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Editing: sys_linux_arm.s
// Copyright 2009 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // // System calls and other sys.stuff for arm, Linux // #include "go_asm.h" #include "go_tls.h" #include "textflag.h" #define CLOCK_REALTIME 0 #define CLOCK_MONOTONIC 1 // for EABI, as we don't support OABI #define SYS_BASE 0x0 #define SYS_exit (SYS_BASE + 1) #define SYS_read (SYS_BASE + 3) #define SYS_write (SYS_BASE + 4) #define SYS_open (SYS_BASE + 5) #define SYS_close (SYS_BASE + 6) #define SYS_getpid (SYS_BASE + 20) #define SYS_kill (SYS_BASE + 37) #define SYS_clone (SYS_BASE + 120) #define SYS_rt_sigreturn (SYS_BASE + 173) #define SYS_rt_sigaction (SYS_BASE + 174) #define SYS_rt_sigprocmask (SYS_BASE + 175) #define SYS_sigaltstack (SYS_BASE + 186) #define SYS_mmap2 (SYS_BASE + 192) #define SYS_futex (SYS_BASE + 240) #define SYS_exit_group (SYS_BASE + 248) #define SYS_munmap (SYS_BASE + 91) #define SYS_madvise (SYS_BASE + 220) #define SYS_setitimer (SYS_BASE + 104) #define SYS_mincore (SYS_BASE + 219) #define SYS_gettid (SYS_BASE + 224) #define SYS_tgkill (SYS_BASE + 268) #define SYS_sched_yield (SYS_BASE + 158) #define SYS_nanosleep (SYS_BASE + 162) #define SYS_sched_getaffinity (SYS_BASE + 242) #define SYS_clock_gettime (SYS_BASE + 263) #define SYS_timer_create (SYS_BASE + 257) #define SYS_timer_settime (SYS_BASE + 258) #define SYS_timer_delete (SYS_BASE + 261) #define SYS_pipe2 (SYS_BASE + 359) #define SYS_access (SYS_BASE + 33) #define SYS_connect (SYS_BASE + 283) #define SYS_socket (SYS_BASE + 281) #define SYS_brk (SYS_BASE + 45) #define ARM_BASE (SYS_BASE + 0x0f0000) TEXT runtime·open(SB),NOSPLIT,$0 MOVW name+0(FP), R0 MOVW mode+4(FP), R1 MOVW perm+8(FP), R2 MOVW $SYS_open, R7 SWI $0 MOVW $0xfffff001, R1 CMP R1, R0 MOVW.HI $-1, R0 MOVW R0, ret+12(FP) RET TEXT runtime·closefd(SB),NOSPLIT,$0 MOVW fd+0(FP), R0 MOVW $SYS_close, R7 SWI $0 MOVW $0xfffff001, R1 CMP R1, R0 MOVW.HI $-1, R0 MOVW R0, ret+4(FP) RET TEXT runtime·write1(SB),NOSPLIT,$0 MOVW fd+0(FP), R0 MOVW p+4(FP), R1 MOVW n+8(FP), R2 MOVW $SYS_write, R7 SWI $0 MOVW R0, ret+12(FP) RET TEXT runtime·read(SB),NOSPLIT,$0 MOVW fd+0(FP), R0 MOVW p+4(FP), R1 MOVW n+8(FP), R2 MOVW $SYS_read, R7 SWI $0 MOVW R0, ret+12(FP) RET // func pipe2(flags int32) (r, w int32, errno int32) TEXT runtime·pipe2(SB),NOSPLIT,$0-16 MOVW $r+4(FP), R0 MOVW flags+0(FP), R1 MOVW $SYS_pipe2, R7 SWI $0 MOVW R0, errno+12(FP) RET TEXT runtime·exit(SB),NOSPLIT|NOFRAME,$0 MOVW code+0(FP), R0 MOVW $SYS_exit_group, R7 SWI $0 MOVW $1234, R0 MOVW $1002, R1 MOVW R0, (R1) // fail hard TEXT exit1<>(SB),NOSPLIT|NOFRAME,$0 MOVW code+0(FP), R0 MOVW $SYS_exit, R7 SWI $0 MOVW $1234, R0 MOVW $1003, R1 MOVW R0, (R1) // fail hard // func exitThread(wait *atomic.Uint32) TEXT runtime·exitThread(SB),NOSPLIT|NOFRAME,$0-4 MOVW wait+0(FP), R0 // We're done using the stack. // Alas, there's no reliable way to make this write atomic // without potentially using the stack. So it goes. MOVW $0, R1 MOVW R1, (R0) MOVW $0, R0 // exit code MOVW $SYS_exit, R7 SWI $0 MOVW $1234, R0 MOVW $1004, R1 MOVW R0, (R1) // fail hard JMP 0(PC) TEXT runtime·gettid(SB),NOSPLIT,$0-4 MOVW $SYS_gettid, R7 SWI $0 MOVW R0, ret+0(FP) RET TEXT runtime·raise(SB),NOSPLIT|NOFRAME,$0 MOVW $SYS_getpid, R7 SWI $0 MOVW R0, R4 MOVW $SYS_gettid, R7 SWI $0 MOVW R0, R1 // arg 2 tid MOVW R4, R0 // arg 1 pid MOVW sig+0(FP), R2 // arg 3 MOVW $SYS_tgkill, R7 SWI $0 RET TEXT runtime·raiseproc(SB),NOSPLIT|NOFRAME,$0 MOVW $SYS_getpid, R7 SWI $0 // arg 1 tid already in R0 from getpid MOVW sig+0(FP), R1 // arg 2 - signal MOVW $SYS_kill, R7 SWI $0 RET TEXT ·getpid(SB),NOSPLIT,$0-4 MOVW $SYS_getpid, R7 SWI $0 MOVW R0, ret+0(FP) RET TEXT ·tgkill(SB),NOSPLIT,$0-12 MOVW tgid+0(FP), R0 MOVW tid+4(FP), R1 MOVW sig+8(FP), R2 MOVW $SYS_tgkill, R7 SWI $0 RET TEXT runtime·mmap(SB),NOSPLIT,$0 MOVW addr+0(FP), R0 MOVW n+4(FP), R1 MOVW prot+8(FP), R2 MOVW flags+12(FP), R3 MOVW fd+16(FP), R4 MOVW off+20(FP), R5 MOVW $SYS_mmap2, R7 SWI $0 MOVW $0xfffff001, R6 CMP R6, R0 MOVW $0, R1 RSB.HI $0, R0 MOVW.HI R0, R1 // if error, put in R1 MOVW.HI $0, R0 MOVW R0, p+24(FP) MOVW R1, err+28(FP) RET TEXT runtime·munmap(SB),NOSPLIT,$0 MOVW addr+0(FP), R0 MOVW n+4(FP), R1 MOVW $SYS_munmap, R7 SWI $0 MOVW $0xfffff001, R6 CMP R6, R0 MOVW.HI $0, R8 // crash on syscall failure MOVW.HI R8, (R8) RET TEXT runtime·madvise(SB),NOSPLIT,$0 MOVW addr+0(FP), R0 MOVW n+4(FP), R1 MOVW flags+8(FP), R2 MOVW $SYS_madvise, R7 SWI $0 MOVW R0, ret+12(FP) RET TEXT runtime·setitimer(SB),NOSPLIT,$0 MOVW mode+0(FP), R0 MOVW new+4(FP), R1 MOVW old+8(FP), R2 MOVW $SYS_setitimer, R7 SWI $0 RET TEXT runtime·timer_create(SB),NOSPLIT,$0-16 MOVW clockid+0(FP), R0 MOVW sevp+4(FP), R1 MOVW timerid+8(FP), R2 MOVW $SYS_timer_create, R7 SWI $0 MOVW R0, ret+12(FP) RET TEXT runtime·timer_settime(SB),NOSPLIT,$0-20 MOVW timerid+0(FP), R0 MOVW flags+4(FP), R1 MOVW new+8(FP), R2 MOVW old+12(FP), R3 MOVW $SYS_timer_settime, R7 SWI $0 MOVW R0, ret+16(FP) RET TEXT runtime·timer_delete(SB),NOSPLIT,$0-8 MOVW timerid+0(FP), R0 MOVW $SYS_timer_delete, R7 SWI $0 MOVW R0, ret+4(FP) RET TEXT runtime·mincore(SB),NOSPLIT,$0 MOVW addr+0(FP), R0 MOVW n+4(FP), R1 MOVW dst+8(FP), R2 MOVW $SYS_mincore, R7 SWI $0 MOVW R0, ret+12(FP) RET // Call a VDSO function. // // R0-R3: arguments to VDSO function (C calling convention) // R4: uintptr function to call // // There is no return value. TEXT runtime·vdsoCall(SB),NOSPLIT,$8-0 // R0-R3 may be arguments to fn, do not touch. // R4 is function to call. // R5-R9 are available as locals. They are unchanged by the C call // (callee-save). // We don't know how much stack space the VDSO code will need, // so switch to g0. // Save old SP. Use R13 instead of SP to avoid linker rewriting the offsets. MOVW R13, R5 MOVW g_m(g), R6 // Set vdsoPC and vdsoSP for SIGPROF traceback. // Save the old values on stack and restore them on exit, // so this function is reentrant. MOVW m_vdsoPC(R6), R7 MOVW m_vdsoSP(R6), R8 MOVW R7, 4(R13) MOVW R8, 8(R13) MOVW $sp-4(FP), R7 // caller's SP MOVW LR, m_vdsoPC(R6) MOVW R7, m_vdsoSP(R6) MOVW m_curg(R6), R7 CMP g, R7 // Only switch if on curg. B.NE noswitch MOVW m_g0(R6), R7 MOVW (g_sched+gobuf_sp)(R7), R13 // Set SP to g0 stack noswitch: BIC $0x7, R13 // Align for C code // Store g on gsignal's stack, so if we receive a signal // during VDSO code we can find the g. // When using cgo, we already saved g on TLS, also don't save g here. MOVB runtime·iscgo(SB), R7 CMP $0, R7 BNE nosaveg // If we don't have a signal stack, we won't receive signal, so don't // bother saving g. MOVW m_gsignal(R6), R7 // g.m.gsignal CMP $0, R7 BEQ nosaveg // Don't save g if we are already on the signal stack, as we won't get // a nested signal. CMP g, R7 BEQ nosaveg // If we don't have a signal stack, we won't receive signal, so don't // bother saving g. MOVW (g_stack+stack_lo)(R7), R7 // g.m.gsignal.stack.lo CMP $0, R7 BEQ nosaveg MOVW g, (R7) BL (R4) MOVW $0, R8 MOVW R8, (R7) // clear g slot JMP finish nosaveg: BL (R4) finish: MOVW R5, R13 // Restore real SP // Restore vdsoPC, vdsoSP // We don't worry about being signaled between the two stores. // If we are not in a signal handler, we'll restore vdsoSP to 0, // and no one will care about vdsoPC. If we are in a signal handler, // we cannot receive another signal. MOVW 8(R13), R7 MOVW R7, m_vdsoSP(R6) MOVW 4(R13), R7 MOVW R7, m_vdsoPC(R6) RET TEXT runtime·walltime(SB),NOSPLIT,$12-12 MOVW $CLOCK_REALTIME, R0 MOVW $spec-12(SP), R1 // timespec MOVW runtime·vdsoClockgettimeSym(SB), R4 CMP $0, R4 B.EQ fallback BL runtime·vdsoCall(SB) JMP finish fallback: MOVW $SYS_clock_gettime, R7 SWI $0 finish: MOVW sec-12(SP), R0 // sec MOVW nsec-8(SP), R2 // nsec MOVW R0, sec_lo+0(FP) MOVW $0, R1 MOVW R1, sec_hi+4(FP) MOVW R2, nsec+8(FP) RET // func nanotime1() int64 TEXT runtime·nanotime1(SB),NOSPLIT,$12-8 MOVW $CLOCK_MONOTONIC, R0 MOVW $spec-12(SP), R1 // timespec MOVW runtime·vdsoClockgettimeSym(SB), R4 CMP $0, R4 B.EQ fallback BL runtime·vdsoCall(SB) JMP finish fallback: MOVW $SYS_clock_gettime, R7 SWI $0 finish: MOVW sec-12(SP), R0 // sec MOVW nsec-8(SP), R2 // nsec MOVW $1000000000, R3 MULLU R0, R3, (R1, R0) ADD.S R2, R0 ADC $0, R1 // Add carry bit to upper half. MOVW R0, ret_lo+0(FP) MOVW R1, ret_hi+4(FP) RET // int32 futex(int32 *uaddr, int32 op, int32 val, // struct timespec *timeout, int32 *uaddr2, int32 val2); TEXT runtime·futex(SB),NOSPLIT,$0 MOVW addr+0(FP), R0 MOVW op+4(FP), R1 MOVW val+8(FP), R2 MOVW ts+12(FP), R3 MOVW addr2+16(FP), R4 MOVW val3+20(FP), R5 MOVW $SYS_futex, R7 SWI $0 MOVW R0, ret+24(FP) RET // int32 clone(int32 flags, void *stack, M *mp, G *gp, void (*fn)(void)); TEXT runtime·clone(SB),NOSPLIT,$0 MOVW flags+0(FP), R0 MOVW stk+4(FP), R1 MOVW $0, R2 // parent tid ptr MOVW $0, R3 // tls_val MOVW $0, R4 // child tid ptr MOVW $0, R5 // Copy mp, gp, fn off parent stack for use by child. MOVW $-16(R1), R1 MOVW mp+8(FP), R6 MOVW R6, 0(R1) MOVW gp+12(FP), R6 MOVW R6, 4(R1) MOVW fn+16(FP), R6 MOVW R6, 8(R1) MOVW $1234, R6 MOVW R6, 12(R1) MOVW $SYS_clone, R7 SWI $0 // In parent, return. CMP $0, R0 BEQ 3(PC) MOVW R0, ret+20(FP) RET // Paranoia: check that SP is as we expect. Use R13 to avoid linker 'fixup' NOP R13 // tell vet SP/R13 changed - stop checking offsets MOVW 12(R13), R0 MOVW $1234, R1 CMP R0, R1 BEQ 2(PC) BL runtime·abort(SB) MOVW 0(R13), R8 // m MOVW 4(R13), R0 // g CMP $0, R8 BEQ nog CMP $0, R0 BEQ nog MOVW R0, g MOVW R8, g_m(g) // paranoia; check they are not nil MOVW 0(R8), R0 MOVW 0(g), R0 BL runtime·emptyfunc(SB) // fault if stack check is wrong // Initialize m->procid to Linux tid MOVW $SYS_gettid, R7 SWI $0 MOVW g_m(g), R8 MOVW R0, m_procid(R8) nog: // Call fn MOVW 8(R13), R0 MOVW $16(R13), R13 BL (R0) // It shouldn't return. If it does, exit that thread. SUB $16, R13 // restore the stack pointer to avoid memory corruption MOVW $0, R0 MOVW R0, 4(R13) BL exit1<>(SB) MOVW $1234, R0 MOVW $1005, R1 MOVW R0, (R1) TEXT runtime·sigaltstack(SB),NOSPLIT,$0 MOVW new+0(FP), R0 MOVW old+4(FP), R1 MOVW $SYS_sigaltstack, R7 SWI $0 MOVW $0xfffff001, R6 CMP R6, R0 MOVW.HI $0, R8 // crash on syscall failure MOVW.HI R8, (R8) RET TEXT runtime·sigfwd(SB),NOSPLIT,$0-16 MOVW sig+4(FP), R0 MOVW info+8(FP), R1 MOVW ctx+12(FP), R2 MOVW fn+0(FP), R11 MOVW R13, R4 SUB $24, R13 BIC $0x7, R13 // alignment for ELF ABI BL (R11) MOVW R4, R13 RET TEXT runtime·sigtramp(SB),NOSPLIT|TOPFRAME,$0 // Reserve space for callee-save registers and arguments. MOVM.DB.W [R4-R11], (R13) SUB $16, R13 // this might be called in external code context, // where g is not set. // first save R0, because runtime·load_g will clobber it MOVW R0, 4(R13) MOVB runtime·iscgo(SB), R0 CMP $0, R0 BL.NE runtime·load_g(SB) MOVW R1, 8(R13) MOVW R2, 12(R13) MOVW $runtime·sigtrampgo(SB), R11 BL (R11) // Restore callee-save registers. ADD $16, R13 MOVM.IA.W (R13), [R4-R11] RET TEXT runtime·cgoSigtramp(SB),NOSPLIT,$0 MOVW $runtime·sigtramp(SB), R11 B (R11) TEXT runtime·rtsigprocmask(SB),NOSPLIT,$0 MOVW how+0(FP), R0 MOVW new+4(FP), R1 MOVW old+8(FP), R2 MOVW size+12(FP), R3 MOVW $SYS_rt_sigprocmask, R7 SWI $0 RET TEXT runtime·rt_sigaction(SB),NOSPLIT,$0 MOVW sig+0(FP), R0 MOVW new+4(FP), R1 MOVW old+8(FP), R2 MOVW size+12(FP), R3 MOVW $SYS_rt_sigaction, R7 SWI $0 MOVW R0, ret+16(FP) RET TEXT runtime·usleep(SB),NOSPLIT,$12 MOVW usec+0(FP), R0 CALL runtime·usplitR0(SB) MOVW R0, 4(R13) MOVW $1000, R0 // usec to nsec MUL R0, R1 MOVW R1, 8(R13) MOVW $4(R13), R0 MOVW $0, R1 MOVW $SYS_nanosleep, R7 SWI $0 RET // As for cas, memory barriers are complicated on ARM, but the kernel // provides a user helper. ARMv5 does not support SMP and has no // memory barrier instruction at all. ARMv6 added SMP support and has // a memory barrier, but it requires writing to a coprocessor // register. ARMv7 introduced the DMB instruction, but it's expensive // even on single-core devices. The kernel helper takes care of all of // this for us. TEXT kernelPublicationBarrier<>(SB),NOSPLIT,$0 // void __kuser_memory_barrier(void); MOVW $0xffff0fa0, R11 CALL (R11) RET TEXT ·publicationBarrier(SB),NOSPLIT,$0 MOVB ·goarm(SB), R11 CMP $7, R11 BLT 2(PC) JMP ·armPublicationBarrier(SB) JMP kernelPublicationBarrier<>(SB) // extra layer so this function is leaf and no SP adjustment on GOARM=7 TEXT runtime·osyield(SB),NOSPLIT,$0 MOVW $SYS_sched_yield, R7 SWI $0 RET TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0 MOVW pid+0(FP), R0 MOVW len+4(FP), R1 MOVW buf+8(FP), R2 MOVW $SYS_sched_getaffinity, R7 SWI $0 MOVW R0, ret+12(FP) RET // b __kuser_get_tls @ 0xffff0fe0 TEXT runtime·read_tls_fallback(SB),NOSPLIT|NOFRAME,$0 MOVW $0xffff0fe0, R0 B (R0) TEXT runtime·access(SB),NOSPLIT,$0 MOVW name+0(FP), R0 MOVW mode+4(FP), R1 MOVW $SYS_access, R7 SWI $0 MOVW R0, ret+8(FP) RET TEXT runtime·connect(SB),NOSPLIT,$0 MOVW fd+0(FP), R0 MOVW addr+4(FP), R1 MOVW len+8(FP), R2 MOVW $SYS_connect, R7 SWI $0 MOVW R0, ret+12(FP) RET TEXT runtime·socket(SB),NOSPLIT,$0 MOVW domain+0(FP), R0 MOVW typ+4(FP), R1 MOVW prot+8(FP), R2 MOVW $SYS_socket, R7 SWI $0 MOVW R0, ret+12(FP) RET // func sbrk0() uintptr TEXT runtime·sbrk0(SB),NOSPLIT,$0-4 // Implemented as brk(NULL). MOVW $0, R0 MOVW $SYS_brk, R7 SWI $0 MOVW R0, ret+0(FP) RET
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