xref: /openbmc/linux/drivers/firmware/arm_scmi/base.c (revision 3d37ef41)
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_base_error_notify {
38 	__le32 event_control;
39 #define BASE_TP_NOTIFY_ALL	BIT(0)
40 };
41 
42 struct scmi_base_error_notify_payld {
43 	__le32 agent_id;
44 	__le32 error_status;
45 #define IS_FATAL_ERROR(x)	((x) & BIT(31))
46 #define ERROR_CMD_COUNT(x)	FIELD_GET(GENMASK(9, 0), (x))
47 	__le64 msg_reports[SCMI_BASE_MAX_CMD_ERR_COUNT];
48 };
49 
50 /**
51  * scmi_base_attributes_get() - gets the implementation details
52  *	that are associated with the base protocol.
53  *
54  * @ph: SCMI protocol handle
55  *
56  * Return: 0 on success, else appropriate SCMI error.
57  */
58 static int scmi_base_attributes_get(const struct scmi_protocol_handle *ph)
59 {
60 	int ret;
61 	struct scmi_xfer *t;
62 	struct scmi_msg_resp_base_attributes *attr_info;
63 	struct scmi_revision_info *rev = ph->get_priv(ph);
64 
65 	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
66 				      0, sizeof(*attr_info), &t);
67 	if (ret)
68 		return ret;
69 
70 	ret = ph->xops->do_xfer(ph, t);
71 	if (!ret) {
72 		attr_info = t->rx.buf;
73 		rev->num_protocols = attr_info->num_protocols;
74 		rev->num_agents = attr_info->num_agents;
75 	}
76 
77 	ph->xops->xfer_put(ph, t);
78 
79 	return ret;
80 }
81 
82 /**
83  * scmi_base_vendor_id_get() - gets vendor/subvendor identifier ASCII string.
84  *
85  * @ph: SCMI protocol handle
86  * @sub_vendor: specify true if sub-vendor ID is needed
87  *
88  * Return: 0 on success, else appropriate SCMI error.
89  */
90 static int
91 scmi_base_vendor_id_get(const struct scmi_protocol_handle *ph, bool sub_vendor)
92 {
93 	u8 cmd;
94 	int ret, size;
95 	char *vendor_id;
96 	struct scmi_xfer *t;
97 	struct scmi_revision_info *rev = ph->get_priv(ph);
98 
99 
100 	if (sub_vendor) {
101 		cmd = BASE_DISCOVER_SUB_VENDOR;
102 		vendor_id = rev->sub_vendor_id;
103 		size = ARRAY_SIZE(rev->sub_vendor_id);
104 	} else {
105 		cmd = BASE_DISCOVER_VENDOR;
106 		vendor_id = rev->vendor_id;
107 		size = ARRAY_SIZE(rev->vendor_id);
108 	}
109 
110 	ret = ph->xops->xfer_get_init(ph, cmd, 0, size, &t);
111 	if (ret)
112 		return ret;
113 
114 	ret = ph->xops->do_xfer(ph, t);
115 	if (!ret)
116 		memcpy(vendor_id, t->rx.buf, size);
117 
118 	ph->xops->xfer_put(ph, t);
119 
120 	return ret;
121 }
122 
123 /**
124  * scmi_base_implementation_version_get() - gets a vendor-specific
125  *	implementation 32-bit version. The format of the version number is
126  *	vendor-specific
127  *
128  * @ph: SCMI protocol handle
129  *
130  * Return: 0 on success, else appropriate SCMI error.
131  */
132 static int
133 scmi_base_implementation_version_get(const struct scmi_protocol_handle *ph)
134 {
135 	int ret;
136 	__le32 *impl_ver;
137 	struct scmi_xfer *t;
138 	struct scmi_revision_info *rev = ph->get_priv(ph);
139 
140 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_IMPLEMENT_VERSION,
141 				      0, sizeof(*impl_ver), &t);
142 	if (ret)
143 		return ret;
144 
145 	ret = ph->xops->do_xfer(ph, t);
146 	if (!ret) {
147 		impl_ver = t->rx.buf;
148 		rev->impl_ver = le32_to_cpu(*impl_ver);
149 	}
150 
151 	ph->xops->xfer_put(ph, t);
152 
153 	return ret;
154 }
155 
156 /**
157  * scmi_base_implementation_list_get() - gets the list of protocols it is
158  *	OSPM is allowed to access
159  *
160  * @ph: SCMI protocol handle
161  * @protocols_imp: pointer to hold the list of protocol identifiers
162  *
163  * Return: 0 on success, else appropriate SCMI error.
164  */
165 static int
166 scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph,
167 				  u8 *protocols_imp)
168 {
169 	u8 *list;
170 	int ret, loop;
171 	struct scmi_xfer *t;
172 	__le32 *num_skip, *num_ret;
173 	u32 tot_num_ret = 0, loop_num_ret;
174 	struct device *dev = ph->dev;
175 
176 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_LIST_PROTOCOLS,
177 				      sizeof(*num_skip), 0, &t);
178 	if (ret)
179 		return ret;
180 
181 	num_skip = t->tx.buf;
182 	num_ret = t->rx.buf;
183 	list = t->rx.buf + sizeof(*num_ret);
184 
185 	do {
186 		/* Set the number of protocols to be skipped/already read */
187 		*num_skip = cpu_to_le32(tot_num_ret);
188 
189 		ret = ph->xops->do_xfer(ph, t);
190 		if (ret)
191 			break;
192 
193 		loop_num_ret = le32_to_cpu(*num_ret);
194 		if (tot_num_ret + loop_num_ret > MAX_PROTOCOLS_IMP) {
195 			dev_err(dev, "No. of Protocol > MAX_PROTOCOLS_IMP");
196 			break;
197 		}
198 
199 		for (loop = 0; loop < loop_num_ret; loop++)
200 			protocols_imp[tot_num_ret + loop] = *(list + loop);
201 
202 		tot_num_ret += loop_num_ret;
203 
204 		ph->xops->reset_rx_to_maxsz(ph, t);
205 	} while (loop_num_ret);
206 
207 	ph->xops->xfer_put(ph, t);
208 
209 	return ret;
210 }
211 
212 /**
213  * scmi_base_discover_agent_get() - discover the name of an agent
214  *
215  * @ph: SCMI protocol handle
216  * @id: Agent identifier
217  * @name: Agent identifier ASCII string
218  *
219  * An agent id of 0 is reserved to identify the platform itself.
220  * Generally operating system is represented as "OSPM"
221  *
222  * Return: 0 on success, else appropriate SCMI error.
223  */
224 static int scmi_base_discover_agent_get(const struct scmi_protocol_handle *ph,
225 					int id, char *name)
226 {
227 	int ret;
228 	struct scmi_xfer *t;
229 
230 	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_AGENT,
231 				      sizeof(__le32), SCMI_MAX_STR_SIZE, &t);
232 	if (ret)
233 		return ret;
234 
235 	put_unaligned_le32(id, t->tx.buf);
236 
237 	ret = ph->xops->do_xfer(ph, t);
238 	if (!ret)
239 		strlcpy(name, t->rx.buf, SCMI_MAX_STR_SIZE);
240 
241 	ph->xops->xfer_put(ph, t);
242 
243 	return ret;
244 }
245 
246 static int scmi_base_error_notify(const struct scmi_protocol_handle *ph,
247 				  bool enable)
248 {
249 	int ret;
250 	u32 evt_cntl = enable ? BASE_TP_NOTIFY_ALL : 0;
251 	struct scmi_xfer *t;
252 	struct scmi_msg_base_error_notify *cfg;
253 
254 	ret = ph->xops->xfer_get_init(ph, BASE_NOTIFY_ERRORS,
255 				      sizeof(*cfg), 0, &t);
256 	if (ret)
257 		return ret;
258 
259 	cfg = t->tx.buf;
260 	cfg->event_control = cpu_to_le32(evt_cntl);
261 
262 	ret = ph->xops->do_xfer(ph, t);
263 
264 	ph->xops->xfer_put(ph, t);
265 	return ret;
266 }
267 
268 static int scmi_base_set_notify_enabled(const struct scmi_protocol_handle *ph,
269 					u8 evt_id, u32 src_id, bool enable)
270 {
271 	int ret;
272 
273 	ret = scmi_base_error_notify(ph, enable);
274 	if (ret)
275 		pr_debug("FAIL_ENABLED - evt[%X] ret:%d\n", evt_id, ret);
276 
277 	return ret;
278 }
279 
280 static void *scmi_base_fill_custom_report(const struct scmi_protocol_handle *ph,
281 					  u8 evt_id, ktime_t timestamp,
282 					  const void *payld, size_t payld_sz,
283 					  void *report, u32 *src_id)
284 {
285 	int i;
286 	const struct scmi_base_error_notify_payld *p = payld;
287 	struct scmi_base_error_report *r = report;
288 
289 	/*
290 	 * BaseError notification payload is variable in size but
291 	 * up to a maximum length determined by the struct ponted by p.
292 	 * Instead payld_sz is the effective length of this notification
293 	 * payload so cannot be greater of the maximum allowed size as
294 	 * pointed by p.
295 	 */
296 	if (evt_id != SCMI_EVENT_BASE_ERROR_EVENT || sizeof(*p) < payld_sz)
297 		return NULL;
298 
299 	r->timestamp = timestamp;
300 	r->agent_id = le32_to_cpu(p->agent_id);
301 	r->fatal = IS_FATAL_ERROR(le32_to_cpu(p->error_status));
302 	r->cmd_count = ERROR_CMD_COUNT(le32_to_cpu(p->error_status));
303 	for (i = 0; i < r->cmd_count; i++)
304 		r->reports[i] = le64_to_cpu(p->msg_reports[i]);
305 	*src_id = 0;
306 
307 	return r;
308 }
309 
310 static const struct scmi_event base_events[] = {
311 	{
312 		.id = SCMI_EVENT_BASE_ERROR_EVENT,
313 		.max_payld_sz = sizeof(struct scmi_base_error_notify_payld),
314 		.max_report_sz = sizeof(struct scmi_base_error_report) +
315 				  SCMI_BASE_MAX_CMD_ERR_COUNT * sizeof(u64),
316 	},
317 };
318 
319 static const struct scmi_event_ops base_event_ops = {
320 	.set_notify_enabled = scmi_base_set_notify_enabled,
321 	.fill_custom_report = scmi_base_fill_custom_report,
322 };
323 
324 static const struct scmi_protocol_events base_protocol_events = {
325 	.queue_sz = 4 * SCMI_PROTO_QUEUE_SZ,
326 	.ops = &base_event_ops,
327 	.evts = base_events,
328 	.num_events = ARRAY_SIZE(base_events),
329 	.num_sources = SCMI_BASE_NUM_SOURCES,
330 };
331 
332 static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
333 {
334 	int id, ret;
335 	u8 *prot_imp;
336 	u32 version;
337 	char name[SCMI_MAX_STR_SIZE];
338 	struct device *dev = ph->dev;
339 	struct scmi_revision_info *rev = scmi_revision_area_get(ph);
340 
341 	ret = ph->xops->version_get(ph, &version);
342 	if (ret)
343 		return ret;
344 
345 	prot_imp = devm_kcalloc(dev, MAX_PROTOCOLS_IMP, sizeof(u8), GFP_KERNEL);
346 	if (!prot_imp)
347 		return -ENOMEM;
348 
349 	rev->major_ver = PROTOCOL_REV_MAJOR(version),
350 	rev->minor_ver = PROTOCOL_REV_MINOR(version);
351 	ph->set_priv(ph, rev);
352 
353 	scmi_base_attributes_get(ph);
354 	scmi_base_vendor_id_get(ph, false);
355 	scmi_base_vendor_id_get(ph, true);
356 	scmi_base_implementation_version_get(ph);
357 	scmi_base_implementation_list_get(ph, prot_imp);
358 
359 	scmi_setup_protocol_implemented(ph, prot_imp);
360 
361 	dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
362 		 rev->major_ver, rev->minor_ver, rev->vendor_id,
363 		 rev->sub_vendor_id, rev->impl_ver);
364 	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
365 		rev->num_agents);
366 
367 	for (id = 0; id < rev->num_agents; id++) {
368 		scmi_base_discover_agent_get(ph, id, name);
369 		dev_dbg(dev, "Agent %d: %s\n", id, name);
370 	}
371 
372 	return 0;
373 }
374 
375 static const struct scmi_protocol scmi_base = {
376 	.id = SCMI_PROTOCOL_BASE,
377 	.owner = NULL,
378 	.instance_init = &scmi_base_protocol_init,
379 	.ops = NULL,
380 	.events = &base_protocol_events,
381 };
382 
383 DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(base, scmi_base)
384