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  1. /*
  2.  * Copyright (c) 2006 Ondrej Palkovsky
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup libcmips32 
  30.  * @{
  31.  */
  32. /** @file
  33.  * @ingroup libcmips32eb   
  34.  */
  35.  
  36. /* TLS for MIPS is described in http://www.linux-mips.org/wiki/NPTL */
  37.  
  38. #ifndef LIBC_mips32THREAD_H_
  39. #define LIBC_mips32THREAD_H_
  40.  
  41. /* I did not find any specification (neither MIPS nor PowerPC), but
  42.  * as I found it
  43.  * - it uses Variant II
  44.  * - TCB is at Address(First TLS Block)+0x7000.
  45.  * - DTV is at Address(First TLS Block)+0x8000
  46.  * - What would happen if the TLS data was larger then 0x7000?
  47.  * - The linker never accesses DTV directly, has the second definition any
  48.  *   sense?
  49.  * We will make it this way:
  50.  * - TCB is at TP-0x7000-sizeof(tcb)
  51.  * - No assumption about DTV etc., but it will not have a fixed address
  52.  */
  53. #define MIPS_TP_OFFSET 0x7000
  54.  
  55. typedef struct {
  56.     void *pst_data;
  57. } tcb_t;
  58.  
  59. static inline void __tcb_set(tcb_t *tcb)
  60. {
  61.     void *tp = tcb;
  62.     tp += MIPS_TP_OFFSET + sizeof(tcb_t);
  63.  
  64.     asm volatile ("add $27, %0, $0" : : "r"(tp)); /* Move tls to K1 */
  65. }
  66.  
  67. static inline tcb_t * __tcb_get(void)
  68. {
  69.     void * retval;
  70.  
  71.     asm volatile("add %0, $27, $0" : "=r"(retval));
  72.  
  73.     return (tcb_t *)(retval - MIPS_TP_OFFSET - sizeof(tcb_t));
  74. }
  75.  
  76. #endif
  77.  
  78. /** @}
  79.  */
  80.