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nuttx/arch/arm/include/syscall.h
chao.an 7b9978883c arch/arm: optimize context switch speed 
The current context save implementation saves registers of each task
to xcp context, which is unnecessary because most of the arm registers are
already saved in the task stack, this commit replace the xcp context with
stack context to improve context switching performance and reduce the tcb
space occupation of tcb instance.

Signed-off-by: chao.an <anchao@xiaomi.com>
2022-03-15 23:03:51 +09:00

341 lines
8.9 KiB
C
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/****************************************************************************
* arch/arm/include/syscall.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/* This file should never be included directly but, rather, only indirectly
* through include/syscall.h or include/sys/sycall.h
*/
#ifndef __ARCH_ARM_INCLUDE_SYSCALL_H
#define __ARCH_ARM_INCLUDE_SYSCALL_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#ifndef __ASSEMBLY__
# include <stdint.h>
#endif
/****************************************************************************
* Pre-processor Prototypes
****************************************************************************/
#define SYS_syscall 0x00
#if defined(__thumb__) || defined(__thumb2__)
# define SYS_smhcall 0xab
#else
# define SYS_smhcall 0x123456
#endif
/* Configuration ************************************************************/
/* This logic uses three system calls {0,1,2} for context switching and one
* for the syscall return.
* So a minimum of four syscall values must be reserved.
* If CONFIG_BUILD_FLAT isn't defined, then four more syscall values must
* be reserved.
*/
#ifndef CONFIG_BUILD_FLAT
# define CONFIG_SYS_RESERVED 8
#else
# define CONFIG_SYS_RESERVED 4
#endif
/* Cortex-M system calls ****************************************************/
/* SYS call 0:
*
* int arm_saveusercontext(uint32_t *saveregs);
*/
#define SYS_save_context (0)
/* SYS call 1:
*
* void arm_fullcontextrestore(uint32_t *restoreregs) noreturn_function;
*/
#define SYS_restore_context (1)
/* SYS call 2:
*
* void arm_switchcontext(uint32_t **saveregs, uint32_t *restoreregs);
*/
#define SYS_switch_context (2)
#ifdef CONFIG_LIB_SYSCALL
/* SYS call 3:
*
* void arm_syscall_return(void);
*/
#define SYS_syscall_return (3)
#endif /* CONFIG_LIB_SYSCALL */
#ifndef CONFIG_BUILD_FLAT
/* SYS call 4:
*
* void up_task_start(main_t taskentry, int argc, FAR char *argv[])
* noreturn_function;
*/
#define SYS_task_start (4)
/* SYS call 5:
*
* void up_pthread_start((pthread_startroutine_t startup,
* pthread_startroutine_t entrypt, pthread_addr_t arg)
* noreturn_function
*/
#define SYS_pthread_start (5)
/* SYS call 6:
*
* void signal_handler(_sa_sigaction_t sighand,
* int signo, FAR siginfo_t *info,
* FAR void *ucontext);
*/
#define SYS_signal_handler (6)
/* SYS call 7:
*
* void signal_handler_return(void);
*/
#define SYS_signal_handler_return (7)
#endif /* !CONFIG_BUILD_FLAT */
/****************************************************************************
* Public Types
****************************************************************************/
/****************************************************************************
* Inline functions
****************************************************************************/
#ifndef __ASSEMBLY__
/* SVC with SYS_ call number and no parameters */
static inline uintptr_t sys_call0(unsigned int nbr)
{
register long reg0 __asm__("r0") = (long)(nbr);
__asm__ __volatile__
(
"svc %1"
: "=r"(reg0)
: "i"(SYS_syscall), "r"(reg0)
: "memory", "r14"
);
return reg0;
}
/* SVC with SYS_ call number and one parameter */
static inline uintptr_t sys_call1(unsigned int nbr, uintptr_t parm1)
{
register long reg0 __asm__("r0") = (long)(nbr);
register long reg1 __asm__("r1") = (long)(parm1);
__asm__ __volatile__
(
"svc %1"
: "=r"(reg0)
: "i"(SYS_syscall), "r"(reg0), "r"(reg1)
: "memory", "r14"
);
return reg0;
}
/* SVC with SYS_ call number and two parameters */
static inline uintptr_t sys_call2(unsigned int nbr, uintptr_t parm1,
uintptr_t parm2)
{
register long reg0 __asm__("r0") = (long)(nbr);
register long reg2 __asm__("r2") = (long)(parm2);
register long reg1 __asm__("r1") = (long)(parm1);
__asm__ __volatile__
(
"svc %1"
: "=r"(reg0)
: "i"(SYS_syscall), "r"(reg0), "r"(reg1), "r"(reg2)
: "memory", "r14"
);
return reg0;
}
/* SVC with SYS_ call number and three parameters */
static inline uintptr_t sys_call3(unsigned int nbr, uintptr_t parm1,
uintptr_t parm2, uintptr_t parm3)
{
register long reg0 __asm__("r0") = (long)(nbr);
register long reg3 __asm__("r3") = (long)(parm3);
register long reg2 __asm__("r2") = (long)(parm2);
register long reg1 __asm__("r1") = (long)(parm1);
__asm__ __volatile__
(
"svc %1"
: "=r"(reg0)
: "i"(SYS_syscall), "r"(reg0), "r"(reg1), "r"(reg2), "r"(reg3)
: "memory", "r14"
);
return reg0;
}
/* SVC with SYS_ call number and four parameters */
static inline uintptr_t sys_call4(unsigned int nbr, uintptr_t parm1,
uintptr_t parm2, uintptr_t parm3,
uintptr_t parm4)
{
register long reg0 __asm__("r0") = (long)(nbr);
register long reg4 __asm__("r4") = (long)(parm4);
register long reg3 __asm__("r3") = (long)(parm3);
register long reg2 __asm__("r2") = (long)(parm2);
register long reg1 __asm__("r1") = (long)(parm1);
__asm__ __volatile__
(
"svc %1"
: "=r"(reg0)
: "i"(SYS_syscall), "r"(reg0), "r"(reg1), "r"(reg2),
"r"(reg3), "r"(reg4)
: "memory", "r14"
);
return reg0;
}
/* SVC with SYS_ call number and five parameters */
static inline uintptr_t sys_call5(unsigned int nbr, uintptr_t parm1,
uintptr_t parm2, uintptr_t parm3,
uintptr_t parm4, uintptr_t parm5)
{
register long reg0 __asm__("r0") = (long)(nbr);
register long reg5 __asm__("r5") = (long)(parm5);
register long reg4 __asm__("r4") = (long)(parm4);
register long reg3 __asm__("r3") = (long)(parm3);
register long reg2 __asm__("r2") = (long)(parm2);
register long reg1 __asm__("r1") = (long)(parm1);
__asm__ __volatile__
(
"svc %1"
: "=r"(reg0)
: "i"(SYS_syscall), "r"(reg0), "r"(reg1), "r"(reg2),
"r"(reg3), "r"(reg4), "r"(reg5)
: "memory", "r14"
);
return reg0;
}
/* SVC with SYS_ call number and six parameters */
static inline 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)
{
register long reg0 __asm__("r0") = (long)(nbr);
register long reg6 __asm__("r6") = (long)(parm6);
register long reg5 __asm__("r5") = (long)(parm5);
register long reg4 __asm__("r4") = (long)(parm4);
register long reg3 __asm__("r3") = (long)(parm3);
register long reg2 __asm__("r2") = (long)(parm2);
register long reg1 __asm__("r1") = (long)(parm1);
__asm__ __volatile__
(
"svc %1"
: "=r"(reg0)
: "i"(SYS_syscall), "r"(reg0), "r"(reg1), "r"(reg2),
"r"(reg3), "r"(reg4), "r"(reg5), "r"(reg6)
: "memory", "r14"
);
return reg0;
}
/* semihosting(SMH) call with call number and one parameter */
static inline long smh_call(unsigned int nbr, void *parm)
{
register long reg0 __asm__("r0") = (long)(nbr);
register long reg1 __asm__("r1") = (long)(parm);
__asm__ __volatile__
(
#if defined(CONFIG_ARCH_ARMV6M) || \
defined(CONFIG_ARCH_ARMV7M) || \
defined(CONFIG_ARCH_ARMV8M)
"bkpt %1"
#else
"svc %1"
#endif
: "=r"(reg0)
: "i"(SYS_smhcall), "r"(reg0), "r"(reg1)
: "memory", "r14"
);
return reg0;
}
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __ASSEMBLY__ */
#endif /* __ARCH_ARM_INCLUDE_SYSCALL_H */
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