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| /* SPDX-License-Identifier: GPL-2.0 */
| // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
|
| #include <linux/linkage.h>
| #include <abi/entry.h>
|
| .text
|
| /*
| * int csky_cmpxchg(int oldval, int newval, int *ptr)
| *
| * If *ptr != oldval && return 1,
| * else *ptr = newval return 0.
| */
| ENTRY(csky_cmpxchg)
| USPTOKSP
| mfcr a3, epc
| addi a3, TRAP0_SIZE
|
| subi sp, 16
| stw a3, (sp, 0)
| mfcr a3, epsr
| stw a3, (sp, 4)
| mfcr a3, usp
| stw a3, (sp, 8)
|
| psrset ee
| #ifdef CONFIG_CPU_HAS_LDSTEX
| 1:
| ldex a3, (a2)
| cmpne a0, a3
| bt16 2f
| mov a3, a1
| stex a3, (a2)
| bez a3, 1b
| 2:
| sync.is
| #else
| 1:
| ldw a3, (a2)
| cmpne a0, a3
| bt16 3f
| 2:
| stw a1, (a2)
| 3:
| #endif
| mvc a0
| ldw a3, (sp, 0)
| mtcr a3, epc
| ldw a3, (sp, 4)
| mtcr a3, epsr
| ldw a3, (sp, 8)
| mtcr a3, usp
| addi sp, 16
| KSPTOUSP
| rte
| END(csky_cmpxchg)
|
| #ifndef CONFIG_CPU_HAS_LDSTEX
| /*
| * Called from tlbmodified exception
| */
| ENTRY(csky_cmpxchg_fixup)
| mfcr a0, epc
| lrw a1, 2b
| cmpne a1, a0
| bt 1f
| subi a1, (2b - 1b)
| stw a1, (sp, LSAVE_PC)
| 1:
| rts
| END(csky_cmpxchg_fixup)
| #endif
|
|
