cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

atomic.S (894B)

      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 */
     15ENTRY(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
     331:
     34	ldex	a3, (a2)
     35	cmpne	a0, a3
     36	bt16	2f
     37	mov	a3, a1
     38	stex	a3, (a2)
     39	bez	a3, 1b
     402:
     41	sync.is
     42#else
     43GLOBAL(csky_cmpxchg_ldw)
     44	ldw	a3, (a2)
     45	cmpne	a0, a3
     46	bt16	3f
     47GLOBAL(csky_cmpxchg_stw)
     48	stw	a1, (a2)
     493:
     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
     61END(csky_cmpxchg)