tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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, r2
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, r2
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