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https://github.com/golang/go
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4fd41e494a
Permit system calls to be designated as non-blocking, meaning that we simply call them without involving the scheduler. This change by itself is mostly performance neutral. In combination with a following change to the net package there is a performance advantage. R=rsc, dfc, r2, iant2, rsc1 CC=golang-dev https://golang.org/cl/4278055
154 lines
3.3 KiB
ArmAsm
154 lines
3.3 KiB
ArmAsm
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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//
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// System calls for arm, Linux
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//
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// TODO(kaib): handle error returns
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// func Syscall(syscall uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
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TEXT ·Syscall(SB),7,$0
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BL runtime·entersyscall(SB)
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MOVW 4(SP), R7
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MOVW 8(SP), R0
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MOVW 12(SP), R1
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MOVW 16(SP), R2
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SWI $0
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MOVW $0xfffff001, R1
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CMP R1, R0
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BLS ok
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MOVW $-1, R1
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MOVW R1, 20(SP) // r1
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MOVW $0, R2
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MOVW R2, 24(SP) // r2
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RSB $0, R0, R0
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MOVW R0, 28(SP) // errno
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BL runtime·exitsyscall(SB)
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RET
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ok:
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MOVW R0, 20(SP) // r1
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MOVW $0, R0
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MOVW R0, 24(SP) // r2
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MOVW R0, 28(SP) // errno
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BL runtime·exitsyscall(SB)
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RET
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// func Syscall6(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr);
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// Actually Syscall5 but the rest of the code expects it to be named Syscall6.
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TEXT ·Syscall6(SB),7,$0
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BL runtime·entersyscall(SB)
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MOVW 4(SP), R7 // syscall entry
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MOVW 8(SP), R0
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MOVW 12(SP), R1
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MOVW 16(SP), R2
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MOVW 20(SP), R3
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MOVW 24(SP), R4
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MOVW 28(SP), R5
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SWI $0
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MOVW $0xfffff001, R6
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CMP R6, R0
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BLS ok6
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MOVW $-1, R1
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MOVW R1, 32(SP) // r1
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MOVW $0, R2
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MOVW R2, 36(SP) // r2
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RSB $0, R0, R0
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MOVW R0, 40(SP) // errno
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BL runtime·exitsyscall(SB)
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RET
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ok6:
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MOVW R0, 32(SP) // r1
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MOVW R1, 36(SP) // r2
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MOVW $0, R0
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MOVW R0, 40(SP) // errno
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BL runtime·exitsyscall(SB)
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RET
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// func RawSyscall6(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr);
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// Actually RawSyscall5 but the rest of the code expects it to be named RawSyscall6.
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TEXT ·RawSyscall6(SB),7,$0
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MOVW 4(SP), R7 // syscall entry
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MOVW 8(SP), R0
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MOVW 12(SP), R1
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MOVW 16(SP), R2
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MOVW 20(SP), R3
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MOVW 24(SP), R4
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MOVW 28(SP), R5
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SWI $0
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MOVW $0xfffff001, R6
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CMP R6, R0
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BLS ok2
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MOVW $-1, R1
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MOVW R1, 32(SP) // r1
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MOVW $0, R2
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MOVW R2, 36(SP) // r2
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RSB $0, R0, R0
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MOVW R0, 40(SP) // errno
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RET
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ok2:
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MOVW R0, 32(SP) // r1
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MOVW R1, 36(SP) // r2
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MOVW $0, R0
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MOVW R0, 40(SP) // errno
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RET
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#define SYS__LLSEEK 140 /* from zsysnum_linux_arm.go */
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// func Seek(fd int, offset int64, whence int) (newoffset int64, errno int)
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// Implemented in assembly to avoid allocation when
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// taking the address of the return value newoffset.
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// Underlying system call is
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// llseek(int fd, int offhi, int offlo, int64 *result, int whence)
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TEXT ·Seek(SB),7,$0
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BL runtime·entersyscall(SB)
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MOVW $SYS__LLSEEK, R7 // syscall entry
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MOVW 4(SP), R0 // fd
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MOVW 12(SP), R1 // offset-high
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MOVW 8(SP), R2 // offset-low
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MOVW $20(SP), R3
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MOVW 16(SP), R4 // whence
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SWI $0
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MOVW $0xfffff001, R6
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CMP R6, R0
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BLS okseek
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MOVW $0, R1
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MOVW R1, 20(SP)
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MOVW R1, 24(SP)
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RSB $0, R0, R0
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MOVW R0, 28(SP) // errno
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BL runtime·exitsyscall(SB)
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RET
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okseek:
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// system call filled in newoffset already
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MOVW $0, R0
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MOVW R0, 28(SP) // errno
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BL runtime·exitsyscall(SB)
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RET
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// func RawSyscall(trap uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
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TEXT ·RawSyscall(SB),7,$0
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MOVW 4(SP), R7 // syscall entry
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MOVW 8(SP), R0
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MOVW 12(SP), R1
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MOVW 16(SP), R2
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SWI $0
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MOVW $0xfffff001, R1
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CMP R1, R0
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BLS ok1
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MOVW $-1, R1
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MOVW R1, 20(SP) // r1
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MOVW $0, R2
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MOVW R2, 24(SP) // r2
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RSB $0, R0, R0
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MOVW R0, 28(SP) // errno
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RET
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ok1:
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MOVW R0, 20(SP) // r1
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MOVW $0, R0
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MOVW R0, 24(SP) // r2
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MOVW R0, 28(SP) // errno
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RET
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