clock_getres.S 1.2 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. * Userland implementation of clock_getres() for 64 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. .text
  14. .align 4
  15. .globl __kernel_clock_getres
  16. .type __kernel_clock_getres,@function
  17. __kernel_clock_getres:
  18. CFI_STARTPROC
  19. larl %r1,3f
  20. lg %r0,0(%r1)
  21. cghi %r2,__CLOCK_REALTIME_COARSE
  22. je 0f
  23. cghi %r2,__CLOCK_MONOTONIC_COARSE
  24. je 0f
  25. larl %r1,_vdso_data
  26. llgf %r0,__VDSO_CLOCK_REALTIME_RES(%r1)
  27. cghi %r2,__CLOCK_REALTIME
  28. je 0f
  29. cghi %r2,__CLOCK_MONOTONIC
  30. je 0f
  31. cghi %r2,__CLOCK_THREAD_CPUTIME_ID
  32. je 0f
  33. cghi %r2,-2 /* Per-thread CPUCLOCK with PID=0, VIRT=1 */
  34. jne 2f
  35. larl %r5,_vdso_data
  36. icm %r0,15,__LC_ECTG_OK(%r5)
  37. jz 2f
  38. 0: ltgr %r3,%r3
  39. jz 1f /* res == NULL */
  40. xc 0(8,%r3),0(%r3) /* set tp->tv_sec to zero */
  41. stg %r0,8(%r3) /* store tp->tv_usec */
  42. 1: lghi %r2,0
  43. br %r14
  44. 2: lghi %r1,__NR_clock_getres /* fallback to svc */
  45. svc 0
  46. br %r14
  47. CFI_ENDPROC
  48. 3: .quad __CLOCK_COARSE_RES
  49. .size __kernel_clock_getres,.-__kernel_clock_getres