xref: /linux/drivers/soc/qcom/cmd-db.c (revision a36e9f5cfe9eb3a1dce8769c7058251c42705357)
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 
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 
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 *
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  */
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_GPL(cmd_db_ready);
143 
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 	strtomem_pad(query, id, 0);
157 
158 	for (i = 0; i < MAX_SLV_ID; i++) {
159 		rsc_hdr = &cmd_db_header->header[i];
160 		if (!rsc_hdr->slv_id)
161 			break;
162 
163 		ent = rsc_to_entry_header(rsc_hdr);
164 		for (j = 0; j < le16_to_cpu(rsc_hdr->cnt); j++, ent++) {
165 			if (memcmp(ent->id, query, sizeof(ent->id)) == 0) {
166 				if (eh)
167 					*eh = ent;
168 				if (rh)
169 					*rh = rsc_hdr;
170 				return 0;
171 			}
172 		}
173 	}
174 
175 	return -ENODEV;
176 }
177 
178 /**
179  * cmd_db_read_addr() - Query command db for resource id address.
180  *
181  * @id: resource id to query for address
182  *
183  * Return: resource address on success, 0 on error
184  *
185  * This is used to retrieve resource address based on resource
186  * id.
187  */
188 u32 cmd_db_read_addr(const char *id)
189 {
190 	int ret;
191 	const struct entry_header *ent;
192 
193 	ret = cmd_db_get_header(id, &ent, NULL);
194 
195 	return ret < 0 ? 0 : le32_to_cpu(ent->addr);
196 }
197 EXPORT_SYMBOL_GPL(cmd_db_read_addr);
198 
199 /**
200  * cmd_db_read_aux_data() - Query command db for aux data.
201  *
202  *  @id: Resource to retrieve AUX Data on
203  *  @len: size of data buffer returned
204  *
205  *  Return: pointer to data on success, error pointer otherwise
206  */
207 const void *cmd_db_read_aux_data(const char *id, size_t *len)
208 {
209 	int ret;
210 	const struct entry_header *ent;
211 	const struct rsc_hdr *rsc_hdr;
212 
213 	ret = cmd_db_get_header(id, &ent, &rsc_hdr);
214 	if (ret)
215 		return ERR_PTR(ret);
216 
217 	if (len)
218 		*len = le16_to_cpu(ent->len);
219 
220 	return rsc_offset(rsc_hdr, ent);
221 }
222 EXPORT_SYMBOL_GPL(cmd_db_read_aux_data);
223 
224 /**
225  * cmd_db_match_resource_addr() - Compare if both Resource addresses are same
226  *
227  * @addr1: Resource address to compare
228  * @addr2: Resource address to compare
229  *
230  * Return: true if two addresses refer to the same resource, false otherwise
231  */
232 bool cmd_db_match_resource_addr(u32 addr1, u32 addr2)
233 {
234 	/*
235 	 * Each RPMh VRM accelerator resource has 3 or 4 contiguous 4-byte
236 	 * aligned addresses associated with it. Ignore the offset to check
237 	 * for VRM requests.
238 	 */
239 	if (addr1 == addr2)
240 		return true;
241 	else if (SLAVE_ID(addr1) == CMD_DB_HW_VRM && VRM_ADDR(addr1) == VRM_ADDR(addr2))
242 		return true;
243 
244 	return false;
245 }
246 EXPORT_SYMBOL_GPL(cmd_db_match_resource_addr);
247 
248 /**
249  * cmd_db_read_slave_id - Get the slave ID for a given resource address
250  *
251  * @id: Resource id to query the DB for version
252  *
253  * Return: cmd_db_hw_type enum on success, CMD_DB_HW_INVALID on error
254  */
255 enum cmd_db_hw_type cmd_db_read_slave_id(const char *id)
256 {
257 	int ret;
258 	const struct entry_header *ent;
259 	u32 addr;
260 
261 	ret = cmd_db_get_header(id, &ent, NULL);
262 	if (ret < 0)
263 		return CMD_DB_HW_INVALID;
264 
265 	addr = le32_to_cpu(ent->addr);
266 	return (addr >> SLAVE_ID_SHIFT) & SLAVE_ID_MASK;
267 }
268 EXPORT_SYMBOL_GPL(cmd_db_read_slave_id);
269 
270 #ifdef CONFIG_DEBUG_FS
271 static int cmd_db_debugfs_dump(struct seq_file *seq, void *p)
272 {
273 	int i, j;
274 	const struct rsc_hdr *rsc;
275 	const struct entry_header *ent;
276 	const char *name;
277 	u16 len, version;
278 	u8 major, minor;
279 
280 	seq_puts(seq, "Command DB DUMP\n");
281 
282 	for (i = 0; i < MAX_SLV_ID; i++) {
283 		rsc = &cmd_db_header->header[i];
284 		if (!rsc->slv_id)
285 			break;
286 
287 		switch (le16_to_cpu(rsc->slv_id)) {
288 		case CMD_DB_HW_ARC:
289 			name = "ARC";
290 			break;
291 		case CMD_DB_HW_VRM:
292 			name = "VRM";
293 			break;
294 		case CMD_DB_HW_BCM:
295 			name = "BCM";
296 			break;
297 		default:
298 			name = "Unknown";
299 			break;
300 		}
301 
302 		version = le16_to_cpu(rsc->version);
303 		major = version >> 8;
304 		minor = version;
305 
306 		seq_printf(seq, "Slave %s (v%u.%u)\n", name, major, minor);
307 		seq_puts(seq, "-------------------------\n");
308 
309 		ent = rsc_to_entry_header(rsc);
310 		for (j = 0; j < le16_to_cpu(rsc->cnt); j++, ent++) {
311 			seq_printf(seq, "0x%05x: %*pEp", le32_to_cpu(ent->addr),
312 				   (int)strnlen(ent->id, sizeof(ent->id)), ent->id);
313 
314 			len = le16_to_cpu(ent->len);
315 			if (len) {
316 				seq_printf(seq, " [%*ph]",
317 					   len, rsc_offset(rsc, ent));
318 			}
319 			seq_putc(seq, '\n');
320 		}
321 	}
322 
323 	return 0;
324 }
325 
326 static int open_cmd_db_debugfs(struct inode *inode, struct file *file)
327 {
328 	return single_open(file, cmd_db_debugfs_dump, inode->i_private);
329 }
330 #endif
331 
332 static const struct file_operations cmd_db_debugfs_ops = {
333 #ifdef CONFIG_DEBUG_FS
334 	.open = open_cmd_db_debugfs,
335 #endif
336 	.read = seq_read,
337 	.llseek = seq_lseek,
338 	.release = single_release,
339 };
340 
341 static int cmd_db_dev_probe(struct platform_device *pdev)
342 {
343 	struct reserved_mem *rmem;
344 	int ret = 0;
345 
346 	rmem = of_reserved_mem_lookup(pdev->dev.of_node);
347 	if (!rmem) {
348 		dev_err(&pdev->dev, "failed to acquire memory region\n");
349 		return -EINVAL;
350 	}
351 
352 	cmd_db_header = memremap(rmem->base, rmem->size, MEMREMAP_WC);
353 	if (!cmd_db_header) {
354 		ret = -ENOMEM;
355 		cmd_db_header = NULL;
356 		return ret;
357 	}
358 
359 	if (!cmd_db_magic_matches(cmd_db_header)) {
360 		dev_err(&pdev->dev, "Invalid Command DB Magic\n");
361 		return -EINVAL;
362 	}
363 
364 	debugfs_create_file("cmd-db", 0400, NULL, NULL, &cmd_db_debugfs_ops);
365 
366 	device_set_pm_not_required(&pdev->dev);
367 
368 	return 0;
369 }
370 
371 static const struct of_device_id cmd_db_match_table[] = {
372 	{ .compatible = "qcom,cmd-db" },
373 	{ }
374 };
375 MODULE_DEVICE_TABLE(of, cmd_db_match_table);
376 
377 static struct platform_driver cmd_db_dev_driver = {
378 	.probe  = cmd_db_dev_probe,
379 	.driver = {
380 		   .name = "cmd-db",
381 		   .of_match_table = cmd_db_match_table,
382 		   .suppress_bind_attrs = true,
383 	},
384 };
385 
386 static int __init cmd_db_device_init(void)
387 {
388 	return platform_driver_register(&cmd_db_dev_driver);
389 }
390 core_initcall(cmd_db_device_init);
391 
392 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Command DB Driver");
393 MODULE_LICENSE("GPL v2");
394