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/*
* Copyright (c) 2020, Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch.h>
#include <asm_macros.S>
.global mtpmu_disable
/* -------------------------------------------------------------
* The functions in this file are called at entrypoint, before
* the CPU has decided whether this is a cold or a warm boot.
* Therefore there are no stack yet to rely on for a C function
* call.
* -------------------------------------------------------------
*/
/*
* bool mtpmu_supported(void)
*
* Return a boolean indicating whether FEAT_MTPMU is supported or not.
*
* Trash registers: r0.
*/
func mtpmu_supported
ldcopr r0, ID_DFR1
and r0, r0, #(ID_DFR1_MTPMU_MASK >> ID_DFR1_MTPMU_SHIFT)
cmp r0, #ID_DFR1_MTPMU_SUPPORTED
mov r0, #0
addeq r0, r0, #1
bx lr
endfunc mtpmu_supported
/*
* bool el_implemented(unsigned int el)
*
* Return a boolean indicating if the specified EL (2 or 3) is implemented.
*
* Trash registers: r0
*/
func el_implemented
cmp r0, #3
ldcopr r0, ID_PFR1
lsreq r0, r0, #ID_PFR1_SEC_SHIFT
lsrne r0, r0, #ID_PFR1_VIRTEXT_SHIFT
/*
* ID_PFR1_VIRTEXT_MASK is the same as ID_PFR1_SEC_MASK
* so use any one of them
*/
and r0, r0, #ID_PFR1_VIRTEXT_MASK
cmp r0, #ID_PFR1_ELx_ENABLED
mov r0, #0
addeq r0, r0, #1
bx lr
endfunc el_implemented
/*
* void mtpmu_disable(void)
*
* Disable mtpmu feature if supported.
*
* Trash register: r0, r1, r2
*/
func mtpmu_disable
mov r2, lr
bl mtpmu_supported
cmp r0, #0
bxeq r2 /* FEAT_MTPMU not supported */
/* FEAT_MTMPU Supported */
mov r0, #3
bl el_implemented
cmp r0, #0
beq 1f
/* EL3 implemented */
ldcopr r0, SDCR
ldr r1, =SDCR_MTPME_BIT
bic r0, r0, r1
stcopr r0, SDCR
/*
* If EL3 is implemented, HDCR.MTPME is implemented as Res0 and
* FEAT_MTPMU is controlled only from EL3, so no need to perform
* any operations for EL2.
*/
isb
bx r2
1:
/* EL3 not implemented */
mov r0, #2
bl el_implemented
cmp r0, #0
bxeq r2 /* No EL2 or EL3 implemented */
/* EL2 implemented */
ldcopr r0, HDCR
ldr r1, =HDCR_MTPME_BIT
orr r0, r0, r1
stcopr r0, HDCR
isb
bx r2
endfunc mtpmu_disable
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