1 /*
2 * xen/arch/arm/psci.c
3 *
4 * PSCI host support
5 *
6 * Andre Przywara <andre.przywara@linaro.org>
7 * Copyright (c) 2013 Linaro Limited.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 */
19
20
21 #include <xen/types.h>
22 #include <xen/mm.h>
23 #include <xen/smp.h>
24 #include <asm/psci.h>
25 #include <asm/acpi.h>
26
27 /*
28 * While a 64-bit OS can make calls with SMC32 calling conventions, for
29 * some calls it is necessary to use SMC64 to pass or return 64-bit values.
30 * For such calls PSCI_0_2_FN_NATIVE(x) will choose the appropriate
31 * (native-width) function ID.
32 */
33 #ifdef CONFIG_ARM_64
34 #define PSCI_0_2_FN_NATIVE(name) PSCI_0_2_FN64(name)
35 #else
36 #define PSCI_0_2_FN_NATIVE(name) PSCI_0_2_FN32(name)
37 #endif
38
39 uint32_t psci_ver;
40
41 static uint32_t psci_cpu_on_nr;
42
call_psci_cpu_on(int cpu)43 int call_psci_cpu_on(int cpu)
44 {
45 return call_smc(psci_cpu_on_nr, cpu_logical_map(cpu), __pa(init_secondary), 0);
46 }
47
call_psci_system_off(void)48 void call_psci_system_off(void)
49 {
50 if ( psci_ver > PSCI_VERSION(0, 1) )
51 call_smc(PSCI_0_2_FN32(SYSTEM_OFF), 0, 0, 0);
52 }
53
call_psci_system_reset(void)54 void call_psci_system_reset(void)
55 {
56 if ( psci_ver > PSCI_VERSION(0, 1) )
57 call_smc(PSCI_0_2_FN32(SYSTEM_RESET), 0, 0, 0);
58 }
59
psci_is_smc_method(const struct dt_device_node * psci)60 int __init psci_is_smc_method(const struct dt_device_node *psci)
61 {
62 int ret;
63 const char *prop_str;
64
65 ret = dt_property_read_string(psci, "method", &prop_str);
66 if ( ret )
67 {
68 printk("/psci node does not provide a method (%d)\n", ret);
69 return -EINVAL;
70 }
71
72 /* Since Xen runs in HYP all of the time, it does not make sense to
73 * let it call into HYP for PSCI handling, since the handler just
74 * won't be there. So bail out with an error if "smc" is not used.
75 */
76 if ( strcmp(prop_str, "smc") )
77 {
78 printk("/psci method must be smc, but is: \"%s\"\n", prop_str);
79 return -EINVAL;
80 }
81
82 return 0;
83 }
84
psci_init_0_1(void)85 int __init psci_init_0_1(void)
86 {
87 int ret;
88 const struct dt_device_node *psci;
89
90 if ( !acpi_disabled )
91 {
92 printk("PSCI 0.1 is not supported when using ACPI\n");
93 return -EINVAL;
94 }
95
96 psci = dt_find_compatible_node(NULL, NULL, "arm,psci");
97 if ( !psci )
98 return -EOPNOTSUPP;
99
100 ret = psci_is_smc_method(psci);
101 if ( ret )
102 return -EINVAL;
103
104 if ( !dt_property_read_u32(psci, "cpu_on", &psci_cpu_on_nr) )
105 {
106 printk("/psci node is missing the \"cpu_on\" property\n");
107 return -ENOENT;
108 }
109
110 psci_ver = PSCI_VERSION(0, 1);
111
112 printk(XENLOG_INFO "Using PSCI-0.1 for SMP bringup\n");
113
114 return 0;
115 }
116
psci_init_0_2(void)117 int __init psci_init_0_2(void)
118 {
119 static const struct dt_device_match psci_ids[] __initconst =
120 {
121 DT_MATCH_COMPATIBLE("arm,psci-0.2"),
122 DT_MATCH_COMPATIBLE("arm,psci-1.0"),
123 { /* sentinel */ },
124 };
125 int ret;
126
127 if ( acpi_disabled )
128 {
129 const struct dt_device_node *psci;
130
131 psci = dt_find_matching_node(NULL, psci_ids);
132 if ( !psci )
133 return -EOPNOTSUPP;
134
135 ret = psci_is_smc_method(psci);
136 if ( ret )
137 return -EINVAL;
138 }
139 else
140 {
141 if ( acpi_psci_hvc_present() ) {
142 printk("PSCI conduit must be SMC, but is HVC\n");
143 return -EINVAL;
144 }
145 }
146
147 psci_ver = call_smc(PSCI_0_2_FN32(PSCI_VERSION), 0, 0, 0);
148
149 /* For the moment, we only support PSCI 0.2 and PSCI 1.x */
150 if ( psci_ver != PSCI_VERSION(0, 2) && PSCI_VERSION_MAJOR(psci_ver) != 1 )
151 {
152 printk("Error: Unrecognized PSCI version %u.%u\n",
153 PSCI_VERSION_MAJOR(psci_ver), PSCI_VERSION_MINOR(psci_ver));
154 return -EOPNOTSUPP;
155 }
156
157 psci_cpu_on_nr = PSCI_0_2_FN_NATIVE(CPU_ON);
158
159 printk(XENLOG_INFO "Using PSCI-%u.%u for SMP bringup\n",
160 PSCI_VERSION_MAJOR(psci_ver), PSCI_VERSION_MINOR(psci_ver));
161
162 return 0;
163 }
164
psci_init(void)165 int __init psci_init(void)
166 {
167 int ret;
168
169 if ( !acpi_disabled && !acpi_psci_present() )
170 return -EOPNOTSUPP;
171
172 ret = psci_init_0_2();
173 if ( ret )
174 ret = psci_init_0_1();
175
176 return ret;
177 }
178
179 /*
180 * Local variables:
181 * mode: C
182 * c-file-style: "BSD"
183 * c-basic-offset: 4
184 * indent-tabs-mode: nil
185 * End:
186 */
187