xref: /aosp_15_r20/external/arm-trusted-firmware/lib/psci/aarch64/psci_helpers.S (revision 54fd6939e177f8ff529b10183254802c76df6d08)
1*54fd6939SJiyong Park/*
2*54fd6939SJiyong Park * Copyright (c) 2014-2018, ARM Limited and Contributors. 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 <asm_macros.S>
8*54fd6939SJiyong Park#include <assert_macros.S>
9*54fd6939SJiyong Park#include <lib/psci/psci.h>
10*54fd6939SJiyong Park#include <platform_def.h>
11*54fd6939SJiyong Park
12*54fd6939SJiyong Park	.globl	psci_do_pwrdown_cache_maintenance
13*54fd6939SJiyong Park	.globl	psci_do_pwrup_cache_maintenance
14*54fd6939SJiyong Park	.globl	psci_power_down_wfi
15*54fd6939SJiyong Park
16*54fd6939SJiyong Park/* -----------------------------------------------------------------------
17*54fd6939SJiyong Park * void psci_do_pwrdown_cache_maintenance(unsigned int power level);
18*54fd6939SJiyong Park *
19*54fd6939SJiyong Park * This function performs cache maintenance for the specified power
20*54fd6939SJiyong Park * level. The levels of cache affected are determined by the power
21*54fd6939SJiyong Park * level which is passed as the argument i.e. level 0 results
22*54fd6939SJiyong Park * in a flush of the L1 cache. Both the L1 and L2 caches are flushed
23*54fd6939SJiyong Park * for a higher power level.
24*54fd6939SJiyong Park *
25*54fd6939SJiyong Park * Additionally, this function also ensures that stack memory is correctly
26*54fd6939SJiyong Park * flushed out to avoid coherency issues due to a change in its memory
27*54fd6939SJiyong Park * attributes after the data cache is disabled.
28*54fd6939SJiyong Park * -----------------------------------------------------------------------
29*54fd6939SJiyong Park */
30*54fd6939SJiyong Parkfunc psci_do_pwrdown_cache_maintenance
31*54fd6939SJiyong Park	stp     x29, x30, [sp,#-16]!
32*54fd6939SJiyong Park	stp     x19, x20, [sp,#-16]!
33*54fd6939SJiyong Park
34*54fd6939SJiyong Park	/* ---------------------------------------------
35*54fd6939SJiyong Park	 * Invoke CPU-specific power down operations for
36*54fd6939SJiyong Park	 * the appropriate level
37*54fd6939SJiyong Park	 * ---------------------------------------------
38*54fd6939SJiyong Park	 */
39*54fd6939SJiyong Park	bl	prepare_cpu_pwr_dwn
40*54fd6939SJiyong Park
41*54fd6939SJiyong Park	/* ---------------------------------------------
42*54fd6939SJiyong Park	 * Do stack maintenance by flushing the used
43*54fd6939SJiyong Park	 * stack to the main memory and invalidating the
44*54fd6939SJiyong Park	 * remainder.
45*54fd6939SJiyong Park	 * ---------------------------------------------
46*54fd6939SJiyong Park	 */
47*54fd6939SJiyong Park	bl	plat_get_my_stack
48*54fd6939SJiyong Park
49*54fd6939SJiyong Park	/* ---------------------------------------------
50*54fd6939SJiyong Park	 * Calculate and store the size of the used
51*54fd6939SJiyong Park	 * stack memory in x1.
52*54fd6939SJiyong Park	 * ---------------------------------------------
53*54fd6939SJiyong Park	 */
54*54fd6939SJiyong Park	mov	x19, x0
55*54fd6939SJiyong Park	mov	x1, sp
56*54fd6939SJiyong Park	sub	x1, x0, x1
57*54fd6939SJiyong Park	mov	x0, sp
58*54fd6939SJiyong Park	bl	flush_dcache_range
59*54fd6939SJiyong Park
60*54fd6939SJiyong Park	/* ---------------------------------------------
61*54fd6939SJiyong Park	 * Calculate and store the size of the unused
62*54fd6939SJiyong Park	 * stack memory in x1. Calculate and store the
63*54fd6939SJiyong Park	 * stack base address in x0.
64*54fd6939SJiyong Park	 * ---------------------------------------------
65*54fd6939SJiyong Park	 */
66*54fd6939SJiyong Park	sub	x0, x19, #PLATFORM_STACK_SIZE
67*54fd6939SJiyong Park	sub	x1, sp, x0
68*54fd6939SJiyong Park	bl	inv_dcache_range
69*54fd6939SJiyong Park
70*54fd6939SJiyong Park	ldp	x19, x20, [sp], #16
71*54fd6939SJiyong Park	ldp	x29, x30, [sp], #16
72*54fd6939SJiyong Park	ret
73*54fd6939SJiyong Parkendfunc psci_do_pwrdown_cache_maintenance
74*54fd6939SJiyong Park
75*54fd6939SJiyong Park
76*54fd6939SJiyong Park/* -----------------------------------------------------------------------
77*54fd6939SJiyong Park * void psci_do_pwrup_cache_maintenance(void);
78*54fd6939SJiyong Park *
79*54fd6939SJiyong Park * This function performs cache maintenance after this cpu is powered up.
80*54fd6939SJiyong Park * Currently, this involves managing the used stack memory before turning
81*54fd6939SJiyong Park * on the data cache.
82*54fd6939SJiyong Park * -----------------------------------------------------------------------
83*54fd6939SJiyong Park */
84*54fd6939SJiyong Parkfunc psci_do_pwrup_cache_maintenance
85*54fd6939SJiyong Park	stp	x29, x30, [sp,#-16]!
86*54fd6939SJiyong Park
87*54fd6939SJiyong Park	/* ---------------------------------------------
88*54fd6939SJiyong Park	 * Ensure any inflight stack writes have made it
89*54fd6939SJiyong Park	 * to main memory.
90*54fd6939SJiyong Park	 * ---------------------------------------------
91*54fd6939SJiyong Park	 */
92*54fd6939SJiyong Park	dmb	st
93*54fd6939SJiyong Park
94*54fd6939SJiyong Park	/* ---------------------------------------------
95*54fd6939SJiyong Park	 * Calculate and store the size of the used
96*54fd6939SJiyong Park	 * stack memory in x1. Calculate and store the
97*54fd6939SJiyong Park	 * stack base address in x0.
98*54fd6939SJiyong Park	 * ---------------------------------------------
99*54fd6939SJiyong Park	 */
100*54fd6939SJiyong Park	bl	plat_get_my_stack
101*54fd6939SJiyong Park	mov	x1, sp
102*54fd6939SJiyong Park	sub	x1, x0, x1
103*54fd6939SJiyong Park	mov	x0, sp
104*54fd6939SJiyong Park	bl	inv_dcache_range
105*54fd6939SJiyong Park
106*54fd6939SJiyong Park	/* ---------------------------------------------
107*54fd6939SJiyong Park	 * Enable the data cache.
108*54fd6939SJiyong Park	 * ---------------------------------------------
109*54fd6939SJiyong Park	 */
110*54fd6939SJiyong Park	mrs	x0, sctlr_el3
111*54fd6939SJiyong Park	orr	x0, x0, #SCTLR_C_BIT
112*54fd6939SJiyong Park	msr	sctlr_el3, x0
113*54fd6939SJiyong Park	isb
114*54fd6939SJiyong Park
115*54fd6939SJiyong Park	ldp	x29, x30, [sp], #16
116*54fd6939SJiyong Park	ret
117*54fd6939SJiyong Parkendfunc psci_do_pwrup_cache_maintenance
118*54fd6939SJiyong Park
119*54fd6939SJiyong Park/* -----------------------------------------------------------------------
120*54fd6939SJiyong Park * void psci_power_down_wfi(void);
121*54fd6939SJiyong Park * This function is called to indicate to the power controller that it
122*54fd6939SJiyong Park * is safe to power down this cpu. It should not exit the wfi and will
123*54fd6939SJiyong Park * be released from reset upon power up.
124*54fd6939SJiyong Park * -----------------------------------------------------------------------
125*54fd6939SJiyong Park */
126*54fd6939SJiyong Parkfunc psci_power_down_wfi
127*54fd6939SJiyong Park	dsb	sy		// ensure write buffer empty
128*54fd6939SJiyong Park	wfi
129*54fd6939SJiyong Park	no_ret	plat_panic_handler
130*54fd6939SJiyong Parkendfunc psci_power_down_wfi
131