firmware/lib/bitops.h

   1         .macro  bitop, instr
   2         and     r2, r0, #7
   3         mov     r3, #1
   4         mov     r3, r3, lsl r2
   5         save_and_disable_irqs ip
   6         ldrb    r2, [r1, r0, lsr #3]
   7         \instr  r2, r2, r3
   8         strb    r2, [r1, r0, lsr #3]
   9         restore_irqs ip
  10         mov     pc, lr
  11         .endm
  12
  13 /**
  14  * testop - implement a test_and_xxx_bit operation.
  15  * @instr: operational instruction
  16  * @store: store instruction
  17  *
  18  * Note: we can trivially conditionalise the store instruction
  19  * to avoid dirting the data cache.
  20  */
  21         .macro  testop, instr, store
  22         add     r1, r1, r0, lsr #3
  23         and     r3, r0, #7
  24         mov     r0, #1
  25         save_and_disable_irqs ip
  26         ldrb    r2, [r1]
  27         tst     r2, r0, lsl r3
  28         \instr  r2, r2, r0, lsl r3
  29         \store  r2, [r1]
  30         restore_irqs ip
  31         moveq   r0, #0
  32         mov     pc, lr
  33         .endm