1 // SPDX-License-Identifier: BSD-3-Clause
2 /*
3 * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
4 * Copyright (c) 2019-2022, Linaro Limited
5 */
6 #include <assert.h>
7 #include <string.h>
8
9 #include <drivers/scmi-msg.h>
10 #include <drivers/scmi.h>
11 #include <lib/utils.h>
12 #include <lib/utils_def.h>
13
14 #include "common.h"
15
16 static bool message_id_is_supported(unsigned int message_id);
17
report_version(struct scmi_msg * msg)18 static void report_version(struct scmi_msg *msg)
19 {
20 struct scmi_protocol_version_p2a return_values = {
21 .status = SCMI_SUCCESS,
22 .version = SCMI_PROTOCOL_VERSION_BASE,
23 };
24
25 if (msg->in_size != 0U) {
26 scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
27 return;
28 }
29
30 scmi_write_response(msg, &return_values, sizeof(return_values));
31 }
32
report_attributes(struct scmi_msg * msg)33 static void report_attributes(struct scmi_msg *msg)
34 {
35 size_t protocol_count = plat_scmi_protocol_count();
36 struct scmi_protocol_attributes_p2a return_values = {
37 .status = SCMI_SUCCESS,
38 /* Null agent count since agent discovery is not supported */
39 .attributes = SCMI_BASE_PROTOCOL_ATTRIBUTES(protocol_count, 0U),
40 };
41
42 if (msg->in_size != 0U) {
43 scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
44 return;
45 }
46
47 scmi_write_response(msg, &return_values, sizeof(return_values));
48 }
49
report_message_attributes(struct scmi_msg * msg)50 static void report_message_attributes(struct scmi_msg *msg)
51 {
52 struct scmi_protocol_message_attributes_a2p *in_args = (void *)msg->in;
53 struct scmi_protocol_message_attributes_p2a return_values = {
54 .status = SCMI_SUCCESS,
55 /* For this protocol, attributes shall be zero */
56 .attributes = 0U,
57 };
58
59 if (msg->in_size != sizeof(*in_args)) {
60 scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
61 return;
62 }
63
64 if (!message_id_is_supported(in_args->message_id)) {
65 scmi_status_response(msg, SCMI_NOT_FOUND);
66 return;
67 }
68
69 scmi_write_response(msg, &return_values, sizeof(return_values));
70 }
71
discover_vendor(struct scmi_msg * msg)72 static void discover_vendor(struct scmi_msg *msg)
73 {
74 const char *name = plat_scmi_vendor_name();
75 struct scmi_base_discover_vendor_p2a return_values = {
76 .status = SCMI_SUCCESS,
77 };
78
79 if (msg->in_size != 0U) {
80 scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
81 return;
82 }
83
84 COPY_NAME_IDENTIFIER(return_values.vendor_identifier, name);
85
86 scmi_write_response(msg, &return_values, sizeof(return_values));
87 }
88
discover_sub_vendor(struct scmi_msg * msg)89 static void discover_sub_vendor(struct scmi_msg *msg)
90 {
91 const char *name = plat_scmi_sub_vendor_name();
92 struct scmi_base_discover_sub_vendor_p2a return_values = {
93 .status = SCMI_SUCCESS,
94 };
95
96 if (msg->in_size != 0U) {
97 scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
98 return;
99 }
100
101 COPY_NAME_IDENTIFIER(return_values.sub_vendor_identifier, name);
102
103 scmi_write_response(msg, &return_values, sizeof(return_values));
104 }
105
discover_implementation_version(struct scmi_msg * msg)106 static void discover_implementation_version(struct scmi_msg *msg)
107 {
108 struct scmi_protocol_version_p2a return_values = {
109 .status = SCMI_SUCCESS,
110 .version = SCMI_IMPL_VERSION,
111 };
112
113 if (msg->in_size != 0U) {
114 scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
115 return;
116 }
117
118 scmi_write_response(msg, &return_values, sizeof(return_values));
119 }
120
count_protocols_in_list(const uint8_t * protocol_list)121 static unsigned int count_protocols_in_list(const uint8_t *protocol_list)
122 {
123 unsigned int count = 0U;
124
125 if (protocol_list != NULL) {
126 while (protocol_list[count] != 0U) {
127 count++;
128 }
129 }
130
131 return count;
132 }
133
discover_list_protocols(struct scmi_msg * msg)134 static void discover_list_protocols(struct scmi_msg *msg)
135 {
136 const struct scmi_base_discover_list_protocols_a2p *a2p = NULL;
137 struct scmi_base_discover_list_protocols_p2a p2a = {
138 .status = SCMI_SUCCESS,
139 };
140 const uint8_t *list = NULL;
141 unsigned int count = 0U;
142
143 if (msg->in_size != sizeof(*a2p)) {
144 scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
145 return;
146 }
147
148 a2p = (void *)msg->in;
149
150 list = plat_scmi_protocol_list(msg->agent_id);
151 count = count_protocols_in_list(list);
152
153 if (count > a2p->skip) {
154 count = MIN(count - a2p->skip, msg->out_size - sizeof(p2a));
155 } else {
156 count = 0U;
157 }
158
159 p2a.num_protocols = count;
160
161 memcpy(msg->out, &p2a, sizeof(p2a));
162 memcpy(msg->out + sizeof(p2a), list + a2p->skip, count);
163 msg->out_size_out = sizeof(p2a) + round_up(count, sizeof(uint32_t));
164 }
165
166 static const scmi_msg_handler_t scmi_base_handler_table[] = {
167 [SCMI_PROTOCOL_VERSION] = report_version,
168 [SCMI_PROTOCOL_ATTRIBUTES] = report_attributes,
169 [SCMI_PROTOCOL_MESSAGE_ATTRIBUTES] = report_message_attributes,
170 [SCMI_BASE_DISCOVER_VENDOR] = discover_vendor,
171 [SCMI_BASE_DISCOVER_SUB_VENDOR] = discover_sub_vendor,
172 [SCMI_BASE_DISCOVER_IMPLEMENTATION_VERSION] =
173 discover_implementation_version,
174 [SCMI_BASE_DISCOVER_LIST_PROTOCOLS] = discover_list_protocols,
175 };
176
message_id_is_supported(unsigned int message_id)177 static bool message_id_is_supported(unsigned int message_id)
178 {
179 return (message_id < ARRAY_SIZE(scmi_base_handler_table)) &&
180 (scmi_base_handler_table[message_id] != NULL);
181 }
182
scmi_msg_get_base_handler(struct scmi_msg * msg)183 scmi_msg_handler_t scmi_msg_get_base_handler(struct scmi_msg *msg)
184 {
185 unsigned int message_id = SPECULATION_SAFE_VALUE(msg->message_id);
186
187 if (message_id >= ARRAY_SIZE(scmi_base_handler_table)) {
188 VERBOSE("Base handle not found %u\n", msg->message_id);
189 return NULL;
190 }
191
192 return scmi_base_handler_table[message_id];
193 }
194