Text file
src/runtime/asm_riscv64.s
Documentation: runtime
1// Copyright 2017 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5#include "go_asm.h"
6#include "funcdata.h"
7#include "textflag.h"
8
9// func rt0_go()
10TEXT runtime·rt0_go(SB),NOSPLIT|TOPFRAME,$0
11 // X2 = stack; A0 = argc; A1 = argv
12 SUB $24, X2
13 MOV A0, 8(X2) // argc
14 MOV A1, 16(X2) // argv
15
16 // create istack out of the given (operating system) stack.
17 // _cgo_init may update stackguard.
18 MOV $runtime·g0(SB), g
19 MOV $(-64*1024), T0
20 ADD T0, X2, T1
21 MOV T1, g_stackguard0(g)
22 MOV T1, g_stackguard1(g)
23 MOV T1, (g_stack+stack_lo)(g)
24 MOV X2, (g_stack+stack_hi)(g)
25
26 // if there is a _cgo_init, call it using the gcc ABI.
27 MOV _cgo_init(SB), T0
28 BEQ T0, ZERO, nocgo
29
30 MOV ZERO, A3 // arg 3: not used
31 MOV ZERO, A2 // arg 2: not used
32 MOV $setg_gcc<>(SB), A1 // arg 1: setg
33 MOV g, A0 // arg 0: G
34 JALR RA, T0
35
36nocgo:
37 // update stackguard after _cgo_init
38 MOV (g_stack+stack_lo)(g), T0
39 ADD $const_stackGuard, T0
40 MOV T0, g_stackguard0(g)
41 MOV T0, g_stackguard1(g)
42
43 // set the per-goroutine and per-mach "registers"
44 MOV $runtime·m0(SB), T0
45
46 // save m->g0 = g0
47 MOV g, m_g0(T0)
48 // save m0 to g0->m
49 MOV T0, g_m(g)
50
51 CALL runtime·check(SB)
52
53 // args are already prepared
54 CALL runtime·args(SB)
55 CALL runtime·osinit(SB)
56 CALL runtime·schedinit(SB)
57
58 // create a new goroutine to start program
59 MOV $runtime·mainPC(SB), T0 // entry
60 SUB $16, X2
61 MOV T0, 8(X2)
62 MOV ZERO, 0(X2)
63 CALL runtime·newproc(SB)
64 ADD $16, X2
65
66 // start this M
67 CALL runtime·mstart(SB)
68
69 WORD $0 // crash if reached
70 RET
71
72TEXT runtime·mstart(SB),NOSPLIT|TOPFRAME,$0
73 CALL runtime·mstart0(SB)
74 RET // not reached
75
76// void setg_gcc(G*); set g called from gcc with g in A0
77TEXT setg_gcc<>(SB),NOSPLIT,$0-0
78 MOV A0, g
79 CALL runtime·save_g(SB)
80 RET
81
82// func cputicks() int64
83TEXT runtime·cputicks(SB),NOSPLIT,$0-8
84 // RDTIME to emulate cpu ticks
85 // RDCYCLE reads counter that is per HART(core) based
86 // according to the riscv manual, see issue 46737
87 RDTIME A0
88 MOV A0, ret+0(FP)
89 RET
90
91// systemstack_switch is a dummy routine that systemstack leaves at the bottom
92// of the G stack. We need to distinguish the routine that
93// lives at the bottom of the G stack from the one that lives
94// at the top of the system stack because the one at the top of
95// the system stack terminates the stack walk (see topofstack()).
96TEXT runtime·systemstack_switch(SB), NOSPLIT, $0-0
97 UNDEF
98 JALR RA, ZERO // make sure this function is not leaf
99 RET
100
101// func systemstack(fn func())
102TEXT runtime·systemstack(SB), NOSPLIT, $0-8
103 MOV fn+0(FP), CTXT // CTXT = fn
104 MOV g_m(g), T0 // T0 = m
105
106 MOV m_gsignal(T0), T1 // T1 = gsignal
107 BEQ g, T1, noswitch
108
109 MOV m_g0(T0), T1 // T1 = g0
110 BEQ g, T1, noswitch
111
112 MOV m_curg(T0), T2
113 BEQ g, T2, switch
114
115 // Bad: g is not gsignal, not g0, not curg. What is it?
116 // Hide call from linker nosplit analysis.
117 MOV $runtime·badsystemstack(SB), T1
118 JALR RA, T1
119
120switch:
121 // save our state in g->sched. Pretend to
122 // be systemstack_switch if the G stack is scanned.
123 CALL gosave_systemstack_switch<>(SB)
124
125 // switch to g0
126 MOV T1, g
127 CALL runtime·save_g(SB)
128 MOV (g_sched+gobuf_sp)(g), T0
129 MOV T0, X2
130
131 // call target function
132 MOV 0(CTXT), T1 // code pointer
133 JALR RA, T1
134
135 // switch back to g
136 MOV g_m(g), T0
137 MOV m_curg(T0), g
138 CALL runtime·save_g(SB)
139 MOV (g_sched+gobuf_sp)(g), X2
140 MOV ZERO, (g_sched+gobuf_sp)(g)
141 RET
142
143noswitch:
144 // already on m stack, just call directly
145 // Using a tail call here cleans up tracebacks since we won't stop
146 // at an intermediate systemstack.
147 MOV 0(CTXT), T1 // code pointer
148 ADD $8, X2
149 JMP (T1)
150
151// func switchToCrashStack0(fn func())
152TEXT runtime·switchToCrashStack0<ABIInternal>(SB), NOSPLIT, $0-8
153 MOV X10, CTXT // context register
154 MOV g_m(g), X11 // curm
155
156 // set g to gcrash
157 MOV $runtime·gcrash(SB), g // g = &gcrash
158 CALL runtime·save_g(SB) // clobbers X31
159 MOV X11, g_m(g) // g.m = curm
160 MOV g, m_g0(X11) // curm.g0 = g
161
162 // switch to crashstack
163 MOV (g_stack+stack_hi)(g), X11
164 SUB $(4*8), X11
165 MOV X11, X2
166
167 // call target function
168 MOV 0(CTXT), X10
169 JALR X1, X10
170
171 // should never return
172 CALL runtime·abort(SB)
173 UNDEF
174
175/*
176 * support for morestack
177 */
178
179// Called during function prolog when more stack is needed.
180// Called with return address (i.e. caller's PC) in X5 (aka T0),
181// and the LR register contains the caller's LR.
182//
183// The traceback routines see morestack on a g0 as being
184// the top of a stack (for example, morestack calling newstack
185// calling the scheduler calling newm calling gc), so we must
186// record an argument size. For that purpose, it has no arguments.
187
188// func morestack()
189TEXT runtime·morestack(SB),NOSPLIT|NOFRAME,$0-0
190 // Called from f.
191 // Set g->sched to context in f.
192 MOV X2, (g_sched+gobuf_sp)(g)
193 MOV T0, (g_sched+gobuf_pc)(g)
194 MOV RA, (g_sched+gobuf_lr)(g)
195 MOV CTXT, (g_sched+gobuf_ctxt)(g)
196
197 // Cannot grow scheduler stack (m->g0).
198 MOV g_m(g), A0
199 MOV m_g0(A0), A1
200 BNE g, A1, 3(PC)
201 CALL runtime·badmorestackg0(SB)
202 CALL runtime·abort(SB)
203
204 // Cannot grow signal stack (m->gsignal).
205 MOV m_gsignal(A0), A1
206 BNE g, A1, 3(PC)
207 CALL runtime·badmorestackgsignal(SB)
208 CALL runtime·abort(SB)
209
210 // Called from f.
211 // Set m->morebuf to f's caller.
212 MOV RA, (m_morebuf+gobuf_pc)(A0) // f's caller's PC
213 MOV X2, (m_morebuf+gobuf_sp)(A0) // f's caller's SP
214 MOV g, (m_morebuf+gobuf_g)(A0)
215
216 // Call newstack on m->g0's stack.
217 MOV m_g0(A0), g
218 CALL runtime·save_g(SB)
219 MOV (g_sched+gobuf_sp)(g), X2
220 // Create a stack frame on g0 to call newstack.
221 MOV ZERO, -8(X2) // Zero saved LR in frame
222 SUB $8, X2
223 CALL runtime·newstack(SB)
224
225 // Not reached, but make sure the return PC from the call to newstack
226 // is still in this function, and not the beginning of the next.
227 UNDEF
228
229// func morestack_noctxt()
230TEXT runtime·morestack_noctxt(SB),NOSPLIT|NOFRAME,$0-0
231 // Force SPWRITE. This function doesn't actually write SP,
232 // but it is called with a special calling convention where
233 // the caller doesn't save LR on stack but passes it as a
234 // register, and the unwinder currently doesn't understand.
235 // Make it SPWRITE to stop unwinding. (See issue 54332)
236 MOV X2, X2
237
238 MOV ZERO, CTXT
239 JMP runtime·morestack(SB)
240
241// AES hashing not implemented for riscv64
242TEXT runtime·memhash<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-32
243 JMP runtime·memhashFallback<ABIInternal>(SB)
244TEXT runtime·strhash<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-24
245 JMP runtime·strhashFallback<ABIInternal>(SB)
246TEXT runtime·memhash32<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-24
247 JMP runtime·memhash32Fallback<ABIInternal>(SB)
248TEXT runtime·memhash64<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-24
249 JMP runtime·memhash64Fallback<ABIInternal>(SB)
250
251// func return0()
252TEXT runtime·return0(SB), NOSPLIT, $0
253 MOV $0, A0
254 RET
255
256// restore state from Gobuf; longjmp
257
258// func gogo(buf *gobuf)
259TEXT runtime·gogo(SB), NOSPLIT|NOFRAME, $0-8
260 MOV buf+0(FP), T0
261 MOV gobuf_g(T0), T1
262 MOV 0(T1), ZERO // make sure g != nil
263 JMP gogo<>(SB)
264
265TEXT gogo<>(SB), NOSPLIT|NOFRAME, $0
266 MOV T1, g
267 CALL runtime·save_g(SB)
268
269 MOV gobuf_sp(T0), X2
270 MOV gobuf_lr(T0), RA
271 MOV gobuf_ret(T0), A0
272 MOV gobuf_ctxt(T0), CTXT
273 MOV ZERO, gobuf_sp(T0)
274 MOV ZERO, gobuf_ret(T0)
275 MOV ZERO, gobuf_lr(T0)
276 MOV ZERO, gobuf_ctxt(T0)
277 MOV gobuf_pc(T0), T0
278 JALR ZERO, T0
279
280// func procyield(cycles uint32)
281TEXT runtime·procyield(SB),NOSPLIT,$0-0
282 RET
283
284// Switch to m->g0's stack, call fn(g).
285// Fn must never return. It should gogo(&g->sched)
286// to keep running g.
287
288// func mcall(fn func(*g))
289TEXT runtime·mcall<ABIInternal>(SB), NOSPLIT|NOFRAME, $0-8
290 MOV X10, CTXT
291
292 // Save caller state in g->sched
293 MOV X2, (g_sched+gobuf_sp)(g)
294 MOV RA, (g_sched+gobuf_pc)(g)
295 MOV ZERO, (g_sched+gobuf_lr)(g)
296
297 // Switch to m->g0 & its stack, call fn.
298 MOV g, X10
299 MOV g_m(g), T1
300 MOV m_g0(T1), g
301 CALL runtime·save_g(SB)
302 BNE g, X10, 2(PC)
303 JMP runtime·badmcall(SB)
304 MOV 0(CTXT), T1 // code pointer
305 MOV (g_sched+gobuf_sp)(g), X2 // sp = m->g0->sched.sp
306 // we don't need special macro for regabi since arg0(X10) = g
307 SUB $16, X2
308 MOV X10, 8(X2) // setup g
309 MOV ZERO, 0(X2) // clear return address
310 JALR RA, T1
311 JMP runtime·badmcall2(SB)
312
313// Save state of caller into g->sched,
314// but using fake PC from systemstack_switch.
315// Must only be called from functions with no locals ($0)
316// or else unwinding from systemstack_switch is incorrect.
317// Smashes X31.
318TEXT gosave_systemstack_switch<>(SB),NOSPLIT|NOFRAME,$0
319 MOV $runtime·systemstack_switch(SB), X31
320 ADD $8, X31 // get past prologue
321 MOV X31, (g_sched+gobuf_pc)(g)
322 MOV X2, (g_sched+gobuf_sp)(g)
323 MOV ZERO, (g_sched+gobuf_lr)(g)
324 MOV ZERO, (g_sched+gobuf_ret)(g)
325 // Assert ctxt is zero. See func save.
326 MOV (g_sched+gobuf_ctxt)(g), X31
327 BEQ ZERO, X31, 2(PC)
328 CALL runtime·abort(SB)
329 RET
330
331// func asmcgocall_no_g(fn, arg unsafe.Pointer)
332// Call fn(arg) aligned appropriately for the gcc ABI.
333// Called on a system stack, and there may be no g yet (during needm).
334TEXT ·asmcgocall_no_g(SB),NOSPLIT,$0-16
335 MOV fn+0(FP), X5
336 MOV arg+8(FP), X10
337 JALR RA, (X5)
338 RET
339
340// func asmcgocall(fn, arg unsafe.Pointer) int32
341// Call fn(arg) on the scheduler stack,
342// aligned appropriately for the gcc ABI.
343// See cgocall.go for more details.
344TEXT ·asmcgocall(SB),NOSPLIT,$0-20
345 MOV fn+0(FP), X5
346 MOV arg+8(FP), X10
347
348 MOV X2, X8 // save original stack pointer
349 MOV g, X9
350
351 // Figure out if we need to switch to m->g0 stack.
352 // We get called to create new OS threads too, and those
353 // come in on the m->g0 stack already. Or we might already
354 // be on the m->gsignal stack.
355 MOV g_m(g), X6
356 MOV m_gsignal(X6), X7
357 BEQ X7, g, g0
358 MOV m_g0(X6), X7
359 BEQ X7, g, g0
360
361 CALL gosave_systemstack_switch<>(SB)
362 MOV X7, g
363 CALL runtime·save_g(SB)
364 MOV (g_sched+gobuf_sp)(g), X2
365
366 // Now on a scheduling stack (a pthread-created stack).
367g0:
368 // Save room for two of our pointers.
369 SUB $16, X2
370 MOV X9, 0(X2) // save old g on stack
371 MOV (g_stack+stack_hi)(X9), X9
372 SUB X8, X9, X8
373 MOV X8, 8(X2) // save depth in old g stack (can't just save SP, as stack might be copied during a callback)
374
375 JALR RA, (X5)
376
377 // Restore g, stack pointer. X10 is return value.
378 MOV 0(X2), g
379 CALL runtime·save_g(SB)
380 MOV (g_stack+stack_hi)(g), X5
381 MOV 8(X2), X6
382 SUB X6, X5, X6
383 MOV X6, X2
384
385 MOVW X10, ret+16(FP)
386 RET
387
388// func asminit()
389TEXT runtime·asminit(SB),NOSPLIT|NOFRAME,$0-0
390 RET
391
392// reflectcall: call a function with the given argument list
393// func call(stackArgsType *_type, f *FuncVal, stackArgs *byte, stackArgsSize, stackRetOffset, frameSize uint32, regArgs *abi.RegArgs).
394// we don't have variable-sized frames, so we use a small number
395// of constant-sized-frame functions to encode a few bits of size in the pc.
396// Caution: ugly multiline assembly macros in your future!
397
398#define DISPATCH(NAME,MAXSIZE) \
399 MOV $MAXSIZE, T1 \
400 BLTU T1, T0, 3(PC) \
401 MOV $NAME(SB), T2; \
402 JALR ZERO, T2
403// Note: can't just "BR NAME(SB)" - bad inlining results.
404
405// func call(stackArgsType *rtype, fn, stackArgs unsafe.Pointer, stackArgsSize, stackRetOffset, frameSize uint32, regArgs *abi.RegArgs).
406TEXT reflect·call(SB), NOSPLIT, $0-0
407 JMP ·reflectcall(SB)
408
409// func call(stackArgsType *_type, fn, stackArgs unsafe.Pointer, stackArgsSize, stackRetOffset, frameSize uint32, regArgs *abi.RegArgs).
410TEXT ·reflectcall(SB), NOSPLIT|NOFRAME, $0-48
411 MOVWU frameSize+32(FP), T0
412 DISPATCH(runtime·call16, 16)
413 DISPATCH(runtime·call32, 32)
414 DISPATCH(runtime·call64, 64)
415 DISPATCH(runtime·call128, 128)
416 DISPATCH(runtime·call256, 256)
417 DISPATCH(runtime·call512, 512)
418 DISPATCH(runtime·call1024, 1024)
419 DISPATCH(runtime·call2048, 2048)
420 DISPATCH(runtime·call4096, 4096)
421 DISPATCH(runtime·call8192, 8192)
422 DISPATCH(runtime·call16384, 16384)
423 DISPATCH(runtime·call32768, 32768)
424 DISPATCH(runtime·call65536, 65536)
425 DISPATCH(runtime·call131072, 131072)
426 DISPATCH(runtime·call262144, 262144)
427 DISPATCH(runtime·call524288, 524288)
428 DISPATCH(runtime·call1048576, 1048576)
429 DISPATCH(runtime·call2097152, 2097152)
430 DISPATCH(runtime·call4194304, 4194304)
431 DISPATCH(runtime·call8388608, 8388608)
432 DISPATCH(runtime·call16777216, 16777216)
433 DISPATCH(runtime·call33554432, 33554432)
434 DISPATCH(runtime·call67108864, 67108864)
435 DISPATCH(runtime·call134217728, 134217728)
436 DISPATCH(runtime·call268435456, 268435456)
437 DISPATCH(runtime·call536870912, 536870912)
438 DISPATCH(runtime·call1073741824, 1073741824)
439 MOV $runtime·badreflectcall(SB), T2
440 JALR ZERO, T2
441
442#define CALLFN(NAME,MAXSIZE) \
443TEXT NAME(SB), WRAPPER, $MAXSIZE-48; \
444 NO_LOCAL_POINTERS; \
445 /* copy arguments to stack */ \
446 MOV stackArgs+16(FP), A1; \
447 MOVWU stackArgsSize+24(FP), A2; \
448 MOV X2, A3; \
449 ADD $8, A3; \
450 ADD A3, A2; \
451 BEQ A3, A2, 6(PC); \
452 MOVBU (A1), A4; \
453 ADD $1, A1; \
454 MOVB A4, (A3); \
455 ADD $1, A3; \
456 JMP -5(PC); \
457 /* set up argument registers */ \
458 MOV regArgs+40(FP), X25; \
459 CALL ·unspillArgs(SB); \
460 /* call function */ \
461 MOV f+8(FP), CTXT; \
462 MOV (CTXT), X25; \
463 PCDATA $PCDATA_StackMapIndex, $0; \
464 JALR RA, X25; \
465 /* copy return values back */ \
466 MOV regArgs+40(FP), X25; \
467 CALL ·spillArgs(SB); \
468 MOV stackArgsType+0(FP), A5; \
469 MOV stackArgs+16(FP), A1; \
470 MOVWU stackArgsSize+24(FP), A2; \
471 MOVWU stackRetOffset+28(FP), A4; \
472 ADD $8, X2, A3; \
473 ADD A4, A3; \
474 ADD A4, A1; \
475 SUB A4, A2; \
476 CALL callRet<>(SB); \
477 RET
478
479// callRet copies return values back at the end of call*. This is a
480// separate function so it can allocate stack space for the arguments
481// to reflectcallmove. It does not follow the Go ABI; it expects its
482// arguments in registers.
483TEXT callRet<>(SB), NOSPLIT, $40-0
484 NO_LOCAL_POINTERS
485 MOV A5, 8(X2)
486 MOV A1, 16(X2)
487 MOV A3, 24(X2)
488 MOV A2, 32(X2)
489 MOV X25, 40(X2)
490 CALL runtime·reflectcallmove(SB)
491 RET
492
493CALLFN(·call16, 16)
494CALLFN(·call32, 32)
495CALLFN(·call64, 64)
496CALLFN(·call128, 128)
497CALLFN(·call256, 256)
498CALLFN(·call512, 512)
499CALLFN(·call1024, 1024)
500CALLFN(·call2048, 2048)
501CALLFN(·call4096, 4096)
502CALLFN(·call8192, 8192)
503CALLFN(·call16384, 16384)
504CALLFN(·call32768, 32768)
505CALLFN(·call65536, 65536)
506CALLFN(·call131072, 131072)
507CALLFN(·call262144, 262144)
508CALLFN(·call524288, 524288)
509CALLFN(·call1048576, 1048576)
510CALLFN(·call2097152, 2097152)
511CALLFN(·call4194304, 4194304)
512CALLFN(·call8388608, 8388608)
513CALLFN(·call16777216, 16777216)
514CALLFN(·call33554432, 33554432)
515CALLFN(·call67108864, 67108864)
516CALLFN(·call134217728, 134217728)
517CALLFN(·call268435456, 268435456)
518CALLFN(·call536870912, 536870912)
519CALLFN(·call1073741824, 1073741824)
520
521// Called from cgo wrappers, this function returns g->m->curg.stack.hi.
522// Must obey the gcc calling convention.
523TEXT _cgo_topofstack(SB),NOSPLIT,$8
524 // g (X27) and REG_TMP (X31) might be clobbered by load_g.
525 // X27 is callee-save in the gcc calling convention, so save it.
526 MOV g, savedX27-8(SP)
527
528 CALL runtime·load_g(SB)
529 MOV g_m(g), X5
530 MOV m_curg(X5), X5
531 MOV (g_stack+stack_hi)(X5), X10 // return value in X10
532
533 MOV savedX27-8(SP), g
534 RET
535
536// func goexit(neverCallThisFunction)
537// The top-most function running on a goroutine
538// returns to goexit+PCQuantum.
539TEXT runtime·goexit(SB),NOSPLIT|NOFRAME|TOPFRAME,$0-0
540 MOV ZERO, ZERO // NOP
541 JMP runtime·goexit1(SB) // does not return
542 // traceback from goexit1 must hit code range of goexit
543 MOV ZERO, ZERO // NOP
544
545// func cgocallback(fn, frame unsafe.Pointer, ctxt uintptr)
546// See cgocall.go for more details.
547TEXT ·cgocallback(SB),NOSPLIT,$24-24
548 NO_LOCAL_POINTERS
549
550 // Skip cgocallbackg, just dropm when fn is nil, and frame is the saved g.
551 // It is used to dropm while thread is exiting.
552 MOV fn+0(FP), X7
553 BNE ZERO, X7, loadg
554 // Restore the g from frame.
555 MOV frame+8(FP), g
556 JMP dropm
557
558loadg:
559 // Load m and g from thread-local storage.
560 MOVBU runtime·iscgo(SB), X5
561 BEQ ZERO, X5, nocgo
562 CALL runtime·load_g(SB)
563nocgo:
564
565 // If g is nil, Go did not create the current thread,
566 // or if this thread never called into Go on pthread platforms.
567 // Call needm to obtain one for temporary use.
568 // In this case, we're running on the thread stack, so there's
569 // lots of space, but the linker doesn't know. Hide the call from
570 // the linker analysis by using an indirect call.
571 BEQ ZERO, g, needm
572
573 MOV g_m(g), X5
574 MOV X5, savedm-8(SP)
575 JMP havem
576
577needm:
578 MOV g, savedm-8(SP) // g is zero, so is m.
579 MOV $runtime·needAndBindM(SB), X6
580 JALR RA, X6
581
582 // Set m->sched.sp = SP, so that if a panic happens
583 // during the function we are about to execute, it will
584 // have a valid SP to run on the g0 stack.
585 // The next few lines (after the havem label)
586 // will save this SP onto the stack and then write
587 // the same SP back to m->sched.sp. That seems redundant,
588 // but if an unrecovered panic happens, unwindm will
589 // restore the g->sched.sp from the stack location
590 // and then systemstack will try to use it. If we don't set it here,
591 // that restored SP will be uninitialized (typically 0) and
592 // will not be usable.
593 MOV g_m(g), X5
594 MOV m_g0(X5), X6
595 MOV X2, (g_sched+gobuf_sp)(X6)
596
597havem:
598 // Now there's a valid m, and we're running on its m->g0.
599 // Save current m->g0->sched.sp on stack and then set it to SP.
600 // Save current sp in m->g0->sched.sp in preparation for
601 // switch back to m->curg stack.
602 // NOTE: unwindm knows that the saved g->sched.sp is at 8(X2) aka savedsp-24(SP).
603 MOV m_g0(X5), X6
604 MOV (g_sched+gobuf_sp)(X6), X7
605 MOV X7, savedsp-24(SP) // must match frame size
606 MOV X2, (g_sched+gobuf_sp)(X6)
607
608 // Switch to m->curg stack and call runtime.cgocallbackg.
609 // Because we are taking over the execution of m->curg
610 // but *not* resuming what had been running, we need to
611 // save that information (m->curg->sched) so we can restore it.
612 // We can restore m->curg->sched.sp easily, because calling
613 // runtime.cgocallbackg leaves SP unchanged upon return.
614 // To save m->curg->sched.pc, we push it onto the curg stack and
615 // open a frame the same size as cgocallback's g0 frame.
616 // Once we switch to the curg stack, the pushed PC will appear
617 // to be the return PC of cgocallback, so that the traceback
618 // will seamlessly trace back into the earlier calls.
619 MOV m_curg(X5), g
620 CALL runtime·save_g(SB)
621 MOV (g_sched+gobuf_sp)(g), X6 // prepare stack as X6
622 MOV (g_sched+gobuf_pc)(g), X7
623 MOV X7, -(24+8)(X6) // "saved LR"; must match frame size
624 // Gather our arguments into registers.
625 MOV fn+0(FP), X7
626 MOV frame+8(FP), X8
627 MOV ctxt+16(FP), X9
628 MOV $-(24+8)(X6), X2 // switch stack; must match frame size
629 MOV X7, 8(X2)
630 MOV X8, 16(X2)
631 MOV X9, 24(X2)
632 CALL runtime·cgocallbackg(SB)
633
634 // Restore g->sched (== m->curg->sched) from saved values.
635 MOV 0(X2), X7
636 MOV X7, (g_sched+gobuf_pc)(g)
637 MOV $(24+8)(X2), X6 // must match frame size
638 MOV X6, (g_sched+gobuf_sp)(g)
639
640 // Switch back to m->g0's stack and restore m->g0->sched.sp.
641 // (Unlike m->curg, the g0 goroutine never uses sched.pc,
642 // so we do not have to restore it.)
643 MOV g_m(g), X5
644 MOV m_g0(X5), g
645 CALL runtime·save_g(SB)
646 MOV (g_sched+gobuf_sp)(g), X2
647 MOV savedsp-24(SP), X6 // must match frame size
648 MOV X6, (g_sched+gobuf_sp)(g)
649
650 // If the m on entry was nil, we called needm above to borrow an m,
651 // 1. for the duration of the call on non-pthread platforms,
652 // 2. or the duration of the C thread alive on pthread platforms.
653 // If the m on entry wasn't nil,
654 // 1. the thread might be a Go thread,
655 // 2. or it wasn't the first call from a C thread on pthread platforms,
656 // since then we skip dropm to reuse the m in the first call.
657 MOV savedm-8(SP), X5
658 BNE ZERO, X5, droppedm
659
660 // Skip dropm to reuse it in the next call, when a pthread key has been created.
661 MOV _cgo_pthread_key_created(SB), X5
662 // It means cgo is disabled when _cgo_pthread_key_created is a nil pointer, need dropm.
663 BEQ ZERO, X5, dropm
664 MOV (X5), X5
665 BNE ZERO, X5, droppedm
666
667dropm:
668 MOV $runtime·dropm(SB), X6
669 JALR RA, X6
670droppedm:
671
672 // Done!
673 RET
674
675TEXT runtime·breakpoint(SB),NOSPLIT|NOFRAME,$0-0
676 EBREAK
677 RET
678
679TEXT runtime·abort(SB),NOSPLIT|NOFRAME,$0-0
680 EBREAK
681 RET
682
683// void setg(G*); set g. for use by needm.
684TEXT runtime·setg(SB), NOSPLIT, $0-8
685 MOV gg+0(FP), g
686 // This only happens if iscgo, so jump straight to save_g
687 CALL runtime·save_g(SB)
688 RET
689
690TEXT ·checkASM(SB),NOSPLIT,$0-1
691 MOV $1, T0
692 MOV T0, ret+0(FP)
693 RET
694
695// spillArgs stores return values from registers to a *internal/abi.RegArgs in X25.
696TEXT ·spillArgs(SB),NOSPLIT,$0-0
697 MOV X10, (0*8)(X25)
698 MOV X11, (1*8)(X25)
699 MOV X12, (2*8)(X25)
700 MOV X13, (3*8)(X25)
701 MOV X14, (4*8)(X25)
702 MOV X15, (5*8)(X25)
703 MOV X16, (6*8)(X25)
704 MOV X17, (7*8)(X25)
705 MOV X8, (8*8)(X25)
706 MOV X9, (9*8)(X25)
707 MOV X18, (10*8)(X25)
708 MOV X19, (11*8)(X25)
709 MOV X20, (12*8)(X25)
710 MOV X21, (13*8)(X25)
711 MOV X22, (14*8)(X25)
712 MOV X23, (15*8)(X25)
713 MOVD F10, (16*8)(X25)
714 MOVD F11, (17*8)(X25)
715 MOVD F12, (18*8)(X25)
716 MOVD F13, (19*8)(X25)
717 MOVD F14, (20*8)(X25)
718 MOVD F15, (21*8)(X25)
719 MOVD F16, (22*8)(X25)
720 MOVD F17, (23*8)(X25)
721 MOVD F8, (24*8)(X25)
722 MOVD F9, (25*8)(X25)
723 MOVD F18, (26*8)(X25)
724 MOVD F19, (27*8)(X25)
725 MOVD F20, (28*8)(X25)
726 MOVD F21, (29*8)(X25)
727 MOVD F22, (30*8)(X25)
728 MOVD F23, (31*8)(X25)
729 RET
730
731// unspillArgs loads args into registers from a *internal/abi.RegArgs in X25.
732TEXT ·unspillArgs(SB),NOSPLIT,$0-0
733 MOV (0*8)(X25), X10
734 MOV (1*8)(X25), X11
735 MOV (2*8)(X25), X12
736 MOV (3*8)(X25), X13
737 MOV (4*8)(X25), X14
738 MOV (5*8)(X25), X15
739 MOV (6*8)(X25), X16
740 MOV (7*8)(X25), X17
741 MOV (8*8)(X25), X8
742 MOV (9*8)(X25), X9
743 MOV (10*8)(X25), X18
744 MOV (11*8)(X25), X19
745 MOV (12*8)(X25), X20
746 MOV (13*8)(X25), X21
747 MOV (14*8)(X25), X22
748 MOV (15*8)(X25), X23
749 MOVD (16*8)(X25), F10
750 MOVD (17*8)(X25), F11
751 MOVD (18*8)(X25), F12
752 MOVD (19*8)(X25), F13
753 MOVD (20*8)(X25), F14
754 MOVD (21*8)(X25), F15
755 MOVD (22*8)(X25), F16
756 MOVD (23*8)(X25), F17
757 MOVD (24*8)(X25), F8
758 MOVD (25*8)(X25), F9
759 MOVD (26*8)(X25), F18
760 MOVD (27*8)(X25), F19
761 MOVD (28*8)(X25), F20
762 MOVD (29*8)(X25), F21
763 MOVD (30*8)(X25), F22
764 MOVD (31*8)(X25), F23
765 RET
766
767// gcWriteBarrier informs the GC about heap pointer writes.
768//
769// gcWriteBarrier does NOT follow the Go ABI. It accepts the
770// number of bytes of buffer needed in X24, and returns a pointer
771// to the buffer space in X24.
772// It clobbers X31 aka T6 (the linker temp register - REG_TMP).
773// The act of CALLing gcWriteBarrier will clobber RA (LR).
774// It does not clobber any other general-purpose registers,
775// but may clobber others (e.g., floating point registers).
776TEXT gcWriteBarrier<>(SB),NOSPLIT,$208
777 // Save the registers clobbered by the fast path.
778 MOV A0, 24*8(X2)
779 MOV A1, 25*8(X2)
780retry:
781 MOV g_m(g), A0
782 MOV m_p(A0), A0
783 MOV (p_wbBuf+wbBuf_next)(A0), A1
784 MOV (p_wbBuf+wbBuf_end)(A0), T6 // T6 is linker temp register (REG_TMP)
785 // Increment wbBuf.next position.
786 ADD X24, A1
787 // Is the buffer full?
788 BLTU T6, A1, flush
789 // Commit to the larger buffer.
790 MOV A1, (p_wbBuf+wbBuf_next)(A0)
791 // Make the return value (the original next position)
792 SUB X24, A1, X24
793 // Restore registers.
794 MOV 24*8(X2), A0
795 MOV 25*8(X2), A1
796 RET
797
798flush:
799 // Save all general purpose registers since these could be
800 // clobbered by wbBufFlush and were not saved by the caller.
801 MOV T0, 1*8(X2)
802 MOV T1, 2*8(X2)
803 // X0 is zero register
804 // X1 is LR, saved by prologue
805 // X2 is SP
806 // X3 is GP
807 // X4 is TP
808 MOV X7, 3*8(X2)
809 MOV X8, 4*8(X2)
810 MOV X9, 5*8(X2)
811 // X10 already saved (A0)
812 // X11 already saved (A1)
813 MOV X12, 6*8(X2)
814 MOV X13, 7*8(X2)
815 MOV X14, 8*8(X2)
816 MOV X15, 9*8(X2)
817 MOV X16, 10*8(X2)
818 MOV X17, 11*8(X2)
819 MOV X18, 12*8(X2)
820 MOV X19, 13*8(X2)
821 MOV X20, 14*8(X2)
822 MOV X21, 15*8(X2)
823 MOV X22, 16*8(X2)
824 MOV X23, 17*8(X2)
825 MOV X24, 18*8(X2)
826 MOV X25, 19*8(X2)
827 MOV X26, 20*8(X2)
828 // X27 is g.
829 MOV X28, 21*8(X2)
830 MOV X29, 22*8(X2)
831 MOV X30, 23*8(X2)
832 // X31 is tmp register.
833
834 CALL runtime·wbBufFlush(SB)
835
836 MOV 1*8(X2), T0
837 MOV 2*8(X2), T1
838 MOV 3*8(X2), X7
839 MOV 4*8(X2), X8
840 MOV 5*8(X2), X9
841 MOV 6*8(X2), X12
842 MOV 7*8(X2), X13
843 MOV 8*8(X2), X14
844 MOV 9*8(X2), X15
845 MOV 10*8(X2), X16
846 MOV 11*8(X2), X17
847 MOV 12*8(X2), X18
848 MOV 13*8(X2), X19
849 MOV 14*8(X2), X20
850 MOV 15*8(X2), X21
851 MOV 16*8(X2), X22
852 MOV 17*8(X2), X23
853 MOV 18*8(X2), X24
854 MOV 19*8(X2), X25
855 MOV 20*8(X2), X26
856 MOV 21*8(X2), X28
857 MOV 22*8(X2), X29
858 MOV 23*8(X2), X30
859
860 JMP retry
861
862TEXT runtime·gcWriteBarrier1<ABIInternal>(SB),NOSPLIT,$0
863 MOV $8, X24
864 JMP gcWriteBarrier<>(SB)
865TEXT runtime·gcWriteBarrier2<ABIInternal>(SB),NOSPLIT,$0
866 MOV $16, X24
867 JMP gcWriteBarrier<>(SB)
868TEXT runtime·gcWriteBarrier3<ABIInternal>(SB),NOSPLIT,$0
869 MOV $24, X24
870 JMP gcWriteBarrier<>(SB)
871TEXT runtime·gcWriteBarrier4<ABIInternal>(SB),NOSPLIT,$0
872 MOV $32, X24
873 JMP gcWriteBarrier<>(SB)
874TEXT runtime·gcWriteBarrier5<ABIInternal>(SB),NOSPLIT,$0
875 MOV $40, X24
876 JMP gcWriteBarrier<>(SB)
877TEXT runtime·gcWriteBarrier6<ABIInternal>(SB),NOSPLIT,$0
878 MOV $48, X24
879 JMP gcWriteBarrier<>(SB)
880TEXT runtime·gcWriteBarrier7<ABIInternal>(SB),NOSPLIT,$0
881 MOV $56, X24
882 JMP gcWriteBarrier<>(SB)
883TEXT runtime·gcWriteBarrier8<ABIInternal>(SB),NOSPLIT,$0
884 MOV $64, X24
885 JMP gcWriteBarrier<>(SB)
886
887// Note: these functions use a special calling convention to save generated code space.
888// Arguments are passed in registers (ssa/gen/RISCV64Ops.go), but the space for those
889// arguments are allocated in the caller's stack frame.
890// These stubs write the args into that stack space and then tail call to the
891// corresponding runtime handler.
892// The tail call makes these stubs disappear in backtraces.
893TEXT runtime·panicIndex<ABIInternal>(SB),NOSPLIT,$0-16
894 MOV T0, X10
895 MOV T1, X11
896 JMP runtime·goPanicIndex<ABIInternal>(SB)
897TEXT runtime·panicIndexU<ABIInternal>(SB),NOSPLIT,$0-16
898 MOV T0, X10
899 MOV T1, X11
900 JMP runtime·goPanicIndexU<ABIInternal>(SB)
901TEXT runtime·panicSliceAlen<ABIInternal>(SB),NOSPLIT,$0-16
902 MOV T1, X10
903 MOV T2, X11
904 JMP runtime·goPanicSliceAlen<ABIInternal>(SB)
905TEXT runtime·panicSliceAlenU<ABIInternal>(SB),NOSPLIT,$0-16
906 MOV T1, X10
907 MOV T2, X11
908 JMP runtime·goPanicSliceAlenU<ABIInternal>(SB)
909TEXT runtime·panicSliceAcap<ABIInternal>(SB),NOSPLIT,$0-16
910 MOV T1, X10
911 MOV T2, X11
912 JMP runtime·goPanicSliceAcap<ABIInternal>(SB)
913TEXT runtime·panicSliceAcapU<ABIInternal>(SB),NOSPLIT,$0-16
914 MOV T1, X10
915 MOV T2, X11
916 JMP runtime·goPanicSliceAcapU<ABIInternal>(SB)
917TEXT runtime·panicSliceB<ABIInternal>(SB),NOSPLIT,$0-16
918 MOV T0, X10
919 MOV T1, X11
920 JMP runtime·goPanicSliceB<ABIInternal>(SB)
921TEXT runtime·panicSliceBU<ABIInternal>(SB),NOSPLIT,$0-16
922 MOV T0, X10
923 MOV T1, X11
924 JMP runtime·goPanicSliceBU<ABIInternal>(SB)
925TEXT runtime·panicSlice3Alen<ABIInternal>(SB),NOSPLIT,$0-16
926 MOV T2, X10
927 MOV T3, X11
928 JMP runtime·goPanicSlice3Alen<ABIInternal>(SB)
929TEXT runtime·panicSlice3AlenU<ABIInternal>(SB),NOSPLIT,$0-16
930 MOV T2, X10
931 MOV T3, X11
932 JMP runtime·goPanicSlice3AlenU<ABIInternal>(SB)
933TEXT runtime·panicSlice3Acap<ABIInternal>(SB),NOSPLIT,$0-16
934 MOV T2, X10
935 MOV T3, X11
936 JMP runtime·goPanicSlice3Acap<ABIInternal>(SB)
937TEXT runtime·panicSlice3AcapU<ABIInternal>(SB),NOSPLIT,$0-16
938 MOV T2, X10
939 MOV T3, X11
940 JMP runtime·goPanicSlice3AcapU<ABIInternal>(SB)
941TEXT runtime·panicSlice3B<ABIInternal>(SB),NOSPLIT,$0-16
942 MOV T1, X10
943 MOV T2, X11
944 JMP runtime·goPanicSlice3B<ABIInternal>(SB)
945TEXT runtime·panicSlice3BU<ABIInternal>(SB),NOSPLIT,$0-16
946 MOV T1, X10
947 MOV T2, X11
948 JMP runtime·goPanicSlice3BU<ABIInternal>(SB)
949TEXT runtime·panicSlice3C<ABIInternal>(SB),NOSPLIT,$0-16
950 MOV T0, X10
951 MOV T1, X11
952 JMP runtime·goPanicSlice3C<ABIInternal>(SB)
953TEXT runtime·panicSlice3CU<ABIInternal>(SB),NOSPLIT,$0-16
954 MOV T0, X10
955 MOV T1, X11
956 JMP runtime·goPanicSlice3CU<ABIInternal>(SB)
957TEXT runtime·panicSliceConvert<ABIInternal>(SB),NOSPLIT,$0-16
958 MOV T2, X10
959 MOV T3, X11
960 JMP runtime·goPanicSliceConvert<ABIInternal>(SB)
961
962DATA runtime·mainPC+0(SB)/8,$runtime·main<ABIInternal>(SB)
963GLOBL runtime·mainPC(SB),RODATA,$8
View as plain text