Fixed MTP to work with TWRP

drivers/firmware/google/Kconfig

@@ -0,0 +1,31 @@
+config GOOGLE_FIRMWARE
+	bool "Google Firmware Drivers"
+	depends on X86
+	default n
+	help
+	  These firmware drivers are used by Google's servers.  They are
+	  only useful if you are working directly on one of their
+	  proprietary servers.  If in doubt, say "N".
+
+menu "Google Firmware Drivers"
+	depends on GOOGLE_FIRMWARE
+
+config GOOGLE_SMI
+	tristate "SMI interface for Google platforms"
+	depends on ACPI && DMI && EFI
+	select EFI_VARS
+	help
+	  Say Y here if you want to enable SMI callbacks for Google
+	  platforms.  This provides an interface for writing to and
+	  clearing the EFI event log and reading and writing NVRAM
+	  variables.
+
+config GOOGLE_MEMCONSOLE
+	tristate "Firmware Memory Console"
+	depends on DMI
+	help
+	  This option enables the kernel to search for a firmware log in
+	  the EBDA on Google servers.  If found, this log is exported to
+	  userland in the file /sys/firmware/log.
+
+endmenu

drivers/firmware/google/Makefile

@@ -0,0 +1,3 @@
+
+obj-$(CONFIG_GOOGLE_SMI)		+= gsmi.o
+obj-$(CONFIG_GOOGLE_MEMCONSOLE)		+= memconsole.o

drivers/firmware/google/gsmi.c

@@ -0,0 +1,942 @@
+/*
+ * 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(&param.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, &param, 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(&param, 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(&param.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, &param, 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(&param, 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, &param.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(&param.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, &param, 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, &param, 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, &param, 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, &param, 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");

drivers/firmware/google/memconsole.c

@@ -0,0 +1,171 @@
+/*
+ * memconsole.c
+ *
+ * Infrastructure for importing the BIOS memory based console
+ * into the kernel log ringbuffer.
+ *
+ * Copyright 2010 Google Inc. All rights reserved.
+ */
+
+#include <linux/ctype.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/dmi.h>
+#include <linux/io.h>
+#include <asm/bios_ebda.h>
+
+#define BIOS_MEMCONSOLE_V1_MAGIC	0xDEADBABE
+#define BIOS_MEMCONSOLE_V2_MAGIC	(('M')|('C'<<8)|('O'<<16)|('N'<<24))
+
+struct biosmemcon_ebda {
+	u32 signature;
+	union {
+		struct {
+			u8  enabled;
+			u32 buffer_addr;
+			u16 start;
+			u16 end;
+			u16 num_chars;
+			u8  wrapped;
+		} __packed v1;
+		struct {
+			u32 buffer_addr;
+			/* Misdocumented as number of pages! */
+			u16 num_bytes;
+			u16 start;
+			u16 end;
+		} __packed v2;
+	};
+} __packed;
+
+static u32 memconsole_baseaddr;
+static size_t memconsole_length;
+
+static ssize_t memconsole_read(struct file *filp, struct kobject *kobp,
+			       struct bin_attribute *bin_attr, char *buf,
+			       loff_t pos, size_t count)
+{
+	char *memconsole;
+	ssize_t ret;
+
+	memconsole = ioremap_cache(memconsole_baseaddr, memconsole_length);
+	if (!memconsole) {
+		pr_err("memconsole: ioremap_cache failed\n");
+		return -ENOMEM;
+	}
+	ret = memory_read_from_buffer(buf, count, &pos, memconsole,
+				      memconsole_length);
+	iounmap(memconsole);
+	return ret;
+}
+
+static struct bin_attribute memconsole_bin_attr = {
+	.attr = {.name = "log", .mode = 0444},
+	.read = memconsole_read,
+};
+
+
+static void __init found_v1_header(struct biosmemcon_ebda *hdr)
+{
+	pr_info("BIOS console v1 EBDA structure found at %p\n", hdr);
+	pr_info("BIOS console buffer at 0x%.8x, "
+	       "start = %d, end = %d, num = %d\n",
+	       hdr->v1.buffer_addr, hdr->v1.start,
+	       hdr->v1.end, hdr->v1.num_chars);
+
+	memconsole_length = hdr->v1.num_chars;
+	memconsole_baseaddr = hdr->v1.buffer_addr;
+}
+
+static void __init found_v2_header(struct biosmemcon_ebda *hdr)
+{
+	pr_info("BIOS console v2 EBDA structure found at %p\n", hdr);
+	pr_info("BIOS console buffer at 0x%.8x, "
+	       "start = %d, end = %d, num_bytes = %d\n",
+	       hdr->v2.buffer_addr, hdr->v2.start,
+	       hdr->v2.end, hdr->v2.num_bytes);
+
+	memconsole_length = hdr->v2.end - hdr->v2.start;
+	memconsole_baseaddr = hdr->v2.buffer_addr + hdr->v2.start;
+}
+
+/*
+ * Search through the EBDA for the BIOS Memory Console, and
+ * set the global variables to point to it.  Return true if found.
+ */
+static bool __init found_memconsole(void)
+{
+	unsigned int address;
+	size_t length, cur;
+
+	address = get_bios_ebda();
+	if (!address) {
+		pr_info("BIOS EBDA non-existent.\n");
+		return false;
+	}
+
+	/* EBDA length is byte 0 of EBDA (in KB) */
+	length = *(u8 *)phys_to_virt(address);
+	length <<= 10; /* convert to bytes */
+
+	/*
+	 * Search through EBDA for BIOS memory console structure
+	 * note: signature is not necessarily dword-aligned
+	 */
+	for (cur = 0; cur < length; cur++) {
+		struct biosmemcon_ebda *hdr = phys_to_virt(address + cur);
+
+		/* memconsole v1 */
+		if (hdr->signature == BIOS_MEMCONSOLE_V1_MAGIC) {
+			found_v1_header(hdr);
+			return true;
+		}
+
+		/* memconsole v2 */
+		if (hdr->signature == BIOS_MEMCONSOLE_V2_MAGIC) {
+			found_v2_header(hdr);
+			return true;
+		}
+	}
+
+	pr_info("BIOS console EBDA structure not found!\n");
+	return false;
+}
+
+static struct dmi_system_id memconsole_dmi_table[] __initdata = {
+	{
+		.ident = "Google Board",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Google, Inc."),
+		},
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(dmi, memconsole_dmi_table);
+
+static int __init memconsole_init(void)
+{
+	if (!dmi_check_system(memconsole_dmi_table))
+		return -ENODEV;
+
+	if (!found_memconsole())
+		return -ENODEV;
+
+	memconsole_bin_attr.size = memconsole_length;
+	return sysfs_create_bin_file(firmware_kobj, &memconsole_bin_attr);
+}
+
+static void __exit memconsole_exit(void)
+{
+	sysfs_remove_bin_file(firmware_kobj, &memconsole_bin_attr);
+}
+
+module_init(memconsole_init);
+module_exit(memconsole_exit);
+
+MODULE_AUTHOR("Google, Inc.");
+MODULE_LICENSE("GPL");