| // Copyright 2014 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 ppc64 ppc64le |
| // +build linux |
| |
| package runtime |
| |
| import "unsafe" |
| |
| // On ppc64, Linux limits the user address space to 46 bits (see |
| // TASK_SIZE_USER64 in the Linux kernel). This has grown over time, |
| // so here we allow 48 bit addresses. |
| // |
| // In addition to the 16 bits taken from the top, we can take 3 from the |
| // bottom, because node must be pointer-aligned, giving a total of 19 bits |
| // of count. |
| const ( |
| addrBits = 48 |
| cntBits = 64 - addrBits + 3 |
| ) |
| |
| func lfstackPack(node *lfnode, cnt uintptr) uint64 { |
| return uint64(uintptr(unsafe.Pointer(node)))<<(64-addrBits) | uint64(cnt&(1<<cntBits-1)) |
| } |
| |
| func lfstackUnpack(val uint64) (node *lfnode, cnt uintptr) { |
| node = (*lfnode)(unsafe.Pointer(uintptr(val >> cntBits << 3))) |
| cnt = uintptr(val & (1<<cntBits - 1)) |
| return |
| } |
