xref: /aosp_15_r20/external/arm-trusted-firmware/lib/extensions/mtpmu/aarch64/mtpmu.S (revision 54fd6939e177f8ff529b10183254802c76df6d08)
1*54fd6939SJiyong Park/*
2*54fd6939SJiyong Park * Copyright (c) 2020, Arm Limited. All rights reserved.
3*54fd6939SJiyong Park *
4*54fd6939SJiyong Park * SPDX-License-Identifier: BSD-3-Clause
5*54fd6939SJiyong Park */
6*54fd6939SJiyong Park
7*54fd6939SJiyong Park#include <arch.h>
8*54fd6939SJiyong Park#include <asm_macros.S>
9*54fd6939SJiyong Park
10*54fd6939SJiyong Park	.global	mtpmu_disable
11*54fd6939SJiyong Park
12*54fd6939SJiyong Park/* -------------------------------------------------------------
13*54fd6939SJiyong Park * The functions in this file are called at entrypoint, before
14*54fd6939SJiyong Park * the CPU has decided whether this is a cold or a warm boot.
15*54fd6939SJiyong Park * Therefore there are no stack yet to rely on for a C function
16*54fd6939SJiyong Park * call.
17*54fd6939SJiyong Park * -------------------------------------------------------------
18*54fd6939SJiyong Park */
19*54fd6939SJiyong Park
20*54fd6939SJiyong Park/*
21*54fd6939SJiyong Park * bool mtpmu_supported(void)
22*54fd6939SJiyong Park *
23*54fd6939SJiyong Park * Return a boolean indicating whether FEAT_MTPMU is supported or not.
24*54fd6939SJiyong Park *
25*54fd6939SJiyong Park * Trash registers: x0, x1
26*54fd6939SJiyong Park */
27*54fd6939SJiyong Parkfunc mtpmu_supported
28*54fd6939SJiyong Park	mrs	x0, id_aa64dfr0_el1
29*54fd6939SJiyong Park	mov_imm	x1, ID_AA64DFR0_MTPMU_MASK
30*54fd6939SJiyong Park	and	x0, x1, x0, LSR #ID_AA64DFR0_MTPMU_SHIFT
31*54fd6939SJiyong Park	cmp	x0, ID_AA64DFR0_MTPMU_SUPPORTED
32*54fd6939SJiyong Park	cset	x0, eq
33*54fd6939SJiyong Park	ret
34*54fd6939SJiyong Parkendfunc mtpmu_supported
35*54fd6939SJiyong Park
36*54fd6939SJiyong Park/*
37*54fd6939SJiyong Park * bool el_implemented(unsigned int el_shift)
38*54fd6939SJiyong Park *
39*54fd6939SJiyong Park * Return a boolean indicating if the specified EL is implemented.
40*54fd6939SJiyong Park * The EL is represented as the bitmask shift on id_aa64pfr0_el1 register.
41*54fd6939SJiyong Park *
42*54fd6939SJiyong Park * Trash registers: x0, x1
43*54fd6939SJiyong Park */
44*54fd6939SJiyong Parkfunc el_implemented
45*54fd6939SJiyong Park	mrs	x1, id_aa64pfr0_el1
46*54fd6939SJiyong Park	lsr	x1, x1, x0
47*54fd6939SJiyong Park	cmp	x1, #ID_AA64PFR0_ELX_MASK
48*54fd6939SJiyong Park	cset	x0, eq
49*54fd6939SJiyong Park	ret
50*54fd6939SJiyong Parkendfunc el_implemented
51*54fd6939SJiyong Park
52*54fd6939SJiyong Park/*
53*54fd6939SJiyong Park * void mtpmu_disable(void)
54*54fd6939SJiyong Park *
55*54fd6939SJiyong Park * Disable mtpmu feature if supported.
56*54fd6939SJiyong Park *
57*54fd6939SJiyong Park * Trash register: x0, x1, x30
58*54fd6939SJiyong Park */
59*54fd6939SJiyong Parkfunc mtpmu_disable
60*54fd6939SJiyong Park	mov	x10, x30
61*54fd6939SJiyong Park	bl	mtpmu_supported
62*54fd6939SJiyong Park	cbz	x0, exit_disable
63*54fd6939SJiyong Park
64*54fd6939SJiyong Park	/* FEAT_MTMPU Supported */
65*54fd6939SJiyong Park	mov_imm	x0, ID_AA64PFR0_EL3_SHIFT
66*54fd6939SJiyong Park	bl	el_implemented
67*54fd6939SJiyong Park	cbz	x0, 1f
68*54fd6939SJiyong Park
69*54fd6939SJiyong Park	/* EL3 implemented */
70*54fd6939SJiyong Park	mrs	x0, mdcr_el3
71*54fd6939SJiyong Park	mov_imm x1, MDCR_MTPME_BIT
72*54fd6939SJiyong Park	bic	x0, x0, x1
73*54fd6939SJiyong Park	msr	mdcr_el3, x0
74*54fd6939SJiyong Park
75*54fd6939SJiyong Park	/*
76*54fd6939SJiyong Park	 * If EL3 is implemented, MDCR_EL2.MTPME is implemented as Res0 and
77*54fd6939SJiyong Park	 * FEAT_MTPMU is controlled only from EL3, so no need to perform
78*54fd6939SJiyong Park	 * any operations for EL2.
79*54fd6939SJiyong Park	 */
80*54fd6939SJiyong Park	isb
81*54fd6939SJiyong Parkexit_disable:
82*54fd6939SJiyong Park	ret	x10
83*54fd6939SJiyong Park1:
84*54fd6939SJiyong Park	/* EL3 not implemented */
85*54fd6939SJiyong Park	mov_imm	x0, ID_AA64PFR0_EL2_SHIFT
86*54fd6939SJiyong Park	bl	el_implemented
87*54fd6939SJiyong Park	cbz	x0, exit_disable
88*54fd6939SJiyong Park
89*54fd6939SJiyong Park	/* EL2 implemented */
90*54fd6939SJiyong Park	mrs	x0, mdcr_el2
91*54fd6939SJiyong Park	mov_imm x1, MDCR_EL2_MTPME
92*54fd6939SJiyong Park	bic	x0, x0, x1
93*54fd6939SJiyong Park	msr	mdcr_el2, x0
94*54fd6939SJiyong Park	isb
95*54fd6939SJiyong Park	ret	x10
96*54fd6939SJiyong Parkendfunc mtpmu_disable
97