1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2/* Copyright (C) 2015-2017 Netronome Systems, Inc. */
3
4/* Parse the hwinfo table that the ARM firmware builds in the ARM scratch SRAM
5 * after chip reset.
6 *
7 * Examples of the fields:
8 *   me.count = 40
9 *   me.mask = 0x7f_ffff_ffff
10 *
11 *   me.count is the total number of MEs on the system.
12 *   me.mask is the bitmask of MEs that are available for application usage.
13 *
14 *   (ie, in this example, ME 39 has been reserved by boardconfig.)
15 */
16
17#include <asm/byteorder.h>
18#include <asm/unaligned.h>
19#include <linux/delay.h>
20#include <linux/log2.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/slab.h>
24
25#define NFP_SUBSYS "nfp_hwinfo"
26
27#include "crc32.h"
28#include "nfp.h"
29#include "nfp_cpp.h"
30#include "nfp6000/nfp6000.h"
31
32#define HWINFO_SIZE_MIN	0x100
33#define HWINFO_WAIT	20	/* seconds */
34
35/* The Hardware Info Table defines the properties of the system.
36 *
37 * HWInfo v1 Table (fixed size)
38 *
39 * 0x0000: u32 version	        Hardware Info Table version (1.0)
40 * 0x0004: u32 size	        Total size of the table, including
41 *			        the CRC32 (IEEE 802.3)
42 * 0x0008: u32 jumptab	        Offset of key/value table
43 * 0x000c: u32 keys	        Total number of keys in the key/value table
44 * NNNNNN:		        Key/value jump table and string data
45 * (size - 4): u32 crc32	CRC32 (same as IEEE 802.3, POSIX csum, etc)
46 *				CRC32("",0) = ~0, CRC32("a",1) = 0x48C279FE
47 *
48 * HWInfo v2 Table (variable size)
49 *
50 * 0x0000: u32 version	        Hardware Info Table version (2.0)
51 * 0x0004: u32 size	        Current size of the data area, excluding CRC32
52 * 0x0008: u32 limit	        Maximum size of the table
53 * 0x000c: u32 reserved	        Unused, set to zero
54 * NNNNNN:			Key/value data
55 * (size - 4): u32 crc32	CRC32 (same as IEEE 802.3, POSIX csum, etc)
56 *				CRC32("",0) = ~0, CRC32("a",1) = 0x48C279FE
57 *
58 * If the HWInfo table is in the process of being updated, the low bit
59 * of version will be set.
60 *
61 * HWInfo v1 Key/Value Table
62 * -------------------------
63 *
64 *  The key/value table is a set of offsets to ASCIIZ strings which have
65 *  been strcmp(3) sorted (yes, please use bsearch(3) on the table).
66 *
67 *  All keys are guaranteed to be unique.
68 *
69 * N+0:	u32 key_1		Offset to the first key
70 * N+4:	u32 val_1		Offset to the first value
71 * N+8: u32 key_2		Offset to the second key
72 * N+c: u32 val_2		Offset to the second value
73 * ...
74 *
75 * HWInfo v2 Key/Value Table
76 * -------------------------
77 *
78 * Packed UTF8Z strings, ie 'key1\000value1\000key2\000value2\000'
79 *
80 * Unsorted.
81 */
82
83#define NFP_HWINFO_VERSION_1 ('H' << 24 | 'I' << 16 | 1 << 8 | 0 << 1 | 0)
84#define NFP_HWINFO_VERSION_2 ('H' << 24 | 'I' << 16 | 2 << 8 | 0 << 1 | 0)
85#define NFP_HWINFO_VERSION_UPDATING	BIT(0)
86
87struct nfp_hwinfo {
88	u8 start[0];
89
90	__le32 version;
91	__le32 size;
92
93	/* v2 specific fields */
94	__le32 limit;
95	__le32 resv;
96
97	char data[];
98};
99
100static bool nfp_hwinfo_is_updating(struct nfp_hwinfo *hwinfo)
101{
102	return le32_to_cpu(hwinfo->version) & NFP_HWINFO_VERSION_UPDATING;
103}
104
105static int
106hwinfo_db_walk(struct nfp_cpp *cpp, struct nfp_hwinfo *hwinfo, u32 size)
107{
108	const char *key, *val, *end = hwinfo->data + size;
109
110	for (key = hwinfo->data; *key && key < end;
111	     key = val + strlen(val) + 1) {
112
113		val = key + strlen(key) + 1;
114		if (val >= end) {
115			nfp_warn(cpp, "Bad HWINFO - overflowing key\n");
116			return -EINVAL;
117		}
118
119		if (val + strlen(val) + 1 > end) {
120			nfp_warn(cpp, "Bad HWINFO - overflowing value\n");
121			return -EINVAL;
122		}
123	}
124
125	return 0;
126}
127
128static int
129hwinfo_db_validate(struct nfp_cpp *cpp, struct nfp_hwinfo *db, u32 len)
130{
131	u32 size, crc;
132
133	size = le32_to_cpu(db->size);
134	if (size > len) {
135		nfp_err(cpp, "Unsupported hwinfo size %u > %u\n", size, len);
136		return -EINVAL;
137	}
138
139	size -= sizeof(u32);
140	crc = crc32_posix(db, size);
141	if (crc != get_unaligned_le32(db->start + size)) {
142		nfp_err(cpp, "Corrupt hwinfo table (CRC mismatch), calculated 0x%x, expected 0x%x\n",
143			crc, get_unaligned_le32(db->start + size));
144
145		return -EINVAL;
146	}
147
148	return hwinfo_db_walk(cpp, db, size);
149}
150
151static struct nfp_hwinfo *
152hwinfo_try_fetch(struct nfp_cpp *cpp, size_t *cpp_size)
153{
154	struct nfp_hwinfo *header;
155	struct nfp_resource *res;
156	u64 cpp_addr;
157	u32 cpp_id;
158	int err;
159	u8 *db;
160
161	res = nfp_resource_acquire(cpp, NFP_RESOURCE_NFP_HWINFO);
162	if (!IS_ERR(res)) {
163		cpp_id = nfp_resource_cpp_id(res);
164		cpp_addr = nfp_resource_address(res);
165		*cpp_size = nfp_resource_size(res);
166
167		nfp_resource_release(res);
168
169		if (*cpp_size < HWINFO_SIZE_MIN)
170			return NULL;
171	} else if (PTR_ERR(res) == -ENOENT) {
172		/* Try getting the HWInfo table from the 'classic' location */
173		cpp_id = NFP_CPP_ISLAND_ID(NFP_CPP_TARGET_MU,
174					   NFP_CPP_ACTION_RW, 0, 1);
175		cpp_addr = 0x30000;
176		*cpp_size = 0x0e000;
177	} else {
178		return NULL;
179	}
180
181	db = kmalloc(*cpp_size + 1, GFP_KERNEL);
182	if (!db)
183		return NULL;
184
185	err = nfp_cpp_read(cpp, cpp_id, cpp_addr, db, *cpp_size);
186	if (err != *cpp_size)
187		goto exit_free;
188
189	header = (void *)db;
190	if (nfp_hwinfo_is_updating(header))
191		goto exit_free;
192
193	if (le32_to_cpu(header->version) != NFP_HWINFO_VERSION_2) {
194		nfp_err(cpp, "Unknown HWInfo version: 0x%08x\n",
195			le32_to_cpu(header->version));
196		goto exit_free;
197	}
198
199	/* NULL-terminate for safety */
200	db[*cpp_size] = '\0';
201
202	return (void *)db;
203exit_free:
204	kfree(db);
205	return NULL;
206}
207
208static struct nfp_hwinfo *hwinfo_fetch(struct nfp_cpp *cpp, size_t *hwdb_size)
209{
210	const unsigned long wait_until = jiffies + HWINFO_WAIT * HZ;
211	struct nfp_hwinfo *db;
212	int err;
213
214	for (;;) {
215		const unsigned long start_time = jiffies;
216
217		db = hwinfo_try_fetch(cpp, hwdb_size);
218		if (db)
219			return db;
220
221		err = msleep_interruptible(100);
222		if (err || time_after(start_time, wait_until)) {
223			nfp_err(cpp, "NFP access error\n");
224			return NULL;
225		}
226	}
227}
228
229struct nfp_hwinfo *nfp_hwinfo_read(struct nfp_cpp *cpp)
230{
231	struct nfp_hwinfo *db;
232	size_t hwdb_size = 0;
233	int err;
234
235	db = hwinfo_fetch(cpp, &hwdb_size);
236	if (!db)
237		return NULL;
238
239	err = hwinfo_db_validate(cpp, db, hwdb_size);
240	if (err) {
241		kfree(db);
242		return NULL;
243	}
244
245	return db;
246}
247
248/**
249 * nfp_hwinfo_lookup() - Find a value in the HWInfo table by name
250 * @hwinfo:	NFP HWinfo table
251 * @lookup:	HWInfo name to search for
252 *
253 * Return: Value of the HWInfo name, or NULL
254 */
255const char *nfp_hwinfo_lookup(struct nfp_hwinfo *hwinfo, const char *lookup)
256{
257	const char *key, *val, *end;
258
259	if (!hwinfo || !lookup)
260		return NULL;
261
262	end = hwinfo->data + le32_to_cpu(hwinfo->size) - sizeof(u32);
263
264	for (key = hwinfo->data; *key && key < end;
265	     key = val + strlen(val) + 1) {
266
267		val = key + strlen(key) + 1;
268
269		if (strcmp(key, lookup) == 0)
270			return val;
271	}
272
273	return NULL;
274}
275
276char *nfp_hwinfo_get_packed_strings(struct nfp_hwinfo *hwinfo)
277{
278	return hwinfo->data;
279}
280
281u32 nfp_hwinfo_get_packed_str_size(struct nfp_hwinfo *hwinfo)
282{
283	return le32_to_cpu(hwinfo->size) - sizeof(u32);
284}
285