bitops.h 2.3 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #include <asm/assembler.h>
  3. #include <asm/unwind.h>
  4. #if __LINUX_ARM_ARCH__ >= 6
  5. .macro bitop, name, instr
  6. ENTRY( \name )
  7. UNWIND( .fnstart )
  8. ands ip, r1, #3
  9. strbne r1, [ip] @ assert word-aligned
  10. mov r2, #1
  11. and r3, r0, #31 @ Get bit offset
  12. mov r0, r0, lsr #5
  13. add r1, r1, r0, lsl #2 @ Get word offset
  14. #if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
  15. .arch_extension mp
  16. ALT_SMP(W(pldw) [r1])
  17. ALT_UP(W(nop))
  18. #endif
  19. mov r3, r2, lsl r3
  20. 1: ldrex r2, [r1]
  21. \instr r2, r2, r3
  22. strex r0, r2, [r1]
  23. cmp r0, #0
  24. bne 1b
  25. bx lr
  26. UNWIND( .fnend )
  27. ENDPROC(\name )
  28. .endm
  29. .macro __testop, name, instr, store, barrier
  30. ENTRY( \name )
  31. UNWIND( .fnstart )
  32. ands ip, r1, #3
  33. strbne r1, [ip] @ assert word-aligned
  34. mov r2, #1
  35. and r3, r0, #31 @ Get bit offset
  36. mov r0, r0, lsr #5
  37. add r1, r1, r0, lsl #2 @ Get word offset
  38. mov r3, r2, lsl r3 @ create mask
  39. \barrier
  40. #if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
  41. .arch_extension mp
  42. ALT_SMP(W(pldw) [r1])
  43. ALT_UP(W(nop))
  44. #endif
  45. 1: ldrex r2, [r1]
  46. ands r0, r2, r3 @ save old value of bit
  47. \instr r2, r2, r3 @ toggle bit
  48. strex ip, r2, [r1]
  49. cmp ip, #0
  50. bne 1b
  51. \barrier
  52. cmp r0, #0
  53. movne r0, #1
  54. 2: bx lr
  55. UNWIND( .fnend )
  56. ENDPROC(\name )
  57. .endm
  58. .macro testop, name, instr, store
  59. __testop \name, \instr, \store, smp_dmb
  60. .endm
  61. .macro sync_testop, name, instr, store
  62. __testop \name, \instr, \store, __smp_dmb
  63. .endm
  64. #else
  65. .macro bitop, name, instr
  66. ENTRY( \name )
  67. UNWIND( .fnstart )
  68. ands ip, r1, #3
  69. strbne r1, [ip] @ assert word-aligned
  70. and r2, r0, #31
  71. mov r0, r0, lsr #5
  72. mov r3, #1
  73. mov r3, r3, lsl r2
  74. save_and_disable_irqs ip
  75. ldr r2, [r1, r0, lsl #2]
  76. \instr r2, r2, r3
  77. str r2, [r1, r0, lsl #2]
  78. restore_irqs ip
  79. ret lr
  80. UNWIND( .fnend )
  81. ENDPROC(\name )
  82. .endm
  83. /**
  84. * testop - implement a test_and_xxx_bit operation.
  85. * @instr: operational instruction
  86. * @store: store instruction
  87. *
  88. * Note: we can trivially conditionalise the store instruction
  89. * to avoid dirtying the data cache.
  90. */
  91. .macro testop, name, instr, store
  92. ENTRY( \name )
  93. UNWIND( .fnstart )
  94. ands ip, r1, #3
  95. strbne r1, [ip] @ assert word-aligned
  96. and r3, r0, #31
  97. mov r0, r0, lsr #5
  98. save_and_disable_irqs ip
  99. ldr r2, [r1, r0, lsl #2]!
  100. mov r0, #1
  101. tst r2, r0, lsl r3
  102. \instr r2, r2, r0, lsl r3
  103. \store r2, [r1]
  104. moveq r0, #0
  105. restore_irqs ip
  106. ret lr
  107. UNWIND( .fnend )
  108. ENDPROC(\name )
  109. .endm
  110. #endif