bitops.h (2194B)
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