xref: /linux/drivers/firmware/arm_scmi/base.c (revision 5ea5880764cbb164afb17a62e76ca75dc371409d)
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/math.h>
11 #include <linux/module.h>
12 #include <linux/scmi_protocol.h>
13 
14 #include "common.h"
15 #include "notify.h"
16 
17 /* Updated only after ALL the mandatory features for that version are merged */
18 #define SCMI_PROTOCOL_SUPPORTED_VERSION		0x20001
19 
20 #define SCMI_BASE_NUM_SOURCES		1
21 #define SCMI_BASE_MAX_CMD_ERR_COUNT	1024
22 
23 enum scmi_base_protocol_cmd {
24 	BASE_DISCOVER_VENDOR = 0x3,
25 	BASE_DISCOVER_SUB_VENDOR = 0x4,
26 	BASE_DISCOVER_IMPLEMENT_VERSION = 0x5,
27 	BASE_DISCOVER_LIST_PROTOCOLS = 0x6,
28 	BASE_DISCOVER_AGENT = 0x7,
29 	BASE_NOTIFY_ERRORS = 0x8,
30 	BASE_SET_DEVICE_PERMISSIONS = 0x9,
31 	BASE_SET_PROTOCOL_PERMISSIONS = 0xa,
32 	BASE_RESET_AGENT_CONFIGURATION = 0xb,
33 };
34 
35 struct scmi_msg_resp_base_attributes {
36 	u8 num_protocols;
37 	u8 num_agents;
38 	__le16 reserved;
39 };
40 
41 struct scmi_msg_resp_base_discover_agent {
42 	__le32 agent_id;
43 	u8 name[SCMI_SHORT_NAME_MAX_SIZE];
44 };
45 
46 struct scmi_msg_base_error_notify {
47 	__le32 event_control;
48 #define BASE_TP_NOTIFY_ALL	BIT(0)
49 };
50 
51 struct scmi_base_error_notify_payld {
52 	__le32 agent_id;
53 	__le32 error_status;
54 #define IS_FATAL_ERROR(x)	((x) & BIT(31))
55 #define ERROR_CMD_COUNT(x)	FIELD_GET(GENMASK(9, 0), (x))
56 	__le64 msg_reports[SCMI_BASE_MAX_CMD_ERR_COUNT];
57 };
58 
59 /**
60  * scmi_base_attributes_get() - gets the implementation details
61  *	that are associated with the base protocol.
62  *
63  * @ph: SCMI protocol handle
64  *
65  * Return: 0 on success, else appropriate SCMI error.
66  */
67 static int scmi_base_attributes_get(const struct scmi_protocol_handle *ph)
68 {
69 	int ret;
70 	struct scmi_xfer *t;
71 	struct scmi_msg_resp_base_attributes *attr_info;
72 	struct scmi_revision_info *rev = ph->get_priv(ph);
73 
74 	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
75 				      0, sizeof(*attr_info), &t);
76 	if (ret)
77 		return ret;
78 
79 	ret = ph->xops->do_xfer(ph, t);
80 	if (!ret) {
81 		attr_info = t->rx.buf;
82 		rev->num_protocols = attr_info->num_protocols;
83 		rev->num_agents = attr_info->num_agents;
84 	}
85 
86 	ph->xops->xfer_put(ph, t);
87 
88 	return ret;
89 }
90 
91 /**
92  * scmi_base_vendor_id_get() - gets vendor/subvendor identifier ASCII string.
93  *
94  * @ph: SCMI protocol handle
95  * @sub_vendor: specify true if sub-vendor ID is needed
96  *
97  * Return: 0 on success, else appropriate SCMI error.
98  */
99 static int
100 scmi_base_vendor_id_get(const struct scmi_protocol_handle *ph, bool sub_vendor)
101 {
102 	u8 cmd;
103 	int ret, size;
104 	char *vendor_id;
105 	struct scmi_xfer *t;
106 	struct scmi_revision_info *rev = ph->get_priv(ph);
107 
108 	if (sub_vendor) {
109 		cmd = BASE_DISCOVER_SUB_VENDOR;
110 		vendor_id = rev->sub_vendor_id;
111 		size = ARRAY_SIZE(rev->sub_vendor_id);
112 	} else {
113 		cmd = BASE_DISCOVER_VENDOR;
114 		vendor_id = rev->vendor_id;
115 		size = ARRAY_SIZE(rev->vendor_id);
116 	}
117 
118 	ret = ph->xops->xfer_get_init(ph, cmd, 0, size, &t);
119 	if (ret)
120 		return ret;
121 
122 	ret = ph->xops->do_xfer(ph, t);
123 	if (!ret)
124 		strscpy(vendor_id, t->rx.buf, size);
125 
126 	ph->xops->xfer_put(ph, t);
127 
128 	return ret;
129 }
130 
131 /**
132  * scmi_base_implementation_version_get() - gets a vendor-specific
133  *	implementation 32-bit version. The format of the version number is
134  *	vendor-specific
135  *
136  * @ph: SCMI protocol handle
137  *
138  * Return: 0 on success, else appropriate SCMI error.
139  */
140 static int
141 scmi_base_implementation_version_get(const struct scmi_protocol_handle *ph)
142 {
143 	int ret;
144 	__le32 *impl_ver;
145 	struct scmi_xfer *t;
146 	struct scmi_revision_info *rev = ph->get_priv(ph);
147 
148 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_IMPLEMENT_VERSION,
149 				      0, sizeof(*impl_ver), &t);
150 	if (ret)
151 		return ret;
152 
153 	ret = ph->xops->do_xfer(ph, t);
154 	if (!ret) {
155 		impl_ver = t->rx.buf;
156 		rev->impl_ver = le32_to_cpu(*impl_ver);
157 	}
158 
159 	ph->xops->xfer_put(ph, t);
160 
161 	return ret;
162 }
163 
164 /**
165  * scmi_base_implementation_list_get() - gets the list of protocols it is
166  *	OSPM is allowed to access
167  *
168  * @ph: SCMI protocol handle
169  * @protocols_imp: pointer to hold the list of protocol identifiers
170  *
171  * Return: 0 on success, else appropriate SCMI error.
172  */
173 static int
174 scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph,
175 				  u8 *protocols_imp)
176 {
177 	u8 *list;
178 	int ret, loop;
179 	struct scmi_xfer *t;
180 	__le32 *num_skip, *num_ret;
181 	u32 tot_num_ret = 0, loop_num_ret;
182 	struct device *dev = ph->dev;
183 	struct scmi_revision_info *rev = ph->get_priv(ph);
184 
185 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_LIST_PROTOCOLS,
186 				      sizeof(*num_skip), 0, &t);
187 	if (ret)
188 		return ret;
189 
190 	num_skip = t->tx.buf;
191 	num_ret = t->rx.buf;
192 	list = t->rx.buf + sizeof(*num_ret);
193 
194 	do {
195 		size_t real_list_sz;
196 		u32 calc_list_sz;
197 
198 		/* Set the number of protocols to be skipped/already read */
199 		*num_skip = cpu_to_le32(tot_num_ret);
200 
201 		ret = ph->xops->do_xfer(ph, t);
202 		if (ret)
203 			break;
204 
205 		loop_num_ret = le32_to_cpu(*num_ret);
206 		if (!loop_num_ret)
207 			break;
208 
209 		if (loop_num_ret > rev->num_protocols - tot_num_ret) {
210 			dev_err(dev,
211 				"No. Returned protocols > Total protocols.\n");
212 			break;
213 		}
214 
215 		if (t->rx.len < (sizeof(u32) * 2)) {
216 			dev_err(dev, "Truncated reply - rx.len:%zd\n",
217 				t->rx.len);
218 			ret = -EPROTO;
219 			break;
220 		}
221 
222 		real_list_sz = t->rx.len - sizeof(u32);
223 		calc_list_sz = round_up(loop_num_ret, sizeof(u32));
224 		if (calc_list_sz != real_list_sz) {
225 			dev_warn(dev,
226 				 "Malformed reply - real_sz:%zd  calc_sz:%u  (loop_num_ret:%d)\n",
227 				 real_list_sz, calc_list_sz, loop_num_ret);
228 			/*
229 			 * Bail out if the expected list size is bigger than the
230 			 * total payload size of the received reply.
231 			 */
232 			if (calc_list_sz > real_list_sz) {
233 				ret = -EPROTO;
234 				break;
235 			}
236 		}
237 
238 		for (loop = 0; loop < loop_num_ret; loop++)
239 			protocols_imp[tot_num_ret + loop] = *(list + loop);
240 
241 		tot_num_ret += loop_num_ret;
242 
243 		ph->xops->reset_rx_to_maxsz(ph, t);
244 	} while (tot_num_ret < rev->num_protocols);
245 
246 	ph->xops->xfer_put(ph, t);
247 
248 	return ret;
249 }
250 
251 /**
252  * scmi_base_discover_agent_get() - discover the name of an agent
253  *
254  * @ph: SCMI protocol handle
255  * @id: Agent identifier
256  * @name: Agent identifier ASCII string
257  *
258  * An agent id of 0 is reserved to identify the platform itself.
259  * Generally operating system is represented as "OSPM"
260  *
261  * Return: 0 on success, else appropriate SCMI error.
262  */
263 static int scmi_base_discover_agent_get(const struct scmi_protocol_handle *ph,
264 					int id, char *name)
265 {
266 	int ret;
267 	struct scmi_msg_resp_base_discover_agent *agent_info;
268 	struct scmi_xfer *t;
269 
270 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_AGENT,
271 				      sizeof(__le32), sizeof(*agent_info), &t);
272 	if (ret)
273 		return ret;
274 
275 	put_unaligned_le32(id, t->tx.buf);
276 
277 	ret = ph->xops->do_xfer(ph, t);
278 	if (!ret) {
279 		agent_info = t->rx.buf;
280 		strscpy(name, agent_info->name, SCMI_SHORT_NAME_MAX_SIZE);
281 	}
282 
283 	ph->xops->xfer_put(ph, t);
284 
285 	return ret;
286 }
287 
288 static int scmi_base_error_notify(const struct scmi_protocol_handle *ph,
289 				  bool enable)
290 {
291 	int ret;
292 	u32 evt_cntl = enable ? BASE_TP_NOTIFY_ALL : 0;
293 	struct scmi_xfer *t;
294 	struct scmi_msg_base_error_notify *cfg;
295 
296 	ret = ph->xops->xfer_get_init(ph, BASE_NOTIFY_ERRORS,
297 				      sizeof(*cfg), 0, &t);
298 	if (ret)
299 		return ret;
300 
301 	cfg = t->tx.buf;
302 	cfg->event_control = cpu_to_le32(evt_cntl);
303 
304 	ret = ph->xops->do_xfer(ph, t);
305 
306 	ph->xops->xfer_put(ph, t);
307 	return ret;
308 }
309 
310 static int scmi_base_set_notify_enabled(const struct scmi_protocol_handle *ph,
311 					u8 evt_id, u32 src_id, bool enable)
312 {
313 	int ret;
314 
315 	ret = scmi_base_error_notify(ph, enable);
316 	if (ret)
317 		pr_debug("FAIL_ENABLED - evt[%X] ret:%d\n", evt_id, ret);
318 
319 	return ret;
320 }
321 
322 static void *scmi_base_fill_custom_report(const struct scmi_protocol_handle *ph,
323 					  u8 evt_id, ktime_t timestamp,
324 					  const void *payld, size_t payld_sz,
325 					  void *report, u32 *src_id)
326 {
327 	int i;
328 	const struct scmi_base_error_notify_payld *p = payld;
329 	struct scmi_base_error_report *r = report;
330 
331 	/*
332 	 * BaseError notification payload is variable in size but
333 	 * up to a maximum length determined by the struct ponted by p.
334 	 * Instead payld_sz is the effective length of this notification
335 	 * payload so cannot be greater of the maximum allowed size as
336 	 * pointed by p.
337 	 */
338 	if (evt_id != SCMI_EVENT_BASE_ERROR_EVENT || sizeof(*p) < payld_sz)
339 		return NULL;
340 
341 	r->timestamp = timestamp;
342 	r->agent_id = le32_to_cpu(p->agent_id);
343 	r->fatal = IS_FATAL_ERROR(le32_to_cpu(p->error_status));
344 	r->cmd_count = ERROR_CMD_COUNT(le32_to_cpu(p->error_status));
345 	for (i = 0; i < r->cmd_count; i++)
346 		r->reports[i] = le64_to_cpu(p->msg_reports[i]);
347 	*src_id = 0;
348 
349 	return r;
350 }
351 
352 static const struct scmi_event base_events[] = {
353 	{
354 		.id = SCMI_EVENT_BASE_ERROR_EVENT,
355 		.max_payld_sz = sizeof(struct scmi_base_error_notify_payld),
356 		.max_report_sz = sizeof(struct scmi_base_error_report) +
357 				  SCMI_BASE_MAX_CMD_ERR_COUNT * sizeof(u64),
358 	},
359 };
360 
361 static const struct scmi_event_ops base_event_ops = {
362 	.set_notify_enabled = scmi_base_set_notify_enabled,
363 	.fill_custom_report = scmi_base_fill_custom_report,
364 };
365 
366 static const struct scmi_protocol_events base_protocol_events = {
367 	.queue_sz = 4 * SCMI_PROTO_QUEUE_SZ,
368 	.ops = &base_event_ops,
369 	.evts = base_events,
370 	.num_events = ARRAY_SIZE(base_events),
371 	.num_sources = SCMI_BASE_NUM_SOURCES,
372 };
373 
374 static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
375 {
376 	int id, ret;
377 	u8 *prot_imp;
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 	rev->major_ver = PROTOCOL_REV_MAJOR(ph->version);
383 	rev->minor_ver = PROTOCOL_REV_MINOR(ph->version);
384 	ph->set_priv(ph, rev);
385 
386 	ret = scmi_base_attributes_get(ph);
387 	if (ret)
388 		return ret;
389 
390 	prot_imp = devm_kcalloc(dev, rev->num_protocols, sizeof(u8),
391 				GFP_KERNEL);
392 	if (!prot_imp)
393 		return -ENOMEM;
394 
395 	scmi_base_vendor_id_get(ph, false);
396 	scmi_base_vendor_id_get(ph, true);
397 	scmi_base_implementation_version_get(ph);
398 	scmi_base_implementation_list_get(ph, prot_imp);
399 
400 	scmi_setup_protocol_implemented(ph, prot_imp);
401 
402 	dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
403 		 rev->major_ver, rev->minor_ver, rev->vendor_id,
404 		 rev->sub_vendor_id, rev->impl_ver);
405 	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
406 		rev->num_agents);
407 
408 	for (id = 0; id < rev->num_agents; id++) {
409 		scmi_base_discover_agent_get(ph, id, name);
410 		dev_dbg(dev, "Agent %d: %s\n", id, name);
411 	}
412 
413 	return 0;
414 }
415 
416 static const struct scmi_protocol scmi_base = {
417 	.id = SCMI_PROTOCOL_BASE,
418 	.owner = NULL,
419 	.instance_init = &scmi_base_protocol_init,
420 	.ops = NULL,
421 	.events = &base_protocol_events,
422 	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
423 };
424 
425 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(base, scmi_base)
426