[1/3] drivers/char/tpm: Add new device driver to support IBM vTPM

diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index c4aac48..915875e 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -73,4 +73,12 @@  config TCG_INFINEON
 	  Further information on this driver and the supported hardware
 	  can be found at http://www.trust.rub.de/projects/linux-device-driver-infineon-tpm/ 

+config TCG_IBMVTPM
+	tristate "IBM VTPM Interface"
+	depends on PPC64
+	---help---
+	  If you have IBM virtual TPM (VTPM) support say Yes and it
+	  will be accessible from within Linux.  To compile this driver
+	  as a module, choose M here; the module will be called tpm_ibmvtpm.
+
 endif # TCG_TPM
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index beac52f..547509d 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -11,3 +11,4 @@  obj-$(CONFIG_TCG_TIS_I2C_INFINEON) += tpm_i2c_infineon.o
 obj-$(CONFIG_TCG_NSC) += tpm_nsc.o
 obj-$(CONFIG_TCG_ATMEL) += tpm_atmel.o
 obj-$(CONFIG_TCG_INFINEON) += tpm_infineon.o
+obj-$(CONFIG_TCG_IBMVTPM) += tpm_ibmvtpm.o
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index b1c5280..aece857 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -94,6 +94,7 @@  struct tpm_vendor_specific {
 	bool timeout_adjusted;
 	unsigned long duration[3]; /* jiffies */
 	bool duration_adjusted;
+	void *data;
 
 	wait_queue_head_t read_queue;
 	wait_queue_head_t int_queue;
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
new file mode 100644
index 0000000..491133f
--- /dev/null
+++ b/drivers/char/tpm/tpm_ibmvtpm.c
@@ -0,0 +1,750 @@ 
+/*
+ * Copyright (C) 2012 IBM Corporation
+ *
+ * Author: Ashley Lai <adlai@us.ibm.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * Device driver for TCG/TCPA TPM (trusted platform module).
+ * Specifications at www.trustedcomputinggroup.org
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/slab.h>
+#include <asm/vio.h>
+#include <asm/irq.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+#include <asm/prom.h>
+
+#include "tpm.h"
+#include "tpm_ibmvtpm.h"
+
+static const char tpm_ibmvtpm_driver_name[] = "tpm_ibmvtpm";
+
+static struct vio_device_id tpm_ibmvtpm_device_table[] __devinitdata = {
+	{ "IBM,vtpm", "IBM,vtpm"},
+	{ "", "" }
+};
+MODULE_DEVICE_TABLE(vio, tpm_ibmvtpm_device_table);
+
+DECLARE_WAIT_QUEUE_HEAD(wq);
+
+/**
+ * ibmvtpm_send_crq - Send a CRQ request
+ * @vdev:	vio device struct
+ * @w1:		first word
+ * @w2:		second word
+ *
+ * Return value:
+ *	0 -Sucess
+ *	Non-zero - Failure
+ */
+static int ibmvtpm_send_crq(struct vio_dev *vdev, u64 w1, u64 w2)
+{
+	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, w1, w2);
+}
+
+/**
+ * ibmvtpm_get_data - Retrieve ibm vtpm data
+ * @dev:	device struct
+ *
+ * Return value:
+ *	vtpm device struct
+ */
+static struct ibmvtpm_dev *ibmvtpm_get_data(const struct device *dev)
+{
+	struct tpm_chip *chip = dev_get_drvdata(dev);
+	if (chip)
+		return (struct ibmvtpm_dev *)chip->vendor.data;
+	return NULL;
+}
+
+/**
+ * tpm_ibmvtpm_recv - Receive data after send
+ * @chip:	tpm chip struct
+ * @buf:	buffer to read
+ * count:	size of buffer
+ *
+ * Return value:
+ *	Number of bytes read
+ */
+static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	struct ibmvtpm_dev *ibmvtpm;
+	u16 len;
+
+	ibmvtpm = (struct ibmvtpm_dev *)chip->vendor.data;
+
+	if (!ibmvtpm->rtce_buf) {
+		dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
+		return 0;
+	}
+
+	wait_event_interruptible(wq, ibmvtpm->crq_res.len != 0);
+
+	if (count < ibmvtpm->crq_res.len) {
+		dev_err(ibmvtpm->dev,
+			"Invalid size in recv: count=%ld, crq_size=%d\n",
+			count, ibmvtpm->crq_res.len);
+		return -EIO;
+	}
+
+	spin_lock(&ibmvtpm->rtce_lock);
+	memcpy((void *)buf, (void *)ibmvtpm->rtce_buf, ibmvtpm->crq_res.len);
+	memset(ibmvtpm->rtce_buf, 0, ibmvtpm->crq_res.len);
+	ibmvtpm->crq_res.valid = 0;
+	ibmvtpm->crq_res.msg = 0;
+	len = ibmvtpm->crq_res.len;
+	ibmvtpm->crq_res.len = 0;
+	spin_unlock(&ibmvtpm->rtce_lock);
+	return len;
+}
+
+/**
+ * tpm_ibmvtpm_send - Send tpm request
+ * @chip:	tpm chip struct
+ * @buf:	buffer contains data to send
+ * count:	size of buffer
+ *
+ * Return value:
+ *	Number of bytes sent
+ */
+static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	struct ibmvtpm_dev *ibmvtpm;
+	struct ibmvtpm_crq crq;
+	u64 *word = (u64 *) &crq;
+	int rc;
+
+	ibmvtpm = (struct ibmvtpm_dev *)chip->vendor.data;
+
+	if (!ibmvtpm->rtce_buf) {
+		dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
+		return 0;
+	}
+
+	if (count > ibmvtpm->rtce_size) {
+		dev_err(ibmvtpm->dev,
+			"Invalid size in send: count=%ld, rtce_size=%d\n",
+			count, ibmvtpm->rtce_size);
+		return -EIO;
+	}
+
+	spin_lock(&ibmvtpm->rtce_lock);
+	memcpy((void *)ibmvtpm->rtce_buf, (void *)buf, count);
+	crq.valid = (u8)IBMVTPM_VALID_CMD;
+	crq.msg = (u8)VTPM_TPM_COMMAND;
+	crq.len = (u16)count;
+	crq.data = ibmvtpm->rtce_dma_handle;
+
+	rc = ibmvtpm_send_crq(ibmvtpm->vdev, word[0], word[1]);
+	if (rc != H_SUCCESS) {
+		dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed rc=%d\n", rc);
+		rc = 0;
+	} else
+		rc = count;
+
+	spin_unlock(&ibmvtpm->rtce_lock);
+	return rc;
+}
+
+static void tpm_ibmvtpm_cancel(struct tpm_chip *chip)
+{
+	return;
+}
+
+static u8 tpm_ibmvtpm_status(struct tpm_chip *chip)
+{
+	return 0;
+}
+
+/**
+ * ibmvtpm_crq_get_rtce_size - Send a CRQ request to get rtce size
+ * @ibmvtpm:	vtpm device struct
+ *
+ * Return value:
+ *	0 - Success
+ *	Non-zero - Failure
+ */
+static int ibmvtpm_crq_get_rtce_size(struct ibmvtpm_dev *ibmvtpm)
+{
+	struct ibmvtpm_crq crq;
+	u64 *buf = (u64 *) &crq;
+	int rc;
+
+	crq.valid = (u8)IBMVTPM_VALID_CMD;
+	crq.msg = (u8)VTPM_GET_RTCE_BUFFER_SIZE;
+
+	rc = ibmvtpm_send_crq(ibmvtpm->vdev, buf[0], buf[1]);
+	if (rc != H_SUCCESS)
+		dev_err(ibmvtpm->dev,
+			"ibmvtpm_crq_get_rtce_size failed rc=%d\n", rc);
+
+	return rc;
+}
+
+/**
+ * ibmvtpm_crq_get_version - Send a CRQ request to get vtpm version
+ *			   - Note that this is vtpm version and not tpm version
+ * @ibmvtpm:	vtpm device struct
+ *
+ * Return value:
+ *	0 - Success
+ *	Non-zero - Failure
+ */
+static int ibmvtpm_crq_get_version(struct ibmvtpm_dev *ibmvtpm)
+{
+	struct ibmvtpm_crq crq;
+	u64 *buf = (u64 *) &crq;
+	int rc;
+
+	crq.valid = (u8)IBMVTPM_VALID_CMD;
+	crq.msg = (u8)VTPM_GET_VERSION;
+
+	rc = ibmvtpm_send_crq(ibmvtpm->vdev, buf[0], buf[1]);
+	if (rc != H_SUCCESS)
+		dev_err(ibmvtpm->dev,
+			"ibmvtpm_crq_get_version failed rc=%d\n", rc);
+
+	return rc;
+}
+
+/**
+ * ibmvtpm_crq_send_init_complete - Send a CRQ initialize complete message
+ * @ibmvtpm:	vtpm device struct
+ *
+ * Return value:
+ *	0 - Success
+ *	Non-zero - Failure
+ */
+static int ibmvtpm_crq_send_init_complete(struct ibmvtpm_dev *ibmvtpm)
+{
+	int rc;
+
+	rc = ibmvtpm_send_crq(ibmvtpm->vdev, INIT_CRQ_COMP_CMD, 0);
+	if (rc != H_SUCCESS)
+		dev_err(ibmvtpm->dev,
+			"ibmvtpm_crq_send_init_complete failed rc=%d\n", rc);
+
+	return rc;
+}
+
+/**
+ * ibmvtpm_crq_send_init - Send a CRQ initialize message
+ * @ibmvtpm:	vtpm device struct
+ *
+ * Return value:
+ *	0 - Success
+ *	Non-zero - Failure
+ */
+static int ibmvtpm_crq_send_init(struct ibmvtpm_dev *ibmvtpm)
+{
+	int rc;
+
+	rc = ibmvtpm_send_crq(ibmvtpm->vdev, INIT_CRQ_CMD, 0);
+	if (rc != H_SUCCESS)
+		dev_err(ibmvtpm->dev,
+			"ibmvtpm_crq_send_init failed rc=%d\n", rc);
+
+	return rc;
+}
+
+/**
+ * tpm_ibmvtpm_remove - ibm vtpm remove entry point
+ * @vdev:	vio device struct
+ *
+ * Return value:
+ *	0
+ */
+static int __devexit tpm_ibmvtpm_remove(struct vio_dev *vdev)
+{
+	struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(&vdev->dev);
+	int rc = 0;
+
+	free_irq(vdev->irq, ibmvtpm);
+	tasklet_kill(&ibmvtpm->tasklet);
+
+	do {
+		if (rc)
+			msleep(100);
+		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
+	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
+
+	dma_unmap_single(ibmvtpm->dev, ibmvtpm->crq_dma_handle,
+			 CRQ_RES_BUF_SIZE, DMA_BIDIRECTIONAL);
+	free_page((unsigned long)ibmvtpm->crq_queue.crq_addr);
+
+	if (ibmvtpm->rtce_buf) {
+		dma_unmap_single(ibmvtpm->dev, ibmvtpm->rtce_dma_handle,
+				 ibmvtpm->rtce_size, DMA_BIDIRECTIONAL);
+		kfree(ibmvtpm->rtce_buf);
+	}
+
+	tpm_remove_hardware(ibmvtpm->dev);
+
+	kfree(ibmvtpm);
+
+	return 0;
+}
+
+/**
+ * tpm_ibmvtpm_get_desired_dma - Get DMA size needed by this driver
+ * @vdev:	vio device struct
+ *
+ * Return value:
+ *	Number of bytes the driver needs to DMA map
+ */
+static unsigned long tpm_ibmvtpm_get_desired_dma(struct vio_dev *vdev)
+{
+	struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(&vdev->dev);
+	return CRQ_RES_BUF_SIZE + ibmvtpm->rtce_size;
+}
+
+/**
+ * tpm_ibmvtpm_suspend - Suspend
+ * @dev:	device struct
+ *
+ * Return value:
+ *	0
+ */
+static int tpm_ibmvtpm_suspend(struct device *dev)
+{
+	struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(dev);
+	struct ibmvtpm_crq crq;
+	u64 *buf = (u64 *) &crq;
+	int rc = 0;
+
+	crq.valid = (u8)IBMVTPM_VALID_CMD;
+	crq.msg = (u8)VTPM_PREPARE_TO_SUSPEND;
+
+	rc = ibmvtpm_send_crq(ibmvtpm->vdev, buf[0], buf[1]);
+	if (rc != H_SUCCESS)
+		dev_err(ibmvtpm->dev,
+			"tpm_ibmvtpm_suspend failed rc=%d\n", rc);
+
+	return rc;
+}
+
+/**
+ * ibmvtpm_reset_crq - Reset CRQ
+ * @ibmvtpm:	ibm vtpm struct
+ *
+ * Return value:
+ *	0 - Success
+ *	Non-zero - Failure
+ */
+static int ibmvtpm_reset_crq(struct ibmvtpm_dev *ibmvtpm)
+{
+	int rc = 0;
+
+	do {
+		if (rc)
+			msleep(100);
+		rc = plpar_hcall_norets(H_FREE_CRQ,
+					ibmvtpm->vdev->unit_address);
+	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
+
+	memset(ibmvtpm->crq_queue.crq_addr, 0, CRQ_RES_BUF_SIZE);
+	ibmvtpm->crq_queue.index = 0;
+
+	return plpar_hcall_norets(H_REG_CRQ, ibmvtpm->vdev->unit_address,
+				  ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
+}
+
+/**
+ * tpm_ibmvtpm_resume - Resume from suspend
+ * @dev:	device struct
+ *
+ * Return value:
+ *	0
+ */
+static int tpm_ibmvtpm_resume(struct device *dev)
+{
+	struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(dev);
+	unsigned long flags;
+	int rc = 0;
+
+	do {
+		if (rc)
+			msleep(100);
+		rc = plpar_hcall_norets(H_ENABLE_CRQ,
+					ibmvtpm->vdev->unit_address);
+	} while (rc == H_IN_PROGRESS || rc == H_BUSY || H_IS_LONG_BUSY(rc));
+
+	if (rc) {
+		dev_err(dev, "Error enabling ibmvtpm rc=%d\n", rc);
+		return rc;
+	}
+
+	spin_lock_irqsave(&ibmvtpm->lock, flags);
+	vio_disable_interrupts(ibmvtpm->vdev);
+	tasklet_schedule(&ibmvtpm->tasklet);
+	spin_unlock_irqrestore(&ibmvtpm->lock, flags);
+
+	rc = ibmvtpm_crq_send_init(ibmvtpm);
+	if (rc)
+		dev_err(dev, "Error send_init rc=%d\n", rc);
+
+	return rc;
+}
+
+static const struct file_operations ibmvtpm_ops = {
+	.owner = THIS_MODULE,
+	.llseek = no_llseek,
+	.open = tpm_open,
+	.read = tpm_read,
+	.write = tpm_write,
+	.release = tpm_release,
+};
+
+static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
+static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
+static DEVICE_ATTR(enabled, S_IRUGO, tpm_show_enabled, NULL);
+static DEVICE_ATTR(active, S_IRUGO, tpm_show_active, NULL);
+static DEVICE_ATTR(owned, S_IRUGO, tpm_show_owned, NULL);
+static DEVICE_ATTR(temp_deactivated, S_IRUGO, tpm_show_temp_deactivated,
+		   NULL);
+static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps_1_2, NULL);
+static DEVICE_ATTR(cancel, S_IWUSR | S_IWGRP, NULL, tpm_store_cancel);
+static DEVICE_ATTR(durations, S_IRUGO, tpm_show_durations, NULL);
+static DEVICE_ATTR(timeouts, S_IRUGO, tpm_show_timeouts, NULL);
+
+static struct attribute *ibmvtpm_attrs[] = {
+	&dev_attr_pubek.attr,
+	&dev_attr_pcrs.attr,
+	&dev_attr_enabled.attr,
+	&dev_attr_active.attr,
+	&dev_attr_owned.attr,
+	&dev_attr_temp_deactivated.attr,
+	&dev_attr_caps.attr,
+	&dev_attr_cancel.attr,
+	&dev_attr_durations.attr,
+	&dev_attr_timeouts.attr, NULL,
+};
+
+static struct attribute_group ibmvtpm_attr_grp = { .attrs = ibmvtpm_attrs };
+
+static const struct tpm_vendor_specific tpm_ibmvtpm = {
+	.recv = tpm_ibmvtpm_recv,
+	.send = tpm_ibmvtpm_send,
+	.cancel = tpm_ibmvtpm_cancel,
+	.status = tpm_ibmvtpm_status,
+	.req_complete_mask = 0,
+	.req_complete_val = 0,
+	.req_canceled = 0,
+	.attr_group = &ibmvtpm_attr_grp,
+	.miscdev = { .fops = &ibmvtpm_ops, },
+};
+
+static const struct dev_pm_ops tpm_ibmvtpm_pm_ops = {
+	.suspend = tpm_ibmvtpm_suspend,
+	.resume = tpm_ibmvtpm_resume,
+};
+
+/**
+ * ibmvtpm_crq_get_next - Get next responded crq
+ * @ibmvtpm	vtpm device struct
+ *
+ * Return value:
+ *	vtpm crq pointer
+ */
+static struct ibmvtpm_crq *ibmvtpm_crq_get_next(struct ibmvtpm_dev *ibmvtpm)
+{
+	struct ibmvtpm_crq_queue *crq_q = &ibmvtpm->crq_queue;
+	struct ibmvtpm_crq *crq = &crq_q->crq_addr[crq_q->index];
+
+	if (crq->valid & VTPM_MSG_RES) {
+		if (++crq_q->index == crq_q->num_entry)
+			crq_q->index = 0;
+		rmb();
+	} else
+		crq = NULL;
+	return crq;
+}
+
+/**
+ * ibmvtpm_crq_process - Process responded crq
+ * @crq		crq to be processed
+ * @ibmvtpm	vtpm device struct
+ *
+ * Return value:
+ *	Nothing
+ */
+static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
+				struct ibmvtpm_dev *ibmvtpm)
+{
+	int rc = 0;
+
+	switch (crq->valid) {
+	case VALID_INIT_CRQ:
+		switch (crq->msg) {
+		case INIT_CRQ_RES:
+			dev_info(ibmvtpm->dev, "CRQ initialized\n");
+			rc = ibmvtpm_crq_send_init_complete(ibmvtpm);
+			if (rc)
+				dev_err(ibmvtpm->dev, "Unable to send CRQ init complete rc=%d\n", rc);
+			return;
+		case INIT_CRQ_COMP_RES:
+			dev_info(ibmvtpm->dev,
+				 "CRQ initialization completed\n");
+			return;
+		default:
+			dev_err(ibmvtpm->dev, "Unknown crq message type: %d\n", crq->msg);
+			return;
+		}
+		return;
+	case IBMVTPM_VALID_CMD:
+		switch (crq->msg) {
+		case VTPM_GET_RTCE_BUFFER_SIZE_RES:
+			if (crq->len <= 0) {
+				dev_err(ibmvtpm->dev, "Invalid rtce size\n");
+				return;
+			}
+			ibmvtpm->rtce_size = crq->len;
+			ibmvtpm->rtce_buf = kmalloc(ibmvtpm->rtce_size,
+						    GFP_KERNEL);
+			if (!ibmvtpm->rtce_buf) {
+				dev_err(ibmvtpm->dev, "Failed to allocate memory for rtce buffer\n");
+				return;
+			}
+
+			ibmvtpm->rtce_dma_handle = dma_map_single(ibmvtpm->dev,
+				ibmvtpm->rtce_buf, ibmvtpm->rtce_size,
+				DMA_BIDIRECTIONAL);
+
+			if (dma_mapping_error(ibmvtpm->dev,
+					      ibmvtpm->rtce_dma_handle)) {
+				kfree(ibmvtpm->rtce_buf);
+				ibmvtpm->rtce_buf = NULL;
+				dev_err(ibmvtpm->dev, "Failed to dma map rtce buffer\n");
+			}
+
+			return;
+		case VTPM_GET_VERSION_RES:
+			ibmvtpm->vtpm_version = crq->data;
+			return;
+		case VTPM_TPM_COMMAND_RES:
+			ibmvtpm->crq_res.valid = crq->valid;
+			ibmvtpm->crq_res.msg = crq->msg;
+			ibmvtpm->crq_res.len = crq->len;
+			ibmvtpm->crq_res.data = crq->data;
+			wake_up_interruptible(&wq);
+			return;
+		default:
+			return;
+		}
+	}
+	return;
+}
+
+/**
+ * ibmvtpm_interrupt -	Interrupt handler
+ * @irq:		irq number to handle
+ * @vtpm_instance:	vtpm that received interrupt
+ *
+ * Returns:
+ *	IRQ_HANDLED
+ **/
+static irqreturn_t ibmvtpm_interrupt(int irq, void *vtpm_instance)
+{
+	struct ibmvtpm_dev *ibmvtpm = (struct ibmvtpm_dev *) vtpm_instance;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ibmvtpm->lock, flags);
+	vio_disable_interrupts(ibmvtpm->vdev);
+	tasklet_schedule(&ibmvtpm->tasklet);
+	spin_unlock_irqrestore(&ibmvtpm->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * ibmvtpm_tasklet - Interrupt handler tasklet
+ * @data:	ibm vtpm device struct
+ *
+ * Returns:
+ *	Nothing
+ **/
+static void ibmvtpm_tasklet(void *data)
+{
+	struct ibmvtpm_dev *ibmvtpm = data;
+	struct ibmvtpm_crq *crq;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ibmvtpm->lock, flags);
+	while ((crq = ibmvtpm_crq_get_next(ibmvtpm)) != NULL) {
+		ibmvtpm_crq_process(crq, ibmvtpm);
+		crq->valid = 0;
+		wmb();
+	}
+
+	vio_enable_interrupts(ibmvtpm->vdev);
+	spin_unlock_irqrestore(&ibmvtpm->lock, flags);
+}
+
+/**
+ * tpm_ibmvtpm_probe - ibm vtpm initialize entry point
+ * @vio_dev:	vio device struct
+ * @id:		vio device id struct
+ *
+ * Return value:
+ *	0 - Success
+ *	Non-zero - Failure
+ */
+static int __devinit tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
+				   const struct vio_device_id *id)
+{
+	struct ibmvtpm_dev *ibmvtpm;
+	struct device *dev = &vio_dev->dev;
+	struct ibmvtpm_crq_queue *crq_q;
+	struct tpm_chip *chip;
+	int rc = -ENOMEM, rc1;
+
+	chip = tpm_register_hardware(dev, &tpm_ibmvtpm);
+	if (!chip) {
+		dev_err(dev, "tpm_register_hardware failed\n");
+		return -ENODEV;
+	}
+
+	ibmvtpm = kzalloc(sizeof(struct ibmvtpm_dev), GFP_KERNEL);
+	if (!ibmvtpm) {
+		dev_err(dev, "kzalloc for ibmvtpm failed\n");
+		goto cleanup;
+	}
+
+	crq_q = &ibmvtpm->crq_queue;
+	crq_q->crq_addr = (struct ibmvtpm_crq *)get_zeroed_page(GFP_KERNEL);
+	if (!crq_q->crq_addr) {
+		dev_err(dev, "Unable to allocate memory for crq_addr\n");
+		goto cleanup;
+	}
+
+	crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr);
+	ibmvtpm->crq_dma_handle = dma_map_single(dev, crq_q->crq_addr,
+						 CRQ_RES_BUF_SIZE,
+						 DMA_BIDIRECTIONAL);
+
+	if (dma_mapping_error(dev, ibmvtpm->crq_dma_handle)) {
+		dev_err(dev, "dma mapping failed\n");
+		goto cleanup;
+	}
+
+	rc = plpar_hcall_norets(H_REG_CRQ, vio_dev->unit_address,
+				ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
+	if (rc == H_RESOURCE)
+		rc = ibmvtpm_reset_crq(ibmvtpm);
+
+	if (rc) {
+		dev_err(dev, "Unable to register CRQ rc=%d\n", rc);
+		goto reg_crq_cleanup;
+	}
+
+	tasklet_init(&ibmvtpm->tasklet, (void *)ibmvtpm_tasklet,
+		     (unsigned long)ibmvtpm);
+
+	rc = request_irq(vio_dev->irq, ibmvtpm_interrupt, 0,
+			 tpm_ibmvtpm_driver_name, ibmvtpm);
+	if (rc) {
+		dev_err(dev, "Error %d register irq 0x%x\n", rc, vio_dev->irq);
+		goto init_irq_cleanup;
+	}
+
+	rc = vio_enable_interrupts(vio_dev);
+	if (rc) {
+		dev_err(dev, "Error %d enabling interrupts\n", rc);
+		goto init_irq_cleanup;
+	}
+
+	crq_q->index = 0;
+
+	ibmvtpm->dev = dev;
+	ibmvtpm->vdev = vio_dev;
+	chip->vendor.data = (void *)ibmvtpm;
+
+	spin_lock_init(&ibmvtpm->lock);
+	spin_lock_init(&ibmvtpm->rtce_lock);
+
+	rc = ibmvtpm_crq_send_init(ibmvtpm);
+	if (rc)
+		goto init_irq_cleanup;
+
+	rc = ibmvtpm_crq_get_version(ibmvtpm);
+	if (rc)
+		goto init_irq_cleanup;
+
+	rc = ibmvtpm_crq_get_rtce_size(ibmvtpm);
+	if (rc)
+		goto init_irq_cleanup;
+
+	return rc;
+init_irq_cleanup:
+	tasklet_kill(&ibmvtpm->tasklet);
+	do {
+		rc1 = plpar_hcall_norets(H_FREE_CRQ, vio_dev->unit_address);
+	} while (rc1 == H_BUSY || H_IS_LONG_BUSY(rc1));
+reg_crq_cleanup:
+	dma_unmap_single(dev, ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE,
+			 DMA_BIDIRECTIONAL);
+cleanup:
+	if (ibmvtpm) {
+		if (crq_q->crq_addr)
+			free_page((unsigned long)crq_q->crq_addr);
+		kfree(ibmvtpm);
+	}
+
+	tpm_remove_hardware(dev);
+
+	return rc;
+}
+
+static struct vio_driver ibmvtpm_driver = {
+	.id_table	 = tpm_ibmvtpm_device_table,
+	.probe		 = tpm_ibmvtpm_probe,
+	.remove		 = tpm_ibmvtpm_remove,
+	.get_desired_dma = tpm_ibmvtpm_get_desired_dma,
+	.name		 = tpm_ibmvtpm_driver_name,
+	.pm		 = &tpm_ibmvtpm_pm_ops,
+};
+
+/**
+ * ibmvtpm_module_init - Initialize ibm vtpm module
+ *
+ * Return value:
+ *	0 -Success
+ *	Non-zero - Failure
+ */
+static int __init ibmvtpm_module_init(void)
+{
+	return vio_register_driver(&ibmvtpm_driver);
+}
+
+/**
+ * ibmvtpm_module_exit - Teardown ibm vtpm module
+ *
+ * Return value:
+ *	Nothing
+ */
+static void __exit ibmvtpm_module_exit(void)
+{
+	vio_unregister_driver(&ibmvtpm_driver);
+}
+
+module_init(ibmvtpm_module_init);
+module_exit(ibmvtpm_module_exit);
+
+
+MODULE_AUTHOR("adlai@us.ibm.com");
+MODULE_DESCRIPTION("IBM vTPM Driver");
+MODULE_VERSION("1.0");
+MODULE_LICENSE("GPL");
diff --git a/drivers/char/tpm/tpm_ibmvtpm.h b/drivers/char/tpm/tpm_ibmvtpm.h
new file mode 100644
index 0000000..fb930dd
--- /dev/null
+++ b/drivers/char/tpm/tpm_ibmvtpm.h
@@ -0,0 +1,83 @@ 
+/*
+ * Copyright (C) 2012 IBM Corporation
+ *
+ * Author: Ashley Lai <adlai@us.ibm.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * Device driver for TCG/TCPA TPM (trusted platform module).
+ * Specifications at www.trustedcomputinggroup.org
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * These difference are required on power because the device must be
+ * discovered through the device tree and iomap must be used to get
+ * around the need for holes in the io_page_mask.  This does not happen
+ * automatically because the tpm is not a normal pci device and lives
+ * under the root node.
+ *
+ */
+
+#ifndef __TPM_IBMVTPM_H__
+#define __TPM_IBMVTPM_H__
+
+/* vTPM Message Format 1 */
+struct ibmvtpm_crq {
+	u8 valid;
+	u8 msg;
+	u16 len;
+	u32 data;
+	u64 reserved;
+} __attribute__((packed, aligned(8)));
+
+struct ibmvtpm_crq_queue {
+	struct ibmvtpm_crq *crq_addr;
+	u32 index;
+	u32 num_entry;
+};
+
+struct ibmvtpm_dev {
+	struct device *dev;
+	struct vio_dev *vdev;
+	struct ibmvtpm_crq_queue crq_queue;
+	dma_addr_t crq_dma_handle;
+	spinlock_t lock;
+	struct tasklet_struct tasklet;
+	u32 rtce_size;
+	void __iomem *rtce_buf;
+	dma_addr_t rtce_dma_handle;
+	spinlock_t rtce_lock;
+	struct ibmvtpm_crq crq_res;
+	u32 vtpm_version;
+};
+
+#define CRQ_RES_BUF_SIZE	PAGE_SIZE
+
+/* Initialize CRQ */
+#define INIT_CRQ_CMD		0xC001000000000000LL /* Init cmd */
+#define INIT_CRQ_COMP_CMD	0xC002000000000000LL /* Init complete cmd */
+#define INIT_CRQ_RES		0x01	/* Init respond */
+#define INIT_CRQ_COMP_RES	0x02	/* Init complete respond */
+#define VALID_INIT_CRQ		0xC0	/* Valid command for init crq */
+
+/* vTPM CRQ response is the message type | 0x80 */
+#define VTPM_MSG_RES		0x80
+#define IBMVTPM_VALID_CMD	0x80
+
+/* vTPM CRQ message types */
+#define VTPM_GET_VERSION			0x01
+#define VTPM_GET_VERSION_RES			(0x01 | VTPM_MSG_RES)
+
+#define VTPM_TPM_COMMAND			0x02
+#define VTPM_TPM_COMMAND_RES			(0x02 | VTPM_MSG_RES)
+
+#define VTPM_GET_RTCE_BUFFER_SIZE		0x03
+#define VTPM_GET_RTCE_BUFFER_SIZE_RES		(0x03 | VTPM_MSG_RES)
+
+#define VTPM_PREPARE_TO_SUSPEND			0x04
+#define VTPM_PREPARE_TO_SUSPEND_RES		(0x04 | VTPM_MSG_RES)
+
+#endif