1 /*
2 * powerpc RTAS
3 *
4 * Copyright (C) 2016, Red Hat Inc, Andrew Jones <drjones@redhat.com>
5 *
6 * This work is licensed under the terms of the GNU LGPL, version 2.
7 */
8 #include <libcflat.h>
9 #include <libfdt/libfdt.h>
10 #include <devicetree.h>
11 #include <asm/spinlock.h>
12 #include <asm/smp.h>
13 #include <asm/hcall.h>
14 #include <asm/io.h>
15 #include <asm/rtas.h>
16
17 extern void enter_rtas(unsigned long);
18
19 unsigned long rtas_entry;
20 static struct rtas_args rtas_args;
21 static struct spinlock rtas_lock;
22
rtas_node(void)23 static int rtas_node(void)
24 {
25 int node = fdt_path_offset(dt_fdt(), "/rtas");
26
27 if (node < 0) {
28 printf("%s: /rtas: %s\n", __func__, fdt_strerror(node));
29 abort();
30 }
31
32 return node;
33 }
34
rtas_init(void)35 void rtas_init(void)
36 {
37 bool broken_sc1 = hcall_have_broken_sc1();
38 int node = rtas_node(), len, words, i;
39 const struct fdt_property *prop;
40 u32 *data, *insns;
41
42 if (!dt_available()) {
43 printf("%s: No device tree!\n", __func__);
44 abort();
45 }
46
47 prop = fdt_get_property(dt_fdt(), node,
48 "linux,rtas-entry", &len);
49 if (!prop) {
50 /* We don't have a qemu provided RTAS blob, enter_rtas
51 * will use H_RTAS directly */
52 return;
53 }
54 data = (u32 *)prop->data;
55 rtas_entry = (unsigned long)fdt32_to_cpu(*data);
56 insns = (u32 *)rtas_entry;
57
58 prop = fdt_get_property(dt_fdt(), node, "rtas-size", &len);
59 if (!prop) {
60 printf("%s: /rtas/rtas-size: %s\n",
61 __func__, fdt_strerror(len));
62 abort();
63 }
64 data = (u32 *)prop->data;
65 words = (int)fdt32_to_cpu(*data)/4;
66
67 for (i = 0; i < words; ++i) {
68 if (broken_sc1 && insns[i] == cpu_to_be32(SC1))
69 insns[i] = cpu_to_be32(SC1_REPLACEMENT);
70 }
71 }
72
rtas_token(const char * service,uint32_t * token)73 int rtas_token(const char *service, uint32_t *token)
74 {
75 const struct fdt_property *prop;
76 u32 *data;
77
78 if (!dt_available())
79 return RTAS_UNKNOWN_SERVICE;
80
81 prop = fdt_get_property(dt_fdt(), rtas_node(), service, NULL);
82 if (!prop)
83 return RTAS_UNKNOWN_SERVICE;
84
85 data = (u32 *)prop->data;
86 *token = fdt32_to_cpu(*data);
87
88 return 0;
89 }
90
__rtas_call(struct rtas_args * args)91 static void __rtas_call(struct rtas_args *args)
92 {
93 enter_rtas(__pa(args));
94 }
95
rtas_call_unlocked_va(struct rtas_args * args,int token,int nargs,int nret,int * outputs,va_list list)96 static int rtas_call_unlocked_va(struct rtas_args *args,
97 int token, int nargs, int nret, int *outputs,
98 va_list list)
99 {
100 int ret, i;
101
102 args->token = cpu_to_be32(token);
103 args->nargs = cpu_to_be32(nargs);
104 args->nret = cpu_to_be32(nret);
105 args->rets = &args->args[nargs];
106
107 for (i = 0; i < nargs; ++i)
108 args->args[i] = cpu_to_be32(va_arg(list, u32));
109
110 for (i = 0; i < nret; ++i)
111 args->rets[i] = 0;
112
113 __rtas_call(args);
114
115 if (nret > 1 && outputs != NULL)
116 for (i = 0; i < nret - 1; ++i)
117 outputs[i] = be32_to_cpu(args->rets[i + 1]);
118
119 ret = nret > 0 ? be32_to_cpu(args->rets[0]) : 0;
120
121 return ret;
122 }
123
rtas_call_unlocked(struct rtas_args * args,int token,int nargs,int nret,int * outputs,...)124 int rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, int *outputs, ...)
125 {
126 va_list list;
127 int ret;
128
129 va_start(list, outputs);
130 ret = rtas_call_unlocked_va(args, token, nargs, nret, outputs, list);
131 va_end(list);
132
133 return ret;
134 }
135
rtas_call(int token,int nargs,int nret,int * outputs,...)136 int rtas_call(int token, int nargs, int nret, int *outputs, ...)
137 {
138 va_list list;
139 int ret;
140
141 assert_msg(!in_usermode(), "May not make RTAS call from user mode\n");
142
143 spin_lock(&rtas_lock);
144
145 va_start(list, outputs);
146 ret = rtas_call_unlocked_va(&rtas_args, token, nargs, nret, outputs, list);
147 va_end(list);
148
149 spin_unlock(&rtas_lock);
150
151 return ret;
152 }
153
rtas_stop_self(void)154 void rtas_stop_self(void)
155 {
156 struct rtas_args args;
157 uint32_t token;
158 int ret;
159
160 ret = rtas_token("stop-self", &token);
161 if (ret) {
162 puts("RTAS stop-self not available\n");
163 return;
164 }
165
166 ret = rtas_call_unlocked(&args, token, 0, 1, NULL);
167 printf("RTAS stop-self returned %d\n", ret);
168 }
169
rtas_power_off(void)170 void rtas_power_off(void)
171 {
172 struct rtas_args args;
173 uint32_t token;
174 int ret;
175
176 ret = rtas_token("power-off", &token);
177 if (ret) {
178 puts("RTAS power-off not available\n");
179 return;
180 }
181
182 ret = rtas_call_unlocked(&args, token, 2, 1, NULL, -1, -1);
183 printf("RTAS power-off returned %d\n", ret);
184 }
185