mem32.S 1.7 KB

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  1. /*
  2. * String handling functions.
  3. *
  4. * Copyright IBM Corp. 2012
  5. */
  6. #include <linux/linkage.h>
  7. /*
  8. * memset implementation
  9. *
  10. * This code corresponds to the C construct below. We do distinguish
  11. * between clearing (c == 0) and setting a memory array (c != 0) simply
  12. * because nearly all memset invocations in the kernel clear memory and
  13. * the xc instruction is preferred in such cases.
  14. *
  15. * void *memset(void *s, int c, size_t n)
  16. * {
  17. * if (likely(c == 0))
  18. * return __builtin_memset(s, 0, n);
  19. * return __builtin_memset(s, c, n);
  20. * }
  21. */
  22. ENTRY(memset)
  23. basr %r5,%r0
  24. .Lmemset_base:
  25. ltr %r4,%r4
  26. bzr %r14
  27. ltr %r3,%r3
  28. jnz .Lmemset_fill
  29. ahi %r4,-1
  30. lr %r3,%r4
  31. srl %r3,8
  32. ltr %r3,%r3
  33. lr %r1,%r2
  34. je .Lmemset_clear_rest
  35. .Lmemset_clear_loop:
  36. xc 0(256,%r1),0(%r1)
  37. la %r1,256(%r1)
  38. brct %r3,.Lmemset_clear_loop
  39. .Lmemset_clear_rest:
  40. ex %r4,.Lmemset_xc-.Lmemset_base(%r5)
  41. br %r14
  42. .Lmemset_fill:
  43. stc %r3,0(%r2)
  44. chi %r4,1
  45. lr %r1,%r2
  46. ber %r14
  47. ahi %r4,-2
  48. lr %r3,%r4
  49. srl %r3,8
  50. ltr %r3,%r3
  51. je .Lmemset_fill_rest
  52. .Lmemset_fill_loop:
  53. mvc 1(256,%r1),0(%r1)
  54. la %r1,256(%r1)
  55. brct %r3,.Lmemset_fill_loop
  56. .Lmemset_fill_rest:
  57. ex %r4,.Lmemset_mvc-.Lmemset_base(%r5)
  58. br %r14
  59. .Lmemset_xc:
  60. xc 0(1,%r1),0(%r1)
  61. .Lmemset_mvc:
  62. mvc 1(1,%r1),0(%r1)
  63. /*
  64. * memcpy implementation
  65. *
  66. * void *memcpy(void *dest, const void *src, size_t n)
  67. */
  68. ENTRY(memcpy)
  69. basr %r5,%r0
  70. .Lmemcpy_base:
  71. ltr %r4,%r4
  72. bzr %r14
  73. ahi %r4,-1
  74. lr %r0,%r4
  75. srl %r0,8
  76. ltr %r0,%r0
  77. lr %r1,%r2
  78. jnz .Lmemcpy_loop
  79. .Lmemcpy_rest:
  80. ex %r4,.Lmemcpy_mvc-.Lmemcpy_base(%r5)
  81. br %r14
  82. .Lmemcpy_loop:
  83. mvc 0(256,%r1),0(%r3)
  84. la %r1,256(%r1)
  85. la %r3,256(%r3)
  86. brct %r0,.Lmemcpy_loop
  87. j .Lmemcpy_rest
  88. .Lmemcpy_mvc:
  89. mvc 0(1,%r1),0(%r3)