xref: /rk3399_ARM-atf/common/runtime_svc.c (revision 532ed6183868036e4a4f83cd7a71b93266a3bdb7)
1 /*
2  * Copyright (c) 2013-2016, 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 <assert.h>
32 #include <debug.h>
33 #include <errno.h>
34 #include <runtime_svc.h>
35 #include <string.h>
36 
37 /*******************************************************************************
38  * The 'rt_svc_descs' array holds the runtime service descriptors exported by
39  * services by placing them in the 'rt_svc_descs' linker section.
40  * The 'rt_svc_descs_indices' array holds the index of a descriptor in the
41  * 'rt_svc_descs' array. When an SMC arrives, the OEN[29:24] bits and the call
42  * type[31] bit in the function id are combined to get an index into the
43  * 'rt_svc_descs_indices' array. This gives the index of the descriptor in the
44  * 'rt_svc_descs' array which contains the SMC handler.
45  ******************************************************************************/
46 #define RT_SVC_DESCS_START	((uintptr_t) (&__RT_SVC_DESCS_START__))
47 #define RT_SVC_DESCS_END	((uintptr_t) (&__RT_SVC_DESCS_END__))
48 uint8_t rt_svc_descs_indices[MAX_RT_SVCS];
49 static rt_svc_desc_t *rt_svc_descs;
50 
51 #define RT_SVC_DECS_NUM		((RT_SVC_DESCS_END - RT_SVC_DESCS_START)\
52 					/ sizeof(rt_svc_desc_t))
53 
54 /*******************************************************************************
55  * Simple routine to sanity check a runtime service descriptor before using it
56  ******************************************************************************/
57 static int32_t validate_rt_svc_desc(rt_svc_desc_t *desc)
58 {
59 	if (desc == NULL)
60 		return -EINVAL;
61 
62 	if (desc->start_oen > desc->end_oen)
63 		return -EINVAL;
64 
65 	if (desc->end_oen >= OEN_LIMIT)
66 		return -EINVAL;
67 
68 	if (desc->call_type != SMC_TYPE_FAST && desc->call_type != SMC_TYPE_STD)
69 		return -EINVAL;
70 
71 	/* A runtime service having no init or handle function doesn't make sense */
72 	if (desc->init == NULL && desc->handle == NULL)
73 		return -EINVAL;
74 
75 	return 0;
76 }
77 
78 /*******************************************************************************
79  * This function calls the initialisation routine in the descriptor exported by
80  * a runtime service. Once a descriptor has been validated, its start & end
81  * owning entity numbers and the call type are combined to form a unique oen.
82  * The unique oen is used as an index into the 'rt_svc_descs_indices' array.
83  * The index of the runtime service descriptor is stored at this index.
84  ******************************************************************************/
85 void runtime_svc_init(void)
86 {
87 	int rc = 0, index, start_idx, end_idx;
88 
89 	/* Assert the number of descriptors detected are less than maximum indices */
90 	assert((RT_SVC_DECS_NUM >= 0) && (RT_SVC_DECS_NUM < MAX_RT_SVCS));
91 
92 	/* If no runtime services are implemented then simply bail out */
93 	if (RT_SVC_DECS_NUM == 0)
94 		return;
95 
96 	/* Initialise internal variables to invalid state */
97 	memset(rt_svc_descs_indices, -1, sizeof(rt_svc_descs_indices));
98 
99 	rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START;
100 	for (index = 0; index < RT_SVC_DECS_NUM; index++) {
101 
102 		/*
103 		 * An invalid descriptor is an error condition since it is
104 		 * difficult to predict the system behaviour in the absence
105 		 * of this service.
106 		 */
107 		rc = validate_rt_svc_desc(&rt_svc_descs[index]);
108 		if (rc) {
109 			ERROR("Invalid runtime service descriptor %p (%s)\n",
110 					(void *) &rt_svc_descs[index],
111 					rt_svc_descs[index].name);
112 			goto error;
113 		}
114 
115 		/*
116 		 * The runtime service may have separate rt_svc_desc_t
117 		 * for its fast smc and standard smc. Since the service itself
118 		 * need to be initialized only once, only one of them will have
119 		 * an initialisation routine defined. Call the initialisation
120 		 * routine for this runtime service, if it is defined.
121 		 */
122 		if (rt_svc_descs[index].init) {
123 			rc = rt_svc_descs[index].init();
124 			if (rc) {
125 				ERROR("Error initializing runtime service %s\n",
126 						rt_svc_descs[index].name);
127 				continue;
128 			}
129 		}
130 
131 		/*
132 		 * Fill the indices corresponding to the start and end
133 		 * owning entity numbers with the index of the
134 		 * descriptor which will handle the SMCs for this owning
135 		 * entity range.
136 		 */
137 		start_idx = get_unique_oen(rt_svc_descs[index].start_oen,
138 				rt_svc_descs[index].call_type);
139 		end_idx = get_unique_oen(rt_svc_descs[index].end_oen,
140 				rt_svc_descs[index].call_type);
141 
142 		for (; start_idx <= end_idx; start_idx++)
143 			rt_svc_descs_indices[start_idx] = index;
144 	}
145 
146 	return;
147 error:
148 	panic();
149 }
150