xref: /openbmc/linux/drivers/soc/qcom/cmd-db.c (revision ef80520b)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (c) 2016-2018, 2020, The Linux Foundation. All rights reserved.
4  * Copyright (c) 2024, Qualcomm Innovation Center, Inc. All rights reserved.
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/debugfs.h>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/of_address.h>
13 #include <linux/of_reserved_mem.h>
14 #include <linux/platform_device.h>
15 #include <linux/seq_file.h>
16 #include <linux/types.h>
17 
18 #include <soc/qcom/cmd-db.h>
19 
20 #define NUM_PRIORITY		2
21 #define MAX_SLV_ID		8
22 #define SLAVE_ID_MASK		0x7
23 #define SLAVE_ID_SHIFT		16
24 #define SLAVE_ID(addr)		FIELD_GET(GENMASK(19, 16), addr)
25 #define VRM_ADDR(addr)		FIELD_GET(GENMASK(19, 4), addr)
26 
27 /**
28  * struct entry_header: header for each entry in cmddb
29  *
30  * @id: resource's identifier
31  * @priority: unused
32  * @addr: the address of the resource
33  * @len: length of the data
34  * @offset: offset from :@data_offset, start of the data
35  */
36 struct entry_header {
37 	u8 id[8];
38 	__le32 priority[NUM_PRIORITY];
39 	__le32 addr;
40 	__le16 len;
41 	__le16 offset;
42 };
43 
44 /**
45  * struct rsc_hdr: resource header information
46  *
47  * @slv_id: id for the resource
48  * @header_offset: entry's header at offset from the end of the cmd_db_header
49  * @data_offset: entry's data at offset from the end of the cmd_db_header
50  * @cnt: number of entries for HW type
51  * @version: MSB is major, LSB is minor
52  * @reserved: reserved for future use.
53  */
54 struct rsc_hdr {
55 	__le16 slv_id;
56 	__le16 header_offset;
57 	__le16 data_offset;
58 	__le16 cnt;
59 	__le16 version;
60 	__le16 reserved[3];
61 };
62 
63 /**
64  * struct cmd_db_header: The DB header information
65  *
66  * @version: The cmd db version
67  * @magic: constant expected in the database
68  * @header: array of resources
69  * @checksum: checksum for the header. Unused.
70  * @reserved: reserved memory
71  * @data: driver specific data
72  */
73 struct cmd_db_header {
74 	__le32 version;
75 	u8 magic[4];
76 	struct rsc_hdr header[MAX_SLV_ID];
77 	__le32 checksum;
78 	__le32 reserved;
79 	u8 data[];
80 };
81 
82 /**
83  * DOC: Description of the Command DB database.
84  *
85  * At the start of the command DB memory is the cmd_db_header structure.
86  * The cmd_db_header holds the version, checksum, magic key as well as an
87  * array for header for each slave (depicted by the rsc_header). Each h/w
88  * based accelerator is a 'slave' (shared resource) and has slave id indicating
89  * the type of accelerator. The rsc_header is the header for such individual
90  * slaves of a given type. The entries for each of these slaves begin at the
91  * rsc_hdr.header_offset. In addition each slave could have auxiliary data
92  * that may be needed by the driver. The data for the slave starts at the
93  * entry_header.offset to the location pointed to by the rsc_hdr.data_offset.
94  *
95  * Drivers have a stringified key to a slave/resource. They can query the slave
96  * information and get the slave id and the auxiliary data and the length of the
97  * data. Using this information, they can format the request to be sent to the
98  * h/w accelerator and request a resource state.
99  */
100 
101 static const u8 CMD_DB_MAGIC[] = { 0xdb, 0x30, 0x03, 0x0c };
102 
cmd_db_magic_matches(const struct cmd_db_header * header)103 static bool cmd_db_magic_matches(const struct cmd_db_header *header)
104 {
105 	const u8 *magic = header->magic;
106 
107 	return memcmp(magic, CMD_DB_MAGIC, ARRAY_SIZE(CMD_DB_MAGIC)) == 0;
108 }
109 
110 static struct cmd_db_header *cmd_db_header;
111 
rsc_to_entry_header(const struct rsc_hdr * hdr)112 static inline const void *rsc_to_entry_header(const struct rsc_hdr *hdr)
113 {
114 	u16 offset = le16_to_cpu(hdr->header_offset);
115 
116 	return cmd_db_header->data + offset;
117 }
118 
119 static inline void *
rsc_offset(const struct rsc_hdr * hdr,const struct entry_header * ent)120 rsc_offset(const struct rsc_hdr *hdr, const struct entry_header *ent)
121 {
122 	u16 offset = le16_to_cpu(hdr->data_offset);
123 	u16 loffset = le16_to_cpu(ent->offset);
124 
125 	return cmd_db_header->data + offset + loffset;
126 }
127 
128 /**
129  * cmd_db_ready - Indicates if command DB is available
130  *
131  * Return: 0 on success, errno otherwise
132  */
cmd_db_ready(void)133 int cmd_db_ready(void)
134 {
135 	if (cmd_db_header == NULL)
136 		return -EPROBE_DEFER;
137 	else if (!cmd_db_magic_matches(cmd_db_header))
138 		return -EINVAL;
139 
140 	return 0;
141 }
142 EXPORT_SYMBOL(cmd_db_ready);
143 
cmd_db_get_header(const char * id,const struct entry_header ** eh,const struct rsc_hdr ** rh)144 static int cmd_db_get_header(const char *id, const struct entry_header **eh,
145 			     const struct rsc_hdr **rh)
146 {
147 	const struct rsc_hdr *rsc_hdr;
148 	const struct entry_header *ent;
149 	int ret, i, j;
150 	u8 query[sizeof(ent->id)] __nonstring;
151 
152 	ret = cmd_db_ready();
153 	if (ret)
154 		return ret;
155 
156 	/*
157 	 * Pad out query string to same length as in DB. NOTE: the output
158 	 * query string is not necessarily '\0' terminated if it bumps up
159 	 * against the max size. That's OK and expected.
160 	 */
161 	strncpy(query, id, sizeof(query));
162 
163 	for (i = 0; i < MAX_SLV_ID; i++) {
164 		rsc_hdr = &cmd_db_header->header[i];
165 		if (!rsc_hdr->slv_id)
166 			break;
167 
168 		ent = rsc_to_entry_header(rsc_hdr);
169 		for (j = 0; j < le16_to_cpu(rsc_hdr->cnt); j++, ent++) {
170 			if (memcmp(ent->id, query, sizeof(ent->id)) == 0) {
171 				if (eh)
172 					*eh = ent;
173 				if (rh)
174 					*rh = rsc_hdr;
175 				return 0;
176 			}
177 		}
178 	}
179 
180 	return -ENODEV;
181 }
182 
183 /**
184  * cmd_db_read_addr() - Query command db for resource id address.
185  *
186  * @id: resource id to query for address
187  *
188  * Return: resource address on success, 0 on error
189  *
190  * This is used to retrieve resource address based on resource
191  * id.
192  */
cmd_db_read_addr(const char * id)193 u32 cmd_db_read_addr(const char *id)
194 {
195 	int ret;
196 	const struct entry_header *ent;
197 
198 	ret = cmd_db_get_header(id, &ent, NULL);
199 
200 	return ret < 0 ? 0 : le32_to_cpu(ent->addr);
201 }
202 EXPORT_SYMBOL(cmd_db_read_addr);
203 
204 /**
205  * cmd_db_read_aux_data() - Query command db for aux data.
206  *
207  *  @id: Resource to retrieve AUX Data on
208  *  @len: size of data buffer returned
209  *
210  *  Return: pointer to data on success, error pointer otherwise
211  */
cmd_db_read_aux_data(const char * id,size_t * len)212 const void *cmd_db_read_aux_data(const char *id, size_t *len)
213 {
214 	int ret;
215 	const struct entry_header *ent;
216 	const struct rsc_hdr *rsc_hdr;
217 
218 	ret = cmd_db_get_header(id, &ent, &rsc_hdr);
219 	if (ret)
220 		return ERR_PTR(ret);
221 
222 	if (len)
223 		*len = le16_to_cpu(ent->len);
224 
225 	return rsc_offset(rsc_hdr, ent);
226 }
227 EXPORT_SYMBOL(cmd_db_read_aux_data);
228 
229 /**
230  * cmd_db_match_resource_addr() - Compare if both Resource addresses are same
231  *
232  * @addr1: Resource address to compare
233  * @addr2: Resource address to compare
234  *
235  * Return: true if two addresses refer to the same resource, false otherwise
236  */
cmd_db_match_resource_addr(u32 addr1,u32 addr2)237 bool cmd_db_match_resource_addr(u32 addr1, u32 addr2)
238 {
239 	/*
240 	 * Each RPMh VRM accelerator resource has 3 or 4 contiguous 4-byte
241 	 * aligned addresses associated with it. Ignore the offset to check
242 	 * for VRM requests.
243 	 */
244 	if (addr1 == addr2)
245 		return true;
246 	else if (SLAVE_ID(addr1) == CMD_DB_HW_VRM && VRM_ADDR(addr1) == VRM_ADDR(addr2))
247 		return true;
248 
249 	return false;
250 }
251 EXPORT_SYMBOL_GPL(cmd_db_match_resource_addr);
252 
253 /**
254  * cmd_db_read_slave_id - Get the slave ID for a given resource address
255  *
256  * @id: Resource id to query the DB for version
257  *
258  * Return: cmd_db_hw_type enum on success, CMD_DB_HW_INVALID on error
259  */
cmd_db_read_slave_id(const char * id)260 enum cmd_db_hw_type cmd_db_read_slave_id(const char *id)
261 {
262 	int ret;
263 	const struct entry_header *ent;
264 	u32 addr;
265 
266 	ret = cmd_db_get_header(id, &ent, NULL);
267 	if (ret < 0)
268 		return CMD_DB_HW_INVALID;
269 
270 	addr = le32_to_cpu(ent->addr);
271 	return (addr >> SLAVE_ID_SHIFT) & SLAVE_ID_MASK;
272 }
273 EXPORT_SYMBOL(cmd_db_read_slave_id);
274 
275 #ifdef CONFIG_DEBUG_FS
cmd_db_debugfs_dump(struct seq_file * seq,void * p)276 static int cmd_db_debugfs_dump(struct seq_file *seq, void *p)
277 {
278 	int i, j;
279 	const struct rsc_hdr *rsc;
280 	const struct entry_header *ent;
281 	const char *name;
282 	u16 len, version;
283 	u8 major, minor;
284 
285 	seq_puts(seq, "Command DB DUMP\n");
286 
287 	for (i = 0; i < MAX_SLV_ID; i++) {
288 		rsc = &cmd_db_header->header[i];
289 		if (!rsc->slv_id)
290 			break;
291 
292 		switch (le16_to_cpu(rsc->slv_id)) {
293 		case CMD_DB_HW_ARC:
294 			name = "ARC";
295 			break;
296 		case CMD_DB_HW_VRM:
297 			name = "VRM";
298 			break;
299 		case CMD_DB_HW_BCM:
300 			name = "BCM";
301 			break;
302 		default:
303 			name = "Unknown";
304 			break;
305 		}
306 
307 		version = le16_to_cpu(rsc->version);
308 		major = version >> 8;
309 		minor = version;
310 
311 		seq_printf(seq, "Slave %s (v%u.%u)\n", name, major, minor);
312 		seq_puts(seq, "-------------------------\n");
313 
314 		ent = rsc_to_entry_header(rsc);
315 		for (j = 0; j < le16_to_cpu(rsc->cnt); j++, ent++) {
316 			seq_printf(seq, "0x%05x: %*pEp", le32_to_cpu(ent->addr),
317 				   (int)strnlen(ent->id, sizeof(ent->id)), ent->id);
318 
319 			len = le16_to_cpu(ent->len);
320 			if (len) {
321 				seq_printf(seq, " [%*ph]",
322 					   len, rsc_offset(rsc, ent));
323 			}
324 			seq_putc(seq, '\n');
325 		}
326 	}
327 
328 	return 0;
329 }
330 
open_cmd_db_debugfs(struct inode * inode,struct file * file)331 static int open_cmd_db_debugfs(struct inode *inode, struct file *file)
332 {
333 	return single_open(file, cmd_db_debugfs_dump, inode->i_private);
334 }
335 #endif
336 
337 static const struct file_operations cmd_db_debugfs_ops = {
338 #ifdef CONFIG_DEBUG_FS
339 	.open = open_cmd_db_debugfs,
340 #endif
341 	.read = seq_read,
342 	.llseek = seq_lseek,
343 	.release = single_release,
344 };
345 
cmd_db_dev_probe(struct platform_device * pdev)346 static int cmd_db_dev_probe(struct platform_device *pdev)
347 {
348 	struct reserved_mem *rmem;
349 	int ret = 0;
350 
351 	rmem = of_reserved_mem_lookup(pdev->dev.of_node);
352 	if (!rmem) {
353 		dev_err(&pdev->dev, "failed to acquire memory region\n");
354 		return -EINVAL;
355 	}
356 
357 	cmd_db_header = memremap(rmem->base, rmem->size, MEMREMAP_WC);
358 	if (!cmd_db_header) {
359 		ret = -ENOMEM;
360 		cmd_db_header = NULL;
361 		return ret;
362 	}
363 
364 	if (!cmd_db_magic_matches(cmd_db_header)) {
365 		dev_err(&pdev->dev, "Invalid Command DB Magic\n");
366 		return -EINVAL;
367 	}
368 
369 	debugfs_create_file("cmd-db", 0400, NULL, NULL, &cmd_db_debugfs_ops);
370 
371 	device_set_pm_not_required(&pdev->dev);
372 
373 	return 0;
374 }
375 
376 static const struct of_device_id cmd_db_match_table[] = {
377 	{ .compatible = "qcom,cmd-db" },
378 	{ }
379 };
380 MODULE_DEVICE_TABLE(of, cmd_db_match_table);
381 
382 static struct platform_driver cmd_db_dev_driver = {
383 	.probe  = cmd_db_dev_probe,
384 	.driver = {
385 		   .name = "cmd-db",
386 		   .of_match_table = cmd_db_match_table,
387 		   .suppress_bind_attrs = true,
388 	},
389 };
390 
cmd_db_device_init(void)391 static int __init cmd_db_device_init(void)
392 {
393 	return platform_driver_register(&cmd_db_dev_driver);
394 }
395 arch_initcall(cmd_db_device_init);
396 
397 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Command DB Driver");
398 MODULE_LICENSE("GPL v2");
399