aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/char/ipmi/ipmi_dmi.c
blob: ff0b199be4729757743bbd72bff2fc61a842d291 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
// SPDX-License-Identifier: GPL-2.0+
/*
 * A hack to create a platform device from a DMI entry.  This will
 * allow autoloading of the IPMI drive based on SMBIOS entries.
 */

#define pr_fmt(fmt) "%s" fmt, "ipmi:dmi: "
#define dev_fmt pr_fmt

#include <linux/ipmi.h>
#include <linux/init.h>
#include <linux/dmi.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include "ipmi_si_sm.h"
#include "ipmi_dmi.h"
#include "ipmi_plat_data.h"

#define IPMI_DMI_TYPE_KCS	0x01
#define IPMI_DMI_TYPE_SMIC	0x02
#define IPMI_DMI_TYPE_BT	0x03
#define IPMI_DMI_TYPE_SSIF	0x04

struct ipmi_dmi_info {
	enum si_type si_type;
	unsigned int space; /* addr space for si, intf# for ssif */
	unsigned long addr;
	u8 slave_addr;
	struct ipmi_dmi_info *next;
};

static struct ipmi_dmi_info *ipmi_dmi_infos;

static int ipmi_dmi_nr __initdata;

static void __init dmi_add_platform_ipmi(unsigned long base_addr,
					 unsigned int space,
					 u8 slave_addr,
					 int irq,
					 int offset,
					 int type)
{
	const char *name;
	struct ipmi_dmi_info *info;
	struct ipmi_plat_data p;

	memset(&p, 0, sizeof(p));

	name = "dmi-ipmi-si";
	switch (type) {
	case IPMI_DMI_TYPE_SSIF:
		name = "dmi-ipmi-ssif";
		p.type = SI_TYPE_INVALID;
		break;
	case IPMI_DMI_TYPE_BT:
		p.type = SI_BT;
		break;
	case IPMI_DMI_TYPE_KCS:
		p.type = SI_KCS;
		break;
	case IPMI_DMI_TYPE_SMIC:
		p.type = SI_SMIC;
		break;
	default:
		pr_err("Invalid IPMI type: %d\n", type);
		return;
	}

	memset(&p, 0, sizeof(p));
	p.addr = base_addr;
	p.space = space;
	p.regspacing = offset;
	p.irq = irq;
	p.slave_addr = slave_addr;
	p.addr_source = SI_SMBIOS;

	info = kmalloc(sizeof(*info), GFP_KERNEL);
	if (!info) {
		pr_warn("Could not allocate dmi info\n");
	} else {
		info->si_type = p.type;
		info->space = space;
		info->addr = base_addr;
		info->slave_addr = slave_addr;
		info->next = ipmi_dmi_infos;
		ipmi_dmi_infos = info;
	}

	if (ipmi_platform_add(name, ipmi_dmi_nr, &p))
		ipmi_dmi_nr++;
}

/*
 * Look up the slave address for a given interface.  This is here
 * because ACPI doesn't have a slave address while SMBIOS does, but we
 * prefer using ACPI so the ACPI code can use the IPMI namespace.
 * This function allows an ACPI-specified IPMI device to look up the
 * slave address from the DMI table.
 */
int ipmi_dmi_get_slave_addr(enum si_type si_type, unsigned int space,
			    unsigned long base_addr)
{
	struct ipmi_dmi_info *info = ipmi_dmi_infos;

	while (info) {
		if (info->si_type == si_type &&
		    info->space == space &&
		    info->addr == base_addr)
			return info->slave_addr;
		info = info->next;
	}

	return 0;
}
EXPORT_SYMBOL(ipmi_dmi_get_slave_addr);

#define DMI_IPMI_MIN_LENGTH	0x10
#define DMI_IPMI_VER2_LENGTH	0x12
#define DMI_IPMI_TYPE		4
#define DMI_IPMI_SLAVEADDR	6
#define DMI_IPMI_ADDR		8
#define DMI_IPMI_ACCESS		0x10
#define DMI_IPMI_IRQ		0x11
#define DMI_IPMI_IO_MASK	0xfffe

static void __init dmi_decode_ipmi(const struct dmi_header *dm)
{
	const u8 *data = (const u8 *) dm;
	int space = IPMI_IO_ADDR_SPACE;
	unsigned long base_addr;
	u8 len = dm->length;
	u8 slave_addr;
	int irq = 0, offset = 0;
	int type;

	if (len < DMI_IPMI_MIN_LENGTH)
		return;

	type = data[DMI_IPMI_TYPE];
	slave_addr = data[DMI_IPMI_SLAVEADDR];

	memcpy(&base_addr, data + DMI_IPMI_ADDR, sizeof(unsigned long));
	if (!base_addr) {
		pr_err("Base address is zero, assuming no IPMI interface\n");
		return;
	}
	if (len >= DMI_IPMI_VER2_LENGTH) {
		if (type == IPMI_DMI_TYPE_SSIF) {
			space = 0; /* Match I2C interface 0. */
			base_addr = data[DMI_IPMI_ADDR] >> 1;
			if (base_addr == 0) {
				/*
				 * Some broken systems put the I2C address in
				 * the slave address field.  We try to
				 * accommodate them here.
				 */
				base_addr = data[DMI_IPMI_SLAVEADDR] >> 1;
				slave_addr = 0;
			}
		} else {
			if (base_addr & 1) {
				/* I/O */
				base_addr &= DMI_IPMI_IO_MASK;
			} else {
				/* Memory */
				space = IPMI_MEM_ADDR_SPACE;
			}

			/*
			 * If bit 4 of byte 0x10 is set, then the lsb
			 * for the address is odd.
			 */
			base_addr |= (data[DMI_IPMI_ACCESS] >> 4) & 1;

			irq = data[DMI_IPMI_IRQ];

			/*
			 * The top two bits of byte 0x10 hold the
			 * register spacing.
			 */
			switch ((data[DMI_IPMI_ACCESS] >> 6) & 3) {
			case 0: /* Byte boundaries */
				offset = 1;
				break;
			case 1: /* 32-bit boundaries */
				offset = 4;
				break;
			case 2: /* 16-byte boundaries */
				offset = 16;
				break;
			default:
				pr_err("Invalid offset: 0\n");
				return;
			}
		}
	} else {
		/* Old DMI spec. */
		/*
		 * Note that technically, the lower bit of the base
		 * address should be 1 if the address is I/O and 0 if
		 * the address is in memory.  So many systems get that
		 * wrong (and all that I have seen are I/O) so we just
		 * ignore that bit and assume I/O.  Systems that use
		 * memory should use the newer spec, anyway.
		 */
		base_addr = base_addr & DMI_IPMI_IO_MASK;
		offset = 1;
	}

	dmi_add_platform_ipmi(base_addr, space, slave_addr, irq,
			      offset, type);
}

static int __init scan_for_dmi_ipmi(void)
{
	const struct dmi_device *dev = NULL;

	while ((dev = dmi_find_device(DMI_DEV_TYPE_IPMI, NULL, dev)))
		dmi_decode_ipmi((const struct dmi_header *) dev->device_data);

	return 0;
}
subsys_initcall(scan_for_dmi_ipmi);