Subject: Re: [PATCH V3 1/3] drivers/char/tpm: Add new device driver to support IBM vTPM

From: Kent Yoder <[email-masked]>
Date: Wed, 22 Aug 2012 16:42:18 -0500

On Wed, Aug 22, 2012 at 04:17:43PM -0500, Ashley Lai wrote:
> This patch adds a new device driver to support IBM virtual TPM
> (vTPM) for PPC64.  IBM vTPM is supported through the adjunct
> partition with firmware release 740 or higher.  With vTPM
> support, each lpar is able to have its own vTPM without the
> physical TPM hardware.
> 
> This driver provides TPM functionalities by communicating with
> the vTPM adjunct partition through Hypervisor calls (Hcalls)
> and Command/Response Queue (CRQ) commands.

 Thanks Ashley, I'll include this in my next pull request to James.

Kent

> Signed-off-by: Ashley Lai <[email-masked]>
> ---
> 
> Oopps... I forgot to remove some invalid comments.  Please use this patch for 1/3.
> 
>  drivers/char/tpm/Kconfig       |    8 +
>  drivers/char/tpm/Makefile      |    1 +
>  drivers/char/tpm/tpm.h         |    1 +
>  drivers/char/tpm/tpm_ibmvtpm.c |  749 ++++++++++++++++++++++++++++++++++++++++
>  drivers/char/tpm/tpm_ibmvtpm.h |   77 ++++
>  5 files changed, 836 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/char/tpm/tpm_ibmvtpm.c
>  create mode 100644 drivers/char/tpm/tpm_ibmvtpm.h
> 
> 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 645136e..870fde7 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -100,6 +100,7 @@ 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..efc4ab3
> --- /dev/null
> +++ b/drivers/char/tpm/tpm_ibmvtpm.c
> @@ -0,0 +1,749 @@
> +/*
> + * Copyright (C) 2012 IBM Corporation
> + *
> + * Author: Ashley Lai <[email-masked]>
> + *
> + * Maintained by: <[email-masked]>
> + *
> + * 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("[email-masked]");
> +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..4296eb4
> --- /dev/null
> +++ b/drivers/char/tpm/tpm_ibmvtpm.h
> @@ -0,0 +1,77 @@
> +/*
> + * Copyright (C) 2012 IBM Corporation
> + *
> + * Author: Ashley Lai <[email-masked]>
> + *
> + * Maintained by: <[email-masked]>
> + *
> + * 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.
> + *
> + */
> +
> +#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
> -- 
> 1.7.1
> 
>