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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Routines to access the system control register
*
* Copyright (c) 2019 Heinrich Schuchardt
*/
#include <linux/linkage.h>
/*
* void allow_unaligned(void) - allow unaligned access
*
* This routine sets the enable unaligned data support flag and clears the
* aligned flag in the system control register.
* After calling this routine unaligned access does no longer leads to a
* data abort or undefined behavior but is handled by the CPU.
* For details see the "ARM Architecture Reference Manual" for ARMv6.
*/
ENTRY(allow_unaligned)
mrc p15, 0, r0, c1, c0, 0 @ load system control register
orr r0, r0, #1 << 22 @ set unaligned data support flag
bic r0, r0, #2 @ clear aligned flag
mcr p15, 0, r0, c1, c0, 0 @ write system control register
bx lr @ return
ENDPROC(allow_unaligned)
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