[dev.power64] cmd/9l, math/big, runtime, syscall: fixes for power64

On the machine I'm using, the hardware page size seems to be 64 kB.
Make ELF rounding and mmap quantum 64 kB to match.

Error numbers returned from kernel are positive; do not negate.

Implement stubs for math/big.

LGTM=minux
R=minux
CC=golang-codereviews
https://golang.org/cl/124300043

src/cmd/9l/obj.c

@@ -88,7 +88,7 @@ archinit(void)
 		if(INITDAT == -1)
 			INITDAT = 0;
 		if(INITRND == -1)
-			INITRND = 4096;
+			INITRND = 0x10000;
 		break;
 	case Hnacl:
 		elfinit();

src/pkg/math/big/arith_power64x.s

@@ -0,0 +1,46 @@
+// Copyright 2013 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.
+
+// +build power64 power64le
+
+#include "../../../cmd/ld/textflag.h"
+
+// This file provides fast assembly versions for the elementary
+// arithmetic operations on vectors implemented in arith.go.
+
+TEXT ·mulWW(SB),NOSPLIT,$0
+	BR ·mulWW_g(SB)
+
+TEXT ·divWW(SB),NOSPLIT,$0
+	BR ·divWW_g(SB)
+
+TEXT ·addVV(SB),NOSPLIT,$0
+	BR ·addVV_g(SB)
+
+TEXT ·subVV(SB),NOSPLIT,$0
+	BR ·subVV_g(SB)
+
+TEXT ·addVW(SB),NOSPLIT,$0
+	BR ·addVW_g(SB)
+
+TEXT ·subVW(SB),NOSPLIT,$0
+	BR ·subVW_g(SB)
+
+TEXT ·shlVU(SB),NOSPLIT,$0
+	BR ·shlVU_g(SB)
+
+TEXT ·shrVU(SB),NOSPLIT,$0
+	BR ·shrVU_g(SB)
+
+TEXT ·mulAddVWW(SB),NOSPLIT,$0
+	BR ·mulAddVWW_g(SB)
+
+TEXT ·addMulVVW(SB),NOSPLIT,$0
+	BR ·addMulVVW_g(SB)
+
+TEXT ·divWVW(SB),NOSPLIT,$0
+	BR ·divWVW_g(SB)
+
+TEXT ·bitLen(SB),NOSPLIT,$0
+	BR ·bitLen_g(SB)

src/pkg/runtime/arch_power64.h

@@ -7,7 +7,7 @@ enum {
 	BigEndian = 1,
 	CacheLineSize = 64,
 	RuntimeGogoBytes = 84,
-	PhysPageSize = 4096,
+	PhysPageSize = 65536,
 	PCQuantum = 4,
 	Int64Align = 8
 };

src/pkg/runtime/asm_power64x.s

@@ -782,8 +782,8 @@ TEXT bytes·IndexByte(SB),NOSPLIT,$0-40
 	MOVD	s+0(FP), R3
 	MOVD	s_len+8(FP), R4
 	MOVBZ	c+24(FP), R5	// byte to find
+	MOVD	R3, R6		// store base for later
 	SUB	$1, R3
-	MOVD	R3, R6		// store base-1 for later
 	ADD	R3, R4		// end-1
 
 _index_loop:
@@ -798,16 +798,16 @@ _index_loop:
 	RETURN
 
 _index_notfound:
-	MOVW	$-1, R3
-	MOVW	R3, ret+32(FP)
+	MOVD	$-1, R3
+	MOVD	R3, ret+32(FP)
 	RETURN
 
 TEXT strings·IndexByte(SB),NOSPLIT,$0
 	MOVD	p+0(FP), R3
 	MOVD	b_len+8(FP), R4
 	MOVBZ	c+16(FP), R5	// byte to find
+	MOVD	R3, R6		// store base for later
 	SUB	$1, R3
-	MOVD	R3, R6		// store base-1 for later
 	ADD	R3, R4		// end-1
 
 _index2_loop:
@@ -822,8 +822,8 @@ _index2_loop:
 	RETURN
 
 _index2_notfound:
-	MOVW	$-1, R3
-	MOVW	R3, ret+24(FP)
+	MOVD	$-1, R3
+	MOVD	R3, ret+24(FP)
 	RETURN
 
 

src/pkg/runtime/mem_linux.c

@@ -10,7 +10,7 @@
 
 enum
 {
-	_PAGE_SIZE = 4096,
+	_PAGE_SIZE = PhysPageSize,
 	EACCES = 13,
 };
 
@@ -35,8 +35,9 @@ addrspace_free(void *v, uintptr n)
 		errval = runtime·mincore((int8*)v + off, chunk, vec);
 		// ENOMEM means unmapped, which is what we want.
 		// Anything else we assume means the pages are mapped.
-		if (errval != -ENOMEM)
+		if (errval != -ENOMEM && errval != ENOMEM) {
 			return 0;
+		}
 	}
 	return 1;
 }
@@ -47,12 +48,15 @@ mmap_fixed(byte *v, uintptr n, int32 prot, int32 flags, int32 fd, uint32 offset)
 	void *p;
 
 	p = runtime·mmap(v, n, prot, flags, fd, offset);
-	if(p != v && addrspace_free(v, n)) {
+	if(p != v) {
+		if(p > (void*)4096) {
+			runtime·munmap(p, n);
+			p = nil;
+		}
 		// On some systems, mmap ignores v without
 		// MAP_FIXED, so retry if the address space is free.
-		if(p > (void*)4096)
-			runtime·munmap(p, n);
-		p = runtime·mmap(v, n, prot, flags|MAP_FIXED, fd, offset);
+		if(addrspace_free(v, n))
+			p = runtime·mmap(v, n, prot, flags|MAP_FIXED, fd, offset);
 	}
 	return p;
 }

src/pkg/runtime/sys_linux_power64x.s

@@ -223,7 +223,6 @@ TEXT runtime·mmap(SB),NOSPLIT,$-8
 
 	SYSCALL	$SYS_mmap
 	BVC	2(PC)
-	NEG	R3, R3
 	RETURN
 
 TEXT runtime·munmap(SB),NOSPLIT,$-8

src/pkg/syscall/asm_linux_power64x.s

@@ -24,7 +24,6 @@ TEXT	·Syscall(SB),NOSPLIT,$0-56
 	MOVD	trap+0(FP), R9	// syscall entry
 	SYSCALL R9
 	BVC	ok
-	NEG	R3, R3
 	MOVD	$-1, R4
 	MOVD	R4, r1+32(FP)	// r1
 	MOVD	R0, r2+40(FP)	// r2
@@ -49,7 +48,6 @@ TEXT ·Syscall6(SB),NOSPLIT,$0-80
 	MOVD	trap+0(FP), R9	// syscall entry
 	SYSCALL R9
 	BVC	ok6
-	NEG	R3, R3
 	MOVD	$-1, R4
 	MOVD	R4, r1+56(FP)	// r1
 	MOVD	R0, r2+64(FP)	// r2
@@ -73,7 +71,6 @@ TEXT ·RawSyscall(SB),NOSPLIT,$0-56
 	MOVD	trap+0(FP), R9	// syscall entry
 	SYSCALL R9
 	BVC	ok1
-	NEG	R3, R3
 	MOVD	$-1, R4
 	MOVD	R4, r1+32(FP)	// r1
 	MOVD	R0, r2+40(FP)	// r2
@@ -95,7 +92,6 @@ TEXT ·RawSyscall6(SB),NOSPLIT,$0-80
 	MOVD	trap+0(FP), R9	// syscall entry
 	SYSCALL R9
 	BVC	ok2
-	NEG	R3, R3
 	MOVD	$-1, R4
 	MOVD	R4, r1+56(FP)	// r1
 	MOVD	R0, r2+64(FP)	// r2