xref: /linux/drivers/firmware/arm_scmi/base.c (revision a1a9b71ebd6582c94090ee5b70fb3eabf7088f22)
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 	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_err(dev,
225 				"Malformed reply - real_sz:%zd  calc_sz:%u\n",
226 				real_list_sz, calc_list_sz);
227 			ret = -EPROTO;
228 			break;
229 		}
230 
231 		for (loop = 0; loop < loop_num_ret; loop++)
232 			protocols_imp[tot_num_ret + loop] = *(list + loop);
233 
234 		tot_num_ret += loop_num_ret;
235 
236 		ph->xops->reset_rx_to_maxsz(ph, t);
237 	} while (tot_num_ret < rev->num_protocols);
238 
239 	ph->xops->xfer_put(ph, t);
240 
241 	return ret;
242 }
243 
244 /**
245  * scmi_base_discover_agent_get() - discover the name of an agent
246  *
247  * @ph: SCMI protocol handle
248  * @id: Agent identifier
249  * @name: Agent identifier ASCII string
250  *
251  * An agent id of 0 is reserved to identify the platform itself.
252  * Generally operating system is represented as "OSPM"
253  *
254  * Return: 0 on success, else appropriate SCMI error.
255  */
256 static int scmi_base_discover_agent_get(const struct scmi_protocol_handle *ph,
257 					int id, char *name)
258 {
259 	int ret;
260 	struct scmi_msg_resp_base_discover_agent *agent_info;
261 	struct scmi_xfer *t;
262 
263 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_AGENT,
264 				      sizeof(__le32), sizeof(*agent_info), &t);
265 	if (ret)
266 		return ret;
267 
268 	put_unaligned_le32(id, t->tx.buf);
269 
270 	ret = ph->xops->do_xfer(ph, t);
271 	if (!ret) {
272 		agent_info = t->rx.buf;
273 		strlcpy(name, agent_info->name, SCMI_MAX_STR_SIZE);
274 	}
275 
276 	ph->xops->xfer_put(ph, t);
277 
278 	return ret;
279 }
280 
281 static int scmi_base_error_notify(const struct scmi_protocol_handle *ph,
282 				  bool enable)
283 {
284 	int ret;
285 	u32 evt_cntl = enable ? BASE_TP_NOTIFY_ALL : 0;
286 	struct scmi_xfer *t;
287 	struct scmi_msg_base_error_notify *cfg;
288 
289 	ret = ph->xops->xfer_get_init(ph, BASE_NOTIFY_ERRORS,
290 				      sizeof(*cfg), 0, &t);
291 	if (ret)
292 		return ret;
293 
294 	cfg = t->tx.buf;
295 	cfg->event_control = cpu_to_le32(evt_cntl);
296 
297 	ret = ph->xops->do_xfer(ph, t);
298 
299 	ph->xops->xfer_put(ph, t);
300 	return ret;
301 }
302 
303 static int scmi_base_set_notify_enabled(const struct scmi_protocol_handle *ph,
304 					u8 evt_id, u32 src_id, bool enable)
305 {
306 	int ret;
307 
308 	ret = scmi_base_error_notify(ph, enable);
309 	if (ret)
310 		pr_debug("FAIL_ENABLED - evt[%X] ret:%d\n", evt_id, ret);
311 
312 	return ret;
313 }
314 
315 static void *scmi_base_fill_custom_report(const struct scmi_protocol_handle *ph,
316 					  u8 evt_id, ktime_t timestamp,
317 					  const void *payld, size_t payld_sz,
318 					  void *report, u32 *src_id)
319 {
320 	int i;
321 	const struct scmi_base_error_notify_payld *p = payld;
322 	struct scmi_base_error_report *r = report;
323 
324 	/*
325 	 * BaseError notification payload is variable in size but
326 	 * up to a maximum length determined by the struct ponted by p.
327 	 * Instead payld_sz is the effective length of this notification
328 	 * payload so cannot be greater of the maximum allowed size as
329 	 * pointed by p.
330 	 */
331 	if (evt_id != SCMI_EVENT_BASE_ERROR_EVENT || sizeof(*p) < payld_sz)
332 		return NULL;
333 
334 	r->timestamp = timestamp;
335 	r->agent_id = le32_to_cpu(p->agent_id);
336 	r->fatal = IS_FATAL_ERROR(le32_to_cpu(p->error_status));
337 	r->cmd_count = ERROR_CMD_COUNT(le32_to_cpu(p->error_status));
338 	for (i = 0; i < r->cmd_count; i++)
339 		r->reports[i] = le64_to_cpu(p->msg_reports[i]);
340 	*src_id = 0;
341 
342 	return r;
343 }
344 
345 static const struct scmi_event base_events[] = {
346 	{
347 		.id = SCMI_EVENT_BASE_ERROR_EVENT,
348 		.max_payld_sz = sizeof(struct scmi_base_error_notify_payld),
349 		.max_report_sz = sizeof(struct scmi_base_error_report) +
350 				  SCMI_BASE_MAX_CMD_ERR_COUNT * sizeof(u64),
351 	},
352 };
353 
354 static const struct scmi_event_ops base_event_ops = {
355 	.set_notify_enabled = scmi_base_set_notify_enabled,
356 	.fill_custom_report = scmi_base_fill_custom_report,
357 };
358 
359 static const struct scmi_protocol_events base_protocol_events = {
360 	.queue_sz = 4 * SCMI_PROTO_QUEUE_SZ,
361 	.ops = &base_event_ops,
362 	.evts = base_events,
363 	.num_events = ARRAY_SIZE(base_events),
364 	.num_sources = SCMI_BASE_NUM_SOURCES,
365 };
366 
367 static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
368 {
369 	int id, ret;
370 	u8 *prot_imp;
371 	u32 version;
372 	char name[SCMI_MAX_STR_SIZE];
373 	struct device *dev = ph->dev;
374 	struct scmi_revision_info *rev = scmi_revision_area_get(ph);
375 
376 	ret = ph->xops->version_get(ph, &version);
377 	if (ret)
378 		return ret;
379 
380 	rev->major_ver = PROTOCOL_REV_MAJOR(version),
381 	rev->minor_ver = PROTOCOL_REV_MINOR(version);
382 	ph->set_priv(ph, rev);
383 
384 	ret = scmi_base_attributes_get(ph);
385 	if (ret)
386 		return ret;
387 
388 	prot_imp = devm_kcalloc(dev, rev->num_protocols, sizeof(u8),
389 				GFP_KERNEL);
390 	if (!prot_imp)
391 		return -ENOMEM;
392 
393 	scmi_base_vendor_id_get(ph, false);
394 	scmi_base_vendor_id_get(ph, true);
395 	scmi_base_implementation_version_get(ph);
396 	scmi_base_implementation_list_get(ph, prot_imp);
397 
398 	scmi_setup_protocol_implemented(ph, prot_imp);
399 
400 	dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
401 		 rev->major_ver, rev->minor_ver, rev->vendor_id,
402 		 rev->sub_vendor_id, rev->impl_ver);
403 	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
404 		rev->num_agents);
405 
406 	for (id = 0; id < rev->num_agents; id++) {
407 		scmi_base_discover_agent_get(ph, id, name);
408 		dev_dbg(dev, "Agent %d: %s\n", id, name);
409 	}
410 
411 	return 0;
412 }
413 
414 static const struct scmi_protocol scmi_base = {
415 	.id = SCMI_PROTOCOL_BASE,
416 	.owner = NULL,
417 	.instance_init = &scmi_base_protocol_init,
418 	.ops = NULL,
419 	.events = &base_protocol_events,
420 };
421 
422 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(base, scmi_base)
423