diff options
Diffstat (limited to 'src/runtime/lfstack_linux_ppc64x.go')
-rw-r--r-- | src/runtime/lfstack_linux_ppc64x.go | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/src/runtime/lfstack_linux_ppc64x.go b/src/runtime/lfstack_linux_ppc64x.go new file mode 100644 index 000000000..7ed502558 --- /dev/null +++ b/src/runtime/lfstack_linux_ppc64x.go @@ -0,0 +1,32 @@ +// 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 +} |