blob: 36d5d7d9ba0a37cc23b16e88a82f8eb50dc2abf8 [file] [log] [blame]
Soby Mathew89d90dc2016-05-05 14:11:23 +01001/*
2 * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * Neither the name of ARM nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without specific
16 * prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <asm_macros.S>
32#include <platform_def.h>
33#include <psci.h>
34
35 .globl psci_do_pwrdown_cache_maintenance
36 .globl psci_do_pwrup_cache_maintenance
37 .globl psci_power_down_wfi
38
39/* -----------------------------------------------------------------------
40 * void psci_do_pwrdown_cache_maintenance(unsigned int power level);
41 *
42 * This function performs cache maintenance for the specified power
43 * level. The levels of cache affected are determined by the power
44 * level which is passed as the argument i.e. level 0 results
45 * in a flush of the L1 cache. Both the L1 and L2 caches are flushed
46 * for a higher power level.
47 *
48 * Additionally, this function also ensures that stack memory is correctly
49 * flushed out to avoid coherency issues due to a change in its memory
50 * attributes after the data cache is disabled.
51 * -----------------------------------------------------------------------
52 */
53func psci_do_pwrdown_cache_maintenance
54 push {r4, lr}
55
56 /* ----------------------------------------------
57 * Turn OFF cache and do stack maintenance
58 * prior to cpu operations . This sequence is
59 * different from AArch64 because in AArch32 the
60 * assembler routines for cpu operations utilize
61 * the stack whereas in AArch64 it doesn't.
62 * ----------------------------------------------
63 */
64 mov r4, r0
65 bl do_stack_maintenance
66
67 /* ---------------------------------------------
68 * Determine how many levels of cache will be
69 * subject to cache maintenance. Power level
70 * 0 implies that only the cpu is being powered
71 * down. Only the L1 data cache needs to be
72 * flushed to the PoU in this case. For a higher
73 * power level we are assuming that a flush
74 * of L1 data and L2 unified cache is enough.
75 * This information should be provided by the
76 * platform.
77 * ---------------------------------------------
78 */
79 cmp r4, #PSCI_CPU_PWR_LVL
80 pop {r4,lr}
81
82 beq prepare_core_pwr_dwn
83 b prepare_cluster_pwr_dwn
84endfunc psci_do_pwrdown_cache_maintenance
85
86
87/* -----------------------------------------------------------------------
88 * void psci_do_pwrup_cache_maintenance(void);
89 *
90 * This function performs cache maintenance after this cpu is powered up.
91 * Currently, this involves managing the used stack memory before turning
92 * on the data cache.
93 * -----------------------------------------------------------------------
94 */
95func psci_do_pwrup_cache_maintenance
96 push {lr}
97
98 /* ---------------------------------------------
99 * Ensure any inflight stack writes have made it
100 * to main memory.
101 * ---------------------------------------------
102 */
103 dmb st
104
105 /* ---------------------------------------------
106 * Calculate and store the size of the used
107 * stack memory in r1. Calculate and store the
108 * stack base address in r0.
109 * ---------------------------------------------
110 */
111 bl plat_get_my_stack
112 mov r1, sp
113 sub r1, r0, r1
114 mov r0, sp
115 bl inv_dcache_range
116
117 /* ---------------------------------------------
118 * Enable the data cache.
119 * ---------------------------------------------
120 */
121 ldcopr r0, SCTLR
122 orr r0, r0, #SCTLR_C_BIT
123 stcopr r0, SCTLR
124 isb
125
126 pop {pc}
127endfunc psci_do_pwrup_cache_maintenance
128
129 /* ---------------------------------------------
130 * void do_stack_maintenance(void)
131 * Do stack maintenance by flushing the used
132 * stack to the main memory and invalidating the
133 * remainder.
134 * ---------------------------------------------
135 */
136func do_stack_maintenance
137 push {r4, lr}
138 bl plat_get_my_stack
139
140 /* Turn off the D-cache */
141 ldcopr r1, SCTLR
142 bic r1, #SCTLR_C_BIT
143 stcopr r1, SCTLR
144 isb
145
146 /* ---------------------------------------------
147 * Calculate and store the size of the used
148 * stack memory in r1.
149 * ---------------------------------------------
150 */
151 mov r4, r0
152 mov r1, sp
153 sub r1, r0, r1
154 mov r0, sp
155 bl flush_dcache_range
156
157 /* ---------------------------------------------
158 * Calculate and store the size of the unused
159 * stack memory in r1. Calculate and store the
160 * stack base address in r0.
161 * ---------------------------------------------
162 */
163 sub r0, r4, #PLATFORM_STACK_SIZE
164 sub r1, sp, r0
165 bl inv_dcache_range
166
167 pop {r4, pc}
168endfunc do_stack_maintenance
169
170/* -----------------------------------------------------------------------
171 * This function is called to indicate to the power controller that it
172 * is safe to power down this cpu. It should not exit the wfi and will
173 * be released from reset upon power up.
174 * -----------------------------------------------------------------------
175 */
176func psci_power_down_wfi
177 dsb sy // ensure write buffer empty
178 wfi
179 bl plat_panic_handler
180endfunc psci_power_down_wfi