xref: /openbmc/linux/drivers/firmware/arm_scmi/base.c (revision 405db98b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * System Control and Management Interface (SCMI) Base Protocol
4  *
5  * Copyright (C) 2018-2021 ARM Ltd.
6  */
7 
8 #define pr_fmt(fmt) "SCMI Notifications BASE - " fmt
9 
10 #include <linux/module.h>
11 #include <linux/scmi_protocol.h>
12 
13 #include "common.h"
14 #include "notify.h"
15 
16 #define SCMI_BASE_NUM_SOURCES		1
17 #define SCMI_BASE_MAX_CMD_ERR_COUNT	1024
18 
19 enum scmi_base_protocol_cmd {
20 	BASE_DISCOVER_VENDOR = 0x3,
21 	BASE_DISCOVER_SUB_VENDOR = 0x4,
22 	BASE_DISCOVER_IMPLEMENT_VERSION = 0x5,
23 	BASE_DISCOVER_LIST_PROTOCOLS = 0x6,
24 	BASE_DISCOVER_AGENT = 0x7,
25 	BASE_NOTIFY_ERRORS = 0x8,
26 	BASE_SET_DEVICE_PERMISSIONS = 0x9,
27 	BASE_SET_PROTOCOL_PERMISSIONS = 0xa,
28 	BASE_RESET_AGENT_CONFIGURATION = 0xb,
29 };
30 
31 struct scmi_msg_resp_base_attributes {
32 	u8 num_protocols;
33 	u8 num_agents;
34 	__le16 reserved;
35 };
36 
37 struct scmi_msg_resp_base_discover_agent {
38 	__le32 agent_id;
39 	u8 name[SCMI_MAX_STR_SIZE];
40 };
41 
42 
43 struct scmi_msg_base_error_notify {
44 	__le32 event_control;
45 #define BASE_TP_NOTIFY_ALL	BIT(0)
46 };
47 
48 struct scmi_base_error_notify_payld {
49 	__le32 agent_id;
50 	__le32 error_status;
51 #define IS_FATAL_ERROR(x)	((x) & BIT(31))
52 #define ERROR_CMD_COUNT(x)	FIELD_GET(GENMASK(9, 0), (x))
53 	__le64 msg_reports[SCMI_BASE_MAX_CMD_ERR_COUNT];
54 };
55 
56 /**
57  * scmi_base_attributes_get() - gets the implementation details
58  *	that are associated with the base protocol.
59  *
60  * @ph: SCMI protocol handle
61  *
62  * Return: 0 on success, else appropriate SCMI error.
63  */
64 static int scmi_base_attributes_get(const struct scmi_protocol_handle *ph)
65 {
66 	int ret;
67 	struct scmi_xfer *t;
68 	struct scmi_msg_resp_base_attributes *attr_info;
69 	struct scmi_revision_info *rev = ph->get_priv(ph);
70 
71 	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
72 				      0, sizeof(*attr_info), &t);
73 	if (ret)
74 		return ret;
75 
76 	ret = ph->xops->do_xfer(ph, t);
77 	if (!ret) {
78 		attr_info = t->rx.buf;
79 		rev->num_protocols = attr_info->num_protocols;
80 		rev->num_agents = attr_info->num_agents;
81 	}
82 
83 	ph->xops->xfer_put(ph, t);
84 
85 	return ret;
86 }
87 
88 /**
89  * scmi_base_vendor_id_get() - gets vendor/subvendor identifier ASCII string.
90  *
91  * @ph: SCMI protocol handle
92  * @sub_vendor: specify true if sub-vendor ID is needed
93  *
94  * Return: 0 on success, else appropriate SCMI error.
95  */
96 static int
97 scmi_base_vendor_id_get(const struct scmi_protocol_handle *ph, bool sub_vendor)
98 {
99 	u8 cmd;
100 	int ret, size;
101 	char *vendor_id;
102 	struct scmi_xfer *t;
103 	struct scmi_revision_info *rev = ph->get_priv(ph);
104 
105 
106 	if (sub_vendor) {
107 		cmd = BASE_DISCOVER_SUB_VENDOR;
108 		vendor_id = rev->sub_vendor_id;
109 		size = ARRAY_SIZE(rev->sub_vendor_id);
110 	} else {
111 		cmd = BASE_DISCOVER_VENDOR;
112 		vendor_id = rev->vendor_id;
113 		size = ARRAY_SIZE(rev->vendor_id);
114 	}
115 
116 	ret = ph->xops->xfer_get_init(ph, cmd, 0, size, &t);
117 	if (ret)
118 		return ret;
119 
120 	ret = ph->xops->do_xfer(ph, t);
121 	if (!ret)
122 		memcpy(vendor_id, t->rx.buf, size);
123 
124 	ph->xops->xfer_put(ph, t);
125 
126 	return ret;
127 }
128 
129 /**
130  * scmi_base_implementation_version_get() - gets a vendor-specific
131  *	implementation 32-bit version. The format of the version number is
132  *	vendor-specific
133  *
134  * @ph: SCMI protocol handle
135  *
136  * Return: 0 on success, else appropriate SCMI error.
137  */
138 static int
139 scmi_base_implementation_version_get(const struct scmi_protocol_handle *ph)
140 {
141 	int ret;
142 	__le32 *impl_ver;
143 	struct scmi_xfer *t;
144 	struct scmi_revision_info *rev = ph->get_priv(ph);
145 
146 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_IMPLEMENT_VERSION,
147 				      0, sizeof(*impl_ver), &t);
148 	if (ret)
149 		return ret;
150 
151 	ret = ph->xops->do_xfer(ph, t);
152 	if (!ret) {
153 		impl_ver = t->rx.buf;
154 		rev->impl_ver = le32_to_cpu(*impl_ver);
155 	}
156 
157 	ph->xops->xfer_put(ph, t);
158 
159 	return ret;
160 }
161 
162 /**
163  * scmi_base_implementation_list_get() - gets the list of protocols it is
164  *	OSPM is allowed to access
165  *
166  * @ph: SCMI protocol handle
167  * @protocols_imp: pointer to hold the list of protocol identifiers
168  *
169  * Return: 0 on success, else appropriate SCMI error.
170  */
171 static int
172 scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph,
173 				  u8 *protocols_imp)
174 {
175 	u8 *list;
176 	int ret, loop;
177 	struct scmi_xfer *t;
178 	__le32 *num_skip, *num_ret;
179 	u32 tot_num_ret = 0, loop_num_ret;
180 	struct device *dev = ph->dev;
181 
182 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_LIST_PROTOCOLS,
183 				      sizeof(*num_skip), 0, &t);
184 	if (ret)
185 		return ret;
186 
187 	num_skip = t->tx.buf;
188 	num_ret = t->rx.buf;
189 	list = t->rx.buf + sizeof(*num_ret);
190 
191 	do {
192 		/* Set the number of protocols to be skipped/already read */
193 		*num_skip = cpu_to_le32(tot_num_ret);
194 
195 		ret = ph->xops->do_xfer(ph, t);
196 		if (ret)
197 			break;
198 
199 		loop_num_ret = le32_to_cpu(*num_ret);
200 		if (tot_num_ret + loop_num_ret > MAX_PROTOCOLS_IMP) {
201 			dev_err(dev, "No. of Protocol > MAX_PROTOCOLS_IMP");
202 			break;
203 		}
204 
205 		for (loop = 0; loop < loop_num_ret; loop++)
206 			protocols_imp[tot_num_ret + loop] = *(list + loop);
207 
208 		tot_num_ret += loop_num_ret;
209 
210 		ph->xops->reset_rx_to_maxsz(ph, t);
211 	} while (loop_num_ret);
212 
213 	ph->xops->xfer_put(ph, t);
214 
215 	return ret;
216 }
217 
218 /**
219  * scmi_base_discover_agent_get() - discover the name of an agent
220  *
221  * @ph: SCMI protocol handle
222  * @id: Agent identifier
223  * @name: Agent identifier ASCII string
224  *
225  * An agent id of 0 is reserved to identify the platform itself.
226  * Generally operating system is represented as "OSPM"
227  *
228  * Return: 0 on success, else appropriate SCMI error.
229  */
230 static int scmi_base_discover_agent_get(const struct scmi_protocol_handle *ph,
231 					int id, char *name)
232 {
233 	int ret;
234 	struct scmi_msg_resp_base_discover_agent *agent_info;
235 	struct scmi_xfer *t;
236 
237 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_AGENT,
238 				      sizeof(__le32), sizeof(*agent_info), &t);
239 	if (ret)
240 		return ret;
241 
242 	put_unaligned_le32(id, t->tx.buf);
243 
244 	ret = ph->xops->do_xfer(ph, t);
245 	if (!ret) {
246 		agent_info = t->rx.buf;
247 		strlcpy(name, agent_info->name, SCMI_MAX_STR_SIZE);
248 	}
249 
250 	ph->xops->xfer_put(ph, t);
251 
252 	return ret;
253 }
254 
255 static int scmi_base_error_notify(const struct scmi_protocol_handle *ph,
256 				  bool enable)
257 {
258 	int ret;
259 	u32 evt_cntl = enable ? BASE_TP_NOTIFY_ALL : 0;
260 	struct scmi_xfer *t;
261 	struct scmi_msg_base_error_notify *cfg;
262 
263 	ret = ph->xops->xfer_get_init(ph, BASE_NOTIFY_ERRORS,
264 				      sizeof(*cfg), 0, &t);
265 	if (ret)
266 		return ret;
267 
268 	cfg = t->tx.buf;
269 	cfg->event_control = cpu_to_le32(evt_cntl);
270 
271 	ret = ph->xops->do_xfer(ph, t);
272 
273 	ph->xops->xfer_put(ph, t);
274 	return ret;
275 }
276 
277 static int scmi_base_set_notify_enabled(const struct scmi_protocol_handle *ph,
278 					u8 evt_id, u32 src_id, bool enable)
279 {
280 	int ret;
281 
282 	ret = scmi_base_error_notify(ph, enable);
283 	if (ret)
284 		pr_debug("FAIL_ENABLED - evt[%X] ret:%d\n", evt_id, ret);
285 
286 	return ret;
287 }
288 
289 static void *scmi_base_fill_custom_report(const struct scmi_protocol_handle *ph,
290 					  u8 evt_id, ktime_t timestamp,
291 					  const void *payld, size_t payld_sz,
292 					  void *report, u32 *src_id)
293 {
294 	int i;
295 	const struct scmi_base_error_notify_payld *p = payld;
296 	struct scmi_base_error_report *r = report;
297 
298 	/*
299 	 * BaseError notification payload is variable in size but
300 	 * up to a maximum length determined by the struct ponted by p.
301 	 * Instead payld_sz is the effective length of this notification
302 	 * payload so cannot be greater of the maximum allowed size as
303 	 * pointed by p.
304 	 */
305 	if (evt_id != SCMI_EVENT_BASE_ERROR_EVENT || sizeof(*p) < payld_sz)
306 		return NULL;
307 
308 	r->timestamp = timestamp;
309 	r->agent_id = le32_to_cpu(p->agent_id);
310 	r->fatal = IS_FATAL_ERROR(le32_to_cpu(p->error_status));
311 	r->cmd_count = ERROR_CMD_COUNT(le32_to_cpu(p->error_status));
312 	for (i = 0; i < r->cmd_count; i++)
313 		r->reports[i] = le64_to_cpu(p->msg_reports[i]);
314 	*src_id = 0;
315 
316 	return r;
317 }
318 
319 static const struct scmi_event base_events[] = {
320 	{
321 		.id = SCMI_EVENT_BASE_ERROR_EVENT,
322 		.max_payld_sz = sizeof(struct scmi_base_error_notify_payld),
323 		.max_report_sz = sizeof(struct scmi_base_error_report) +
324 				  SCMI_BASE_MAX_CMD_ERR_COUNT * sizeof(u64),
325 	},
326 };
327 
328 static const struct scmi_event_ops base_event_ops = {
329 	.set_notify_enabled = scmi_base_set_notify_enabled,
330 	.fill_custom_report = scmi_base_fill_custom_report,
331 };
332 
333 static const struct scmi_protocol_events base_protocol_events = {
334 	.queue_sz = 4 * SCMI_PROTO_QUEUE_SZ,
335 	.ops = &base_event_ops,
336 	.evts = base_events,
337 	.num_events = ARRAY_SIZE(base_events),
338 	.num_sources = SCMI_BASE_NUM_SOURCES,
339 };
340 
341 static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
342 {
343 	int id, ret;
344 	u8 *prot_imp;
345 	u32 version;
346 	char name[SCMI_MAX_STR_SIZE];
347 	struct device *dev = ph->dev;
348 	struct scmi_revision_info *rev = scmi_revision_area_get(ph);
349 
350 	ret = ph->xops->version_get(ph, &version);
351 	if (ret)
352 		return ret;
353 
354 	prot_imp = devm_kcalloc(dev, MAX_PROTOCOLS_IMP, sizeof(u8), GFP_KERNEL);
355 	if (!prot_imp)
356 		return -ENOMEM;
357 
358 	rev->major_ver = PROTOCOL_REV_MAJOR(version),
359 	rev->minor_ver = PROTOCOL_REV_MINOR(version);
360 	ph->set_priv(ph, rev);
361 
362 	scmi_base_attributes_get(ph);
363 	scmi_base_vendor_id_get(ph, false);
364 	scmi_base_vendor_id_get(ph, true);
365 	scmi_base_implementation_version_get(ph);
366 	scmi_base_implementation_list_get(ph, prot_imp);
367 
368 	scmi_setup_protocol_implemented(ph, prot_imp);
369 
370 	dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
371 		 rev->major_ver, rev->minor_ver, rev->vendor_id,
372 		 rev->sub_vendor_id, rev->impl_ver);
373 	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
374 		rev->num_agents);
375 
376 	for (id = 0; id < rev->num_agents; id++) {
377 		scmi_base_discover_agent_get(ph, id, name);
378 		dev_dbg(dev, "Agent %d: %s\n", id, name);
379 	}
380 
381 	return 0;
382 }
383 
384 static const struct scmi_protocol scmi_base = {
385 	.id = SCMI_PROTOCOL_BASE,
386 	.owner = NULL,
387 	.instance_init = &scmi_base_protocol_init,
388 	.ops = NULL,
389 	.events = &base_protocol_events,
390 };
391 
392 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(base, scmi_base)
393