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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_mips32_TLS_H_
  39. #define LIBC_mips32_TLS_H_
  40.  
  41. /*
  42.  * FIXME: Note that the use of variant I contradicts the observations made in
  43.  * the note below. Nevertheless the scheme we have used for allocating and
  44.  * deallocatin TLS corresponds to TLS variant I.
  45.  */
  46. #define CONFIG_TLS_VARIANT_1
  47.  
  48. /* I did not find any specification (neither MIPS nor PowerPC), but
  49.  * as I found it
  50.  * - it uses Variant II
  51.  * - TCB is at Address(First TLS Block)+0x7000.
  52.  * - DTV is at Address(First TLS Block)+0x8000
  53.  * - What would happen if the TLS data was larger then 0x7000?
  54.  * - The linker never accesses DTV directly, has the second definition any
  55.  *   sense?
  56.  * We will make it this way:
  57.  * - TCB is at TP-0x7000-sizeof(tcb)
  58.  * - No assumption about DTV etc., but it will not have a fixed address
  59.  */
  60. #define MIPS_TP_OFFSET 0x7000
  61.  
  62. typedef struct {
  63.     void *fibril_data;
  64. } tcb_t;
  65.  
  66. static inline void __tcb_set(tcb_t *tcb)
  67. {
  68.     void *tp = tcb;
  69.     tp += MIPS_TP_OFFSET + sizeof(tcb_t);
  70.  
  71.     asm volatile ("add $27, %0, $0" : : "r"(tp)); /* Move tls to K1 */
  72. }
  73.  
  74. static inline tcb_t * __tcb_get(void)
  75. {
  76.     void * retval;
  77.  
  78.     asm volatile("add %0, $27, $0" : "=r"(retval));
  79.  
  80.     return (tcb_t *)(retval - MIPS_TP_OFFSET - sizeof(tcb_t));
  81. }
  82.  
  83. #endif
  84.  
  85. /** @}
  86.  */
  87.