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