xref: /linux/drivers/firmware/arm_scmi/base.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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		0x20000
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 
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 
109 	if (sub_vendor) {
110 		cmd = BASE_DISCOVER_SUB_VENDOR;
111 		vendor_id = rev->sub_vendor_id;
112 		size = ARRAY_SIZE(rev->sub_vendor_id);
113 	} else {
114 		cmd = BASE_DISCOVER_VENDOR;
115 		vendor_id = rev->vendor_id;
116 		size = ARRAY_SIZE(rev->vendor_id);
117 	}
118 
119 	ret = ph->xops->xfer_get_init(ph, cmd, 0, size, &t);
120 	if (ret)
121 		return ret;
122 
123 	ret = ph->xops->do_xfer(ph, t);
124 	if (!ret)
125 		strscpy(vendor_id, t->rx.buf, size);
126 
127 	ph->xops->xfer_put(ph, t);
128 
129 	return ret;
130 }
131 
132 /**
133  * scmi_base_implementation_version_get() - gets a vendor-specific
134  *	implementation 32-bit version. The format of the version number is
135  *	vendor-specific
136  *
137  * @ph: SCMI protocol handle
138  *
139  * Return: 0 on success, else appropriate SCMI error.
140  */
141 static int
142 scmi_base_implementation_version_get(const struct scmi_protocol_handle *ph)
143 {
144 	int ret;
145 	__le32 *impl_ver;
146 	struct scmi_xfer *t;
147 	struct scmi_revision_info *rev = ph->get_priv(ph);
148 
149 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_IMPLEMENT_VERSION,
150 				      0, sizeof(*impl_ver), &t);
151 	if (ret)
152 		return ret;
153 
154 	ret = ph->xops->do_xfer(ph, t);
155 	if (!ret) {
156 		impl_ver = t->rx.buf;
157 		rev->impl_ver = le32_to_cpu(*impl_ver);
158 	}
159 
160 	ph->xops->xfer_put(ph, t);
161 
162 	return ret;
163 }
164 
165 /**
166  * scmi_base_implementation_list_get() - gets the list of protocols it is
167  *	OSPM is allowed to access
168  *
169  * @ph: SCMI protocol handle
170  * @protocols_imp: pointer to hold the list of protocol identifiers
171  *
172  * Return: 0 on success, else appropriate SCMI error.
173  */
174 static int
175 scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph,
176 				  u8 *protocols_imp)
177 {
178 	u8 *list;
179 	int ret, loop;
180 	struct scmi_xfer *t;
181 	__le32 *num_skip, *num_ret;
182 	u32 tot_num_ret = 0, loop_num_ret;
183 	struct device *dev = ph->dev;
184 	struct scmi_revision_info *rev = ph->get_priv(ph);
185 
186 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_LIST_PROTOCOLS,
187 				      sizeof(*num_skip), 0, &t);
188 	if (ret)
189 		return ret;
190 
191 	num_skip = t->tx.buf;
192 	num_ret = t->rx.buf;
193 	list = t->rx.buf + sizeof(*num_ret);
194 
195 	do {
196 		size_t real_list_sz;
197 		u32 calc_list_sz;
198 
199 		/* Set the number of protocols to be skipped/already read */
200 		*num_skip = cpu_to_le32(tot_num_ret);
201 
202 		ret = ph->xops->do_xfer(ph, t);
203 		if (ret)
204 			break;
205 
206 		loop_num_ret = le32_to_cpu(*num_ret);
207 		if (!loop_num_ret)
208 			break;
209 
210 		if (loop_num_ret > rev->num_protocols - tot_num_ret) {
211 			dev_err(dev,
212 				"No. Returned protocols > Total protocols.\n");
213 			break;
214 		}
215 
216 		if (t->rx.len < (sizeof(u32) * 2)) {
217 			dev_err(dev, "Truncated reply - rx.len:%zd\n",
218 				t->rx.len);
219 			ret = -EPROTO;
220 			break;
221 		}
222 
223 		real_list_sz = t->rx.len - sizeof(u32);
224 		calc_list_sz = (1 + (loop_num_ret - 1) / sizeof(u32)) *
225 				sizeof(u32);
226 		if (calc_list_sz != real_list_sz) {
227 			dev_warn(dev,
228 				 "Malformed reply - real_sz:%zd  calc_sz:%u  (loop_num_ret:%d)\n",
229 				 real_list_sz, calc_list_sz, loop_num_ret);
230 			/*
231 			 * Bail out if the expected list size is bigger than the
232 			 * total payload size of the received reply.
233 			 */
234 			if (calc_list_sz > real_list_sz) {
235 				ret = -EPROTO;
236 				break;
237 			}
238 		}
239 
240 		for (loop = 0; loop < loop_num_ret; loop++)
241 			protocols_imp[tot_num_ret + loop] = *(list + loop);
242 
243 		tot_num_ret += loop_num_ret;
244 
245 		ph->xops->reset_rx_to_maxsz(ph, t);
246 	} while (tot_num_ret < rev->num_protocols);
247 
248 	ph->xops->xfer_put(ph, t);
249 
250 	return ret;
251 }
252 
253 /**
254  * scmi_base_discover_agent_get() - discover the name of an agent
255  *
256  * @ph: SCMI protocol handle
257  * @id: Agent identifier
258  * @name: Agent identifier ASCII string
259  *
260  * An agent id of 0 is reserved to identify the platform itself.
261  * Generally operating system is represented as "OSPM"
262  *
263  * Return: 0 on success, else appropriate SCMI error.
264  */
265 static int scmi_base_discover_agent_get(const struct scmi_protocol_handle *ph,
266 					int id, char *name)
267 {
268 	int ret;
269 	struct scmi_msg_resp_base_discover_agent *agent_info;
270 	struct scmi_xfer *t;
271 
272 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_AGENT,
273 				      sizeof(__le32), sizeof(*agent_info), &t);
274 	if (ret)
275 		return ret;
276 
277 	put_unaligned_le32(id, t->tx.buf);
278 
279 	ret = ph->xops->do_xfer(ph, t);
280 	if (!ret) {
281 		agent_info = t->rx.buf;
282 		strscpy(name, agent_info->name, SCMI_SHORT_NAME_MAX_SIZE);
283 	}
284 
285 	ph->xops->xfer_put(ph, t);
286 
287 	return ret;
288 }
289 
290 static int scmi_base_error_notify(const struct scmi_protocol_handle *ph,
291 				  bool enable)
292 {
293 	int ret;
294 	u32 evt_cntl = enable ? BASE_TP_NOTIFY_ALL : 0;
295 	struct scmi_xfer *t;
296 	struct scmi_msg_base_error_notify *cfg;
297 
298 	ret = ph->xops->xfer_get_init(ph, BASE_NOTIFY_ERRORS,
299 				      sizeof(*cfg), 0, &t);
300 	if (ret)
301 		return ret;
302 
303 	cfg = t->tx.buf;
304 	cfg->event_control = cpu_to_le32(evt_cntl);
305 
306 	ret = ph->xops->do_xfer(ph, t);
307 
308 	ph->xops->xfer_put(ph, t);
309 	return ret;
310 }
311 
312 static int scmi_base_set_notify_enabled(const struct scmi_protocol_handle *ph,
313 					u8 evt_id, u32 src_id, bool enable)
314 {
315 	int ret;
316 
317 	ret = scmi_base_error_notify(ph, enable);
318 	if (ret)
319 		pr_debug("FAIL_ENABLED - evt[%X] ret:%d\n", evt_id, ret);
320 
321 	return ret;
322 }
323 
324 static void *scmi_base_fill_custom_report(const struct scmi_protocol_handle *ph,
325 					  u8 evt_id, ktime_t timestamp,
326 					  const void *payld, size_t payld_sz,
327 					  void *report, u32 *src_id)
328 {
329 	int i;
330 	const struct scmi_base_error_notify_payld *p = payld;
331 	struct scmi_base_error_report *r = report;
332 
333 	/*
334 	 * BaseError notification payload is variable in size but
335 	 * up to a maximum length determined by the struct ponted by p.
336 	 * Instead payld_sz is the effective length of this notification
337 	 * payload so cannot be greater of the maximum allowed size as
338 	 * pointed by p.
339 	 */
340 	if (evt_id != SCMI_EVENT_BASE_ERROR_EVENT || sizeof(*p) < payld_sz)
341 		return NULL;
342 
343 	r->timestamp = timestamp;
344 	r->agent_id = le32_to_cpu(p->agent_id);
345 	r->fatal = IS_FATAL_ERROR(le32_to_cpu(p->error_status));
346 	r->cmd_count = ERROR_CMD_COUNT(le32_to_cpu(p->error_status));
347 	for (i = 0; i < r->cmd_count; i++)
348 		r->reports[i] = le64_to_cpu(p->msg_reports[i]);
349 	*src_id = 0;
350 
351 	return r;
352 }
353 
354 static const struct scmi_event base_events[] = {
355 	{
356 		.id = SCMI_EVENT_BASE_ERROR_EVENT,
357 		.max_payld_sz = sizeof(struct scmi_base_error_notify_payld),
358 		.max_report_sz = sizeof(struct scmi_base_error_report) +
359 				  SCMI_BASE_MAX_CMD_ERR_COUNT * sizeof(u64),
360 	},
361 };
362 
363 static const struct scmi_event_ops base_event_ops = {
364 	.set_notify_enabled = scmi_base_set_notify_enabled,
365 	.fill_custom_report = scmi_base_fill_custom_report,
366 };
367 
368 static const struct scmi_protocol_events base_protocol_events = {
369 	.queue_sz = 4 * SCMI_PROTO_QUEUE_SZ,
370 	.ops = &base_event_ops,
371 	.evts = base_events,
372 	.num_events = ARRAY_SIZE(base_events),
373 	.num_sources = SCMI_BASE_NUM_SOURCES,
374 };
375 
376 static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
377 {
378 	int id, ret;
379 	u8 *prot_imp;
380 	u32 version;
381 	char name[SCMI_SHORT_NAME_MAX_SIZE];
382 	struct device *dev = ph->dev;
383 	struct scmi_revision_info *rev = scmi_revision_area_get(ph);
384 
385 	ret = ph->xops->version_get(ph, &version);
386 	if (ret)
387 		return ret;
388 
389 	rev->major_ver = PROTOCOL_REV_MAJOR(version),
390 	rev->minor_ver = PROTOCOL_REV_MINOR(version);
391 	ph->set_priv(ph, rev, version);
392 
393 	ret = scmi_base_attributes_get(ph);
394 	if (ret)
395 		return ret;
396 
397 	prot_imp = devm_kcalloc(dev, rev->num_protocols, sizeof(u8),
398 				GFP_KERNEL);
399 	if (!prot_imp)
400 		return -ENOMEM;
401 
402 	scmi_base_vendor_id_get(ph, false);
403 	scmi_base_vendor_id_get(ph, true);
404 	scmi_base_implementation_version_get(ph);
405 	scmi_base_implementation_list_get(ph, prot_imp);
406 
407 	scmi_setup_protocol_implemented(ph, prot_imp);
408 
409 	dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
410 		 rev->major_ver, rev->minor_ver, rev->vendor_id,
411 		 rev->sub_vendor_id, rev->impl_ver);
412 	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
413 		rev->num_agents);
414 
415 	for (id = 0; id < rev->num_agents; id++) {
416 		scmi_base_discover_agent_get(ph, id, name);
417 		dev_dbg(dev, "Agent %d: %s\n", id, name);
418 	}
419 
420 	return 0;
421 }
422 
423 static const struct scmi_protocol scmi_base = {
424 	.id = SCMI_PROTOCOL_BASE,
425 	.owner = NULL,
426 	.instance_init = &scmi_base_protocol_init,
427 	.ops = NULL,
428 	.events = &base_protocol_events,
429 	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
430 };
431 
432 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(base, scmi_base)
433