runtime: add async preemption support on ARM64

This CL adds support of call injection and async preemption on
ARM64.

There seems no way to return from the injected call without
clobbering *any* register. So we have to clobber one, which is
chosen to be REGTMP. Previous CLs have marked code sequences
that use REGTMP async-nonpreemtible.

Change-Id: Ieca4e3ba5557adf3d0f5d923bce5f1769b58e30b
Reviewed-on: https://go-review.googlesource.com/c/go/+/203461
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

1 files changed, 138 insertions, 2 deletions

diff --git a/src/runtime/preempt_arm64.s b/src/runtime/preempt_arm64.s
index 5697268ce1..3a7cdf489b 100644
--- a/src/runtime/preempt_arm64.s
+++ b/src/runtime/preempt_arm64.s
@@ -4,5 +4,141 @@
 #include "textflag.h"
 
 TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
-	// Not implemented yet
-	JMP ·abort(SB)
+	MOVD R30, -496(RSP)
+	SUB $496, RSP
+	#ifdef GOOS_linux
+	MOVD R29, -8(RSP)
+	SUB $8, RSP, R29
+	#endif
+	MOVD R0, 8(RSP)
+	MOVD R1, 16(RSP)
+	MOVD R2, 24(RSP)
+	MOVD R3, 32(RSP)
+	MOVD R4, 40(RSP)
+	MOVD R5, 48(RSP)
+	MOVD R6, 56(RSP)
+	MOVD R7, 64(RSP)
+	MOVD R8, 72(RSP)
+	MOVD R9, 80(RSP)
+	MOVD R10, 88(RSP)
+	MOVD R11, 96(RSP)
+	MOVD R12, 104(RSP)
+	MOVD R13, 112(RSP)
+	MOVD R14, 120(RSP)
+	MOVD R15, 128(RSP)
+	MOVD R16, 136(RSP)
+	MOVD R17, 144(RSP)
+	MOVD R19, 152(RSP)
+	MOVD R20, 160(RSP)
+	MOVD R21, 168(RSP)
+	MOVD R22, 176(RSP)
+	MOVD R23, 184(RSP)
+	MOVD R24, 192(RSP)
+	MOVD R25, 200(RSP)
+	MOVD R26, 208(RSP)
+	MOVD NZCV, R0
+	MOVD R0, 216(RSP)
+	MOVD FPSR, R0
+	MOVD R0, 224(RSP)
+	FMOVD F0, 232(RSP)
+	FMOVD F1, 240(RSP)
+	FMOVD F2, 248(RSP)
+	FMOVD F3, 256(RSP)
+	FMOVD F4, 264(RSP)
+	FMOVD F5, 272(RSP)
+	FMOVD F6, 280(RSP)
+	FMOVD F7, 288(RSP)
+	FMOVD F8, 296(RSP)
+	FMOVD F9, 304(RSP)
+	FMOVD F10, 312(RSP)
+	FMOVD F11, 320(RSP)
+	FMOVD F12, 328(RSP)
+	FMOVD F13, 336(RSP)
+	FMOVD F14, 344(RSP)
+	FMOVD F15, 352(RSP)
+	FMOVD F16, 360(RSP)
+	FMOVD F17, 368(RSP)
+	FMOVD F18, 376(RSP)
+	FMOVD F19, 384(RSP)
+	FMOVD F20, 392(RSP)
+	FMOVD F21, 400(RSP)
+	FMOVD F22, 408(RSP)
+	FMOVD F23, 416(RSP)
+	FMOVD F24, 424(RSP)
+	FMOVD F25, 432(RSP)
+	FMOVD F26, 440(RSP)
+	FMOVD F27, 448(RSP)
+	FMOVD F28, 456(RSP)
+	FMOVD F29, 464(RSP)
+	FMOVD F30, 472(RSP)
+	FMOVD F31, 480(RSP)
+	CALL ·asyncPreempt2(SB)
+	FMOVD 480(RSP), F31
+	FMOVD 472(RSP), F30
+	FMOVD 464(RSP), F29
+	FMOVD 456(RSP), F28
+	FMOVD 448(RSP), F27
+	FMOVD 440(RSP), F26
+	FMOVD 432(RSP), F25
+	FMOVD 424(RSP), F24
+	FMOVD 416(RSP), F23
+	FMOVD 408(RSP), F22
+	FMOVD 400(RSP), F21
+	FMOVD 392(RSP), F20
+	FMOVD 384(RSP), F19
+	FMOVD 376(RSP), F18
+	FMOVD 368(RSP), F17
+	FMOVD 360(RSP), F16
+	FMOVD 352(RSP), F15
+	FMOVD 344(RSP), F14
+	FMOVD 336(RSP), F13
+	FMOVD 328(RSP), F12
+	FMOVD 320(RSP), F11
+	FMOVD 312(RSP), F10
+	FMOVD 304(RSP), F9
+	FMOVD 296(RSP), F8
+	FMOVD 288(RSP), F7
+	FMOVD 280(RSP), F6
+	FMOVD 272(RSP), F5
+	FMOVD 264(RSP), F4
+	FMOVD 256(RSP), F3
+	FMOVD 248(RSP), F2
+	FMOVD 240(RSP), F1
+	FMOVD 232(RSP), F0
+	MOVD 224(RSP), R0
+	MOVD R0, FPSR
+	MOVD 216(RSP), R0
+	MOVD R0, NZCV
+	MOVD 208(RSP), R26
+	MOVD 200(RSP), R25
+	MOVD 192(RSP), R24
+	MOVD 184(RSP), R23
+	MOVD 176(RSP), R22
+	MOVD 168(RSP), R21
+	MOVD 160(RSP), R20
+	MOVD 152(RSP), R19
+	MOVD 144(RSP), R17
+	MOVD 136(RSP), R16
+	MOVD 128(RSP), R15
+	MOVD 120(RSP), R14
+	MOVD 112(RSP), R13
+	MOVD 104(RSP), R12
+	MOVD 96(RSP), R11
+	MOVD 88(RSP), R10
+	MOVD 80(RSP), R9
+	MOVD 72(RSP), R8
+	MOVD 64(RSP), R7
+	MOVD 56(RSP), R6
+	MOVD 48(RSP), R5
+	MOVD 40(RSP), R4
+	MOVD 32(RSP), R3
+	MOVD 24(RSP), R2
+	MOVD 16(RSP), R1
+	MOVD 8(RSP), R0
+	MOVD 496(RSP), R30
+	#ifdef GOOS_linux
+	MOVD -8(RSP), R29
+	#endif
+	MOVD (RSP), R27
+	ADD $512, RSP
+	JMP (R27)