gettimeofday.S 2.0 KB

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  1. /*
  2. * Userland implementation of gettimeofday() for 32 bits processes in a
  3. * s390 kernel for use in the vDSO
  4. *
  5. * Copyright IBM Corp. 2008
  6. * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
  7. *
  8. * This program is free software; you can redistribute it and/or modify
  9. * it under the terms of the GNU General Public License (version 2 only)
  10. * as published by the Free Software Foundation.
  11. */
  12. #include <asm/vdso.h>
  13. #include <asm/asm-offsets.h>
  14. #include <asm/unistd.h>
  15. .text
  16. .align 4
  17. .globl __kernel_gettimeofday
  18. .type __kernel_gettimeofday,@function
  19. __kernel_gettimeofday:
  20. .cfi_startproc
  21. basr %r5,0
  22. 0: al %r5,13f-0b(%r5) /* get &_vdso_data */
  23. 1: ltr %r3,%r3 /* check if tz is NULL */
  24. je 2f
  25. mvc 0(8,%r3),__VDSO_TIMEZONE(%r5)
  26. 2: ltr %r2,%r2 /* check if tv is NULL */
  27. je 10f
  28. l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */
  29. tml %r4,0x0001 /* pending update ? loop */
  30. jnz 1b
  31. stck 24(%r15) /* Store TOD clock */
  32. lm %r0,%r1,24(%r15)
  33. s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
  34. sl %r1,__VDSO_XTIME_STAMP+4(%r5)
  35. brc 3,3f
  36. ahi %r0,-1
  37. 3: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */
  38. st %r0,24(%r15)
  39. l %r0,__VDSO_TK_MULT(%r5)
  40. ltr %r1,%r1
  41. mr %r0,%r0
  42. jnm 4f
  43. a %r0,__VDSO_TK_MULT(%r5)
  44. 4: al %r0,24(%r15)
  45. al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */
  46. al %r1,__VDSO_XTIME_NSEC+4(%r5)
  47. brc 12,5f
  48. ahi %r0,1
  49. 5: mvc 24(4,%r15),__VDSO_XTIME_SEC+4(%r5)
  50. cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */
  51. jne 1b
  52. l %r4,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
  53. srdl %r0,0(%r4) /* >> tk->shift */
  54. l %r4,24(%r15) /* get tv_sec from stack */
  55. basr %r5,0
  56. 6: ltr %r0,%r0
  57. jnz 7f
  58. cl %r1,11f-6b(%r5)
  59. jl 8f
  60. 7: ahi %r4,1
  61. sl %r1,11f-6b(%r5)
  62. brc 3,6b
  63. ahi %r0,-1
  64. j 6b
  65. 8: st %r4,0(%r2) /* store tv->tv_sec */
  66. ltr %r1,%r1
  67. m %r0,12f-6b(%r5)
  68. jnm 9f
  69. al %r0,12f-6b(%r5)
  70. 9: srl %r0,6
  71. st %r0,4(%r2) /* store tv->tv_usec */
  72. 10: slr %r2,%r2
  73. br %r14
  74. 11: .long 1000000000
  75. 12: .long 274877907
  76. 13: .long _vdso_data - 0b
  77. .cfi_endproc
  78. .size __kernel_gettimeofday,.-__kernel_gettimeofday