xref: /freebsd/sys/dev/ipmi/ipmi_smbios.c (revision ac099daf6742ead81ea7ea86351a8ef4e783041b)
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 #if defined(__amd64__) || defined(__i386__)
43 #include <machine/pc/bios.h>
44 #endif
45 #include <dev/smbios/smbios.h>
46 
47 #ifdef LOCAL_MODULE
48 #include <ipmi.h>
49 #include <ipmivars.h>
50 #else
51 #include <sys/ipmi.h>
52 #include <dev/ipmi/ipmivars.h>
53 #endif
54 
55 struct ipmi_entry {
56 	uint8_t		type;
57 	uint8_t		length;
58 	uint16_t	handle;
59 	uint8_t		interface_type;
60 	uint8_t		spec_revision;
61 	uint8_t		i2c_slave_address;
62 	uint8_t		NV_storage_device_address;
63 	uint64_t	base_address;
64 	uint8_t		base_address_modifier;
65 	uint8_t		interrupt_number;
66 };
67 
68 /* Fields in the base_address field of an IPMI entry. */
69 #define	IPMI_BAR_MODE(ba)	((ba) & 0x0000000000000001)
70 #define	IPMI_BAR_ADDR(ba)	((ba) & 0xfffffffffffffffe)
71 
72 /* Fields in the base_address_modifier field of an IPMI entry. */
73 #define	IPMI_BAM_IRQ_TRIGGER	0x01
74 #define	IPMI_BAM_IRQ_POLARITY	0x02
75 #define	IPMI_BAM_IRQ_VALID	0x08
76 #define	IPMI_BAM_ADDR_LSB(bam)	(((bam) & 0x10) >> 4)
77 #define	IPMI_BAM_REG_SPACING(bam) (((bam) & 0xc0) >> 6)
78 #define	SPACING_8		0x0
79 #define	SPACING_32		0x1
80 #define	SPACING_16		0x2
81 
82 static struct ipmi_get_info ipmi_info;
83 static int ipmi_probed;
84 static struct mtx ipmi_info_mtx;
85 MTX_SYSINIT(ipmi_info, &ipmi_info_mtx, "ipmi info", MTX_DEF);
86 
87 static void	ipmi_smbios_probe(struct ipmi_get_info *);
88 static int	smbios_cksum(struct smbios_eps *);
89 static void	smbios_ipmi_info(struct smbios_structure_header *, void *);
90 
91 static void
92 smbios_ipmi_info(struct smbios_structure_header *h, void *arg)
93 {
94 	struct ipmi_get_info *info;
95 	struct ipmi_entry *s;
96 
97 	if (h->type != 38 || h->length <
98 	    offsetof(struct ipmi_entry, interrupt_number))
99 		return;
100 	s = (struct ipmi_entry *)h;
101 	info = arg;
102 	bzero(info, sizeof(struct ipmi_get_info));
103 	switch (s->interface_type) {
104 	case KCS_MODE:
105 	case SMIC_MODE:
106 		info->address = IPMI_BAR_ADDR(s->base_address) |
107 		    IPMI_BAM_ADDR_LSB(s->base_address_modifier);
108 		info->io_mode = IPMI_BAR_MODE(s->base_address);
109 		switch (IPMI_BAM_REG_SPACING(s->base_address_modifier)) {
110 		case SPACING_8:
111 			info->offset = 1;
112 			break;
113 		case SPACING_32:
114 			info->offset = 4;
115 			break;
116 		case SPACING_16:
117 			info->offset = 2;
118 			break;
119 		default:
120 			printf("SMBIOS: Invalid register spacing\n");
121 			return;
122 		}
123 		break;
124 	case SSIF_MODE:
125 		if ((s->base_address & 0xffffffffffffff00) != 0) {
126 			printf("SMBIOS: Invalid SSIF SMBus address, using BMC I2C slave address instead\n");
127 			info->address = s->i2c_slave_address;
128 			break;
129 		}
130 		info->address = IPMI_BAR_ADDR(s->base_address);
131 		break;
132 	default:
133 		return;
134 	}
135 	if (s->length > offsetof(struct ipmi_entry, interrupt_number)) {
136 		if (s->interrupt_number > 15)
137 			printf("SMBIOS: Non-ISA IRQ %d for IPMI\n",
138 			    s->interrupt_number);
139 		else
140 			info->irq = s->interrupt_number;
141 	}
142 	info->iface_type = s->interface_type;
143 }
144 
145 /*
146  * Walk the SMBIOS table looking for an IPMI (type 38) entry.  If we find
147  * one, return the parsed data in the passed in ipmi_get_info structure and
148  * return true.  If we don't find one, return false.
149  */
150 static void
151 ipmi_smbios_probe(struct ipmi_get_info *info)
152 {
153 	struct smbios_eps *header;
154 	void *table;
155 	u_int32_t addr;
156 
157 	bzero(info, sizeof(struct ipmi_get_info));
158 
159 	/* Find the SMBIOS table header. */
160 	addr = bios_sigsearch(SMBIOS_START, SMBIOS_SIG, SMBIOS_LEN,
161 			      SMBIOS_STEP, SMBIOS_OFF);
162 	if (addr == 0)
163 		return;
164 
165 	/*
166 	 * Map the header.  We first map a fixed size to get the actual
167 	 * length and then map it a second time with the actual length so
168 	 * we can verify the checksum.
169 	 */
170 	header = pmap_mapbios(addr, sizeof(struct smbios_eps));
171 	table = pmap_mapbios(addr, header->length);
172 	pmap_unmapbios((vm_offset_t)header, sizeof(struct smbios_eps));
173 	header = table;
174 	if (smbios_cksum(header) != 0) {
175 		pmap_unmapbios((vm_offset_t)header, header->length);
176 		return;
177 	}
178 
179 	/* Now map the actual table and walk it looking for an IPMI entry. */
180 	table = pmap_mapbios(header->structure_table_address,
181 	    header->structure_table_length);
182 	smbios_walk_table(table, header->number_structures, smbios_ipmi_info,
183 	    info);
184 
185 	/* Unmap everything. */
186 	pmap_unmapbios((vm_offset_t)table, header->structure_table_length);
187 	pmap_unmapbios((vm_offset_t)header, header->length);
188 }
189 
190 /*
191  * Return the SMBIOS IPMI table entry info to the caller.  If we haven't
192  * searched the IPMI table yet, search it.  Otherwise, return a cached
193  * copy of the data.
194  */
195 int
196 ipmi_smbios_identify(struct ipmi_get_info *info)
197 {
198 
199 	mtx_lock(&ipmi_info_mtx);
200 	switch (ipmi_probed) {
201 	case 0:
202 		/* Need to probe the SMBIOS table. */
203 		ipmi_probed++;
204 		mtx_unlock(&ipmi_info_mtx);
205 		ipmi_smbios_probe(&ipmi_info);
206 		mtx_lock(&ipmi_info_mtx);
207 		ipmi_probed++;
208 		wakeup(&ipmi_info);
209 		break;
210 	case 1:
211 		/* Another thread is currently probing the table, so wait. */
212 		while (ipmi_probed == 1)
213 			msleep(&ipmi_info, &ipmi_info_mtx, 0, "ipmi info", 0);
214 		break;
215 	default:
216 		/* The cached data is available. */
217 		break;
218 	}
219 
220 	bcopy(&ipmi_info, info, sizeof(ipmi_info));
221 	mtx_unlock(&ipmi_info_mtx);
222 
223 	return (info->iface_type != 0);
224 }
225 
226 static int
227 smbios_cksum(struct smbios_eps *e)
228 {
229 	u_int8_t *ptr;
230 	u_int8_t cksum;
231 	int i;
232 
233 	ptr = (u_int8_t *)e;
234 	cksum = 0;
235 	for (i = 0; i < e->length; i++) {
236 		cksum += ptr[i];
237 	}
238 
239 	return (cksum);
240 }
241