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arch/riscv: Optimize the syscall performance in kernel mode

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by renaming riscv_dispatch_syscall to sys_callx, so the caller
don't need the immediate step(syscallx->riscv_dispatch_syscall)

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
This commit is contained in:
Xiang Xiao 2022-04-27 02:52:00 +08:00 committed by Petro Karashchenko
parent efce8bd198
commit 1e23799455
5 changed files with 60 additions and 30 deletions
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41
arch/risc-v/include/syscall.h
View file

@ -124,18 +124,6 @@
#define SYS_signal_handler_return (7)
#endif /* !CONFIG_BUILD_FLAT */
#if defined (CONFIG_ARCH_USE_S_MODE) && defined (__KERNEL__)
# define ASM_SYS_CALL \
" addi sp, sp, -16\n" /* Make room */ \
REGSTORE " ra, 0(sp)\n" /* Save ra */ \
" jal ra, riscv_dispatch_syscall\n" /* Dispatch (modifies ra) */ \
REGLOAD " ra, 0(sp)\n" /* Restore ra */ \
" addi sp, sp, 16\n" /* Restore sp */
#else
# define ASM_SYS_CALL \
"ecall"
#endif
/****************************************************************************
* Public Types
****************************************************************************/
@ -162,6 +150,20 @@ extern "C"
#define EXTERN extern
#endif
#if defined(CONFIG_ARCH_USE_S_MODE) && defined(__KERNEL__)
uintptr_t sys_call0(unsigned int nbr);
uintptr_t sys_call1(unsigned int nbr, uintptr_t parm1);
uintptr_t sys_call2(unsigned int nbr, uintptr_t parm1, uintptr_t parm2);
uintptr_t sys_call3(unsigned int nbr, uintptr_t parm1, uintptr_t parm2,
uintptr_t parm3);
uintptr_t sys_call4(unsigned int nbr, uintptr_t parm1, uintptr_t parm2,
uintptr_t parm3, uintptr_t parm4);
uintptr_t sys_call5(unsigned int nbr, uintptr_t parm1, uintptr_t parm2,
uintptr_t parm3, uintptr_t parm4, uintptr_t parm5);
uintptr_t sys_call6(unsigned int nbr, uintptr_t parm1, uintptr_t parm2,
uintptr_t parm3, uintptr_t parm4, uintptr_t parm5,
uintptr_t parm6);
#else
/****************************************************************************
* Name: sys_call0
*
@ -176,7 +178,7 @@ static inline uintptr_t sys_call0(unsigned int nbr)
asm volatile
(
ASM_SYS_CALL
"ecall"
:: "r"(r0)
: "memory"
);
@ -201,7 +203,7 @@ static inline uintptr_t sys_call1(unsigned int nbr, uintptr_t parm1)
asm volatile
(
ASM_SYS_CALL
"ecall"
:: "r"(r0), "r"(r1)
: "memory"
);
@ -228,7 +230,7 @@ static inline uintptr_t sys_call2(unsigned int nbr, uintptr_t parm1,
asm volatile
(
ASM_SYS_CALL
"ecall"
:: "r"(r0), "r"(r1), "r"(r2)
: "memory"
);
@ -256,7 +258,7 @@ static inline uintptr_t sys_call3(unsigned int nbr, uintptr_t parm1,
asm volatile
(
ASM_SYS_CALL
"ecall"
:: "r"(r0), "r"(r1), "r"(r2), "r"(r3)
: "memory"
);
@ -286,7 +288,7 @@ static inline uintptr_t sys_call4(unsigned int nbr, uintptr_t parm1,
asm volatile
(
ASM_SYS_CALL
"ecall"
:: "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4)
: "memory"
);
@ -317,7 +319,7 @@ static inline uintptr_t sys_call5(unsigned int nbr, uintptr_t parm1,
asm volatile
(
ASM_SYS_CALL
"ecall"
:: "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r5)
: "memory"
);
@ -350,7 +352,7 @@ static inline uintptr_t sys_call6(unsigned int nbr, uintptr_t parm1,
asm volatile
(
ASM_SYS_CALL
"ecall"
:: "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r5), "r"(r6)
: "memory"
);
@ -359,6 +361,7 @@ static inline uintptr_t sys_call6(unsigned int nbr, uintptr_t parm1,
return r0;
}
#endif
#undef EXTERN
#ifdef __cplusplus

1
arch/risc-v/src/common/riscv_internal.h
View file

@ -323,7 +323,6 @@ uintptr_t riscv_mhartid(void);
/* If kernel runs in Supervisor mode, a system call trampoline is needed */
#ifdef CONFIG_ARCH_USE_S_MODE
void riscv_dispatch_syscall(void) noreturn_function;
void *riscv_perform_syscall(uintptr_t *regs);
#endif

4
arch/risc-v/src/common/riscv_swint.c
View file

@ -130,9 +130,9 @@ static void dispatch_syscall(void)
"mv a2, a0\n" /* a2=Save return value in a0 */
"li a0, 3\n" /* a0=SYS_syscall_return (3) */
#ifdef CONFIG_ARCH_USE_S_MODE
"j riscv_dispatch_syscall" /* Return from the syscall */
"j sys_call2" /* Return from the syscall */
#else
" ecall" /* Return from the syscall */
"ecall" /* Return from the syscall */
#endif
);
}

2
arch/risc-v/src/common/supervisor/Make.defs
View file

@ -20,7 +20,7 @@
# If the NuttX kernel runs in S-mode
CMN_ASRCS += riscv_dispatch_syscall.S
CMN_ASRCS += riscv_syscall.S
CMN_CSRCS += riscv_perform_syscall.c
CMN_CSRCS += riscv_percpu.c riscv_sbi.c

42
arch/risc-v/src/common/supervisor/riscv_dispatch_syscall.S → arch/risc-v/src/common/supervisor/riscv_syscall.S
View file

@ -1,5 +1,5 @@
/****************************************************************************
* arch/risc-v/src/common/supervisor/riscv_dispatch_syscall.S
* arch/risc-v/src/common/supervisor/riscv_syscall.S
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
@ -18,7 +18,7 @@
*
****************************************************************************/
.file "riscv_dispatch_syscall.S"
.file "riscv_syscall.S"
/****************************************************************************
* Included Files
@ -39,16 +39,22 @@
* Public Symbols
****************************************************************************/
.globl riscv_dispatch_syscall
.globl sys_call0
.globl sys_call1
.globl sys_call2
.globl sys_call3
.globl sys_call4
.globl sys_call5
.globl sys_call6
/****************************************************************************
* Name: riscv_dispatch_syscall
* Name: sys_callx
*
* Description:
* Dispatch syscall from kernel
*
* C Function Prototype:
* void riscv_dispatch_syscall(void);
* uintptr_t sys_callx(unsigned int nbr, ...);
*
* Input Parameters:
* Assumes the context to return is already set up
@ -61,9 +67,21 @@
*
****************************************************************************/
.type riscv_dispatch_syscall, function
.type sys_call0, function
.type sys_call1, function
.type sys_call2, function
.type sys_call3, function
.type sys_call4, function
.type sys_call5, function
.type sys_call6, function
riscv_dispatch_syscall:
sys_call0:
sys_call1:
sys_call2:
sys_call3:
sys_call4:
sys_call5:
sys_call6:
addi sp, sp, -XCPTCONTEXT_SIZE /* make room */
save_ctx sp /* save current context */
@ -135,3 +153,13 @@ riscv_dispatch_syscall:
/* return from exception, which updates the status register */
ERET
.size sys_call0, .-sys_call0
.size sys_call1, .-sys_call1
.size sys_call2, .-sys_call2
.size sys_call3, .-sys_call3
.size sys_call4, .-sys_call4
.size sys_call5, .-sys_call5
.size sys_call6, .-sys_call6
.end