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Diffstat (limited to 'src/runtime/asm_s390x.s')
| -rw-r--r-- | src/runtime/asm_s390x.s | 904 |
1 files changed, 904 insertions, 0 deletions
diff --git a/src/runtime/asm_s390x.s b/src/runtime/asm_s390x.s new file mode 100644 index 0000000..334e1aa --- /dev/null +++ b/src/runtime/asm_s390x.s @@ -0,0 +1,904 @@ +// Copyright 2016 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. + +#include "go_asm.h" +#include "go_tls.h" +#include "funcdata.h" +#include "textflag.h" + +// _rt0_s390x_lib is common startup code for s390x systems when +// using -buildmode=c-archive or -buildmode=c-shared. The linker will +// arrange to invoke this function as a global constructor (for +// c-archive) or when the shared library is loaded (for c-shared). +// We expect argc and argv to be passed in the usual C ABI registers +// R2 and R3. +TEXT _rt0_s390x_lib(SB), NOSPLIT|NOFRAME, $0 + STMG R6, R15, 48(R15) + MOVD R2, _rt0_s390x_lib_argc<>(SB) + MOVD R3, _rt0_s390x_lib_argv<>(SB) + + // Save R6-R15 in the register save area of the calling function. + STMG R6, R15, 48(R15) + + // Allocate 80 bytes on the stack. + MOVD $-80(R15), R15 + + // Save F8-F15 in our stack frame. + FMOVD F8, 16(R15) + FMOVD F9, 24(R15) + FMOVD F10, 32(R15) + FMOVD F11, 40(R15) + FMOVD F12, 48(R15) + FMOVD F13, 56(R15) + FMOVD F14, 64(R15) + FMOVD F15, 72(R15) + + // Synchronous initialization. + MOVD $runtime·libpreinit(SB), R1 + BL R1 + + // Create a new thread to finish Go runtime initialization. + MOVD _cgo_sys_thread_create(SB), R1 + CMP R1, $0 + BEQ nocgo + MOVD $_rt0_s390x_lib_go(SB), R2 + MOVD $0, R3 + BL R1 + BR restore + +nocgo: + MOVD $0x800000, R1 // stacksize + MOVD R1, 0(R15) + MOVD $_rt0_s390x_lib_go(SB), R1 + MOVD R1, 8(R15) // fn + MOVD $runtime·newosproc(SB), R1 + BL R1 + +restore: + // Restore F8-F15 from our stack frame. + FMOVD 16(R15), F8 + FMOVD 24(R15), F9 + FMOVD 32(R15), F10 + FMOVD 40(R15), F11 + FMOVD 48(R15), F12 + FMOVD 56(R15), F13 + FMOVD 64(R15), F14 + FMOVD 72(R15), F15 + MOVD $80(R15), R15 + + // Restore R6-R15. + LMG 48(R15), R6, R15 + RET + +// _rt0_s390x_lib_go initializes the Go runtime. +// This is started in a separate thread by _rt0_s390x_lib. +TEXT _rt0_s390x_lib_go(SB), NOSPLIT|NOFRAME, $0 + MOVD _rt0_s390x_lib_argc<>(SB), R2 + MOVD _rt0_s390x_lib_argv<>(SB), R3 + MOVD $runtime·rt0_go(SB), R1 + BR R1 + +DATA _rt0_s390x_lib_argc<>(SB)/8, $0 +GLOBL _rt0_s390x_lib_argc<>(SB), NOPTR, $8 +DATA _rt0_s90x_lib_argv<>(SB)/8, $0 +GLOBL _rt0_s390x_lib_argv<>(SB), NOPTR, $8 + +TEXT runtime·rt0_go(SB),NOSPLIT|TOPFRAME,$0 + // R2 = argc; R3 = argv; R11 = temp; R13 = g; R15 = stack pointer + // C TLS base pointer in AR0:AR1 + + // initialize essential registers + XOR R0, R0 + + SUB $24, R15 + MOVW R2, 8(R15) // argc + MOVD R3, 16(R15) // argv + + // create istack out of the given (operating system) stack. + // _cgo_init may update stackguard. + MOVD $runtime·g0(SB), g + MOVD R15, R11 + SUB $(64*1024), R11 + MOVD R11, g_stackguard0(g) + MOVD R11, g_stackguard1(g) + MOVD R11, (g_stack+stack_lo)(g) + MOVD R15, (g_stack+stack_hi)(g) + + // if there is a _cgo_init, call it using the gcc ABI. + MOVD _cgo_init(SB), R11 + CMPBEQ R11, $0, nocgo + MOVW AR0, R4 // (AR0 << 32 | AR1) is the TLS base pointer; MOVD is translated to EAR + SLD $32, R4, R4 + MOVW AR1, R4 // arg 2: TLS base pointer + MOVD $setg_gcc<>(SB), R3 // arg 1: setg + MOVD g, R2 // arg 0: G + // C functions expect 160 bytes of space on caller stack frame + // and an 8-byte aligned stack pointer + MOVD R15, R9 // save current stack (R9 is preserved in the Linux ABI) + SUB $160, R15 // reserve 160 bytes + MOVD $~7, R6 + AND R6, R15 // 8-byte align + BL R11 // this call clobbers volatile registers according to Linux ABI (R0-R5, R14) + MOVD R9, R15 // restore stack + XOR R0, R0 // zero R0 + +nocgo: + // update stackguard after _cgo_init + MOVD (g_stack+stack_lo)(g), R2 + ADD $const__StackGuard, R2 + MOVD R2, g_stackguard0(g) + MOVD R2, g_stackguard1(g) + + // set the per-goroutine and per-mach "registers" + MOVD $runtime·m0(SB), R2 + + // save m->g0 = g0 + MOVD g, m_g0(R2) + // save m0 to g0->m + MOVD R2, g_m(g) + + BL runtime·check(SB) + + // argc/argv are already prepared on stack + BL runtime·args(SB) + BL runtime·osinit(SB) + BL runtime·schedinit(SB) + + // create a new goroutine to start program + MOVD $runtime·mainPC(SB), R2 // entry + SUB $16, R15 + MOVD R2, 8(R15) + MOVD $0, 0(R15) + BL runtime·newproc(SB) + ADD $16, R15 + + // start this M + BL runtime·mstart(SB) + + MOVD $0, 1(R0) + RET + +DATA runtime·mainPC+0(SB)/8,$runtime·main(SB) +GLOBL runtime·mainPC(SB),RODATA,$8 + +TEXT runtime·breakpoint(SB),NOSPLIT|NOFRAME,$0-0 + MOVD $0, 2(R0) + RET + +TEXT runtime·asminit(SB),NOSPLIT|NOFRAME,$0-0 + RET + +TEXT runtime·mstart(SB),NOSPLIT|TOPFRAME,$0 + CALL runtime·mstart0(SB) + RET // not reached + +/* + * go-routine + */ + +// void gogo(Gobuf*) +// restore state from Gobuf; longjmp +TEXT runtime·gogo(SB), NOSPLIT|NOFRAME, $0-8 + MOVD buf+0(FP), R5 + MOVD gobuf_g(R5), R6 + MOVD 0(R6), R7 // make sure g != nil + BR gogo<>(SB) + +TEXT gogo<>(SB), NOSPLIT|NOFRAME, $0 + MOVD R6, g + BL runtime·save_g(SB) + + MOVD 0(g), R4 + MOVD gobuf_sp(R5), R15 + MOVD gobuf_lr(R5), LR + MOVD gobuf_ret(R5), R3 + MOVD gobuf_ctxt(R5), R12 + MOVD $0, gobuf_sp(R5) + MOVD $0, gobuf_ret(R5) + MOVD $0, gobuf_lr(R5) + MOVD $0, gobuf_ctxt(R5) + CMP R0, R0 // set condition codes for == test, needed by stack split + MOVD gobuf_pc(R5), R6 + BR (R6) + +// void mcall(fn func(*g)) +// Switch to m->g0's stack, call fn(g). +// Fn must never return. It should gogo(&g->sched) +// to keep running g. +TEXT runtime·mcall(SB), NOSPLIT, $-8-8 + // Save caller state in g->sched + MOVD R15, (g_sched+gobuf_sp)(g) + MOVD LR, (g_sched+gobuf_pc)(g) + MOVD $0, (g_sched+gobuf_lr)(g) + + // Switch to m->g0 & its stack, call fn. + MOVD g, R3 + MOVD g_m(g), R8 + MOVD m_g0(R8), g + BL runtime·save_g(SB) + CMP g, R3 + BNE 2(PC) + BR runtime·badmcall(SB) + MOVD fn+0(FP), R12 // context + MOVD 0(R12), R4 // code pointer + MOVD (g_sched+gobuf_sp)(g), R15 // sp = m->g0->sched.sp + SUB $16, R15 + MOVD R3, 8(R15) + MOVD $0, 0(R15) + BL (R4) + BR runtime·badmcall2(SB) + +// systemstack_switch is a dummy routine that systemstack leaves at the bottom +// of the G stack. We need to distinguish the routine that +// lives at the bottom of the G stack from the one that lives +// at the top of the system stack because the one at the top of +// the system stack terminates the stack walk (see topofstack()). +TEXT runtime·systemstack_switch(SB), NOSPLIT, $0-0 + UNDEF + BL (LR) // make sure this function is not leaf + RET + +// func systemstack(fn func()) +TEXT runtime·systemstack(SB), NOSPLIT, $0-8 + MOVD fn+0(FP), R3 // R3 = fn + MOVD R3, R12 // context + MOVD g_m(g), R4 // R4 = m + + MOVD m_gsignal(R4), R5 // R5 = gsignal + CMPBEQ g, R5, noswitch + + MOVD m_g0(R4), R5 // R5 = g0 + CMPBEQ g, R5, noswitch + + MOVD m_curg(R4), R6 + CMPBEQ g, R6, switch + + // Bad: g is not gsignal, not g0, not curg. What is it? + // Hide call from linker nosplit analysis. + MOVD $runtime·badsystemstack(SB), R3 + BL (R3) + BL runtime·abort(SB) + +switch: + // save our state in g->sched. Pretend to + // be systemstack_switch if the G stack is scanned. + BL gosave_systemstack_switch<>(SB) + + // switch to g0 + MOVD R5, g + BL runtime·save_g(SB) + MOVD (g_sched+gobuf_sp)(g), R15 + + // call target function + MOVD 0(R12), R3 // code pointer + BL (R3) + + // switch back to g + MOVD g_m(g), R3 + MOVD m_curg(R3), g + BL runtime·save_g(SB) + MOVD (g_sched+gobuf_sp)(g), R15 + MOVD $0, (g_sched+gobuf_sp)(g) + RET + +noswitch: + // already on m stack, just call directly + // Using a tail call here cleans up tracebacks since we won't stop + // at an intermediate systemstack. + MOVD 0(R12), R3 // code pointer + MOVD 0(R15), LR // restore LR + ADD $8, R15 + BR (R3) + +/* + * support for morestack + */ + +// Called during function prolog when more stack is needed. +// Caller has already loaded: +// R3: framesize, R4: argsize, R5: LR +// +// The traceback routines see morestack on a g0 as being +// the top of a stack (for example, morestack calling newstack +// calling the scheduler calling newm calling gc), so we must +// record an argument size. For that purpose, it has no arguments. +TEXT runtime·morestack(SB),NOSPLIT|NOFRAME,$0-0 + // Cannot grow scheduler stack (m->g0). + MOVD g_m(g), R7 + MOVD m_g0(R7), R8 + CMPBNE g, R8, 3(PC) + BL runtime·badmorestackg0(SB) + BL runtime·abort(SB) + + // Cannot grow signal stack (m->gsignal). + MOVD m_gsignal(R7), R8 + CMP g, R8 + BNE 3(PC) + BL runtime·badmorestackgsignal(SB) + BL runtime·abort(SB) + + // Called from f. + // Set g->sched to context in f. + MOVD R15, (g_sched+gobuf_sp)(g) + MOVD LR, R8 + MOVD R8, (g_sched+gobuf_pc)(g) + MOVD R5, (g_sched+gobuf_lr)(g) + MOVD R12, (g_sched+gobuf_ctxt)(g) + + // Called from f. + // Set m->morebuf to f's caller. + MOVD R5, (m_morebuf+gobuf_pc)(R7) // f's caller's PC + MOVD R15, (m_morebuf+gobuf_sp)(R7) // f's caller's SP + MOVD g, (m_morebuf+gobuf_g)(R7) + + // Call newstack on m->g0's stack. + MOVD m_g0(R7), g + BL runtime·save_g(SB) + MOVD (g_sched+gobuf_sp)(g), R15 + // Create a stack frame on g0 to call newstack. + MOVD $0, -8(R15) // Zero saved LR in frame + SUB $8, R15 + BL runtime·newstack(SB) + + // Not reached, but make sure the return PC from the call to newstack + // is still in this function, and not the beginning of the next. + UNDEF + +TEXT runtime·morestack_noctxt(SB),NOSPLIT|NOFRAME,$0-0 + // Force SPWRITE. This function doesn't actually write SP, + // but it is called with a special calling convention where + // the caller doesn't save LR on stack but passes it as a + // register (R5), and the unwinder currently doesn't understand. + // Make it SPWRITE to stop unwinding. (See issue 54332) + MOVD R15, R15 + + MOVD $0, R12 + BR runtime·morestack(SB) + +// reflectcall: call a function with the given argument list +// func call(stackArgsType *_type, f *FuncVal, stackArgs *byte, stackArgsSize, stackRetOffset, frameSize uint32, regArgs *abi.RegArgs). +// we don't have variable-sized frames, so we use a small number +// of constant-sized-frame functions to encode a few bits of size in the pc. +// Caution: ugly multiline assembly macros in your future! + +#define DISPATCH(NAME,MAXSIZE) \ + MOVD $MAXSIZE, R4; \ + CMP R3, R4; \ + BGT 3(PC); \ + MOVD $NAME(SB), R5; \ + BR (R5) +// Note: can't just "BR NAME(SB)" - bad inlining results. + +TEXT ·reflectcall(SB), NOSPLIT, $-8-48 + MOVWZ frameSize+32(FP), R3 + DISPATCH(runtime·call16, 16) + DISPATCH(runtime·call32, 32) + DISPATCH(runtime·call64, 64) + DISPATCH(runtime·call128, 128) + DISPATCH(runtime·call256, 256) + DISPATCH(runtime·call512, 512) + DISPATCH(runtime·call1024, 1024) + DISPATCH(runtime·call2048, 2048) + DISPATCH(runtime·call4096, 4096) + DISPATCH(runtime·call8192, 8192) + DISPATCH(runtime·call16384, 16384) + DISPATCH(runtime·call32768, 32768) + DISPATCH(runtime·call65536, 65536) + DISPATCH(runtime·call131072, 131072) + DISPATCH(runtime·call262144, 262144) + DISPATCH(runtime·call524288, 524288) + DISPATCH(runtime·call1048576, 1048576) + DISPATCH(runtime·call2097152, 2097152) + DISPATCH(runtime·call4194304, 4194304) + DISPATCH(runtime·call8388608, 8388608) + DISPATCH(runtime·call16777216, 16777216) + DISPATCH(runtime·call33554432, 33554432) + DISPATCH(runtime·call67108864, 67108864) + DISPATCH(runtime·call134217728, 134217728) + DISPATCH(runtime·call268435456, 268435456) + DISPATCH(runtime·call536870912, 536870912) + DISPATCH(runtime·call1073741824, 1073741824) + MOVD $runtime·badreflectcall(SB), R5 + BR (R5) + +#define CALLFN(NAME,MAXSIZE) \ +TEXT NAME(SB), WRAPPER, $MAXSIZE-48; \ + NO_LOCAL_POINTERS; \ + /* copy arguments to stack */ \ + MOVD stackArgs+16(FP), R4; \ + MOVWZ stackArgsSize+24(FP), R5; \ + MOVD $stack-MAXSIZE(SP), R6; \ +loopArgs: /* copy 256 bytes at a time */ \ + CMP R5, $256; \ + BLT tailArgs; \ + SUB $256, R5; \ + MVC $256, 0(R4), 0(R6); \ + MOVD $256(R4), R4; \ + MOVD $256(R6), R6; \ + BR loopArgs; \ +tailArgs: /* copy remaining bytes */ \ + CMP R5, $0; \ + BEQ callFunction; \ + SUB $1, R5; \ + EXRL $callfnMVC<>(SB), R5; \ +callFunction: \ + MOVD f+8(FP), R12; \ + MOVD (R12), R8; \ + PCDATA $PCDATA_StackMapIndex, $0; \ + BL (R8); \ + /* copy return values back */ \ + MOVD stackArgsType+0(FP), R7; \ + MOVD stackArgs+16(FP), R6; \ + MOVWZ stackArgsSize+24(FP), R5; \ + MOVD $stack-MAXSIZE(SP), R4; \ + MOVWZ stackRetOffset+28(FP), R1; \ + ADD R1, R4; \ + ADD R1, R6; \ + SUB R1, R5; \ + BL callRet<>(SB); \ + RET + +// callRet copies return values back at the end of call*. This is a +// separate function so it can allocate stack space for the arguments +// to reflectcallmove. It does not follow the Go ABI; it expects its +// arguments in registers. +TEXT callRet<>(SB), NOSPLIT, $40-0 + MOVD R7, 8(R15) + MOVD R6, 16(R15) + MOVD R4, 24(R15) + MOVD R5, 32(R15) + MOVD $0, 40(R15) + BL runtime·reflectcallmove(SB) + RET + +CALLFN(·call16, 16) +CALLFN(·call32, 32) +CALLFN(·call64, 64) +CALLFN(·call128, 128) +CALLFN(·call256, 256) +CALLFN(·call512, 512) +CALLFN(·call1024, 1024) +CALLFN(·call2048, 2048) +CALLFN(·call4096, 4096) +CALLFN(·call8192, 8192) +CALLFN(·call16384, 16384) +CALLFN(·call32768, 32768) +CALLFN(·call65536, 65536) +CALLFN(·call131072, 131072) +CALLFN(·call262144, 262144) +CALLFN(·call524288, 524288) +CALLFN(·call1048576, 1048576) +CALLFN(·call2097152, 2097152) +CALLFN(·call4194304, 4194304) +CALLFN(·call8388608, 8388608) +CALLFN(·call16777216, 16777216) +CALLFN(·call33554432, 33554432) +CALLFN(·call67108864, 67108864) +CALLFN(·call134217728, 134217728) +CALLFN(·call268435456, 268435456) +CALLFN(·call536870912, 536870912) +CALLFN(·call1073741824, 1073741824) + +// Not a function: target for EXRL (execute relative long) instruction. +TEXT callfnMVC<>(SB),NOSPLIT|NOFRAME,$0-0 + MVC $1, 0(R4), 0(R6) + +TEXT runtime·procyield(SB),NOSPLIT,$0-0 + RET + +// Save state of caller into g->sched, +// but using fake PC from systemstack_switch. +// Must only be called from functions with no locals ($0) +// or else unwinding from systemstack_switch is incorrect. +// Smashes R1. +TEXT gosave_systemstack_switch<>(SB),NOSPLIT|NOFRAME,$0 + MOVD $runtime·systemstack_switch(SB), R1 + ADD $16, R1 // get past prologue + MOVD R1, (g_sched+gobuf_pc)(g) + MOVD R15, (g_sched+gobuf_sp)(g) + MOVD $0, (g_sched+gobuf_lr)(g) + MOVD $0, (g_sched+gobuf_ret)(g) + // Assert ctxt is zero. See func save. + MOVD (g_sched+gobuf_ctxt)(g), R1 + CMPBEQ R1, $0, 2(PC) + BL runtime·abort(SB) + RET + +// func asmcgocall(fn, arg unsafe.Pointer) int32 +// Call fn(arg) on the scheduler stack, +// aligned appropriately for the gcc ABI. +// See cgocall.go for more details. +TEXT ·asmcgocall(SB),NOSPLIT,$0-20 + // R2 = argc; R3 = argv; R11 = temp; R13 = g; R15 = stack pointer + // C TLS base pointer in AR0:AR1 + MOVD fn+0(FP), R3 + MOVD arg+8(FP), R4 + + MOVD R15, R2 // save original stack pointer + MOVD g, R5 + + // Figure out if we need to switch to m->g0 stack. + // We get called to create new OS threads too, and those + // come in on the m->g0 stack already. Or we might already + // be on the m->gsignal stack. + MOVD g_m(g), R6 + MOVD m_gsignal(R6), R7 + CMPBEQ R7, g, g0 + MOVD m_g0(R6), R7 + CMPBEQ R7, g, g0 + BL gosave_systemstack_switch<>(SB) + MOVD R7, g + BL runtime·save_g(SB) + MOVD (g_sched+gobuf_sp)(g), R15 + + // Now on a scheduling stack (a pthread-created stack). +g0: + // Save room for two of our pointers, plus 160 bytes of callee + // save area that lives on the caller stack. + SUB $176, R15 + MOVD $~7, R6 + AND R6, R15 // 8-byte alignment for gcc ABI + MOVD R5, 168(R15) // save old g on stack + MOVD (g_stack+stack_hi)(R5), R5 + SUB R2, R5 + MOVD R5, 160(R15) // save depth in old g stack (can't just save SP, as stack might be copied during a callback) + MOVD $0, 0(R15) // clear back chain pointer (TODO can we give it real back trace information?) + MOVD R4, R2 // arg in R2 + BL R3 // can clobber: R0-R5, R14, F0-F3, F5, F7-F15 + + XOR R0, R0 // set R0 back to 0. + // Restore g, stack pointer. + MOVD 168(R15), g + BL runtime·save_g(SB) + MOVD (g_stack+stack_hi)(g), R5 + MOVD 160(R15), R6 + SUB R6, R5 + MOVD R5, R15 + + MOVW R2, ret+16(FP) + RET + +// cgocallback(fn, frame unsafe.Pointer, ctxt uintptr) +// See cgocall.go for more details. +TEXT ·cgocallback(SB),NOSPLIT,$24-24 + NO_LOCAL_POINTERS + + // Load m and g from thread-local storage. + MOVB runtime·iscgo(SB), R3 + CMPBEQ R3, $0, nocgo + BL runtime·load_g(SB) + +nocgo: + // If g is nil, Go did not create the current thread. + // Call needm to obtain one for temporary use. + // In this case, we're running on the thread stack, so there's + // lots of space, but the linker doesn't know. Hide the call from + // the linker analysis by using an indirect call. + CMPBEQ g, $0, needm + + MOVD g_m(g), R8 + MOVD R8, savedm-8(SP) + BR havem + +needm: + MOVD g, savedm-8(SP) // g is zero, so is m. + MOVD $runtime·needm(SB), R3 + BL (R3) + + // Set m->sched.sp = SP, so that if a panic happens + // during the function we are about to execute, it will + // have a valid SP to run on the g0 stack. + // The next few lines (after the havem label) + // will save this SP onto the stack and then write + // the same SP back to m->sched.sp. That seems redundant, + // but if an unrecovered panic happens, unwindm will + // restore the g->sched.sp from the stack location + // and then systemstack will try to use it. If we don't set it here, + // that restored SP will be uninitialized (typically 0) and + // will not be usable. + MOVD g_m(g), R8 + MOVD m_g0(R8), R3 + MOVD R15, (g_sched+gobuf_sp)(R3) + +havem: + // Now there's a valid m, and we're running on its m->g0. + // Save current m->g0->sched.sp on stack and then set it to SP. + // Save current sp in m->g0->sched.sp in preparation for + // switch back to m->curg stack. + // NOTE: unwindm knows that the saved g->sched.sp is at 8(R1) aka savedsp-16(SP). + MOVD m_g0(R8), R3 + MOVD (g_sched+gobuf_sp)(R3), R4 + MOVD R4, savedsp-24(SP) // must match frame size + MOVD R15, (g_sched+gobuf_sp)(R3) + + // Switch to m->curg stack and call runtime.cgocallbackg. + // Because we are taking over the execution of m->curg + // but *not* resuming what had been running, we need to + // save that information (m->curg->sched) so we can restore it. + // We can restore m->curg->sched.sp easily, because calling + // runtime.cgocallbackg leaves SP unchanged upon return. + // To save m->curg->sched.pc, we push it onto the curg stack and + // open a frame the same size as cgocallback's g0 frame. + // Once we switch to the curg stack, the pushed PC will appear + // to be the return PC of cgocallback, so that the traceback + // will seamlessly trace back into the earlier calls. + MOVD m_curg(R8), g + BL runtime·save_g(SB) + MOVD (g_sched+gobuf_sp)(g), R4 // prepare stack as R4 + MOVD (g_sched+gobuf_pc)(g), R5 + MOVD R5, -(24+8)(R4) // "saved LR"; must match frame size + // Gather our arguments into registers. + MOVD fn+0(FP), R1 + MOVD frame+8(FP), R2 + MOVD ctxt+16(FP), R3 + MOVD $-(24+8)(R4), R15 // switch stack; must match frame size + MOVD R1, 8(R15) + MOVD R2, 16(R15) + MOVD R3, 24(R15) + BL runtime·cgocallbackg(SB) + + // Restore g->sched (== m->curg->sched) from saved values. + MOVD 0(R15), R5 + MOVD R5, (g_sched+gobuf_pc)(g) + MOVD $(24+8)(R15), R4 // must match frame size + MOVD R4, (g_sched+gobuf_sp)(g) + + // Switch back to m->g0's stack and restore m->g0->sched.sp. + // (Unlike m->curg, the g0 goroutine never uses sched.pc, + // so we do not have to restore it.) + MOVD g_m(g), R8 + MOVD m_g0(R8), g + BL runtime·save_g(SB) + MOVD (g_sched+gobuf_sp)(g), R15 + MOVD savedsp-24(SP), R4 // must match frame size + MOVD R4, (g_sched+gobuf_sp)(g) + + // If the m on entry was nil, we called needm above to borrow an m + // for the duration of the call. Since the call is over, return it with dropm. + MOVD savedm-8(SP), R6 + CMPBNE R6, $0, droppedm + MOVD $runtime·dropm(SB), R3 + BL (R3) +droppedm: + + // Done! + RET + +// void setg(G*); set g. for use by needm. +TEXT runtime·setg(SB), NOSPLIT, $0-8 + MOVD gg+0(FP), g + // This only happens if iscgo, so jump straight to save_g + BL runtime·save_g(SB) + RET + +// void setg_gcc(G*); set g in C TLS. +// Must obey the gcc calling convention. +TEXT setg_gcc<>(SB),NOSPLIT|NOFRAME,$0-0 + // The standard prologue clobbers LR (R14), which is callee-save in + // the C ABI, so we have to use NOFRAME and save LR ourselves. + MOVD LR, R1 + // Also save g, R10, and R11 since they're callee-save in C ABI + MOVD R10, R3 + MOVD g, R4 + MOVD R11, R5 + + MOVD R2, g + BL runtime·save_g(SB) + + MOVD R5, R11 + MOVD R4, g + MOVD R3, R10 + MOVD R1, LR + RET + +TEXT runtime·abort(SB),NOSPLIT|NOFRAME,$0-0 + MOVW (R0), R0 + UNDEF + +// int64 runtime·cputicks(void) +TEXT runtime·cputicks(SB),NOSPLIT,$0-8 + // The TOD clock on s390 counts from the year 1900 in ~250ps intervals. + // This means that since about 1972 the msb has been set, making the + // result of a call to STORE CLOCK (stck) a negative number. + // We clear the msb to make it positive. + STCK ret+0(FP) // serialises before and after call + MOVD ret+0(FP), R3 // R3 will wrap to 0 in the year 2043 + SLD $1, R3 + SRD $1, R3 + MOVD R3, ret+0(FP) + RET + +// AES hashing not implemented for s390x +TEXT runtime·memhash(SB),NOSPLIT|NOFRAME,$0-32 + JMP runtime·memhashFallback(SB) +TEXT runtime·strhash(SB),NOSPLIT|NOFRAME,$0-24 + JMP runtime·strhashFallback(SB) +TEXT runtime·memhash32(SB),NOSPLIT|NOFRAME,$0-24 + JMP runtime·memhash32Fallback(SB) +TEXT runtime·memhash64(SB),NOSPLIT|NOFRAME,$0-24 + JMP runtime·memhash64Fallback(SB) + +TEXT runtime·return0(SB), NOSPLIT, $0 + MOVW $0, R3 + RET + +// Called from cgo wrappers, this function returns g->m->curg.stack.hi. +// Must obey the gcc calling convention. +TEXT _cgo_topofstack(SB),NOSPLIT|NOFRAME,$0 + // g (R13), R10, R11 and LR (R14) are callee-save in the C ABI, so save them + MOVD g, R1 + MOVD R10, R3 + MOVD LR, R4 + MOVD R11, R5 + + BL runtime·load_g(SB) // clobbers g (R13), R10, R11 + MOVD g_m(g), R2 + MOVD m_curg(R2), R2 + MOVD (g_stack+stack_hi)(R2), R2 + + MOVD R1, g + MOVD R3, R10 + MOVD R4, LR + MOVD R5, R11 + RET + +// The top-most function running on a goroutine +// returns to goexit+PCQuantum. +TEXT runtime·goexit(SB),NOSPLIT|NOFRAME|TOPFRAME,$0-0 + BYTE $0x07; BYTE $0x00; // 2-byte nop + BL runtime·goexit1(SB) // does not return + // traceback from goexit1 must hit code range of goexit + BYTE $0x07; BYTE $0x00; // 2-byte nop + +TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0 + // Stores are already ordered on s390x, so this is just a + // compile barrier. + RET + +// This is called from .init_array and follows the platform, not Go, ABI. +// We are overly conservative. We could only save the registers we use. +// However, since this function is only called once per loaded module +// performance is unimportant. +TEXT runtime·addmoduledata(SB),NOSPLIT|NOFRAME,$0-0 + // Save R6-R15 in the register save area of the calling function. + // Don't bother saving F8-F15 as we aren't doing any calls. + STMG R6, R15, 48(R15) + + // append the argument (passed in R2, as per the ELF ABI) to the + // moduledata linked list. + MOVD runtime·lastmoduledatap(SB), R1 + MOVD R2, moduledata_next(R1) + MOVD R2, runtime·lastmoduledatap(SB) + + // Restore R6-R15. + LMG 48(R15), R6, R15 + RET + +TEXT ·checkASM(SB),NOSPLIT,$0-1 + MOVB $1, ret+0(FP) + RET + +// gcWriteBarrier performs a heap pointer write and informs the GC. +// +// gcWriteBarrier does NOT follow the Go ABI. It takes two arguments: +// - R2 is the destination of the write +// - R3 is the value being written at R2. +// It clobbers R10 (the temp register) and R1 (used by PLT stub). +// It does not clobber any other general-purpose registers, +// but may clobber others (e.g., floating point registers). +TEXT runtime·gcWriteBarrier(SB),NOSPLIT,$96 + // Save the registers clobbered by the fast path. + MOVD R4, 96(R15) + MOVD g_m(g), R1 + MOVD m_p(R1), R1 + // Increment wbBuf.next position. + MOVD $16, R4 + ADD (p_wbBuf+wbBuf_next)(R1), R4 + MOVD R4, (p_wbBuf+wbBuf_next)(R1) + MOVD (p_wbBuf+wbBuf_end)(R1), R1 + // Record the write. + MOVD R3, -16(R4) // Record value + MOVD (R2), R10 // TODO: This turns bad writes into bad reads. + MOVD R10, -8(R4) // Record *slot + // Is the buffer full? + CMPBEQ R4, R1, flush +ret: + MOVD 96(R15), R4 + // Do the write. + MOVD R3, (R2) + RET + +flush: + // Save all general purpose registers since these could be + // clobbered by wbBufFlush and were not saved by the caller. + STMG R2, R3, 8(R15) // set R2 and R3 as arguments for wbBufFlush + MOVD R0, 24(R15) + // R1 already saved. + // R4 already saved. + STMG R5, R12, 32(R15) // save R5 - R12 + // R13 is g. + // R14 is LR. + // R15 is SP. + + // This takes arguments R2 and R3. + CALL runtime·wbBufFlush(SB) + + LMG 8(R15), R2, R3 // restore R2 - R3 + MOVD 24(R15), R0 // restore R0 + LMG 32(R15), R5, R12 // restore R5 - R12 + JMP ret + +// Note: these functions use a special calling convention to save generated code space. +// Arguments are passed in registers, but the space for those arguments are allocated +// in the caller's stack frame. These stubs write the args into that stack space and +// then tail call to the corresponding runtime handler. +// The tail call makes these stubs disappear in backtraces. +TEXT runtime·panicIndex(SB),NOSPLIT,$0-16 + MOVD R0, x+0(FP) + MOVD R1, y+8(FP) + JMP runtime·goPanicIndex(SB) +TEXT runtime·panicIndexU(SB),NOSPLIT,$0-16 + MOVD R0, x+0(FP) + MOVD R1, y+8(FP) + JMP runtime·goPanicIndexU(SB) +TEXT runtime·panicSliceAlen(SB),NOSPLIT,$0-16 + MOVD R1, x+0(FP) + MOVD R2, y+8(FP) + JMP runtime·goPanicSliceAlen(SB) +TEXT runtime·panicSliceAlenU(SB),NOSPLIT,$0-16 + MOVD R1, x+0(FP) + MOVD R2, y+8(FP) + JMP runtime·goPanicSliceAlenU(SB) +TEXT runtime·panicSliceAcap(SB),NOSPLIT,$0-16 + MOVD R1, x+0(FP) + MOVD R2, y+8(FP) + JMP runtime·goPanicSliceAcap(SB) +TEXT runtime·panicSliceAcapU(SB),NOSPLIT,$0-16 + MOVD R1, x+0(FP) + MOVD R2, y+8(FP) + JMP runtime·goPanicSliceAcapU(SB) +TEXT runtime·panicSliceB(SB),NOSPLIT,$0-16 + MOVD R0, x+0(FP) + MOVD R1, y+8(FP) + JMP runtime·goPanicSliceB(SB) +TEXT runtime·panicSliceBU(SB),NOSPLIT,$0-16 + MOVD R0, x+0(FP) + MOVD R1, y+8(FP) + JMP runtime·goPanicSliceBU(SB) +TEXT runtime·panicSlice3Alen(SB),NOSPLIT,$0-16 + MOVD R2, x+0(FP) + MOVD R3, y+8(FP) + JMP runtime·goPanicSlice3Alen(SB) +TEXT runtime·panicSlice3AlenU(SB),NOSPLIT,$0-16 + MOVD R2, x+0(FP) + MOVD R3, y+8(FP) + JMP runtime·goPanicSlice3AlenU(SB) +TEXT runtime·panicSlice3Acap(SB),NOSPLIT,$0-16 + MOVD R2, x+0(FP) + MOVD R3, y+8(FP) + JMP runtime·goPanicSlice3Acap(SB) +TEXT runtime·panicSlice3AcapU(SB),NOSPLIT,$0-16 + MOVD R2, x+0(FP) + MOVD R3, y+8(FP) + JMP runtime·goPanicSlice3AcapU(SB) +TEXT runtime·panicSlice3B(SB),NOSPLIT,$0-16 + MOVD R1, x+0(FP) + MOVD R2, y+8(FP) + JMP runtime·goPanicSlice3B(SB) +TEXT runtime·panicSlice3BU(SB),NOSPLIT,$0-16 + MOVD R1, x+0(FP) + MOVD R2, y+8(FP) + JMP runtime·goPanicSlice3BU(SB) +TEXT runtime·panicSlice3C(SB),NOSPLIT,$0-16 + MOVD R0, x+0(FP) + MOVD R1, y+8(FP) + JMP runtime·goPanicSlice3C(SB) +TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16 + MOVD R0, x+0(FP) + MOVD R1, y+8(FP) + JMP runtime·goPanicSlice3CU(SB) +TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-16 + MOVD R2, x+0(FP) + MOVD R3, y+8(FP) + JMP runtime·goPanicSliceConvert(SB) |