr = 0; fe310_in_isr = 0;
} }
/* Marking this as interrupt to ensure an mret at the end, provided by the
* compiler. Aligned to 4-byte boundary as per RISC-V spec */
static void __attribute((aligned(4))) __attribute__((interrupt)) trap_entry(void) {
__asm__ volatile (
"addi sp, sp, -"XTSTR(CONTEXT_FRAME_SIZE)" \n"
/* Save caller-saved registers */
"sw ra, "XTSTR(ra_OFFSET)"(sp) \n"
"sw t0, "XTSTR(t0_OFFSET)"(sp) \n"
"sw t1, "XTSTR(t1_OFFSET)"(sp) \n"
"sw t2, "XTSTR(t2_OFFSET)"(sp) \n"
"sw t3, "XTSTR(t3_OFFSET)"(sp) \n"
"sw t4, "XTSTR(t4_OFFSET)"(sp) \n"
"sw t5, "XTSTR(t5_OFFSET)"(sp) \n"
"sw t6, "XTSTR(t6_OFFSET)"(sp) \n"
"sw a0, "XTSTR(a0_OFFSET)"(sp) \n"
"sw a1, "XTSTR(a1_OFFSET)"(sp) \n"
"sw a2, "XTSTR(a2_OFFSET)"(sp) \n"
"sw a3, "XTSTR(a3_OFFSET)"(sp) \n"
"sw a4, "XTSTR(a4_OFFSET)"(sp) \n"
"sw a5, "XTSTR(a5_OFFSET)"(sp) \n"
"sw a6, "XTSTR(a6_OFFSET)"(sp) \n"
"sw a7, "XTSTR(a7_OFFSET)"(sp) \n"
/* Save s0 and s1 extra for the active thread and the stack ptr */
"sw s0, "XTSTR(s0_OFFSET)"(sp) \n"
"sw s1, "XTSTR(s1_OFFSET)"(sp) \n"
/* Save the user stack ptr */
"mv s0, sp \n"
/* Load exception stack ptr */
"la sp, _sp \n"
/* Get the interrupt cause */
"csrr a0, mcause \n"
/* Call trap handler, a0 contains mcause before, and the return value after
* the call */
"call handle_trap \n"
/* Load the sched_context_switch_request */
"lw a0, sched_context_switch_request \n"
/* And skip the context switch if not requested */
"beqz a0, no_sched \n"
/* Get the previous active thread (could be NULL) */
"lw s1, sched_active_thread \n"
/* Run the scheduler */
"call sched_run \n"
"no_sched: \n"
/* Restore the thread stack pointer and check if a new thread must be
* scheduled */
"mv sp, s0 \n"
/* No context switch required, shortcut to restore. a0 contains the return
* value of sched_run, or the sched_context_switch_request if the sched_run
* was skipped */
"beqz a0, no_switch \n"
/* Skips the rest of the save if no active thread */
"beqz s1, null_thread \n"
/* Store s2-s11 */
"sw s2, "XTSTR(s2_OFFSET)"(sp) \n"
"sw s3, "XTSTR(s3_OFFSET)"(sp) \n"
"sw s4, "XTSTR(s4_OFFSET)"(sp) \n"
"sw s5, "XTSTR(s5_OFFSET)"(sp) \n"
"sw s6, "XTSTR(s6_OFFSET)"(sp) \n"
"sw s7, "XTSTR(s7_OFFSET)"(sp) \n"
"sw s8, "XTSTR(s8_OFFSET)"(sp) \n"
"sw s9, "XTSTR(s9_OFFSET)"(sp) \n"
"sw s10, "XTSTR(s10_OFFSET)"(sp) \n"
"sw s11, "XTSTR(s11_OFFSET)"(sp) \n"
/* Grab mepc to save it to the stack */
"csrr s2, mepc \n"
/* Save return PC in stack frame */
"sw s2, "XTSTR(pc_OFFSET)"(sp) \n"
/* Save stack pointer of current thread */
"sw sp, "XTSTR(SP_OFFSET_IN_THREAD)"(s1) \n"
/* Context saving done, from here on the new thread is scheduled */
"null_thread: \n"
/* Get the new active thread (guaranteed to be non NULL) */
"lw s1, sched_active_thread \n"
/* Load the thread SP of scheduled thread */
"lw sp, "XTSTR(SP_OFFSET_IN_THREAD)"(s1) \n"
/* Set return PC to mepc */
"lw a1, "XTSTR(pc_OFFSET)"(sp) \n"
"csrw mepc, a1 \n"
/* restore s2-s11 */
"lw s2, "XTSTR(s2_OFFSET)"(sp) \n"
"lw s3, "XTSTR(s3_OFFSET)"(sp) \n"
"lw s4, "XTSTR(s4_OFFSET)"(sp) \n"
"lw s5, "XTSTR(s5_OFFSET)"(sp) \n"
"lw s6, "XTSTR(s6_OFFSET)"(sp) \n"
"lw s7, "XTSTR(s7_OFFSET)"(sp) \n"
"lw s8, "XTSTR(s8_OFFSET)"(sp) \n"
"lw s9, "XTSTR(s9_OFFSET)"(sp) \n"
"lw s10, "XTSTR(s10_OFFSET)"(sp) \n"
"lw s11, "XTSTR(s11_OFFSET)"(sp) \n"
"no_switch: \n"
/* restore the caller-saved registers */
"lw ra, "XTSTR(ra_OFFSET)"(sp) \n"
"lw t0, "XTSTR(t0_OFFSET)"(sp) \n"
"lw t1, "XTSTR(t1_OFFSET)"(sp) \n"
"lw t2, "XTSTR(t2_OFFSET)"(sp) \n"
"lw t3, "XTSTR(t3_OFFSET)"(sp) \n"
"lw t4, "XTSTR(t4_OFFSET)"(sp) \n"
"lw t5, "XTSTR(t5_OFFSET)"(sp) \n"
"lw t6, "XTSTR(t6_OFFSET)"(sp) \n"
"lw a0, "XTSTR(a0_OFFSET)"(sp) \n"
"lw a1, "XTSTR(a1_OFFSET)"(sp) \n"
"lw a2, "XTSTR(a2_OFFSET)"(sp) \n"
"lw a3, "XTSTR(a3_OFFSET)"(sp) \n"
"lw a4, "XTSTR(a4_OFFSET)"(sp) \n"
"lw a5, "XTSTR(a5_OFFSET)"(sp) \n"
"lw a6, "XTSTR(a6_OFFSET)"(sp) \n"
"lw a7, "XTSTR(a7_OFFSET)"(sp) \n"
"lw s0, "XTSTR(s0_OFFSET)"(sp) \n"
"lw s1, "XTSTR(s1_OFFSET)"(sp) \n"
"addi sp, sp, "XTSTR(CONTEXT_FRAME_SIZE)" \n"
:
:
:
);
}