sysdeps/unix/sysv/linux/tile/swapcontext.S

   1 /* Copyright (C) 2011-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library.  If not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <sysdep.h>
  20
  21 #include "ucontext_i.h"
  22
  23 /* int swapcontext (ucontext_t *oucp, const ucontext_t *ucp) */
  24
  25         .text
  26 ENTRY (__swapcontext)
  27         FEEDBACK_ENTER(__swapcontext)
  28         /* Set up a frame and save r0 and r1.  */
  29         {
  30          ST sp, lr
  31          ADDI_PTR r11, sp, -(3 * REGSIZE)
  32          move r10, sp
  33         }
  34         ADDI_PTR sp, sp, -(4 * REGSIZE)
  35         cfi_def_cfa_offset (4 * REGSIZE)
  36         cfi_offset (lr, 0)
  37         {
  38          ST r11, r10
  39          ADDI_PTR r10, sp, (2 * REGSIZE)
  40         }
  41         {
  42          ST r10, r0
  43          ADDI_PTR r10, sp, (3 * REGSIZE)
  44         }
  45         ST r10, r1
  46
  47         /* Save the current context.  */
  48         jal __getcontext
  49
  50         /* Tear down the frame and restore r0, r1, and lr. */
  51         {
  52          BNEZ r0, .Lerror
  53          ADDI_PTR r1, sp, 3 * REGSIZE
  54         }
  55         {
  56          LD r1, r1
  57          ADDI_PTR r0, sp, 2 * REGSIZE
  58         }
  59         {
  60          LD r0, r0
  61          ADDI_PTR sp, sp, 4 * REGSIZE
  62         }
  63         cfi_def_cfa_offset (0)
  64         {
  65          LD lr, sp
  66          ADDLI_PTR r10, r0, UC_REG(54)
  67         }
  68
  69         /* Update the stored sp and lr.  */
  70         {
  71          ST r10, sp
  72          ADDLI_PTR r10, r0, UC_REG(55)
  73         }
  74         ST r10, lr
  75
  76         /* Tail-call setcontext to finish up.  */
  77         {
  78          move r0, r1
  79          j __setcontext
  80         }
  81
  82 .Lerror:
  83         ADDI_PTR sp, sp, 4 * REGSIZE
  84         cfi_def_cfa_offset (0)
  85         LD lr, sp
  86         jrp lr
  87 END (__swapcontext)
  88
  89 weak_alias (__swapcontext, swapcontext)