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-rw-r--r--src/runtime/asm_s390x.s918
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diff --git a/src/runtime/asm_s390x.s b/src/runtime/asm_s390x.s
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+// 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,$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 $24, R15
+ MOVD R2, 16(R15)
+ MOVD $0, 8(R15)
+ MOVD $0, 0(R15)
+ BL runtime·newproc(SB)
+ ADD $24, 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
+
+/*
+ * go-routine
+ */
+
+// void gosave(Gobuf*)
+// save state in Gobuf; setjmp
+TEXT runtime·gosave(SB), NOSPLIT, $-8-8
+ MOVD buf+0(FP), R3
+ MOVD R15, gobuf_sp(R3)
+ MOVD LR, gobuf_pc(R3)
+ MOVD g, gobuf_g(R3)
+ MOVD $0, gobuf_lr(R3)
+ MOVD $0, gobuf_ret(R3)
+ // Assert ctxt is zero. See func save.
+ MOVD gobuf_ctxt(R3), R3
+ CMPBEQ R3, $0, 2(PC)
+ BL runtime·badctxt(SB)
+ RET
+
+// void gogo(Gobuf*)
+// restore state from Gobuf; longjmp
+TEXT runtime·gogo(SB), NOSPLIT, $16-8
+ MOVD buf+0(FP), R5
+ MOVD gobuf_g(R5), g // make sure g is not nil
+ 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)
+ MOVD g, (g_sched+gobuf_g)(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.
+ MOVD $runtime·systemstack_switch(SB), R6
+ ADD $16, R6 // get past prologue
+ MOVD R6, (g_sched+gobuf_pc)(g)
+ MOVD R15, (g_sched+gobuf_sp)(g)
+ MOVD $0, (g_sched+gobuf_lr)(g)
+ MOVD g, (g_sched+gobuf_g)(g)
+
+ // switch to g0
+ MOVD R5, g
+ BL runtime·save_g(SB)
+ MOVD (g_sched+gobuf_sp)(g), R3
+ // make it look like mstart called systemstack on g0, to stop traceback
+ SUB $8, R3
+ MOVD $runtime·mstart(SB), R4
+ MOVD R4, 0(R3)
+ MOVD R3, 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
+ MOVD $0, R12
+ BR runtime·morestack(SB)
+
+// reflectcall: call a function with the given argument list
+// func call(argtype *_type, f *FuncVal, arg *byte, argsize, retoffset uint32).
+// 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, $-8-32
+ MOVWZ argsize+24(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-24; \
+ NO_LOCAL_POINTERS; \
+ /* copy arguments to stack */ \
+ MOVD arg+16(FP), R4; \
+ MOVWZ argsize+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 argtype+0(FP), R7; \
+ MOVD arg+16(FP), R6; \
+ MOVWZ n+24(FP), R5; \
+ MOVD $stack-MAXSIZE(SP), R4; \
+ MOVWZ retoffset+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, $32-0
+ MOVD R7, 8(R15)
+ MOVD R6, 16(R15)
+ MOVD R4, 24(R15)
+ MOVD R5, 32(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
+
+// void jmpdefer(fv, sp);
+// called from deferreturn.
+// 1. grab stored LR for caller
+// 2. sub 6 bytes to get back to BL deferreturn (size of BRASL instruction)
+// 3. BR to fn
+TEXT runtime·jmpdefer(SB),NOSPLIT|NOFRAME,$0-16
+ MOVD 0(R15), R1
+ SUB $6, R1, LR
+
+ MOVD fv+0(FP), R12
+ MOVD argp+8(FP), R15
+ SUB $8, R15
+ MOVD 0(R12), R3
+ BR (R3)
+
+// Save state of caller into g->sched. Smashes R1.
+TEXT gosave<>(SB),NOSPLIT|NOFRAME,$0
+ MOVD LR, (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·badctxt(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.
+ MOVD g_m(g), R6
+ MOVD m_g0(R6), R6
+ CMPBEQ R6, g, g0
+ BL gosave<>(SB)
+ MOVD R6, 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).
+// It does not clobber any other general-purpose registers,
+// but may clobber others (e.g., floating point registers).
+TEXT runtime·gcWriteBarrier(SB),NOSPLIT,$104
+ // Save the registers clobbered by the fast path.
+ MOVD R1, 96(R15)
+ MOVD R4, 104(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), R1
+ MOVD 104(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)
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-14 02:46:28 +0000