--- /dev/null
+/*
+ * Copyright 2010 Google Inc. All Rights Reserved.
+ * Author: dlaurie@google.com (Duncan Laurie)
+ *
+ * Re-worked to expose sysfs APIs by mikew@google.com (Mike Waychison)
+ *
+ * EFI SMI interface for Google platforms
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/spinlock.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/ioctl.h>
+#include <linux/acpi.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/dmi.h>
+#include <linux/kdebug.h>
+#include <linux/reboot.h>
+#include <linux/efi.h>
+#include <linux/module.h>
+#include <linux/ucs2_string.h>
+
+#define GSMI_SHUTDOWN_CLEAN 0 /* Clean Shutdown */
+/* TODO(mikew@google.com): Tie in HARDLOCKUP_DETECTOR with NMIWDT */
+#define GSMI_SHUTDOWN_NMIWDT 1 /* NMI Watchdog */
+#define GSMI_SHUTDOWN_PANIC 2 /* Panic */
+#define GSMI_SHUTDOWN_OOPS 3 /* Oops */
+#define GSMI_SHUTDOWN_DIE 4 /* Die -- No longer meaningful */
+#define GSMI_SHUTDOWN_MCE 5 /* Machine Check */
+#define GSMI_SHUTDOWN_SOFTWDT 6 /* Software Watchdog */
+#define GSMI_SHUTDOWN_MBE 7 /* Uncorrected ECC */
+#define GSMI_SHUTDOWN_TRIPLE 8 /* Triple Fault */
+
+#define DRIVER_VERSION "1.0"
+#define GSMI_GUID_SIZE 16
+#define GSMI_BUF_SIZE 1024
+#define GSMI_BUF_ALIGN sizeof(u64)
+#define GSMI_CALLBACK 0xef
+
+/* SMI return codes */
+#define GSMI_SUCCESS 0x00
+#define GSMI_UNSUPPORTED2 0x03
+#define GSMI_LOG_FULL 0x0b
+#define GSMI_VAR_NOT_FOUND 0x0e
+#define GSMI_HANDSHAKE_SPIN 0x7d
+#define GSMI_HANDSHAKE_CF 0x7e
+#define GSMI_HANDSHAKE_NONE 0x7f
+#define GSMI_INVALID_PARAMETER 0x82
+#define GSMI_UNSUPPORTED 0x83
+#define GSMI_BUFFER_TOO_SMALL 0x85
+#define GSMI_NOT_READY 0x86
+#define GSMI_DEVICE_ERROR 0x87
+#define GSMI_NOT_FOUND 0x8e
+
+#define QUIRKY_BOARD_HASH 0x78a30a50
+
+/* Internally used commands passed to the firmware */
+#define GSMI_CMD_GET_NVRAM_VAR 0x01
+#define GSMI_CMD_GET_NEXT_VAR 0x02
+#define GSMI_CMD_SET_NVRAM_VAR 0x03
+#define GSMI_CMD_SET_EVENT_LOG 0x08
+#define GSMI_CMD_CLEAR_EVENT_LOG 0x09
+#define GSMI_CMD_CLEAR_CONFIG 0x20
+#define GSMI_CMD_HANDSHAKE_TYPE 0xC1
+
+/* Magic entry type for kernel events */
+#define GSMI_LOG_ENTRY_TYPE_KERNEL 0xDEAD
+
+/* SMI buffers must be in 32bit physical address space */
+struct gsmi_buf {
+ u8 *start; /* start of buffer */
+ size_t length; /* length of buffer */
+ dma_addr_t handle; /* dma allocation handle */
+ u32 address; /* physical address of buffer */
+};
+
+struct gsmi_device {
+ struct platform_device *pdev; /* platform device */
+ struct gsmi_buf *name_buf; /* variable name buffer */
+ struct gsmi_buf *data_buf; /* generic data buffer */
+ struct gsmi_buf *param_buf; /* parameter buffer */
+ spinlock_t lock; /* serialize access to SMIs */
+ u16 smi_cmd; /* SMI command port */
+ int handshake_type; /* firmware handler interlock type */
+ struct dma_pool *dma_pool; /* DMA buffer pool */
+} gsmi_dev;
+
+/* Packed structures for communicating with the firmware */
+struct gsmi_nvram_var_param {
+ efi_guid_t guid;
+ u32 name_ptr;
+ u32 attributes;
+ u32 data_len;
+ u32 data_ptr;
+} __packed;
+
+struct gsmi_get_next_var_param {
+ u8 guid[GSMI_GUID_SIZE];
+ u32 name_ptr;
+ u32 name_len;
+} __packed;
+
+struct gsmi_set_eventlog_param {
+ u32 data_ptr;
+ u32 data_len;
+ u32 type;
+} __packed;
+
+/* Event log formats */
+struct gsmi_log_entry_type_1 {
+ u16 type;
+ u32 instance;
+} __packed;
+
+
+/*
+ * Some platforms don't have explicit SMI handshake
+ * and need to wait for SMI to complete.
+ */
+#define GSMI_DEFAULT_SPINCOUNT 0x10000
+static unsigned int spincount = GSMI_DEFAULT_SPINCOUNT;
+module_param(spincount, uint, 0600);
+MODULE_PARM_DESC(spincount,
+ "The number of loop iterations to use when using the spin handshake.");
+
+static struct gsmi_buf *gsmi_buf_alloc(void)
+{
+ struct gsmi_buf *smibuf;
+
+ smibuf = kzalloc(sizeof(*smibuf), GFP_KERNEL);
+ if (!smibuf) {
+ printk(KERN_ERR "gsmi: out of memory\n");
+ return NULL;
+ }
+
+ /* allocate buffer in 32bit address space */
+ smibuf->start = dma_pool_alloc(gsmi_dev.dma_pool, GFP_KERNEL,
+ &smibuf->handle);
+ if (!smibuf->start) {
+ printk(KERN_ERR "gsmi: failed to allocate name buffer\n");
+ kfree(smibuf);
+ return NULL;
+ }
+
+ /* fill in the buffer handle */
+ smibuf->length = GSMI_BUF_SIZE;
+ smibuf->address = (u32)virt_to_phys(smibuf->start);
+
+ return smibuf;
+}
+
+static void gsmi_buf_free(struct gsmi_buf *smibuf)
+{
+ if (smibuf) {
+ if (smibuf->start)
+ dma_pool_free(gsmi_dev.dma_pool, smibuf->start,
+ smibuf->handle);
+ kfree(smibuf);
+ }
+}
+
+/*
+ * Make a call to gsmi func(sub). GSMI error codes are translated to
+ * in-kernel errnos (0 on success, -ERRNO on error).
+ */
+static int gsmi_exec(u8 func, u8 sub)
+{
+ u16 cmd = (sub << 8) | func;
+ u16 result = 0;
+ int rc = 0;
+
+ /*
+ * AH : Subfunction number
+ * AL : Function number
+ * EBX : Parameter block address
+ * DX : SMI command port
+ *
+ * Three protocols here. See also the comment in gsmi_init().
+ */
+ if (gsmi_dev.handshake_type == GSMI_HANDSHAKE_CF) {
+ /*
+ * If handshake_type == HANDSHAKE_CF then set CF on the
+ * way in and wait for the handler to clear it; this avoids
+ * corrupting register state on those chipsets which have
+ * a delay between writing the SMI trigger register and
+ * entering SMM.
+ */
+ asm volatile (
+ "stc\n"
+ "outb %%al, %%dx\n"
+ "1: jc 1b\n"
+ : "=a" (result)
+ : "0" (cmd),
+ "d" (gsmi_dev.smi_cmd),
+ "b" (gsmi_dev.param_buf->address)
+ : "memory", "cc"
+ );
+ } else if (gsmi_dev.handshake_type == GSMI_HANDSHAKE_SPIN) {
+ /*
+ * If handshake_type == HANDSHAKE_SPIN we spin a
+ * hundred-ish usecs to ensure the SMI has triggered.
+ */
+ asm volatile (
+ "outb %%al, %%dx\n"
+ "1: loop 1b\n"
+ : "=a" (result)
+ : "0" (cmd),
+ "d" (gsmi_dev.smi_cmd),
+ "b" (gsmi_dev.param_buf->address),
+ "c" (spincount)
+ : "memory", "cc"
+ );
+ } else {
+ /*
+ * If handshake_type == HANDSHAKE_NONE we do nothing;
+ * either we don't need to or it's legacy firmware that
+ * doesn't understand the CF protocol.
+ */
+ asm volatile (
+ "outb %%al, %%dx\n\t"
+ : "=a" (result)
+ : "0" (cmd),
+ "d" (gsmi_dev.smi_cmd),
+ "b" (gsmi_dev.param_buf->address)
+ : "memory", "cc"
+ );
+ }
+
+ /* check return code from SMI handler */
+ switch (result) {
+ case GSMI_SUCCESS:
+ break;
+ case GSMI_VAR_NOT_FOUND:
+ /* not really an error, but let the caller know */
+ rc = 1;
+ break;
+ case GSMI_INVALID_PARAMETER:
+ printk(KERN_ERR "gsmi: exec 0x%04x: Invalid parameter\n", cmd);
+ rc = -EINVAL;
+ break;
+ case GSMI_BUFFER_TOO_SMALL:
+ printk(KERN_ERR "gsmi: exec 0x%04x: Buffer too small\n", cmd);
+ rc = -ENOMEM;
+ break;
+ case GSMI_UNSUPPORTED:
+ case GSMI_UNSUPPORTED2:
+ if (sub != GSMI_CMD_HANDSHAKE_TYPE)
+ printk(KERN_ERR "gsmi: exec 0x%04x: Not supported\n",
+ cmd);
+ rc = -ENOSYS;
+ break;
+ case GSMI_NOT_READY:
+ printk(KERN_ERR "gsmi: exec 0x%04x: Not ready\n", cmd);
+ rc = -EBUSY;
+ break;
+ case GSMI_DEVICE_ERROR:
+ printk(KERN_ERR "gsmi: exec 0x%04x: Device error\n", cmd);
+ rc = -EFAULT;
+ break;
+ case GSMI_NOT_FOUND:
+ printk(KERN_ERR "gsmi: exec 0x%04x: Data not found\n", cmd);
+ rc = -ENOENT;
+ break;
+ case GSMI_LOG_FULL:
+ printk(KERN_ERR "gsmi: exec 0x%04x: Log full\n", cmd);
+ rc = -ENOSPC;
+ break;
+ case GSMI_HANDSHAKE_CF:
+ case GSMI_HANDSHAKE_SPIN:
+ case GSMI_HANDSHAKE_NONE:
+ rc = result;
+ break;
+ default:
+ printk(KERN_ERR "gsmi: exec 0x%04x: Unknown error 0x%04x\n",
+ cmd, result);
+ rc = -ENXIO;
+ }
+
+ return rc;
+}
+
+static efi_status_t gsmi_get_variable(efi_char16_t *name,
+ efi_guid_t *vendor, u32 *attr,
+ unsigned long *data_size,
+ void *data)
+{
+ struct gsmi_nvram_var_param param = {
+ .name_ptr = gsmi_dev.name_buf->address,
+ .data_ptr = gsmi_dev.data_buf->address,
+ .data_len = (u32)*data_size,
+ };
+ efi_status_t ret = EFI_SUCCESS;
+ unsigned long flags;
+ size_t name_len = ucs2_strnlen(name, GSMI_BUF_SIZE / 2);
+ int rc;
+
+ if (name_len >= GSMI_BUF_SIZE / 2)
+ return EFI_BAD_BUFFER_SIZE;
+
+ spin_lock_irqsave(&gsmi_dev.lock, flags);
+
+ /* Vendor guid */
+ memcpy(¶m.guid, vendor, sizeof(param.guid));
+
+ /* variable name, already in UTF-16 */
+ memset(gsmi_dev.name_buf->start, 0, gsmi_dev.name_buf->length);
+ memcpy(gsmi_dev.name_buf->start, name, name_len * 2);
+
+ /* data pointer */
+ memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
+
+ /* parameter buffer */
+ memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
+ memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
+
+ rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_GET_NVRAM_VAR);
+ if (rc < 0) {
+ printk(KERN_ERR "gsmi: Get Variable failed\n");
+ ret = EFI_LOAD_ERROR;
+ } else if (rc == 1) {
+ /* variable was not found */
+ ret = EFI_NOT_FOUND;
+ } else {
+ /* Get the arguments back */
+ memcpy(¶m, gsmi_dev.param_buf->start, sizeof(param));
+
+ /* The size reported is the min of all of our buffers */
+ *data_size = min_t(unsigned long, *data_size,
+ gsmi_dev.data_buf->length);
+ *data_size = min_t(unsigned long, *data_size, param.data_len);
+
+ /* Copy data back to return buffer. */
+ memcpy(data, gsmi_dev.data_buf->start, *data_size);
+
+ /* All variables are have the following attributes */
+ *attr = EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS;
+ }
+
+ spin_unlock_irqrestore(&gsmi_dev.lock, flags);
+
+ return ret;
+}
+
+static efi_status_t gsmi_get_next_variable(unsigned long *name_size,
+ efi_char16_t *name,
+ efi_guid_t *vendor)
+{
+ struct gsmi_get_next_var_param param = {
+ .name_ptr = gsmi_dev.name_buf->address,
+ .name_len = gsmi_dev.name_buf->length,
+ };
+ efi_status_t ret = EFI_SUCCESS;
+ int rc;
+ unsigned long flags;
+
+ /* For the moment, only support buffers that exactly match in size */
+ if (*name_size != GSMI_BUF_SIZE)
+ return EFI_BAD_BUFFER_SIZE;
+
+ /* Let's make sure the thing is at least null-terminated */
+ if (ucs2_strnlen(name, GSMI_BUF_SIZE / 2) == GSMI_BUF_SIZE / 2)
+ return EFI_INVALID_PARAMETER;
+
+ spin_lock_irqsave(&gsmi_dev.lock, flags);
+
+ /* guid */
+ memcpy(¶m.guid, vendor, sizeof(param.guid));
+
+ /* variable name, already in UTF-16 */
+ memcpy(gsmi_dev.name_buf->start, name, *name_size);
+
+ /* parameter buffer */
+ memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
+ memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
+
+ rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_GET_NEXT_VAR);
+ if (rc < 0) {
+ printk(KERN_ERR "gsmi: Get Next Variable Name failed\n");
+ ret = EFI_LOAD_ERROR;
+ } else if (rc == 1) {
+ /* variable not found -- end of list */
+ ret = EFI_NOT_FOUND;
+ } else {
+ /* copy variable data back to return buffer */
+ memcpy(¶m, gsmi_dev.param_buf->start, sizeof(param));
+
+ /* Copy the name back */
+ memcpy(name, gsmi_dev.name_buf->start, GSMI_BUF_SIZE);
+ *name_size = ucs2_strnlen(name, GSMI_BUF_SIZE / 2) * 2;
+
+ /* copy guid to return buffer */
+ memcpy(vendor, ¶m.guid, sizeof(param.guid));
+ ret = EFI_SUCCESS;
+ }
+
+ spin_unlock_irqrestore(&gsmi_dev.lock, flags);
+
+ return ret;
+}
+
+static efi_status_t gsmi_set_variable(efi_char16_t *name,
+ efi_guid_t *vendor,
+ u32 attr,
+ unsigned long data_size,
+ void *data)
+{
+ struct gsmi_nvram_var_param param = {
+ .name_ptr = gsmi_dev.name_buf->address,
+ .data_ptr = gsmi_dev.data_buf->address,
+ .data_len = (u32)data_size,
+ .attributes = EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS,
+ };
+ size_t name_len = ucs2_strnlen(name, GSMI_BUF_SIZE / 2);
+ efi_status_t ret = EFI_SUCCESS;
+ int rc;
+ unsigned long flags;
+
+ if (name_len >= GSMI_BUF_SIZE / 2)
+ return EFI_BAD_BUFFER_SIZE;
+
+ spin_lock_irqsave(&gsmi_dev.lock, flags);
+
+ /* guid */
+ memcpy(¶m.guid, vendor, sizeof(param.guid));
+
+ /* variable name, already in UTF-16 */
+ memset(gsmi_dev.name_buf->start, 0, gsmi_dev.name_buf->length);
+ memcpy(gsmi_dev.name_buf->start, name, name_len * 2);
+
+ /* data pointer */
+ memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
+ memcpy(gsmi_dev.data_buf->start, data, data_size);
+
+ /* parameter buffer */
+ memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
+ memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
+
+ rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_NVRAM_VAR);
+ if (rc < 0) {
+ printk(KERN_ERR "gsmi: Set Variable failed\n");
+ ret = EFI_INVALID_PARAMETER;
+ }
+
+ spin_unlock_irqrestore(&gsmi_dev.lock, flags);
+
+ return ret;
+}
+
+static const struct efivar_operations efivar_ops = {
+ .get_variable = gsmi_get_variable,
+ .set_variable = gsmi_set_variable,
+ .get_next_variable = gsmi_get_next_variable,
+};
+
+static ssize_t eventlog_write(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buf, loff_t pos, size_t count)
+{
+ struct gsmi_set_eventlog_param param = {
+ .data_ptr = gsmi_dev.data_buf->address,
+ };
+ int rc = 0;
+ unsigned long flags;
+
+ /* Pull the type out */
+ if (count < sizeof(u32))
+ return -EINVAL;
+ param.type = *(u32 *)buf;
+ count -= sizeof(u32);
+ buf += sizeof(u32);
+
+ /* The remaining buffer is the data payload */
+ if (count > gsmi_dev.data_buf->length)
+ return -EINVAL;
+ param.data_len = count - sizeof(u32);
+
+ spin_lock_irqsave(&gsmi_dev.lock, flags);
+
+ /* data pointer */
+ memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
+ memcpy(gsmi_dev.data_buf->start, buf, param.data_len);
+
+ /* parameter buffer */
+ memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
+ memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
+
+ rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_EVENT_LOG);
+ if (rc < 0)
+ printk(KERN_ERR "gsmi: Set Event Log failed\n");
+
+ spin_unlock_irqrestore(&gsmi_dev.lock, flags);
+
+ return rc;
+
+}
+
+static struct bin_attribute eventlog_bin_attr = {
+ .attr = {.name = "append_to_eventlog", .mode = 0200},
+ .write = eventlog_write,
+};
+
+static ssize_t gsmi_clear_eventlog_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int rc;
+ unsigned long flags;
+ unsigned long val;
+ struct {
+ u32 percentage;
+ u32 data_type;
+ } param;
+
+ rc = kstrtoul(buf, 0, &val);
+ if (rc)
+ return rc;
+
+ /*
+ * Value entered is a percentage, 0 through 100, anything else
+ * is invalid.
+ */
+ if (val > 100)
+ return -EINVAL;
+
+ /* data_type here selects the smbios event log. */
+ param.percentage = val;
+ param.data_type = 0;
+
+ spin_lock_irqsave(&gsmi_dev.lock, flags);
+
+ /* parameter buffer */
+ memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
+ memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
+
+ rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_CLEAR_EVENT_LOG);
+
+ spin_unlock_irqrestore(&gsmi_dev.lock, flags);
+
+ if (rc)
+ return rc;
+ return count;
+}
+
+static struct kobj_attribute gsmi_clear_eventlog_attr = {
+ .attr = {.name = "clear_eventlog", .mode = 0200},
+ .store = gsmi_clear_eventlog_store,
+};
+
+static ssize_t gsmi_clear_config_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int rc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&gsmi_dev.lock, flags);
+
+ /* clear parameter buffer */
+ memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
+
+ rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_CLEAR_CONFIG);
+
+ spin_unlock_irqrestore(&gsmi_dev.lock, flags);
+
+ if (rc)
+ return rc;
+ return count;
+}
+
+static struct kobj_attribute gsmi_clear_config_attr = {
+ .attr = {.name = "clear_config", .mode = 0200},
+ .store = gsmi_clear_config_store,
+};
+
+static const struct attribute *gsmi_attrs[] = {
+ &gsmi_clear_config_attr.attr,
+ &gsmi_clear_eventlog_attr.attr,
+ NULL,
+};
+
+static int gsmi_shutdown_reason(int reason)
+{
+ struct gsmi_log_entry_type_1 entry = {
+ .type = GSMI_LOG_ENTRY_TYPE_KERNEL,
+ .instance = reason,
+ };
+ struct gsmi_set_eventlog_param param = {
+ .data_len = sizeof(entry),
+ .type = 1,
+ };
+ static int saved_reason;
+ int rc = 0;
+ unsigned long flags;
+
+ /* avoid duplicate entries in the log */
+ if (saved_reason & (1 << reason))
+ return 0;
+
+ spin_lock_irqsave(&gsmi_dev.lock, flags);
+
+ saved_reason |= (1 << reason);
+
+ /* data pointer */
+ memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
+ memcpy(gsmi_dev.data_buf->start, &entry, sizeof(entry));
+
+ /* parameter buffer */
+ param.data_ptr = gsmi_dev.data_buf->address;
+ memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
+ memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
+
+ rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_EVENT_LOG);
+
+ spin_unlock_irqrestore(&gsmi_dev.lock, flags);
+
+ if (rc < 0)
+ printk(KERN_ERR "gsmi: Log Shutdown Reason failed\n");
+ else
+ printk(KERN_EMERG "gsmi: Log Shutdown Reason 0x%02x\n",
+ reason);
+
+ return rc;
+}
+
+static int gsmi_reboot_callback(struct notifier_block *nb,
+ unsigned long reason, void *arg)
+{
+ gsmi_shutdown_reason(GSMI_SHUTDOWN_CLEAN);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block gsmi_reboot_notifier = {
+ .notifier_call = gsmi_reboot_callback
+};
+
+static int gsmi_die_callback(struct notifier_block *nb,
+ unsigned long reason, void *arg)
+{
+ if (reason == DIE_OOPS)
+ gsmi_shutdown_reason(GSMI_SHUTDOWN_OOPS);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block gsmi_die_notifier = {
+ .notifier_call = gsmi_die_callback
+};
+
+static int gsmi_panic_callback(struct notifier_block *nb,
+ unsigned long reason, void *arg)
+{
+ gsmi_shutdown_reason(GSMI_SHUTDOWN_PANIC);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block gsmi_panic_notifier = {
+ .notifier_call = gsmi_panic_callback,
+};
+
+/*
+ * This hash function was blatantly copied from include/linux/hash.h.
+ * It is used by this driver to obfuscate a board name that requires a
+ * quirk within this driver.
+ *
+ * Please do not remove this copy of the function as any changes to the
+ * global utility hash_64() function would break this driver's ability
+ * to identify a board and provide the appropriate quirk -- mikew@google.com
+ */
+static u64 __init local_hash_64(u64 val, unsigned bits)
+{
+ u64 hash = val;
+
+ /* Sigh, gcc can't optimise this alone like it does for 32 bits. */
+ u64 n = hash;
+ n <<= 18;
+ hash -= n;
+ n <<= 33;
+ hash -= n;
+ n <<= 3;
+ hash += n;
+ n <<= 3;
+ hash -= n;
+ n <<= 4;
+ hash += n;
+ n <<= 2;
+ hash += n;
+
+ /* High bits are more random, so use them. */
+ return hash >> (64 - bits);
+}
+
+static u32 __init hash_oem_table_id(char s[8])
+{
+ u64 input;
+ memcpy(&input, s, 8);
+ return local_hash_64(input, 32);
+}
+
+static struct dmi_system_id gsmi_dmi_table[] __initdata = {
+ {
+ .ident = "Google Board",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Google, Inc."),
+ },
+ },
+ {}
+};
+MODULE_DEVICE_TABLE(dmi, gsmi_dmi_table);
+
+static __init int gsmi_system_valid(void)
+{
+ u32 hash;
+
+ if (!dmi_check_system(gsmi_dmi_table))
+ return -ENODEV;
+
+ /*
+ * Only newer firmware supports the gsmi interface. All older
+ * firmware that didn't support this interface used to plug the
+ * table name in the first four bytes of the oem_table_id field.
+ * Newer firmware doesn't do that though, so use that as the
+ * discriminant factor. We have to do this in order to
+ * whitewash our board names out of the public driver.
+ */
+ if (!strncmp(acpi_gbl_FADT.header.oem_table_id, "FACP", 4)) {
+ printk(KERN_INFO "gsmi: Board is too old\n");
+ return -ENODEV;
+ }
+
+ /* Disable on board with 1.0 BIOS due to Google bug 2602657 */
+ hash = hash_oem_table_id(acpi_gbl_FADT.header.oem_table_id);
+ if (hash == QUIRKY_BOARD_HASH) {
+ const char *bios_ver = dmi_get_system_info(DMI_BIOS_VERSION);
+ if (strncmp(bios_ver, "1.0", 3) == 0) {
+ pr_info("gsmi: disabled on this board's BIOS %s\n",
+ bios_ver);
+ return -ENODEV;
+ }
+ }
+
+ /* check for valid SMI command port in ACPI FADT */
+ if (acpi_gbl_FADT.smi_command == 0) {
+ pr_info("gsmi: missing smi_command\n");
+ return -ENODEV;
+ }
+
+ /* Found */
+ return 0;
+}
+
+static struct kobject *gsmi_kobj;
+static struct efivars efivars;
+
+static const struct platform_device_info gsmi_dev_info = {
+ .name = "gsmi",
+ .id = -1,
+ /* SMI callbacks require 32bit addresses */
+ .dma_mask = DMA_BIT_MASK(32),
+};
+
+static __init int gsmi_init(void)
+{
+ unsigned long flags;
+ int ret;
+
+ ret = gsmi_system_valid();
+ if (ret)
+ return ret;
+
+ gsmi_dev.smi_cmd = acpi_gbl_FADT.smi_command;
+
+ /* register device */
+ gsmi_dev.pdev = platform_device_register_full(&gsmi_dev_info);
+ if (IS_ERR(gsmi_dev.pdev)) {
+ printk(KERN_ERR "gsmi: unable to register platform device\n");
+ return PTR_ERR(gsmi_dev.pdev);
+ }
+
+ /* SMI access needs to be serialized */
+ spin_lock_init(&gsmi_dev.lock);
+
+ ret = -ENOMEM;
+ gsmi_dev.dma_pool = dma_pool_create("gsmi", &gsmi_dev.pdev->dev,
+ GSMI_BUF_SIZE, GSMI_BUF_ALIGN, 0);
+ if (!gsmi_dev.dma_pool)
+ goto out_err;
+
+ /*
+ * pre-allocate buffers because sometimes we are called when
+ * this is not feasible: oops, panic, die, mce, etc
+ */
+ gsmi_dev.name_buf = gsmi_buf_alloc();
+ if (!gsmi_dev.name_buf) {
+ printk(KERN_ERR "gsmi: failed to allocate name buffer\n");
+ goto out_err;
+ }
+
+ gsmi_dev.data_buf = gsmi_buf_alloc();
+ if (!gsmi_dev.data_buf) {
+ printk(KERN_ERR "gsmi: failed to allocate data buffer\n");
+ goto out_err;
+ }
+
+ gsmi_dev.param_buf = gsmi_buf_alloc();
+ if (!gsmi_dev.param_buf) {
+ printk(KERN_ERR "gsmi: failed to allocate param buffer\n");
+ goto out_err;
+ }
+
+ /*
+ * Determine type of handshake used to serialize the SMI
+ * entry. See also gsmi_exec().
+ *
+ * There's a "behavior" present on some chipsets where writing the
+ * SMI trigger register in the southbridge doesn't result in an
+ * immediate SMI. Rather, the processor can execute "a few" more
+ * instructions before the SMI takes effect. To ensure synchronous
+ * behavior, implement a handshake between the kernel driver and the
+ * firmware handler to spin until released. This ioctl determines
+ * the type of handshake.
+ *
+ * NONE: The firmware handler does not implement any
+ * handshake. Either it doesn't need to, or it's legacy firmware
+ * that doesn't know it needs to and never will.
+ *
+ * CF: The firmware handler will clear the CF in the saved
+ * state before returning. The driver may set the CF and test for
+ * it to clear before proceeding.
+ *
+ * SPIN: The firmware handler does not implement any handshake
+ * but the driver should spin for a hundred or so microseconds
+ * to ensure the SMI has triggered.
+ *
+ * Finally, the handler will return -ENOSYS if
+ * GSMI_CMD_HANDSHAKE_TYPE is unimplemented, which implies
+ * HANDSHAKE_NONE.
+ */
+ spin_lock_irqsave(&gsmi_dev.lock, flags);
+ gsmi_dev.handshake_type = GSMI_HANDSHAKE_SPIN;
+ gsmi_dev.handshake_type =
+ gsmi_exec(GSMI_CALLBACK, GSMI_CMD_HANDSHAKE_TYPE);
+ if (gsmi_dev.handshake_type == -ENOSYS)
+ gsmi_dev.handshake_type = GSMI_HANDSHAKE_NONE;
+ spin_unlock_irqrestore(&gsmi_dev.lock, flags);
+
+ /* Remove and clean up gsmi if the handshake could not complete. */
+ if (gsmi_dev.handshake_type == -ENXIO) {
+ printk(KERN_INFO "gsmi version " DRIVER_VERSION
+ " failed to load\n");
+ ret = -ENODEV;
+ goto out_err;
+ }
+
+ /* Register in the firmware directory */
+ ret = -ENOMEM;
+ gsmi_kobj = kobject_create_and_add("gsmi", firmware_kobj);
+ if (!gsmi_kobj) {
+ printk(KERN_INFO "gsmi: Failed to create firmware kobj\n");
+ goto out_err;
+ }
+
+ /* Setup eventlog access */
+ ret = sysfs_create_bin_file(gsmi_kobj, &eventlog_bin_attr);
+ if (ret) {
+ printk(KERN_INFO "gsmi: Failed to setup eventlog");
+ goto out_err;
+ }
+
+ /* Other attributes */
+ ret = sysfs_create_files(gsmi_kobj, gsmi_attrs);
+ if (ret) {
+ printk(KERN_INFO "gsmi: Failed to add attrs");
+ goto out_remove_bin_file;
+ }
+
+ ret = efivars_register(&efivars, &efivar_ops, gsmi_kobj);
+ if (ret) {
+ printk(KERN_INFO "gsmi: Failed to register efivars\n");
+ goto out_remove_sysfs_files;
+ }
+
+ register_reboot_notifier(&gsmi_reboot_notifier);
+ register_die_notifier(&gsmi_die_notifier);
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &gsmi_panic_notifier);
+
+ printk(KERN_INFO "gsmi version " DRIVER_VERSION " loaded\n");
+
+ return 0;
+
+out_remove_sysfs_files:
+ sysfs_remove_files(gsmi_kobj, gsmi_attrs);
+out_remove_bin_file:
+ sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr);
+out_err:
+ kobject_put(gsmi_kobj);
+ gsmi_buf_free(gsmi_dev.param_buf);
+ gsmi_buf_free(gsmi_dev.data_buf);
+ gsmi_buf_free(gsmi_dev.name_buf);
+ if (gsmi_dev.dma_pool)
+ dma_pool_destroy(gsmi_dev.dma_pool);
+ platform_device_unregister(gsmi_dev.pdev);
+ pr_info("gsmi: failed to load: %d\n", ret);
+ return ret;
+}
+
+static void __exit gsmi_exit(void)
+{
+ unregister_reboot_notifier(&gsmi_reboot_notifier);
+ unregister_die_notifier(&gsmi_die_notifier);
+ atomic_notifier_chain_unregister(&panic_notifier_list,
+ &gsmi_panic_notifier);
+ efivars_unregister(&efivars);
+
+ sysfs_remove_files(gsmi_kobj, gsmi_attrs);
+ sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr);
+ kobject_put(gsmi_kobj);
+ gsmi_buf_free(gsmi_dev.param_buf);
+ gsmi_buf_free(gsmi_dev.data_buf);
+ gsmi_buf_free(gsmi_dev.name_buf);
+ dma_pool_destroy(gsmi_dev.dma_pool);
+ platform_device_unregister(gsmi_dev.pdev);
+}
+
+module_init(gsmi_init);
+module_exit(gsmi_exit);
+
+MODULE_AUTHOR("Google, Inc.");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff