xref: /freebsd/sys/dev/ipmi/ipmi_smbios.c (revision aa0a1e58)
1 /*-
2  * Copyright (c) 2006 IronPort Systems Inc. <ambrisko@ironport.com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/condvar.h>
34 #include <sys/eventhandler.h>
35 #include <sys/kernel.h>
36 #include <sys/selinfo.h>
37 
38 #include <vm/vm.h>
39 #include <vm/pmap.h>
40 #include <machine/pc/bios.h>
41 
42 #ifdef LOCAL_MODULE
43 #include <ipmi.h>
44 #include <ipmivars.h>
45 #else
46 #include <sys/ipmi.h>
47 #include <dev/ipmi/ipmivars.h>
48 #endif
49 
50 #if __FreeBSD_version < 602110
51 #define	pmap_mapbios		pmap_mapdev
52 #define	pmap_unmapbios		pmap_unmapdev
53 #endif
54 
55 struct smbios_table {
56 	uint8_t		anchor_string[4];
57 	uint8_t		checksum;
58 	uint8_t		length;
59 	uint8_t		major_version;
60 	uint8_t		minor_version;
61 	uint16_t	maximum_structure_size;
62 	uint8_t		entry_point_revision;
63 	uint8_t		formatted_area[5];
64 	uint8_t		DMI_anchor_string[5];
65 	uint8_t		intermediate_checksum;
66 	uint16_t	structure_table_length;
67 	uint32_t	structure_table_address;
68 	uint16_t	number_structures;
69 	uint8_t		BCD_revision;
70 };
71 
72 struct structure_header {
73 	uint8_t		type;
74 	uint8_t		length;
75 	uint16_t	handle;
76 };
77 
78 struct ipmi_entry {
79 	uint8_t		type;
80 	uint8_t		length;
81 	uint16_t	handle;
82 	uint8_t		interface_type;
83 	uint8_t		spec_revision;
84 	uint8_t		i2c_slave_address;
85 	uint8_t		NV_storage_device_address;
86 	uint64_t	base_address;
87 	uint8_t		base_address_modifier;
88 	uint8_t		interrupt_number;
89 };
90 
91 /* Fields in the base_address field of an IPMI entry. */
92 #define	IPMI_BAR_MODE(ba)	((ba) & 0x0000000000000001)
93 #define	IPMI_BAR_ADDR(ba)	((ba) & 0xfffffffffffffffe)
94 
95 /* Fields in the base_address_modifier field of an IPMI entry. */
96 #define	IPMI_BAM_IRQ_TRIGGER	0x01
97 #define	IPMI_BAM_IRQ_POLARITY	0x02
98 #define	IPMI_BAM_IRQ_VALID	0x08
99 #define	IPMI_BAM_ADDR_LSB(bam)	(((bam) & 0x10) >> 4)
100 #define	IPMI_BAM_REG_SPACING(bam) (((bam) & 0xc0) >> 6)
101 #define	SPACING_8		0x0
102 #define	SPACING_32		0x1
103 #define	SPACING_16		0x2
104 
105 #define	SMBIOS_START		0xf0000
106 #define	SMBIOS_STEP		0x10
107 #define	SMBIOS_OFF		0
108 #define	SMBIOS_LEN		4
109 #define	SMBIOS_SIG		"_SM_"
110 
111 typedef void (*smbios_callback_t)(struct structure_header *, void *);
112 
113 static struct ipmi_get_info ipmi_info;
114 static int ipmi_probed;
115 static struct mtx ipmi_info_mtx;
116 MTX_SYSINIT(ipmi_info, &ipmi_info_mtx, "ipmi info", MTX_DEF);
117 
118 static void	ipmi_smbios_probe(struct ipmi_get_info *);
119 static int	smbios_cksum(struct smbios_table *);
120 static void	smbios_walk_table(uint8_t *, int, smbios_callback_t,
121 		    void *);
122 static void	smbios_ipmi_info(struct structure_header *, void *);
123 
124 static void
125 smbios_ipmi_info(struct structure_header *h, void *arg)
126 {
127 	struct ipmi_get_info *info;
128 	struct ipmi_entry *s;
129 
130 	if (h->type != 38 || h->length <
131 	    offsetof(struct ipmi_entry, interrupt_number))
132 		return;
133 	s = (struct ipmi_entry *)h;
134 	info = arg;
135 	bzero(info, sizeof(struct ipmi_get_info));
136 	switch (s->interface_type) {
137 	case KCS_MODE:
138 	case SMIC_MODE:
139 		info->address = IPMI_BAR_ADDR(s->base_address) |
140 		    IPMI_BAM_ADDR_LSB(s->base_address_modifier);
141 		info->io_mode = IPMI_BAR_MODE(s->base_address);
142 		switch (IPMI_BAM_REG_SPACING(s->base_address_modifier)) {
143 		case SPACING_8:
144 			info->offset = 1;
145 			break;
146 		case SPACING_32:
147 			info->offset = 4;
148 			break;
149 		case SPACING_16:
150 			info->offset = 2;
151 			break;
152 		default:
153 			printf("SMBIOS: Invalid register spacing\n");
154 			return;
155 		}
156 		break;
157 	case SSIF_MODE:
158 		if ((s->base_address & 0xffffffffffffff00) != 0) {
159 			printf("SMBIOS: Invalid SSIF SMBus address, using BMC I2C slave address instead\n");
160 			info->address = s->i2c_slave_address;
161 			break;
162 		}
163 		info->address = IPMI_BAR_ADDR(s->base_address);
164 		break;
165 	default:
166 		return;
167 	}
168 	if (s->length > offsetof(struct ipmi_entry, interrupt_number)) {
169 		if (s->interrupt_number > 15)
170 			printf("SMBIOS: Non-ISA IRQ %d for IPMI\n",
171 			    s->interrupt_number);
172 		else
173 			info->irq = s->interrupt_number;
174 	}
175 	info->iface_type = s->interface_type;
176 }
177 
178 static void
179 smbios_walk_table(uint8_t *p, int entries, smbios_callback_t cb, void *arg)
180 {
181 	struct structure_header *s;
182 
183 	while (entries--) {
184 		s = (struct structure_header *)p;
185 		cb(s, arg);
186 
187 		/*
188 		 * Look for a double-nul after the end of the
189 		 * formatted area of this structure.
190 		 */
191 		p += s->length;
192 		while (!(p[0] == 0 && p[1] == 0))
193 			p++;
194 
195 		/*
196 		 * Skip over the double-nul to the start of the next
197 		 * structure.
198 		 */
199 		p += 2;
200 	}
201 }
202 
203 /*
204  * Walk the SMBIOS table looking for an IPMI (type 38) entry.  If we find
205  * one, return the parsed data in the passed in ipmi_get_info structure and
206  * return true.  If we don't find one, return false.
207  */
208 static void
209 ipmi_smbios_probe(struct ipmi_get_info *info)
210 {
211 	struct smbios_table *header;
212 	void *table;
213 	u_int32_t addr;
214 
215 	bzero(info, sizeof(struct ipmi_get_info));
216 
217 	/* Find the SMBIOS table header. */
218 	addr = bios_sigsearch(SMBIOS_START, SMBIOS_SIG, SMBIOS_LEN,
219 			      SMBIOS_STEP, SMBIOS_OFF);
220 	if (addr == 0)
221 		return;
222 
223 	/*
224 	 * Map the header.  We first map a fixed size to get the actual
225 	 * length and then map it a second time with the actual length so
226 	 * we can verify the checksum.
227 	 */
228 	header = pmap_mapbios(addr, sizeof(struct smbios_table));
229 	table = pmap_mapbios(addr, header->length);
230 	pmap_unmapbios((vm_offset_t)header, sizeof(struct smbios_table));
231 	header = table;
232 	if (smbios_cksum(header) != 0) {
233 		pmap_unmapbios((vm_offset_t)header, header->length);
234 		return;
235 	}
236 
237 	/* Now map the actual table and walk it looking for an IPMI entry. */
238 	table = pmap_mapbios(header->structure_table_address,
239 	    header->structure_table_length);
240 	smbios_walk_table(table, header->number_structures, smbios_ipmi_info,
241 	    info);
242 
243 	/* Unmap everything. */
244 	pmap_unmapbios((vm_offset_t)table, header->structure_table_length);
245 	pmap_unmapbios((vm_offset_t)header, header->length);
246 }
247 
248 /*
249  * Return the SMBIOS IPMI table entry info to the caller.  If we haven't
250  * searched the IPMI table yet, search it.  Otherwise, return a cached
251  * copy of the data.
252  */
253 int
254 ipmi_smbios_identify(struct ipmi_get_info *info)
255 {
256 
257 	mtx_lock(&ipmi_info_mtx);
258 	switch (ipmi_probed) {
259 	case 0:
260 		/* Need to probe the SMBIOS table. */
261 		ipmi_probed++;
262 		mtx_unlock(&ipmi_info_mtx);
263 		ipmi_smbios_probe(&ipmi_info);
264 		mtx_lock(&ipmi_info_mtx);
265 		ipmi_probed++;
266 		wakeup(&ipmi_info);
267 		break;
268 	case 1:
269 		/* Another thread is currently probing the table, so wait. */
270 		while (ipmi_probed == 1)
271 			msleep(&ipmi_info, &ipmi_info_mtx, 0, "ipmi info", 0);
272 		break;
273 	default:
274 		/* The cached data is available. */
275 		break;
276 	}
277 
278 	bcopy(&ipmi_info, info, sizeof(ipmi_info));
279 	mtx_unlock(&ipmi_info_mtx);
280 
281 	return (info->iface_type != 0);
282 }
283 
284 static int
285 smbios_cksum(struct smbios_table *e)
286 {
287 	u_int8_t *ptr;
288 	u_int8_t cksum;
289 	int i;
290 
291 	ptr = (u_int8_t *)e;
292 	cksum = 0;
293 	for (i = 0; i < e->length; i++) {
294 		cksum += ptr[i];
295 	}
296 
297 	return (cksum);
298 }
299