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newlib-cygwin/libgloss/riscv/internal_syscall.h

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RISC-V: Moved syscalls to separate files to fix aliasing problems.
2017-12-27 04:27:52 +08:00
/* Copyright (c) 2017 SiFive Inc. All rights reserved.
This copyrighted material is made available to anyone wishing to use,
modify, copy, or redistribute it subject to the terms and conditions
of the FreeBSD License. This program is distributed in the hope that
it will be useful, but WITHOUT ANY WARRANTY expressed or implied,
including the implied warranties of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. A copy of this license is available at
http://www.opensource.org/licenses.
*/
#ifndef _INTERNAL_SYSCALL_H
#define _INTERNAL_SYSCALL_H
#include <errno.h>
static inline long
__syscall_error(long a0)
{
errno = -a0;
return -1;
}
static inline long
Only pass the minimum number of syscall arguments Previously, __internal_syscall() compiled into asm-code that unconditionally sets the syscall argument registers a0 to a5. For example, the instruction sequence for a exit syscall looked like this: li a0, 1 # in ther caller of exit() # ... # in newlib: li a1, 0 # unused arguments li a2, 0 li a3, 0 li a4, 0 li a5, 0 li a7, 93 # exit syscall number (i.e. the binary contains then 5 superfluous instructions for this one argument syscall) This commit changes the RISC-V syscall code such that only the required syscall argument registers are set. GCC detects that argc is known at compile time and thus evaluates all the if-statements where argc is used at compile time (tested with -O2 and -Os).
2020-02-11 04:19:58 +08:00
__internal_syscall(long n, int argc, long _a0, long _a1, long _a2, long _a3, long _a4, long _a5)
RISC-V: Moved syscalls to separate files to fix aliasing problems.
2017-12-27 04:27:52 +08:00
{
Only pass the minimum number of syscall arguments Previously, __internal_syscall() compiled into asm-code that unconditionally sets the syscall argument registers a0 to a5. For example, the instruction sequence for a exit syscall looked like this: li a0, 1 # in ther caller of exit() # ... # in newlib: li a1, 0 # unused arguments li a2, 0 li a3, 0 li a4, 0 li a5, 0 li a7, 93 # exit syscall number (i.e. the binary contains then 5 superfluous instructions for this one argument syscall) This commit changes the RISC-V syscall code such that only the required syscall argument registers are set. GCC detects that argc is known at compile time and thus evaluates all the if-statements where argc is used at compile time (tested with -O2 and -Os).
2020-02-11 04:19:58 +08:00
#ifdef __riscv_32e
register long syscall_id asm("t0") = n;
#else
register long syscall_id asm("a7") = n;
#endif
RISC-V: Moved syscalls to separate files to fix aliasing problems.
2017-12-27 04:27:52 +08:00
register long a0 asm("a0") = _a0;
Only pass the minimum number of syscall arguments Previously, __internal_syscall() compiled into asm-code that unconditionally sets the syscall argument registers a0 to a5. For example, the instruction sequence for a exit syscall looked like this: li a0, 1 # in ther caller of exit() # ... # in newlib: li a1, 0 # unused arguments li a2, 0 li a3, 0 li a4, 0 li a5, 0 li a7, 93 # exit syscall number (i.e. the binary contains then 5 superfluous instructions for this one argument syscall) This commit changes the RISC-V syscall code such that only the required syscall argument registers are set. GCC detects that argc is known at compile time and thus evaluates all the if-statements where argc is used at compile time (tested with -O2 and -Os).
2020-02-11 04:19:58 +08:00
if (argc < 2) {
asm volatile ("ecall" : "+r"(a0) : "r"(syscall_id));
return a0;
}
RISC-V: Moved syscalls to separate files to fix aliasing problems.
2017-12-27 04:27:52 +08:00
register long a1 asm("a1") = _a1;
Only pass the minimum number of syscall arguments Previously, __internal_syscall() compiled into asm-code that unconditionally sets the syscall argument registers a0 to a5. For example, the instruction sequence for a exit syscall looked like this: li a0, 1 # in ther caller of exit() # ... # in newlib: li a1, 0 # unused arguments li a2, 0 li a3, 0 li a4, 0 li a5, 0 li a7, 93 # exit syscall number (i.e. the binary contains then 5 superfluous instructions for this one argument syscall) This commit changes the RISC-V syscall code such that only the required syscall argument registers are set. GCC detects that argc is known at compile time and thus evaluates all the if-statements where argc is used at compile time (tested with -O2 and -Os).
2020-02-11 04:19:58 +08:00
if (argc == 2) {
asm volatile ("ecall" : "+r"(a0) : "r"(a1), "r"(syscall_id));
return a0;
}
RISC-V: Moved syscalls to separate files to fix aliasing problems.
2017-12-27 04:27:52 +08:00
register long a2 asm("a2") = _a2;
Only pass the minimum number of syscall arguments Previously, __internal_syscall() compiled into asm-code that unconditionally sets the syscall argument registers a0 to a5. For example, the instruction sequence for a exit syscall looked like this: li a0, 1 # in ther caller of exit() # ... # in newlib: li a1, 0 # unused arguments li a2, 0 li a3, 0 li a4, 0 li a5, 0 li a7, 93 # exit syscall number (i.e. the binary contains then 5 superfluous instructions for this one argument syscall) This commit changes the RISC-V syscall code such that only the required syscall argument registers are set. GCC detects that argc is known at compile time and thus evaluates all the if-statements where argc is used at compile time (tested with -O2 and -Os).
2020-02-11 04:19:58 +08:00
if (argc == 3) {
asm volatile ("ecall" : "+r"(a0) : "r"(a1), "r"(a2), "r"(syscall_id));
return a0;
}
RISC-V: Moved syscalls to separate files to fix aliasing problems.
2017-12-27 04:27:52 +08:00
register long a3 asm("a3") = _a3;
Only pass the minimum number of syscall arguments Previously, __internal_syscall() compiled into asm-code that unconditionally sets the syscall argument registers a0 to a5. For example, the instruction sequence for a exit syscall looked like this: li a0, 1 # in ther caller of exit() # ... # in newlib: li a1, 0 # unused arguments li a2, 0 li a3, 0 li a4, 0 li a5, 0 li a7, 93 # exit syscall number (i.e. the binary contains then 5 superfluous instructions for this one argument syscall) This commit changes the RISC-V syscall code such that only the required syscall argument registers are set. GCC detects that argc is known at compile time and thus evaluates all the if-statements where argc is used at compile time (tested with -O2 and -Os).
2020-02-11 04:19:58 +08:00
if (argc == 4) {
asm volatile ("ecall" : "+r"(a0) : "r"(a1), "r"(a2), "r"(a3), "r"(syscall_id));
return a0;
}
RISC-V: Moved syscalls to separate files to fix aliasing problems.
2017-12-27 04:27:52 +08:00
register long a4 asm("a4") = _a4;
Only pass the minimum number of syscall arguments Previously, __internal_syscall() compiled into asm-code that unconditionally sets the syscall argument registers a0 to a5. For example, the instruction sequence for a exit syscall looked like this: li a0, 1 # in ther caller of exit() # ... # in newlib: li a1, 0 # unused arguments li a2, 0 li a3, 0 li a4, 0 li a5, 0 li a7, 93 # exit syscall number (i.e. the binary contains then 5 superfluous instructions for this one argument syscall) This commit changes the RISC-V syscall code such that only the required syscall argument registers are set. GCC detects that argc is known at compile time and thus evaluates all the if-statements where argc is used at compile time (tested with -O2 and -Os).
2020-02-11 04:19:58 +08:00
if (argc == 5) {
asm volatile ("ecall" : "+r"(a0) : "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(syscall_id));
return a0;
}
RISC-V: Moved syscalls to separate files to fix aliasing problems.
2017-12-27 04:27:52 +08:00
register long a5 asm("a5") = _a5;
Only pass the minimum number of syscall arguments Previously, __internal_syscall() compiled into asm-code that unconditionally sets the syscall argument registers a0 to a5. For example, the instruction sequence for a exit syscall looked like this: li a0, 1 # in ther caller of exit() # ... # in newlib: li a1, 0 # unused arguments li a2, 0 li a3, 0 li a4, 0 li a5, 0 li a7, 93 # exit syscall number (i.e. the binary contains then 5 superfluous instructions for this one argument syscall) This commit changes the RISC-V syscall code such that only the required syscall argument registers are set. GCC detects that argc is known at compile time and thus evaluates all the if-statements where argc is used at compile time (tested with -O2 and -Os).
2020-02-11 04:19:58 +08:00
asm volatile ("ecall" : "+r"(a0) : "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5), "r"(syscall_id));
RISC-V: Moved syscalls to separate files to fix aliasing problems.
2017-12-27 04:27:52 +08:00
RISC-V: Fix _sbrk, it's failed only when return value is -1. Signed-off-by: Kito Cheng <kito.cheng@gmail.com>
2018-07-07 00:03:23 +08:00
return a0;
}
static inline long
RISC-V: Fix -Wint-conversion warning Upstream GCC has change this warning into error by default, so...we need to explicitly convert the type from pointer from/to integer, generally it's unsafe, but we know what we are doing here. However it's not safe for ilp32 on RV64, but we didn't support that yet, so I think this fix is good enough now :)
2023-12-04 15:41:28 +08:00
_syscall_errno(long n, int argc, long _a0, long _a1, long _a2, long _a3, long _a4, long _a5)
RISC-V: Fix _sbrk, it's failed only when return value is -1. Signed-off-by: Kito Cheng <kito.cheng@gmail.com>
2018-07-07 00:03:23 +08:00
{
Only pass the minimum number of syscall arguments Previously, __internal_syscall() compiled into asm-code that unconditionally sets the syscall argument registers a0 to a5. For example, the instruction sequence for a exit syscall looked like this: li a0, 1 # in ther caller of exit() # ... # in newlib: li a1, 0 # unused arguments li a2, 0 li a3, 0 li a4, 0 li a5, 0 li a7, 93 # exit syscall number (i.e. the binary contains then 5 superfluous instructions for this one argument syscall) This commit changes the RISC-V syscall code such that only the required syscall argument registers are set. GCC detects that argc is known at compile time and thus evaluates all the if-statements where argc is used at compile time (tested with -O2 and -Os).
2020-02-11 04:19:58 +08:00
long a0 = __internal_syscall (n, argc, _a0, _a1, _a2, _a3, _a4, _a5);
RISC-V: Fix _sbrk, it's failed only when return value is -1. Signed-off-by: Kito Cheng <kito.cheng@gmail.com>
2018-07-07 00:03:23 +08:00
RISC-V: Moved syscalls to separate files to fix aliasing problems.
2017-12-27 04:27:52 +08:00
if (a0 < 0)
return __syscall_error (a0);
else
return a0;
}
RISC-V: Fix -Wint-conversion warning Upstream GCC has change this warning into error by default, so...we need to explicitly convert the type from pointer from/to integer, generally it's unsafe, but we know what we are doing here. However it's not safe for ilp32 on RV64, but we didn't support that yet, so I think this fix is good enough now :)
2023-12-04 15:41:28 +08:00
#define syscall_errno(N, ARGC, A0, A1, A2, A3, A4, A5) \
_syscall_errno(N, ARGC, (long)A0, (long)A1, (long)A2, \
(long)A3, (long)A4, (long)A5)
RISC-V: Moved syscalls to separate files to fix aliasing problems.
2017-12-27 04:27:52 +08:00
#endif