1 /*
   2  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
   4  * Copyright (c) 2015, Linaro Ltd. All rights reserved.
   5  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   6  *
   7  * This code is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 only, as
   9  * published by the Free Software Foundation.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  *
  25  */
  26 
  27 #include "precompiled.hpp"
  28 #include "asm/macroAssembler.hpp"
  29 #include "asm/macroAssembler.inline.hpp"
  30 #include "runtime/os.hpp"
  31 #include "runtime/threadLocalStorage.hpp"
  32 
  33 
  34 // get_thread can be called anywhere inside generated code so we need
  35 // to save whatever non-callee save context might get clobbered by the
  36 // call to the C thread_local lookup call or, indeed, the call setup
  37 // code. x86 appears to save C arg registers.
  38 
  39 void MacroAssembler::get_thread(Register dst) {
  40   // call pthread_getspecific
  41   // void * pthread_getspecific(pthread_key_t key);
  42 
  43   // Save all call-clobbered regs except dst, plus rscratch1 and rscratch2.
  44   RegSet saved_regs = RegSet::range(r0, r3) + rscratch1 + rscratch2 + lr - dst;
  45   push(saved_regs, sp);
  46 
  47   // Align stack and save value for return
  48   mov(c_rarg1, sp);
  49   sub(sp, sp, wordSize);
  50   bic(sp, sp, 7);
  51   str(c_rarg1, Address(sp));
  52 
  53   mov(c_rarg0, ThreadLocalStorage::thread_index());
  54   mov(r14, CAST_FROM_FN_PTR(address, pthread_getspecific));
  55 
  56   bl(r14);
  57   //undo alignment
  58   ldr(sp, Address(sp));
  59 
  60   if (dst != c_rarg0) {
  61     mov(dst, c_rarg0);
  62   }
  63 
  64   // restore pushed registers
  65   pop(saved_regs, sp);
  66 }
  67