diff options
Diffstat (limited to 'kernel/arch/arm/lib/bitops.h')
| -rw-r--r-- | kernel/arch/arm/lib/bitops.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/kernel/arch/arm/lib/bitops.h b/kernel/arch/arm/lib/bitops.h new file mode 100644 index 000000000..7d807cfd8 --- /dev/null +++ b/kernel/arch/arm/lib/bitops.h @@ -0,0 +1,106 @@ +#include <asm/assembler.h> +#include <asm/unwind.h> + +#if __LINUX_ARM_ARCH__ >= 6 + .macro bitop, name, instr +ENTRY( \name ) +UNWIND( .fnstart ) + ands ip, r1, #3 + strneb r1, [ip] @ assert word-aligned + mov r2, #1 + and r3, r0, #31 @ Get bit offset + mov r0, r0, lsr #5 + add r1, r1, r0, lsl #2 @ Get word offset +#if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP) + .arch_extension mp + ALT_SMP(W(pldw) [r1]) + ALT_UP(W(nop)) +#endif + mov r3, r2, lsl r3 +1: ldrex r2, [r1] + \instr r2, r2, r3 + strex r0, r2, [r1] + cmp r0, #0 + bne 1b + bx lr +UNWIND( .fnend ) +ENDPROC(\name ) + .endm + + .macro testop, name, instr, store +ENTRY( \name ) +UNWIND( .fnstart ) + ands ip, r1, #3 + strneb r1, [ip] @ assert word-aligned + mov r2, #1 + and r3, r0, #31 @ Get bit offset + mov r0, r0, lsr #5 + add r1, r1, r0, lsl #2 @ Get word offset + mov r3, r2, lsl r3 @ create mask + smp_dmb +#if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP) + .arch_extension mp + ALT_SMP(W(pldw) [r1]) + ALT_UP(W(nop)) +#endif +1: ldrex r2, [r1] + ands r0, r2, r3 @ save old value of bit + \instr r2, r2, r3 @ toggle bit + strex ip, r2, [r1] + cmp ip, #0 + bne 1b + smp_dmb + cmp r0, #0 + movne r0, #1 +2: bx lr +UNWIND( .fnend ) +ENDPROC(\name ) + .endm +#else + .macro bitop, name, instr +ENTRY( \name ) +UNWIND( .fnstart ) + ands ip, r1, #3 + strneb r1, [ip] @ assert word-aligned + and r2, r0, #31 + mov r0, r0, lsr #5 + mov r3, #1 + mov r3, r3, lsl r2 + save_and_disable_irqs ip + ldr r2, [r1, r0, lsl #2] + \instr r2, r2, r3 + str r2, [r1, r0, lsl #2] + restore_irqs ip + ret lr +UNWIND( .fnend ) +ENDPROC(\name ) + .endm + +/** + * testop - implement a test_and_xxx_bit operation. + * @instr: operational instruction + * @store: store instruction + * + * Note: we can trivially conditionalise the store instruction + * to avoid dirtying the data cache. + */ + .macro testop, name, instr, store +ENTRY( \name ) +UNWIND( .fnstart ) + ands ip, r1, #3 + strneb r1, [ip] @ assert word-aligned + and r3, r0, #31 + mov r0, r0, lsr #5 + save_and_disable_irqs ip + ldr r2, [r1, r0, lsl #2]! + mov r0, #1 + tst r2, r0, lsl r3 + \instr r2, r2, r0, lsl r3 + \store r2, [r1] + moveq r0, #0 + restore_irqs ip + ret lr +UNWIND( .fnend ) +ENDPROC(\name ) + .endm +#endif |