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 
87 struct 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 
nfp_hwinfo_is_updating(struct nfp_hwinfo * hwinfo)100 static bool nfp_hwinfo_is_updating(struct nfp_hwinfo *hwinfo)
101 {
102 	return le32_to_cpu(hwinfo->version) & NFP_HWINFO_VERSION_UPDATING;
103 }
104 
105 static int
hwinfo_db_walk(struct nfp_cpp * cpp,struct nfp_hwinfo * hwinfo,u32 size)106 hwinfo_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 
128 static int
hwinfo_db_validate(struct nfp_cpp * cpp,struct nfp_hwinfo * db,u32 len)129 hwinfo_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 
151 static struct nfp_hwinfo *
hwinfo_try_fetch(struct nfp_cpp * cpp,size_t * cpp_size)152 hwinfo_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;
203 exit_free:
204 	kfree(db);
205 	return NULL;
206 }
207 
hwinfo_fetch(struct nfp_cpp * cpp,size_t * hwdb_size)208 static 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 
nfp_hwinfo_read(struct nfp_cpp * cpp)229 struct 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  */
nfp_hwinfo_lookup(struct nfp_hwinfo * hwinfo,const char * lookup)255 const 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 
nfp_hwinfo_get_packed_strings(struct nfp_hwinfo * hwinfo)276 char *nfp_hwinfo_get_packed_strings(struct nfp_hwinfo *hwinfo)
277 {
278 	return hwinfo->data;
279 }
280 
nfp_hwinfo_get_packed_str_size(struct nfp_hwinfo * hwinfo)281 u32 nfp_hwinfo_get_packed_str_size(struct nfp_hwinfo *hwinfo)
282 {
283 	return le32_to_cpu(hwinfo->size) - sizeof(u32);
284 }
285