xref: /linux/drivers/firmware/arm_scmi/base.c (revision 55d0969c451159cff86949b38c39171cab962069)
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 /* Updated only after ALL the mandatory features for that version are merged */
17 #define SCMI_PROTOCOL_SUPPORTED_VERSION		0x20001
18 
19 #define SCMI_BASE_NUM_SOURCES		1
20 #define SCMI_BASE_MAX_CMD_ERR_COUNT	1024
21 
22 enum scmi_base_protocol_cmd {
23 	BASE_DISCOVER_VENDOR = 0x3,
24 	BASE_DISCOVER_SUB_VENDOR = 0x4,
25 	BASE_DISCOVER_IMPLEMENT_VERSION = 0x5,
26 	BASE_DISCOVER_LIST_PROTOCOLS = 0x6,
27 	BASE_DISCOVER_AGENT = 0x7,
28 	BASE_NOTIFY_ERRORS = 0x8,
29 	BASE_SET_DEVICE_PERMISSIONS = 0x9,
30 	BASE_SET_PROTOCOL_PERMISSIONS = 0xa,
31 	BASE_RESET_AGENT_CONFIGURATION = 0xb,
32 };
33 
34 struct scmi_msg_resp_base_attributes {
35 	u8 num_protocols;
36 	u8 num_agents;
37 	__le16 reserved;
38 };
39 
40 struct scmi_msg_resp_base_discover_agent {
41 	__le32 agent_id;
42 	u8 name[SCMI_SHORT_NAME_MAX_SIZE];
43 };
44 
45 struct scmi_msg_base_error_notify {
46 	__le32 event_control;
47 #define BASE_TP_NOTIFY_ALL	BIT(0)
48 };
49 
50 struct scmi_base_error_notify_payld {
51 	__le32 agent_id;
52 	__le32 error_status;
53 #define IS_FATAL_ERROR(x)	((x) & BIT(31))
54 #define ERROR_CMD_COUNT(x)	FIELD_GET(GENMASK(9, 0), (x))
55 	__le64 msg_reports[SCMI_BASE_MAX_CMD_ERR_COUNT];
56 };
57 
58 /**
59  * scmi_base_attributes_get() - gets the implementation details
60  *	that are associated with the base protocol.
61  *
62  * @ph: SCMI protocol handle
63  *
64  * Return: 0 on success, else appropriate SCMI error.
65  */
66 static int scmi_base_attributes_get(const struct scmi_protocol_handle *ph)
67 {
68 	int ret;
69 	struct scmi_xfer *t;
70 	struct scmi_msg_resp_base_attributes *attr_info;
71 	struct scmi_revision_info *rev = ph->get_priv(ph);
72 
73 	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
74 				      0, sizeof(*attr_info), &t);
75 	if (ret)
76 		return ret;
77 
78 	ret = ph->xops->do_xfer(ph, t);
79 	if (!ret) {
80 		attr_info = t->rx.buf;
81 		rev->num_protocols = attr_info->num_protocols;
82 		rev->num_agents = attr_info->num_agents;
83 	}
84 
85 	ph->xops->xfer_put(ph, t);
86 
87 	return ret;
88 }
89 
90 /**
91  * scmi_base_vendor_id_get() - gets vendor/subvendor identifier ASCII string.
92  *
93  * @ph: SCMI protocol handle
94  * @sub_vendor: specify true if sub-vendor ID is needed
95  *
96  * Return: 0 on success, else appropriate SCMI error.
97  */
98 static int
99 scmi_base_vendor_id_get(const struct scmi_protocol_handle *ph, bool sub_vendor)
100 {
101 	u8 cmd;
102 	int ret, size;
103 	char *vendor_id;
104 	struct scmi_xfer *t;
105 	struct scmi_revision_info *rev = ph->get_priv(ph);
106 
107 	if (sub_vendor) {
108 		cmd = BASE_DISCOVER_SUB_VENDOR;
109 		vendor_id = rev->sub_vendor_id;
110 		size = ARRAY_SIZE(rev->sub_vendor_id);
111 	} else {
112 		cmd = BASE_DISCOVER_VENDOR;
113 		vendor_id = rev->vendor_id;
114 		size = ARRAY_SIZE(rev->vendor_id);
115 	}
116 
117 	ret = ph->xops->xfer_get_init(ph, cmd, 0, size, &t);
118 	if (ret)
119 		return ret;
120 
121 	ret = ph->xops->do_xfer(ph, t);
122 	if (!ret)
123 		strscpy(vendor_id, t->rx.buf, size);
124 
125 	ph->xops->xfer_put(ph, t);
126 
127 	return ret;
128 }
129 
130 /**
131  * scmi_base_implementation_version_get() - gets a vendor-specific
132  *	implementation 32-bit version. The format of the version number is
133  *	vendor-specific
134  *
135  * @ph: SCMI protocol handle
136  *
137  * Return: 0 on success, else appropriate SCMI error.
138  */
139 static int
140 scmi_base_implementation_version_get(const struct scmi_protocol_handle *ph)
141 {
142 	int ret;
143 	__le32 *impl_ver;
144 	struct scmi_xfer *t;
145 	struct scmi_revision_info *rev = ph->get_priv(ph);
146 
147 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_IMPLEMENT_VERSION,
148 				      0, sizeof(*impl_ver), &t);
149 	if (ret)
150 		return ret;
151 
152 	ret = ph->xops->do_xfer(ph, t);
153 	if (!ret) {
154 		impl_ver = t->rx.buf;
155 		rev->impl_ver = le32_to_cpu(*impl_ver);
156 	}
157 
158 	ph->xops->xfer_put(ph, t);
159 
160 	return ret;
161 }
162 
163 /**
164  * scmi_base_implementation_list_get() - gets the list of protocols it is
165  *	OSPM is allowed to access
166  *
167  * @ph: SCMI protocol handle
168  * @protocols_imp: pointer to hold the list of protocol identifiers
169  *
170  * Return: 0 on success, else appropriate SCMI error.
171  */
172 static int
173 scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph,
174 				  u8 *protocols_imp)
175 {
176 	u8 *list;
177 	int ret, loop;
178 	struct scmi_xfer *t;
179 	__le32 *num_skip, *num_ret;
180 	u32 tot_num_ret = 0, loop_num_ret;
181 	struct device *dev = ph->dev;
182 	struct scmi_revision_info *rev = ph->get_priv(ph);
183 
184 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_LIST_PROTOCOLS,
185 				      sizeof(*num_skip), 0, &t);
186 	if (ret)
187 		return ret;
188 
189 	num_skip = t->tx.buf;
190 	num_ret = t->rx.buf;
191 	list = t->rx.buf + sizeof(*num_ret);
192 
193 	do {
194 		size_t real_list_sz;
195 		u32 calc_list_sz;
196 
197 		/* Set the number of protocols to be skipped/already read */
198 		*num_skip = cpu_to_le32(tot_num_ret);
199 
200 		ret = ph->xops->do_xfer(ph, t);
201 		if (ret)
202 			break;
203 
204 		loop_num_ret = le32_to_cpu(*num_ret);
205 		if (!loop_num_ret)
206 			break;
207 
208 		if (loop_num_ret > rev->num_protocols - tot_num_ret) {
209 			dev_err(dev,
210 				"No. Returned protocols > Total protocols.\n");
211 			break;
212 		}
213 
214 		if (t->rx.len < (sizeof(u32) * 2)) {
215 			dev_err(dev, "Truncated reply - rx.len:%zd\n",
216 				t->rx.len);
217 			ret = -EPROTO;
218 			break;
219 		}
220 
221 		real_list_sz = t->rx.len - sizeof(u32);
222 		calc_list_sz = (1 + (loop_num_ret - 1) / sizeof(u32)) *
223 				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 	u32 version;
379 	char name[SCMI_SHORT_NAME_MAX_SIZE];
380 	struct device *dev = ph->dev;
381 	struct scmi_revision_info *rev = scmi_revision_area_get(ph);
382 
383 	ret = ph->xops->version_get(ph, &version);
384 	if (ret)
385 		return ret;
386 
387 	rev->major_ver = PROTOCOL_REV_MAJOR(version);
388 	rev->minor_ver = PROTOCOL_REV_MINOR(version);
389 	ph->set_priv(ph, rev, version);
390 
391 	ret = scmi_base_attributes_get(ph);
392 	if (ret)
393 		return ret;
394 
395 	prot_imp = devm_kcalloc(dev, rev->num_protocols, sizeof(u8),
396 				GFP_KERNEL);
397 	if (!prot_imp)
398 		return -ENOMEM;
399 
400 	scmi_base_vendor_id_get(ph, false);
401 	scmi_base_vendor_id_get(ph, true);
402 	scmi_base_implementation_version_get(ph);
403 	scmi_base_implementation_list_get(ph, prot_imp);
404 
405 	scmi_setup_protocol_implemented(ph, prot_imp);
406 
407 	dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
408 		 rev->major_ver, rev->minor_ver, rev->vendor_id,
409 		 rev->sub_vendor_id, rev->impl_ver);
410 	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
411 		rev->num_agents);
412 
413 	for (id = 0; id < rev->num_agents; id++) {
414 		scmi_base_discover_agent_get(ph, id, name);
415 		dev_dbg(dev, "Agent %d: %s\n", id, name);
416 	}
417 
418 	return 0;
419 }
420 
421 static const struct scmi_protocol scmi_base = {
422 	.id = SCMI_PROTOCOL_BASE,
423 	.owner = NULL,
424 	.instance_init = &scmi_base_protocol_init,
425 	.ops = NULL,
426 	.events = &base_protocol_events,
427 	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
428 };
429 
430 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(base, scmi_base)
431