xref: /openbmc/linux/drivers/firmware/arm_scmi/base.c (revision be2b81b5)
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_SHORT_NAME_MAX_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 		strscpy(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 	struct scmi_revision_info *rev = ph->get_priv(ph);
182 
183 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_LIST_PROTOCOLS,
184 				      sizeof(*num_skip), 0, &t);
185 	if (ret)
186 		return ret;
187 
188 	num_skip = t->tx.buf;
189 	num_ret = t->rx.buf;
190 	list = t->rx.buf + sizeof(*num_ret);
191 
192 	do {
193 		size_t real_list_sz;
194 		u32 calc_list_sz;
195 
196 		/* Set the number of protocols to be skipped/already read */
197 		*num_skip = cpu_to_le32(tot_num_ret);
198 
199 		ret = ph->xops->do_xfer(ph, t);
200 		if (ret)
201 			break;
202 
203 		loop_num_ret = le32_to_cpu(*num_ret);
204 		if (!loop_num_ret)
205 			break;
206 
207 		if (loop_num_ret > rev->num_protocols - tot_num_ret) {
208 			dev_err(dev,
209 				"No. Returned protocols > Total protocols.\n");
210 			break;
211 		}
212 
213 		if (t->rx.len < (sizeof(u32) * 2)) {
214 			dev_err(dev, "Truncated reply - rx.len:%zd\n",
215 				t->rx.len);
216 			ret = -EPROTO;
217 			break;
218 		}
219 
220 		real_list_sz = t->rx.len - sizeof(u32);
221 		calc_list_sz = (1 + (loop_num_ret - 1) / sizeof(u32)) *
222 				sizeof(u32);
223 		if (calc_list_sz != real_list_sz) {
224 			dev_warn(dev,
225 				 "Malformed reply - real_sz:%zd  calc_sz:%u  (loop_num_ret:%d)\n",
226 				 real_list_sz, calc_list_sz, loop_num_ret);
227 			/*
228 			 * Bail out if the expected list size is bigger than the
229 			 * total payload size of the received reply.
230 			 */
231 			if (calc_list_sz > real_list_sz) {
232 				ret = -EPROTO;
233 				break;
234 			}
235 		}
236 
237 		for (loop = 0; loop < loop_num_ret; loop++)
238 			protocols_imp[tot_num_ret + loop] = *(list + loop);
239 
240 		tot_num_ret += loop_num_ret;
241 
242 		ph->xops->reset_rx_to_maxsz(ph, t);
243 	} while (tot_num_ret < rev->num_protocols);
244 
245 	ph->xops->xfer_put(ph, t);
246 
247 	return ret;
248 }
249 
250 /**
251  * scmi_base_discover_agent_get() - discover the name of an agent
252  *
253  * @ph: SCMI protocol handle
254  * @id: Agent identifier
255  * @name: Agent identifier ASCII string
256  *
257  * An agent id of 0 is reserved to identify the platform itself.
258  * Generally operating system is represented as "OSPM"
259  *
260  * Return: 0 on success, else appropriate SCMI error.
261  */
262 static int scmi_base_discover_agent_get(const struct scmi_protocol_handle *ph,
263 					int id, char *name)
264 {
265 	int ret;
266 	struct scmi_msg_resp_base_discover_agent *agent_info;
267 	struct scmi_xfer *t;
268 
269 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_AGENT,
270 				      sizeof(__le32), sizeof(*agent_info), &t);
271 	if (ret)
272 		return ret;
273 
274 	put_unaligned_le32(id, t->tx.buf);
275 
276 	ret = ph->xops->do_xfer(ph, t);
277 	if (!ret) {
278 		agent_info = t->rx.buf;
279 		strscpy(name, agent_info->name, SCMI_SHORT_NAME_MAX_SIZE);
280 	}
281 
282 	ph->xops->xfer_put(ph, t);
283 
284 	return ret;
285 }
286 
287 static int scmi_base_error_notify(const struct scmi_protocol_handle *ph,
288 				  bool enable)
289 {
290 	int ret;
291 	u32 evt_cntl = enable ? BASE_TP_NOTIFY_ALL : 0;
292 	struct scmi_xfer *t;
293 	struct scmi_msg_base_error_notify *cfg;
294 
295 	ret = ph->xops->xfer_get_init(ph, BASE_NOTIFY_ERRORS,
296 				      sizeof(*cfg), 0, &t);
297 	if (ret)
298 		return ret;
299 
300 	cfg = t->tx.buf;
301 	cfg->event_control = cpu_to_le32(evt_cntl);
302 
303 	ret = ph->xops->do_xfer(ph, t);
304 
305 	ph->xops->xfer_put(ph, t);
306 	return ret;
307 }
308 
309 static int scmi_base_set_notify_enabled(const struct scmi_protocol_handle *ph,
310 					u8 evt_id, u32 src_id, bool enable)
311 {
312 	int ret;
313 
314 	ret = scmi_base_error_notify(ph, enable);
315 	if (ret)
316 		pr_debug("FAIL_ENABLED - evt[%X] ret:%d\n", evt_id, ret);
317 
318 	return ret;
319 }
320 
321 static void *scmi_base_fill_custom_report(const struct scmi_protocol_handle *ph,
322 					  u8 evt_id, ktime_t timestamp,
323 					  const void *payld, size_t payld_sz,
324 					  void *report, u32 *src_id)
325 {
326 	int i;
327 	const struct scmi_base_error_notify_payld *p = payld;
328 	struct scmi_base_error_report *r = report;
329 
330 	/*
331 	 * BaseError notification payload is variable in size but
332 	 * up to a maximum length determined by the struct ponted by p.
333 	 * Instead payld_sz is the effective length of this notification
334 	 * payload so cannot be greater of the maximum allowed size as
335 	 * pointed by p.
336 	 */
337 	if (evt_id != SCMI_EVENT_BASE_ERROR_EVENT || sizeof(*p) < payld_sz)
338 		return NULL;
339 
340 	r->timestamp = timestamp;
341 	r->agent_id = le32_to_cpu(p->agent_id);
342 	r->fatal = IS_FATAL_ERROR(le32_to_cpu(p->error_status));
343 	r->cmd_count = ERROR_CMD_COUNT(le32_to_cpu(p->error_status));
344 	for (i = 0; i < r->cmd_count; i++)
345 		r->reports[i] = le64_to_cpu(p->msg_reports[i]);
346 	*src_id = 0;
347 
348 	return r;
349 }
350 
351 static const struct scmi_event base_events[] = {
352 	{
353 		.id = SCMI_EVENT_BASE_ERROR_EVENT,
354 		.max_payld_sz = sizeof(struct scmi_base_error_notify_payld),
355 		.max_report_sz = sizeof(struct scmi_base_error_report) +
356 				  SCMI_BASE_MAX_CMD_ERR_COUNT * sizeof(u64),
357 	},
358 };
359 
360 static const struct scmi_event_ops base_event_ops = {
361 	.set_notify_enabled = scmi_base_set_notify_enabled,
362 	.fill_custom_report = scmi_base_fill_custom_report,
363 };
364 
365 static const struct scmi_protocol_events base_protocol_events = {
366 	.queue_sz = 4 * SCMI_PROTO_QUEUE_SZ,
367 	.ops = &base_event_ops,
368 	.evts = base_events,
369 	.num_events = ARRAY_SIZE(base_events),
370 	.num_sources = SCMI_BASE_NUM_SOURCES,
371 };
372 
373 static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
374 {
375 	int id, ret;
376 	u8 *prot_imp;
377 	u32 version;
378 	char name[SCMI_SHORT_NAME_MAX_SIZE];
379 	struct device *dev = ph->dev;
380 	struct scmi_revision_info *rev = scmi_revision_area_get(ph);
381 
382 	ret = ph->xops->version_get(ph, &version);
383 	if (ret)
384 		return ret;
385 
386 	rev->major_ver = PROTOCOL_REV_MAJOR(version),
387 	rev->minor_ver = PROTOCOL_REV_MINOR(version);
388 	ph->set_priv(ph, rev);
389 
390 	ret = scmi_base_attributes_get(ph);
391 	if (ret)
392 		return ret;
393 
394 	prot_imp = devm_kcalloc(dev, rev->num_protocols, sizeof(u8),
395 				GFP_KERNEL);
396 	if (!prot_imp)
397 		return -ENOMEM;
398 
399 	scmi_base_vendor_id_get(ph, false);
400 	scmi_base_vendor_id_get(ph, true);
401 	scmi_base_implementation_version_get(ph);
402 	scmi_base_implementation_list_get(ph, prot_imp);
403 
404 	scmi_setup_protocol_implemented(ph, prot_imp);
405 
406 	dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
407 		 rev->major_ver, rev->minor_ver, rev->vendor_id,
408 		 rev->sub_vendor_id, rev->impl_ver);
409 	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
410 		rev->num_agents);
411 
412 	for (id = 0; id < rev->num_agents; id++) {
413 		scmi_base_discover_agent_get(ph, id, name);
414 		dev_dbg(dev, "Agent %d: %s\n", id, name);
415 	}
416 
417 	return 0;
418 }
419 
420 static const struct scmi_protocol scmi_base = {
421 	.id = SCMI_PROTOCOL_BASE,
422 	.owner = NULL,
423 	.instance_init = &scmi_base_protocol_init,
424 	.ops = NULL,
425 	.events = &base_protocol_events,
426 };
427 
428 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(base, scmi_base)
429