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1// SPDX-License-Identifier: GPL-2.0+2/*3 * A hack to create a platform device from a DMI entry. This will4 * allow autoloading of the IPMI drive based on SMBIOS entries.5 */6 7#define pr_fmt(fmt) "%s" fmt, "ipmi:dmi: "8#define dev_fmt pr_fmt9 10#include <linux/ipmi.h>11#include <linux/init.h>12#include <linux/dmi.h>13#include <linux/platform_device.h>14#include <linux/property.h>15#include "ipmi_dmi.h"16#include "ipmi_plat_data.h"17 18#define IPMI_DMI_TYPE_KCS 0x0119#define IPMI_DMI_TYPE_SMIC 0x0220#define IPMI_DMI_TYPE_BT 0x0321#define IPMI_DMI_TYPE_SSIF 0x0422 23struct ipmi_dmi_info {24 enum si_type si_type;25 unsigned int space; /* addr space for si, intf# for ssif */26 unsigned long addr;27 u8 slave_addr;28 struct ipmi_dmi_info *next;29};30 31static struct ipmi_dmi_info *ipmi_dmi_infos;32 33static int ipmi_dmi_nr __initdata;34 35static void __init dmi_add_platform_ipmi(unsigned long base_addr,36 unsigned int space,37 u8 slave_addr,38 int irq,39 int offset,40 int type)41{42 const char *name;43 struct ipmi_dmi_info *info;44 struct ipmi_plat_data p;45 46 memset(&p, 0, sizeof(p));47 48 name = "dmi-ipmi-si";49 p.iftype = IPMI_PLAT_IF_SI;50 switch (type) {51 case IPMI_DMI_TYPE_SSIF:52 name = "dmi-ipmi-ssif";53 p.iftype = IPMI_PLAT_IF_SSIF;54 p.type = SI_TYPE_INVALID;55 break;56 case IPMI_DMI_TYPE_BT:57 p.type = SI_BT;58 break;59 case IPMI_DMI_TYPE_KCS:60 p.type = SI_KCS;61 break;62 case IPMI_DMI_TYPE_SMIC:63 p.type = SI_SMIC;64 break;65 default:66 pr_err("Invalid IPMI type: %d\n", type);67 return;68 }69 70 p.addr = base_addr;71 p.space = space;72 p.regspacing = offset;73 p.irq = irq;74 p.slave_addr = slave_addr;75 p.addr_source = SI_SMBIOS;76 77 info = kmalloc(sizeof(*info), GFP_KERNEL);78 if (!info) {79 pr_warn("Could not allocate dmi info\n");80 } else {81 info->si_type = p.type;82 info->space = space;83 info->addr = base_addr;84 info->slave_addr = slave_addr;85 info->next = ipmi_dmi_infos;86 ipmi_dmi_infos = info;87 }88 89 if (ipmi_platform_add(name, ipmi_dmi_nr, &p))90 ipmi_dmi_nr++;91}92 93/*94 * Look up the slave address for a given interface. This is here95 * because ACPI doesn't have a slave address while SMBIOS does, but we96 * prefer using ACPI so the ACPI code can use the IPMI namespace.97 * This function allows an ACPI-specified IPMI device to look up the98 * slave address from the DMI table.99 */100int ipmi_dmi_get_slave_addr(enum si_type si_type, unsigned int space,101 unsigned long base_addr)102{103 struct ipmi_dmi_info *info = ipmi_dmi_infos;104 105 while (info) {106 if (info->si_type == si_type &&107 info->space == space &&108 info->addr == base_addr)109 return info->slave_addr;110 info = info->next;111 }112 113 return 0;114}115EXPORT_SYMBOL(ipmi_dmi_get_slave_addr);116 117#define DMI_IPMI_MIN_LENGTH 0x10118#define DMI_IPMI_VER2_LENGTH 0x12119#define DMI_IPMI_TYPE 4120#define DMI_IPMI_SLAVEADDR 6121#define DMI_IPMI_ADDR 8122#define DMI_IPMI_ACCESS 0x10123#define DMI_IPMI_IRQ 0x11124#define DMI_IPMI_IO_MASK 0xfffe125 126static void __init dmi_decode_ipmi(const struct dmi_header *dm)127{128 const u8 *data = (const u8 *) dm;129 int space = IPMI_IO_ADDR_SPACE;130 unsigned long base_addr;131 u8 len = dm->length;132 u8 slave_addr;133 int irq = 0, offset = 0;134 int type;135 136 if (len < DMI_IPMI_MIN_LENGTH)137 return;138 139 type = data[DMI_IPMI_TYPE];140 slave_addr = data[DMI_IPMI_SLAVEADDR];141 142 memcpy(&base_addr, data + DMI_IPMI_ADDR, sizeof(unsigned long));143 if (!base_addr) {144 pr_err("Base address is zero, assuming no IPMI interface\n");145 return;146 }147 if (len >= DMI_IPMI_VER2_LENGTH) {148 if (type == IPMI_DMI_TYPE_SSIF) {149 space = 0; /* Match I2C interface 0. */150 base_addr = data[DMI_IPMI_ADDR] >> 1;151 if (base_addr == 0) {152 /*153 * Some broken systems put the I2C address in154 * the slave address field. We try to155 * accommodate them here.156 */157 base_addr = data[DMI_IPMI_SLAVEADDR] >> 1;158 slave_addr = 0;159 }160 } else {161 if (base_addr & 1) {162 /* I/O */163 base_addr &= DMI_IPMI_IO_MASK;164 } else {165 /* Memory */166 space = IPMI_MEM_ADDR_SPACE;167 }168 169 /*170 * If bit 4 of byte 0x10 is set, then the lsb171 * for the address is odd.172 */173 base_addr |= (data[DMI_IPMI_ACCESS] >> 4) & 1;174 175 irq = data[DMI_IPMI_IRQ];176 177 /*178 * The top two bits of byte 0x10 hold the179 * register spacing.180 */181 switch ((data[DMI_IPMI_ACCESS] >> 6) & 3) {182 case 0: /* Byte boundaries */183 offset = 1;184 break;185 case 1: /* 32-bit boundaries */186 offset = 4;187 break;188 case 2: /* 16-byte boundaries */189 offset = 16;190 break;191 default:192 pr_err("Invalid offset: 0\n");193 return;194 }195 }196 } else {197 /* Old DMI spec. */198 /*199 * Note that technically, the lower bit of the base200 * address should be 1 if the address is I/O and 0 if201 * the address is in memory. So many systems get that202 * wrong (and all that I have seen are I/O) so we just203 * ignore that bit and assume I/O. Systems that use204 * memory should use the newer spec, anyway.205 */206 base_addr = base_addr & DMI_IPMI_IO_MASK;207 offset = 1;208 }209 210 dmi_add_platform_ipmi(base_addr, space, slave_addr, irq,211 offset, type);212}213 214static int __init scan_for_dmi_ipmi(void)215{216 const struct dmi_device *dev = NULL;217 218 while ((dev = dmi_find_device(DMI_DEV_TYPE_IPMI, NULL, dev)))219 dmi_decode_ipmi((const struct dmi_header *) dev->device_data);220 221 return 0;222}223subsys_initcall(scan_for_dmi_ipmi);224