xref: /openbmc/linux/drivers/firmware/arm_scmi/base.c (revision 29c37341)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * System Control and Management Interface (SCMI) Base Protocol
4  *
5  * Copyright (C) 2018 ARM Ltd.
6  */
7 
8 #define pr_fmt(fmt) "SCMI Notifications BASE - " fmt
9 
10 #include <linux/scmi_protocol.h>
11 
12 #include "common.h"
13 #include "notify.h"
14 
15 #define SCMI_BASE_NUM_SOURCES		1
16 #define SCMI_BASE_MAX_CMD_ERR_COUNT	1024
17 
18 enum scmi_base_protocol_cmd {
19 	BASE_DISCOVER_VENDOR = 0x3,
20 	BASE_DISCOVER_SUB_VENDOR = 0x4,
21 	BASE_DISCOVER_IMPLEMENT_VERSION = 0x5,
22 	BASE_DISCOVER_LIST_PROTOCOLS = 0x6,
23 	BASE_DISCOVER_AGENT = 0x7,
24 	BASE_NOTIFY_ERRORS = 0x8,
25 	BASE_SET_DEVICE_PERMISSIONS = 0x9,
26 	BASE_SET_PROTOCOL_PERMISSIONS = 0xa,
27 	BASE_RESET_AGENT_CONFIGURATION = 0xb,
28 };
29 
30 struct scmi_msg_resp_base_attributes {
31 	u8 num_protocols;
32 	u8 num_agents;
33 	__le16 reserved;
34 };
35 
36 struct scmi_msg_base_error_notify {
37 	__le32 event_control;
38 #define BASE_TP_NOTIFY_ALL	BIT(0)
39 };
40 
41 struct scmi_base_error_notify_payld {
42 	__le32 agent_id;
43 	__le32 error_status;
44 #define IS_FATAL_ERROR(x)	((x) & BIT(31))
45 #define ERROR_CMD_COUNT(x)	FIELD_GET(GENMASK(9, 0), (x))
46 	__le64 msg_reports[SCMI_BASE_MAX_CMD_ERR_COUNT];
47 };
48 
49 /**
50  * scmi_base_attributes_get() - gets the implementation details
51  *	that are associated with the base protocol.
52  *
53  * @handle: SCMI entity handle
54  *
55  * Return: 0 on success, else appropriate SCMI error.
56  */
57 static int scmi_base_attributes_get(const struct scmi_handle *handle)
58 {
59 	int ret;
60 	struct scmi_xfer *t;
61 	struct scmi_msg_resp_base_attributes *attr_info;
62 	struct scmi_revision_info *rev = handle->version;
63 
64 	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
65 				 SCMI_PROTOCOL_BASE, 0, sizeof(*attr_info), &t);
66 	if (ret)
67 		return ret;
68 
69 	ret = scmi_do_xfer(handle, t);
70 	if (!ret) {
71 		attr_info = t->rx.buf;
72 		rev->num_protocols = attr_info->num_protocols;
73 		rev->num_agents = attr_info->num_agents;
74 	}
75 
76 	scmi_xfer_put(handle, t);
77 
78 	return ret;
79 }
80 
81 /**
82  * scmi_base_vendor_id_get() - gets vendor/subvendor identifier ASCII string.
83  *
84  * @handle: SCMI entity handle
85  * @sub_vendor: specify true if sub-vendor ID is needed
86  *
87  * Return: 0 on success, else appropriate SCMI error.
88  */
89 static int
90 scmi_base_vendor_id_get(const struct scmi_handle *handle, bool sub_vendor)
91 {
92 	u8 cmd;
93 	int ret, size;
94 	char *vendor_id;
95 	struct scmi_xfer *t;
96 	struct scmi_revision_info *rev = handle->version;
97 
98 	if (sub_vendor) {
99 		cmd = BASE_DISCOVER_SUB_VENDOR;
100 		vendor_id = rev->sub_vendor_id;
101 		size = ARRAY_SIZE(rev->sub_vendor_id);
102 	} else {
103 		cmd = BASE_DISCOVER_VENDOR;
104 		vendor_id = rev->vendor_id;
105 		size = ARRAY_SIZE(rev->vendor_id);
106 	}
107 
108 	ret = scmi_xfer_get_init(handle, cmd, SCMI_PROTOCOL_BASE, 0, size, &t);
109 	if (ret)
110 		return ret;
111 
112 	ret = scmi_do_xfer(handle, t);
113 	if (!ret)
114 		memcpy(vendor_id, t->rx.buf, size);
115 
116 	scmi_xfer_put(handle, t);
117 
118 	return ret;
119 }
120 
121 /**
122  * scmi_base_implementation_version_get() - gets a vendor-specific
123  *	implementation 32-bit version. The format of the version number is
124  *	vendor-specific
125  *
126  * @handle: SCMI entity handle
127  *
128  * Return: 0 on success, else appropriate SCMI error.
129  */
130 static int
131 scmi_base_implementation_version_get(const struct scmi_handle *handle)
132 {
133 	int ret;
134 	__le32 *impl_ver;
135 	struct scmi_xfer *t;
136 	struct scmi_revision_info *rev = handle->version;
137 
138 	ret = scmi_xfer_get_init(handle, BASE_DISCOVER_IMPLEMENT_VERSION,
139 				 SCMI_PROTOCOL_BASE, 0, sizeof(*impl_ver), &t);
140 	if (ret)
141 		return ret;
142 
143 	ret = scmi_do_xfer(handle, t);
144 	if (!ret) {
145 		impl_ver = t->rx.buf;
146 		rev->impl_ver = le32_to_cpu(*impl_ver);
147 	}
148 
149 	scmi_xfer_put(handle, t);
150 
151 	return ret;
152 }
153 
154 /**
155  * scmi_base_implementation_list_get() - gets the list of protocols it is
156  *	OSPM is allowed to access
157  *
158  * @handle: SCMI entity handle
159  * @protocols_imp: pointer to hold the list of protocol identifiers
160  *
161  * Return: 0 on success, else appropriate SCMI error.
162  */
163 static int scmi_base_implementation_list_get(const struct scmi_handle *handle,
164 					     u8 *protocols_imp)
165 {
166 	u8 *list;
167 	int ret, loop;
168 	struct scmi_xfer *t;
169 	__le32 *num_skip, *num_ret;
170 	u32 tot_num_ret = 0, loop_num_ret;
171 	struct device *dev = handle->dev;
172 
173 	ret = scmi_xfer_get_init(handle, BASE_DISCOVER_LIST_PROTOCOLS,
174 				 SCMI_PROTOCOL_BASE, sizeof(*num_skip), 0, &t);
175 	if (ret)
176 		return ret;
177 
178 	num_skip = t->tx.buf;
179 	num_ret = t->rx.buf;
180 	list = t->rx.buf + sizeof(*num_ret);
181 
182 	do {
183 		/* Set the number of protocols to be skipped/already read */
184 		*num_skip = cpu_to_le32(tot_num_ret);
185 
186 		ret = scmi_do_xfer(handle, t);
187 		if (ret)
188 			break;
189 
190 		loop_num_ret = le32_to_cpu(*num_ret);
191 		if (tot_num_ret + loop_num_ret > MAX_PROTOCOLS_IMP) {
192 			dev_err(dev, "No. of Protocol > MAX_PROTOCOLS_IMP");
193 			break;
194 		}
195 
196 		for (loop = 0; loop < loop_num_ret; loop++)
197 			protocols_imp[tot_num_ret + loop] = *(list + loop);
198 
199 		tot_num_ret += loop_num_ret;
200 	} while (loop_num_ret);
201 
202 	scmi_xfer_put(handle, t);
203 
204 	return ret;
205 }
206 
207 /**
208  * scmi_base_discover_agent_get() - discover the name of an agent
209  *
210  * @handle: SCMI entity handle
211  * @id: Agent identifier
212  * @name: Agent identifier ASCII string
213  *
214  * An agent id of 0 is reserved to identify the platform itself.
215  * Generally operating system is represented as "OSPM"
216  *
217  * Return: 0 on success, else appropriate SCMI error.
218  */
219 static int scmi_base_discover_agent_get(const struct scmi_handle *handle,
220 					int id, char *name)
221 {
222 	int ret;
223 	struct scmi_xfer *t;
224 
225 	ret = scmi_xfer_get_init(handle, BASE_DISCOVER_AGENT,
226 				 SCMI_PROTOCOL_BASE, sizeof(__le32),
227 				 SCMI_MAX_STR_SIZE, &t);
228 	if (ret)
229 		return ret;
230 
231 	put_unaligned_le32(id, t->tx.buf);
232 
233 	ret = scmi_do_xfer(handle, t);
234 	if (!ret)
235 		strlcpy(name, t->rx.buf, SCMI_MAX_STR_SIZE);
236 
237 	scmi_xfer_put(handle, t);
238 
239 	return ret;
240 }
241 
242 static int scmi_base_error_notify(const struct scmi_handle *handle, bool enable)
243 {
244 	int ret;
245 	u32 evt_cntl = enable ? BASE_TP_NOTIFY_ALL : 0;
246 	struct scmi_xfer *t;
247 	struct scmi_msg_base_error_notify *cfg;
248 
249 	ret = scmi_xfer_get_init(handle, BASE_NOTIFY_ERRORS,
250 				 SCMI_PROTOCOL_BASE, sizeof(*cfg), 0, &t);
251 	if (ret)
252 		return ret;
253 
254 	cfg = t->tx.buf;
255 	cfg->event_control = cpu_to_le32(evt_cntl);
256 
257 	ret = scmi_do_xfer(handle, t);
258 
259 	scmi_xfer_put(handle, t);
260 	return ret;
261 }
262 
263 static int scmi_base_set_notify_enabled(const struct scmi_handle *handle,
264 					u8 evt_id, u32 src_id, bool enable)
265 {
266 	int ret;
267 
268 	ret = scmi_base_error_notify(handle, enable);
269 	if (ret)
270 		pr_debug("FAIL_ENABLED - evt[%X] ret:%d\n", evt_id, ret);
271 
272 	return ret;
273 }
274 
275 static void *scmi_base_fill_custom_report(const struct scmi_handle *handle,
276 					  u8 evt_id, ktime_t timestamp,
277 					  const void *payld, size_t payld_sz,
278 					  void *report, u32 *src_id)
279 {
280 	int i;
281 	const struct scmi_base_error_notify_payld *p = payld;
282 	struct scmi_base_error_report *r = report;
283 
284 	/*
285 	 * BaseError notification payload is variable in size but
286 	 * up to a maximum length determined by the struct ponted by p.
287 	 * Instead payld_sz is the effective length of this notification
288 	 * payload so cannot be greater of the maximum allowed size as
289 	 * pointed by p.
290 	 */
291 	if (evt_id != SCMI_EVENT_BASE_ERROR_EVENT || sizeof(*p) < payld_sz)
292 		return NULL;
293 
294 	r->timestamp = timestamp;
295 	r->agent_id = le32_to_cpu(p->agent_id);
296 	r->fatal = IS_FATAL_ERROR(le32_to_cpu(p->error_status));
297 	r->cmd_count = ERROR_CMD_COUNT(le32_to_cpu(p->error_status));
298 	for (i = 0; i < r->cmd_count; i++)
299 		r->reports[i] = le64_to_cpu(p->msg_reports[i]);
300 	*src_id = 0;
301 
302 	return r;
303 }
304 
305 static const struct scmi_event base_events[] = {
306 	{
307 		.id = SCMI_EVENT_BASE_ERROR_EVENT,
308 		.max_payld_sz = sizeof(struct scmi_base_error_notify_payld),
309 		.max_report_sz = sizeof(struct scmi_base_error_report) +
310 				  SCMI_BASE_MAX_CMD_ERR_COUNT * sizeof(u64),
311 	},
312 };
313 
314 static const struct scmi_event_ops base_event_ops = {
315 	.set_notify_enabled = scmi_base_set_notify_enabled,
316 	.fill_custom_report = scmi_base_fill_custom_report,
317 };
318 
319 int scmi_base_protocol_init(struct scmi_handle *h)
320 {
321 	int id, ret;
322 	u8 *prot_imp;
323 	u32 version;
324 	char name[SCMI_MAX_STR_SIZE];
325 	const struct scmi_handle *handle = h;
326 	struct device *dev = handle->dev;
327 	struct scmi_revision_info *rev = handle->version;
328 
329 	ret = scmi_version_get(handle, SCMI_PROTOCOL_BASE, &version);
330 	if (ret)
331 		return ret;
332 
333 	prot_imp = devm_kcalloc(dev, MAX_PROTOCOLS_IMP, sizeof(u8), GFP_KERNEL);
334 	if (!prot_imp)
335 		return -ENOMEM;
336 
337 	rev->major_ver = PROTOCOL_REV_MAJOR(version),
338 	rev->minor_ver = PROTOCOL_REV_MINOR(version);
339 
340 	scmi_base_attributes_get(handle);
341 	scmi_base_vendor_id_get(handle, false);
342 	scmi_base_vendor_id_get(handle, true);
343 	scmi_base_implementation_version_get(handle);
344 	scmi_base_implementation_list_get(handle, prot_imp);
345 	scmi_setup_protocol_implemented(handle, prot_imp);
346 
347 	dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
348 		 rev->major_ver, rev->minor_ver, rev->vendor_id,
349 		 rev->sub_vendor_id, rev->impl_ver);
350 	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
351 		rev->num_agents);
352 
353 	scmi_register_protocol_events(handle, SCMI_PROTOCOL_BASE,
354 				      (4 * SCMI_PROTO_QUEUE_SZ),
355 				      &base_event_ops, base_events,
356 				      ARRAY_SIZE(base_events),
357 				      SCMI_BASE_NUM_SOURCES);
358 
359 	for (id = 0; id < rev->num_agents; id++) {
360 		scmi_base_discover_agent_get(handle, id, name);
361 		dev_dbg(dev, "Agent %d: %s\n", id, name);
362 	}
363 
364 	return 0;
365 }
366