cmd/link, runtime: implement & call addmoduledata on ppc64le

Change-Id: I3980d82c7df95e69522c3d2c90311f89c6fef0e1
Reviewed-on: https://go-review.googlesource.com/15972Reviewed-by: Russ Cox <rsc@golang.org>

src/cmd/link/internal/ppc64/asm.go

@@ -38,7 +38,7 @@ import (
 	"log"
 )
 
-func gentext() {
+func genplt() {
 	var s *ld.LSym
 	var stub *ld.LSym
 	var pprevtextp **ld.LSym
@@ -137,6 +137,84 @@ func gentext() {
 			ld.Ctxt.Arch.ByteOrder.PutUint32(s.P[r.Off+4:], o1)
 		}
 	}
+
+}
+
+func genaddmoduledata() {
+	addmoduledata := ld.Linkrlookup(ld.Ctxt, "runtime.addmoduledata", 0)
+	if addmoduledata.Type == obj.STEXT {
+		return
+	}
+	addmoduledata.Reachable = true
+	initfunc := ld.Linklookup(ld.Ctxt, "go.link.addmoduledata", 0)
+	initfunc.Type = obj.STEXT
+	initfunc.Local = true
+	initfunc.Reachable = true
+	o := func(op uint32) {
+		ld.Adduint32(ld.Ctxt, initfunc, op)
+	}
+	// addis r2, r12, .TOC.-func@ha
+	rel := ld.Addrel(initfunc)
+	rel.Off = int32(initfunc.Size)
+	rel.Siz = 8
+	rel.Sym = ld.Linklookup(ld.Ctxt, ".TOC.", 0)
+	rel.Type = obj.R_ADDRPOWER_PCREL
+	o(0x3c4c0000)
+	// addi r2, r2, .TOC.-func@l
+	o(0x38420000)
+	// mflr r31
+	o(0x7c0802a6)
+	// stdu r31, -32(r1)
+	o(0xf801ffe1)
+	// addis r3, r2, local.moduledata@got@ha
+	rel = ld.Addrel(initfunc)
+	rel.Off = int32(initfunc.Size)
+	rel.Siz = 8
+	rel.Sym = ld.Linklookup(ld.Ctxt, "local.moduledata", 0)
+	rel.Type = obj.R_ADDRPOWER_GOT
+	o(0x3c620000)
+	// ld r3, local.moduledata@got@l(r3)
+	o(0xe8630000)
+	// bl runtime.addmoduledata
+	rel = ld.Addrel(initfunc)
+	rel.Off = int32(initfunc.Size)
+	rel.Siz = 4
+	rel.Sym = addmoduledata
+	rel.Type = obj.R_CALLPOWER
+	o(0x48000001)
+	// nop
+	o(0x60000000)
+	// ld r31, 0(r1)
+	o(0xe8010000)
+	// mtlr r31
+	o(0x7c0803a6)
+	// addi r1,r1,32
+	o(0x38210020)
+	// blr
+	o(0x4e800020)
+
+	if ld.Ctxt.Etextp != nil {
+		ld.Ctxt.Etextp.Next = initfunc
+	} else {
+		ld.Ctxt.Textp = initfunc
+	}
+	ld.Ctxt.Etextp = initfunc
+
+	initarray_entry := ld.Linklookup(ld.Ctxt, "go.link.addmoduledatainit", 0)
+	initarray_entry.Reachable = true
+	initarray_entry.Local = true
+	initarray_entry.Type = obj.SINITARR
+	ld.Addaddr(ld.Ctxt, initarray_entry, initfunc)
+}
+
+func gentext() {
+	if ld.DynlinkingGo() {
+		genaddmoduledata()
+	}
+
+	if ld.Linkmode == ld.LinkInternal {
+		genplt()
+	}
 }
 
 // Construct a call stub in stub that calls symbol targ via its PLT

src/runtime/asm_ppc64x.s

@@ -1070,3 +1070,13 @@ TEXT runtime·prepGoExitFrame(SB),NOSPLIT,$0-8
       MOVD    sp+0(FP), R3
       MOVD    R2, 24(R3)
       RET
+
+TEXT runtime·addmoduledata(SB),NOSPLIT|NOFRAME,$0-0
+	ADD	$-8, R1
+	MOVD	R31, 0(R1)
+	MOVD	runtime·lastmoduledatap(SB), R4
+	MOVD	R3, moduledata_next(R4)
+	MOVD	R3, runtime·lastmoduledatap(SB)
+	MOVD	0(R1), R31
+	ADD	$8, R1
+	RET