gettimeofday.S 2.5 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103
  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. * Userland implementation of gettimeofday() for 32 bits processes in a
  4. * s390 kernel for use in the vDSO
  5. *
  6. * Copyright IBM Corp. 2008
  7. * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
  8. */
  9. #include <asm/vdso.h>
  10. #include <asm/asm-offsets.h>
  11. #include <asm/unistd.h>
  12. #include <asm/dwarf.h>
  13. #include <asm/ptrace.h>
  14. .text
  15. .align 4
  16. .globl __kernel_gettimeofday
  17. .type __kernel_gettimeofday,@function
  18. __kernel_gettimeofday:
  19. CFI_STARTPROC
  20. ahi %r15,-16
  21. CFI_ADJUST_CFA_OFFSET 16
  22. CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
  23. basr %r5,0
  24. 0: al %r5,13f-0b(%r5) /* get &_vdso_data */
  25. 1: ltr %r3,%r3 /* check if tz is NULL */
  26. je 2f
  27. mvc 0(8,%r3),__VDSO_TIMEZONE(%r5)
  28. 2: ltr %r2,%r2 /* check if tv is NULL */
  29. je 10f
  30. l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */
  31. tml %r4,0x0001 /* pending update ? loop */
  32. jnz 1b
  33. stcke 0(%r15) /* Store TOD clock */
  34. lm %r0,%r1,__VDSO_TS_END(%r5) /* TOD steering end time */
  35. s %r0,1(%r15)
  36. sl %r1,5(%r15)
  37. brc 3,14f
  38. ahi %r0,-1
  39. 14: ltr %r0,%r0 /* past end of steering? */
  40. jm 16f
  41. srdl %r0,15 /* 1 per 2^16 */
  42. tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */
  43. jz 15f
  44. lcr %r0,%r0 /* negative TOD offset */
  45. lcr %r1,%r1
  46. je 15f
  47. ahi %r0,-1
  48. 15: a %r0,1(%r15) /* add TOD timestamp */
  49. al %r1,5(%r15)
  50. brc 12,17f
  51. ahi %r0,1
  52. j 17f
  53. 16: lm %r0,%r1,1(%r15) /* load TOD timestamp */
  54. 17: s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
  55. sl %r1,__VDSO_XTIME_STAMP+4(%r5)
  56. brc 3,3f
  57. ahi %r0,-1
  58. 3: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */
  59. st %r0,0(%r15)
  60. l %r0,__VDSO_TK_MULT(%r5)
  61. ltr %r1,%r1
  62. mr %r0,%r0
  63. jnm 4f
  64. a %r0,__VDSO_TK_MULT(%r5)
  65. 4: al %r0,0(%r15)
  66. al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */
  67. al %r1,__VDSO_XTIME_NSEC+4(%r5)
  68. brc 12,5f
  69. ahi %r0,1
  70. 5: mvc 0(4,%r15),__VDSO_XTIME_SEC+4(%r5)
  71. cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */
  72. jne 1b
  73. l %r4,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
  74. srdl %r0,0(%r4) /* >> tk->shift */
  75. l %r4,0(%r15) /* get tv_sec from stack */
  76. basr %r5,0
  77. 6: ltr %r0,%r0
  78. jnz 7f
  79. cl %r1,11f-6b(%r5)
  80. jl 8f
  81. 7: ahi %r4,1
  82. sl %r1,11f-6b(%r5)
  83. brc 3,6b
  84. ahi %r0,-1
  85. j 6b
  86. 8: st %r4,0(%r2) /* store tv->tv_sec */
  87. ltr %r1,%r1
  88. m %r0,12f-6b(%r5)
  89. jnm 9f
  90. al %r0,12f-6b(%r5)
  91. 9: srl %r0,6
  92. st %r0,4(%r2) /* store tv->tv_usec */
  93. 10: slr %r2,%r2
  94. ahi %r15,16
  95. CFI_ADJUST_CFA_OFFSET -16
  96. CFI_RESTORE 15
  97. br %r14
  98. CFI_ENDPROC
  99. 11: .long 1000000000
  100. 12: .long 274877907
  101. 13: .long _vdso_data - 0b
  102. .size __kernel_gettimeofday,.-__kernel_gettimeofday