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path: root/drivers/char/ipmi/ipmi_dmi.c
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Diffstat (limited to 'drivers/char/ipmi/ipmi_dmi.c')
-rw-r--r--drivers/char/ipmi/ipmi_dmi.c223
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 0000000000..bbf7029e22
--- /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);