xref: /openbmc/linux/arch/arm/lib/bitops.h (revision 367b8112)
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 1:	ldrexb	r2, [r1]
22 	ands	r0, r2, r3		@ save old value of bit
23 	\instr	r2, r2, r3			@ toggle bit
24 	strexb	ip, r2, [r1]
25 	cmp	ip, #0
26 	bne	1b
27 	cmp	r0, #0
28 	movne	r0, #1
29 2:	mov	pc, lr
30 	.endm
31 #else
32 	.macro	bitop, instr
33 	and	r2, r0, #7
34 	mov	r3, #1
35 	mov	r3, r3, lsl r2
36 	save_and_disable_irqs ip
37 	ldrb	r2, [r1, r0, lsr #3]
38 	\instr	r2, r2, r3
39 	strb	r2, [r1, r0, lsr #3]
40 	restore_irqs ip
41 	mov	pc, lr
42 	.endm
43 
44 /**
45  * testop - implement a test_and_xxx_bit operation.
46  * @instr: operational instruction
47  * @store: store instruction
48  *
49  * Note: we can trivially conditionalise the store instruction
50  * to avoid dirtying the data cache.
51  */
52 	.macro	testop, instr, store
53 	add	r1, r1, r0, lsr #3
54 	and	r3, r0, #7
55 	mov	r0, #1
56 	save_and_disable_irqs ip
57 	ldrb	r2, [r1]
58 	tst	r2, r0, lsl r3
59 	\instr	r2, r2, r0, lsl r3
60 	\store	r2, [r1]
61 	restore_irqs ip
62 	moveq	r0, #0
63 	mov	pc, lr
64 	.endm
65 #endif
66