xref: /linux/arch/arm/lib/bitops.h (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
1 
2 #if __LINUX_ARM_ARCH__ >= 6 && defined(CONFIG_CPU_32v6K)
3 	.macro	bitop, instr
4 	mov	r2, #1
5 	and	r3, r0, #7		@ Get bit offset
6 	add	r1, r1, r0, lsr #3	@ Get byte offset
7 	mov	r3, r2, lsl r3
8 1:	ldrexb	r2, [r1]
9 	\instr	r2, r2, r3
10 	strexb	r0, r2, [r1]
11 	cmp	r0, #0
12 	bne	1b
13 	mov	pc, lr
14 	.endm
15 
16 	.macro	testop, instr, store
17 	and	r3, r0, #7		@ Get bit offset
18 	mov	r2, #1
19 	add	r1, r1, r0, lsr #3	@ Get byte offset
20 	mov	r3, r2, lsl r3		@ create mask
21 	smp_dmb
22 1:	ldrexb	r2, [r1]
23 	ands	r0, r2, r3		@ save old value of bit
24 	\instr	r2, r2, r3			@ toggle bit
25 	strexb	ip, r2, [r1]
26 	cmp	ip, #0
27 	bne	1b
28 	smp_dmb
29 	cmp	r0, #0
30 	movne	r0, #1
31 2:	mov	pc, lr
32 	.endm
33 #else
34 	.macro	bitop, instr
35 	and	r2, r0, #7
36 	mov	r3, #1
37 	mov	r3, r3, lsl r2
38 	save_and_disable_irqs ip
39 	ldrb	r2, [r1, r0, lsr #3]
40 	\instr	r2, r2, r3
41 	strb	r2, [r1, r0, lsr #3]
42 	restore_irqs ip
43 	mov	pc, lr
44 	.endm
45 
46 /**
47  * testop - implement a test_and_xxx_bit operation.
48  * @instr: operational instruction
49  * @store: store instruction
50  *
51  * Note: we can trivially conditionalise the store instruction
52  * to avoid dirtying the data cache.
53  */
54 	.macro	testop, instr, store
55 	add	r1, r1, r0, lsr #3
56 	and	r3, r0, #7
57 	mov	r0, #1
58 	save_and_disable_irqs ip
59 	ldrb	r2, [r1]
60 	tst	r2, r0, lsl r3
61 	\instr	r2, r2, r0, lsl r3
62 	\store	r2, [r1]
63 	moveq	r0, #0
64 	restore_irqs ip
65 	mov	pc, lr
66 	.endm
67 #endif
68