xref: /freebsd/sys/dev/ipmi/ipmi_smbios.c (revision a0b9e2e854027e6ff61fb075a1309dbc71c42b54)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2006 IronPort Systems Inc. <ambrisko@ironport.com>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/condvar.h>
36 #include <sys/eventhandler.h>
37 #include <sys/kernel.h>
38 #include <sys/selinfo.h>
39 
40 #include <vm/vm.h>
41 #include <vm/pmap.h>
42 #include <machine/pc/bios.h>
43 
44 #ifdef LOCAL_MODULE
45 #include <ipmi.h>
46 #include <ipmivars.h>
47 #else
48 #include <sys/ipmi.h>
49 #include <dev/ipmi/ipmivars.h>
50 #endif
51 
52 struct ipmi_entry {
53 	uint8_t		type;
54 	uint8_t		length;
55 	uint16_t	handle;
56 	uint8_t		interface_type;
57 	uint8_t		spec_revision;
58 	uint8_t		i2c_slave_address;
59 	uint8_t		NV_storage_device_address;
60 	uint64_t	base_address;
61 	uint8_t		base_address_modifier;
62 	uint8_t		interrupt_number;
63 };
64 
65 /* Fields in the base_address field of an IPMI entry. */
66 #define	IPMI_BAR_MODE(ba)	((ba) & 0x0000000000000001)
67 #define	IPMI_BAR_ADDR(ba)	((ba) & 0xfffffffffffffffe)
68 
69 /* Fields in the base_address_modifier field of an IPMI entry. */
70 #define	IPMI_BAM_IRQ_TRIGGER	0x01
71 #define	IPMI_BAM_IRQ_POLARITY	0x02
72 #define	IPMI_BAM_IRQ_VALID	0x08
73 #define	IPMI_BAM_ADDR_LSB(bam)	(((bam) & 0x10) >> 4)
74 #define	IPMI_BAM_REG_SPACING(bam) (((bam) & 0xc0) >> 6)
75 #define	SPACING_8		0x0
76 #define	SPACING_32		0x1
77 #define	SPACING_16		0x2
78 
79 typedef void (*smbios_callback_t)(struct smbios_structure_header *, void *);
80 
81 static struct ipmi_get_info ipmi_info;
82 static int ipmi_probed;
83 static struct mtx ipmi_info_mtx;
84 MTX_SYSINIT(ipmi_info, &ipmi_info_mtx, "ipmi info", MTX_DEF);
85 
86 static void	ipmi_smbios_probe(struct ipmi_get_info *);
87 static int	smbios_cksum(struct smbios_eps *);
88 static void	smbios_walk_table(uint8_t *, int, smbios_callback_t,
89 		    void *);
90 static void	smbios_ipmi_info(struct smbios_structure_header *, void *);
91 
92 static void
93 smbios_ipmi_info(struct smbios_structure_header *h, void *arg)
94 {
95 	struct ipmi_get_info *info;
96 	struct ipmi_entry *s;
97 
98 	if (h->type != 38 || h->length <
99 	    offsetof(struct ipmi_entry, interrupt_number))
100 		return;
101 	s = (struct ipmi_entry *)h;
102 	info = arg;
103 	bzero(info, sizeof(struct ipmi_get_info));
104 	switch (s->interface_type) {
105 	case KCS_MODE:
106 	case SMIC_MODE:
107 		info->address = IPMI_BAR_ADDR(s->base_address) |
108 		    IPMI_BAM_ADDR_LSB(s->base_address_modifier);
109 		info->io_mode = IPMI_BAR_MODE(s->base_address);
110 		switch (IPMI_BAM_REG_SPACING(s->base_address_modifier)) {
111 		case SPACING_8:
112 			info->offset = 1;
113 			break;
114 		case SPACING_32:
115 			info->offset = 4;
116 			break;
117 		case SPACING_16:
118 			info->offset = 2;
119 			break;
120 		default:
121 			printf("SMBIOS: Invalid register spacing\n");
122 			return;
123 		}
124 		break;
125 	case SSIF_MODE:
126 		if ((s->base_address & 0xffffffffffffff00) != 0) {
127 			printf("SMBIOS: Invalid SSIF SMBus address, using BMC I2C slave address instead\n");
128 			info->address = s->i2c_slave_address;
129 			break;
130 		}
131 		info->address = IPMI_BAR_ADDR(s->base_address);
132 		break;
133 	default:
134 		return;
135 	}
136 	if (s->length > offsetof(struct ipmi_entry, interrupt_number)) {
137 		if (s->interrupt_number > 15)
138 			printf("SMBIOS: Non-ISA IRQ %d for IPMI\n",
139 			    s->interrupt_number);
140 		else
141 			info->irq = s->interrupt_number;
142 	}
143 	info->iface_type = s->interface_type;
144 }
145 
146 static void
147 smbios_walk_table(uint8_t *p, int entries, smbios_callback_t cb, void *arg)
148 {
149 	struct smbios_structure_header *s;
150 
151 	while (entries--) {
152 		s = (struct smbios_structure_header *)p;
153 		cb(s, arg);
154 
155 		/*
156 		 * Look for a double-nul after the end of the
157 		 * formatted area of this structure.
158 		 */
159 		p += s->length;
160 		while (!(p[0] == 0 && p[1] == 0))
161 			p++;
162 
163 		/*
164 		 * Skip over the double-nul to the start of the next
165 		 * structure.
166 		 */
167 		p += 2;
168 	}
169 }
170 
171 /*
172  * Walk the SMBIOS table looking for an IPMI (type 38) entry.  If we find
173  * one, return the parsed data in the passed in ipmi_get_info structure and
174  * return true.  If we don't find one, return false.
175  */
176 static void
177 ipmi_smbios_probe(struct ipmi_get_info *info)
178 {
179 	struct smbios_eps *header;
180 	void *table;
181 	u_int32_t addr;
182 
183 	bzero(info, sizeof(struct ipmi_get_info));
184 
185 	/* Find the SMBIOS table header. */
186 	addr = bios_sigsearch(SMBIOS_START, SMBIOS_SIG, SMBIOS_LEN,
187 			      SMBIOS_STEP, SMBIOS_OFF);
188 	if (addr == 0)
189 		return;
190 
191 	/*
192 	 * Map the header.  We first map a fixed size to get the actual
193 	 * length and then map it a second time with the actual length so
194 	 * we can verify the checksum.
195 	 */
196 	header = pmap_mapbios(addr, sizeof(struct smbios_eps));
197 	table = pmap_mapbios(addr, header->length);
198 	pmap_unmapbios((vm_offset_t)header, sizeof(struct smbios_eps));
199 	header = table;
200 	if (smbios_cksum(header) != 0) {
201 		pmap_unmapbios((vm_offset_t)header, header->length);
202 		return;
203 	}
204 
205 	/* Now map the actual table and walk it looking for an IPMI entry. */
206 	table = pmap_mapbios(header->structure_table_address,
207 	    header->structure_table_length);
208 	smbios_walk_table(table, header->number_structures, smbios_ipmi_info,
209 	    info);
210 
211 	/* Unmap everything. */
212 	pmap_unmapbios((vm_offset_t)table, header->structure_table_length);
213 	pmap_unmapbios((vm_offset_t)header, header->length);
214 }
215 
216 /*
217  * Return the SMBIOS IPMI table entry info to the caller.  If we haven't
218  * searched the IPMI table yet, search it.  Otherwise, return a cached
219  * copy of the data.
220  */
221 int
222 ipmi_smbios_identify(struct ipmi_get_info *info)
223 {
224 
225 	mtx_lock(&ipmi_info_mtx);
226 	switch (ipmi_probed) {
227 	case 0:
228 		/* Need to probe the SMBIOS table. */
229 		ipmi_probed++;
230 		mtx_unlock(&ipmi_info_mtx);
231 		ipmi_smbios_probe(&ipmi_info);
232 		mtx_lock(&ipmi_info_mtx);
233 		ipmi_probed++;
234 		wakeup(&ipmi_info);
235 		break;
236 	case 1:
237 		/* Another thread is currently probing the table, so wait. */
238 		while (ipmi_probed == 1)
239 			msleep(&ipmi_info, &ipmi_info_mtx, 0, "ipmi info", 0);
240 		break;
241 	default:
242 		/* The cached data is available. */
243 		break;
244 	}
245 
246 	bcopy(&ipmi_info, info, sizeof(ipmi_info));
247 	mtx_unlock(&ipmi_info_mtx);
248 
249 	return (info->iface_type != 0);
250 }
251 
252 static int
253 smbios_cksum(struct smbios_eps *e)
254 {
255 	u_int8_t *ptr;
256 	u_int8_t cksum;
257 	int i;
258 
259 	ptr = (u_int8_t *)e;
260 	cksum = 0;
261 	for (i = 0; i < e->length; i++) {
262 		cksum += ptr[i];
263 	}
264 
265 	return (cksum);
266 }
267