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1/*
2 * Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7#include <asm_macros.S>
8#include <assert_macros.S>
9#include <platform_def.h>
10#include <psci.h>
11
12	.globl	psci_do_pwrdown_cache_maintenance
13	.globl	psci_do_pwrup_cache_maintenance
14	.globl	psci_power_down_wfi
15#if !ERROR_DEPRECATED
16	.globl psci_entrypoint
17#endif
18
19/* -----------------------------------------------------------------------
20 * void psci_do_pwrdown_cache_maintenance(unsigned int power level);
21 *
22 * This function performs cache maintenance for the specified power
23 * level. The levels of cache affected are determined by the power
24 * level which is passed as the argument i.e. level 0 results
25 * in a flush of the L1 cache. Both the L1 and L2 caches are flushed
26 * for a higher power level.
27 *
28 * Additionally, this function also ensures that stack memory is correctly
29 * flushed out to avoid coherency issues due to a change in its memory
30 * attributes after the data cache is disabled.
31 * -----------------------------------------------------------------------
32 */
33func psci_do_pwrdown_cache_maintenance
34	stp     x29, x30, [sp,#-16]!
35	stp     x19, x20, [sp,#-16]!
36
37	/* ---------------------------------------------
38	 * Invoke CPU-specific power down operations for
39	 * the appropriate level
40	 * ---------------------------------------------
41	 */
42	bl	prepare_cpu_pwr_dwn
43
44	/* ---------------------------------------------
45	 * Do stack maintenance by flushing the used
46	 * stack to the main memory and invalidating the
47	 * remainder.
48	 * ---------------------------------------------
49	 */
50	bl	plat_get_my_stack
51
52	/* ---------------------------------------------
53	 * Calculate and store the size of the used
54	 * stack memory in x1.
55	 * ---------------------------------------------
56	 */
57	mov	x19, x0
58	mov	x1, sp
59	sub	x1, x0, x1
60	mov	x0, sp
61	bl	flush_dcache_range
62
63	/* ---------------------------------------------
64	 * Calculate and store the size of the unused
65	 * stack memory in x1. Calculate and store the
66	 * stack base address in x0.
67	 * ---------------------------------------------
68	 */
69	sub	x0, x19, #PLATFORM_STACK_SIZE
70	sub	x1, sp, x0
71	bl	inv_dcache_range
72
73	ldp	x19, x20, [sp], #16
74	ldp	x29, x30, [sp], #16
75	ret
76endfunc psci_do_pwrdown_cache_maintenance
77
78
79/* -----------------------------------------------------------------------
80 * void psci_do_pwrup_cache_maintenance(void);
81 *
82 * This function performs cache maintenance after this cpu is powered up.
83 * Currently, this involves managing the used stack memory before turning
84 * on the data cache.
85 * -----------------------------------------------------------------------
86 */
87func psci_do_pwrup_cache_maintenance
88	stp	x29, x30, [sp,#-16]!
89
90	/* ---------------------------------------------
91	 * Ensure any inflight stack writes have made it
92	 * to main memory.
93	 * ---------------------------------------------
94	 */
95	dmb	st
96
97	/* ---------------------------------------------
98	 * Calculate and store the size of the used
99	 * stack memory in x1. Calculate and store the
100	 * stack base address in x0.
101	 * ---------------------------------------------
102	 */
103	bl	plat_get_my_stack
104	mov	x1, sp
105	sub	x1, x0, x1
106	mov	x0, sp
107	bl	inv_dcache_range
108
109	/* ---------------------------------------------
110	 * Enable the data cache.
111	 * ---------------------------------------------
112	 */
113	mrs	x0, sctlr_el3
114	orr	x0, x0, #SCTLR_C_BIT
115	msr	sctlr_el3, x0
116	isb
117
118	ldp	x29, x30, [sp], #16
119	ret
120endfunc psci_do_pwrup_cache_maintenance
121
122/* -----------------------------------------------------------------------
123 * void psci_power_down_wfi(void);
124 * This function is called to indicate to the power controller that it
125 * is safe to power down this cpu. It should not exit the wfi and will
126 * be released from reset upon power up.
127 * -----------------------------------------------------------------------
128 */
129func psci_power_down_wfi
130	dsb	sy		// ensure write buffer empty
131	wfi
132	no_ret	plat_panic_handler
133endfunc psci_power_down_wfi
134
135/* -----------------------------------------------------------------------
136 * void psci_entrypoint(void);
137 * The deprecated entry point for PSCI on warm boot for AArch64.
138 * -----------------------------------------------------------------------
139 */
140func_deprecated psci_entrypoint
141	b	bl31_warm_entrypoint
142endfunc_deprecated psci_entrypoint
143