LXR linux/arch/arm/lib/bitops.h

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