diff options
Diffstat (limited to 'drivers/char/ipmi/ipmi_dmi.c')
| -rw-r--r-- | drivers/char/ipmi/ipmi_dmi.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/char/ipmi/ipmi_dmi.c b/drivers/char/ipmi/ipmi_dmi.c new file mode 100644 index 000000000..bbf7029e2 --- /dev/null +++ b/drivers/char/ipmi/ipmi_dmi.c @@ -0,0 +1,223 @@ +// 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_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"; + p.iftype = IPMI_PLAT_IF_SI; + switch (type) { + case IPMI_DMI_TYPE_SSIF: + name = "dmi-ipmi-ssif"; + p.iftype = IPMI_PLAT_IF_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; + } + + 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); |