1 /* SPDX-License-Identifier: GPL-2.0 */ 2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. 3 4 #include <linux/linkage.h> 5 #include <abi/entry.h> 6 7 .text 8 9 /* 10 * int csky_cmpxchg(int oldval, int newval, int *ptr) 11 * 12 * If *ptr != oldval && return 1, 13 * else *ptr = newval return 0. 14 */ 15 ENTRY(csky_cmpxchg) 16 USPTOKSP 17 18 RD_MEH a3 19 WR_MEH a3 20 21 mfcr a3, epc 22 addi a3, TRAP0_SIZE 23 24 subi sp, 16 25 stw a3, (sp, 0) 26 mfcr a3, epsr 27 stw a3, (sp, 4) 28 mfcr a3, usp 29 stw a3, (sp, 8) 30 31 psrset ee 32 #ifdef CONFIG_CPU_HAS_LDSTEX 33 1: 34 ldex a3, (a2) 35 cmpne a0, a3 36 bt16 2f 37 mov a3, a1 38 stex a3, (a2) 39 bez a3, 1b 40 2: 41 sync.is 42 #else 43 GLOBAL(csky_cmpxchg_ldw) 44 ldw a3, (a2) 45 cmpne a0, a3 46 bt16 3f 47 GLOBAL(csky_cmpxchg_stw) 48 stw a1, (a2) 49 3: 50 #endif 51 mvc a0 52 ldw a3, (sp, 0) 53 mtcr a3, epc 54 ldw a3, (sp, 4) 55 mtcr a3, epsr 56 ldw a3, (sp, 8) 57 mtcr a3, usp 58 addi sp, 16 59 KSPTOUSP 60 rte 61 END(csky_cmpxchg)
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