Commit 313d21ee authored by Jarkko Sakkinen's avatar Jarkko Sakkinen Committed by Peter Huewe
Browse files

tpm: device class for tpm 



Added own device class for TPM. Uses MISC_MAJOR:TPM_MINOR for the
first character device in order to retain backwards compatibility.
Added tpm_dev_release() back attached to the character device.

I've been running this code now for a while on my laptop (Lenovo
T430S) TrouSerS works perfectly without modifications. I don't
believe it breaks anything significantly.

The sysfs attributes that have been placed under the wrong place
and are against sysfs-rules.txt should be probably left to
stagnate under platform device directory and start defining
new sysfs attributes to the char device directory.

Guidelines for future TPM sysfs attributes should be probably
along the lines of

- Single flat set of mandatory sysfs attributes. For example,
  current PPI interface is way way too rich when you only want
  to use it to clear and activate the TPM.

- Define sysfs attribute if and only if there's no way to get
  the value from ring-3. No attributes for TPM properties. It's
  just unnecessary maintenance hurdle that we don't want.

Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: default avatarJasob Gunthorpe <jason.gunthorpe@obsidianresearch.com>
Reviewed-by: default avatarStefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: default avatarScot Doyle <lkml14@scotdoyle.com>
Tested-by: default avatarPeter Huewe <peterhuewe@gmx.de>
Signed-off-by: default avatarPeter Huewe <peterhuewe@gmx.de>
parent 71ed848f

Documentation/ABI/stable/sysfs-class-tpm

+11 −11
Original line number Diff line number Diff line 
What:		/sys/class/misc/tpmX/device/

What:		/sys/class/tpm/tpmX/device/

Date:		April 2005

KernelVersion:	2.6.12

Contact:	tpmdd-devel@lists.sf.net
@@ -6,7 +6,7 @@ Description: The device/ directory under a specific TPM instance exposes 
		the properties of that TPM chip





What:		/sys/class/misc/tpmX/device/active

What:		/sys/class/tpm/tpmX/device/active

Date:		April 2006

KernelVersion:	2.6.17

Contact:	tpmdd-devel@lists.sf.net
@@ -18,7 +18,7 @@ Description: The "active" property prints a '1' if the TPM chip is accepting 
		section 17 for more information on which commands are

		available.



What:		/sys/class/misc/tpmX/device/cancel

What:		/sys/class/tpm/tpmX/device/cancel

Date:		June 2005

KernelVersion:	2.6.13

Contact:	tpmdd-devel@lists.sf.net
@@ -26,7 +26,7 @@ Description: The "cancel" property allows you to cancel the currently 
		pending TPM command. Writing any value to cancel will call the

		TPM vendor specific cancel operation.



What:		/sys/class/misc/tpmX/device/caps

What:		/sys/class/tpm/tpmX/device/caps

Date:		April 2005

KernelVersion:	2.6.12

Contact:	tpmdd-devel@lists.sf.net
@@ -43,7 +43,7 @@ Description: The "caps" property contains TPM manufacturer and version info. 
		the chip supports. Firmware version is that of the chip and

		is manufacturer specific.



What:		/sys/class/misc/tpmX/device/durations

What:		/sys/class/tpm/tpmX/device/durations

Date:		March 2011

KernelVersion:	3.1

Contact:	tpmdd-devel@lists.sf.net
@@ -66,7 +66,7 @@ Description: The "durations" property shows the 3 vendor-specific values 
		scaled to be displayed in usecs. In this case "[adjusted]"

		will be displayed in place of "[original]".



What:		/sys/class/misc/tpmX/device/enabled

What:		/sys/class/tpm/tpmX/device/enabled

Date:		April 2006

KernelVersion:	2.6.17

Contact:	tpmdd-devel@lists.sf.net
@@ -75,7 +75,7 @@ Description: The "enabled" property prints a '1' if the TPM chip is enabled, 
		may be visible but produce a '0' after some operation that

		disables the TPM.



What:		/sys/class/misc/tpmX/device/owned

What:		/sys/class/tpm/tpmX/device/owned

Date:		April 2006

KernelVersion:	2.6.17

Contact:	tpmdd-devel@lists.sf.net
@@ -83,7 +83,7 @@ Description: The "owned" property produces a '1' if the TPM_TakeOwnership 
		ordinal has been executed successfully in the chip. A '0'

		indicates that ownership hasn't been taken.



What:		/sys/class/misc/tpmX/device/pcrs

What:		/sys/class/tpm/tpmX/device/pcrs

Date:		April 2005

KernelVersion:	2.6.12

Contact:	tpmdd-devel@lists.sf.net
@@ -106,7 +106,7 @@ Description: The "pcrs" property will dump the current value of all Platform 
		1.2 chips, PCRs represent SHA-1 hashes, which are 20 bytes

		long. Use the "caps" property to determine TPM version.



What:		/sys/class/misc/tpmX/device/pubek

What:		/sys/class/tpm/tpmX/device/pubek

Date:		April 2005

KernelVersion:	2.6.12

Contact:	tpmdd-devel@lists.sf.net
@@ -158,7 +158,7 @@ Description: The "pubek" property will return the TPM's public endorsement 
		Modulus Length: 256 (bytes)

		Modulus:	The 256 byte Endorsement Key modulus



What:		/sys/class/misc/tpmX/device/temp_deactivated

What:		/sys/class/tpm/tpmX/device/temp_deactivated

Date:		April 2006

KernelVersion:	2.6.17

Contact:	tpmdd-devel@lists.sf.net
@@ -167,7 +167,7 @@ Description: The "temp_deactivated" property returns a '1' if the chip has 
		cycle. Whether a warm boot (reboot) will clear a TPM chip

		from a temp_deactivated state is platform specific.



What:		/sys/class/misc/tpmX/device/timeouts

What:		/sys/class/tpm/tpmX/device/timeouts

Date:		March 2011

KernelVersion:	3.1

Contact:	tpmdd-devel@lists.sf.net

drivers/char/tpm/tpm-chip.c

+62 −10
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/mutex.h>

#include <linux/spinlock.h>

#include <linux/freezer.h>

#include <linux/major.h>

#include "tpm.h"

#include "tpm_eventlog.h"
@@ -32,6 +33,9 @@ static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES); 
static LIST_HEAD(tpm_chip_list);

static DEFINE_SPINLOCK(driver_lock);



struct class *tpm_class;

dev_t tpm_devt;



/*

 * tpm_chip_find_get - return tpm_chip for a given chip number

 * @chip_num the device number for the chip
@@ -55,16 +59,14 @@ struct tpm_chip *tpm_chip_find_get(int chip_num) 
}



/**

 * tpmm_chip_remove() - free chip memory and device number

 * @data: points to struct tpm_chip instance

 * tpm_dev_release() - free chip memory and the device number

 * @dev: the character device for the TPM chip

 *

 * This is used internally by tpmm_chip_alloc() and called by devres

 * when the device is released. This function does the opposite of

 * tpmm_chip_alloc() freeing memory and the device number.

 * This is used as the release function for the character device.

 */

static void tpmm_chip_remove(void *data)

static void tpm_dev_release(struct device *dev)

{

	struct tpm_chip *chip = (struct tpm_chip *) data;

	struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);



	spin_lock(&driver_lock);

	clear_bit(chip->dev_num, dev_mask);
@@ -111,18 +113,68 @@ struct tpm_chip *tpmm_chip_alloc(struct device *dev, 
	scnprintf(chip->devname, sizeof(chip->devname), "tpm%d", chip->dev_num);



	chip->pdev = dev;

	devm_add_action(dev, tpmm_chip_remove, chip);



	dev_set_drvdata(dev, chip);



	chip->dev.class = tpm_class;

	chip->dev.release = tpm_dev_release;

	chip->dev.parent = chip->pdev;



	if (chip->dev_num == 0)

		chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR);

	else

		chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num);



	dev_set_name(&chip->dev, chip->devname);



	device_initialize(&chip->dev);



	chip->cdev.owner = chip->pdev->driver->owner;

	cdev_init(&chip->cdev, &tpm_fops);



	return chip;

}

EXPORT_SYMBOL_GPL(tpmm_chip_alloc);



static int tpm_dev_add_device(struct tpm_chip *chip)

{

	int rc;



	rc = device_add(&chip->dev);

	if (rc) {

		dev_err(&chip->dev,

			"unable to device_register() %s, major %d, minor %d, err=%d\n",

			chip->devname, MAJOR(chip->dev.devt),

			MINOR(chip->dev.devt), rc);



		return rc;

	}



	rc = cdev_add(&chip->cdev, chip->dev.devt, 1);

	if (rc) {

		dev_err(&chip->dev,

			"unable to cdev_add() %s, major %d, minor %d, err=%d\n",

			chip->devname, MAJOR(chip->dev.devt),

			MINOR(chip->dev.devt), rc);



		device_unregister(&chip->dev);

		return rc;

	}



	return rc;

}



static void tpm_dev_del_device(struct tpm_chip *chip)

{

	cdev_del(&chip->cdev);

	device_unregister(&chip->dev);

}



/*

 * tpm_chip_register() - create a misc driver for the TPM chip

 * tpm_chip_register() - create a character device for the TPM chip

 * @chip: TPM chip to use.

 *

 * Creates a misc driver for the TPM chip and adds sysfs interfaces for

 * Creates a character device for the TPM chip and adds sysfs interfaces for

 * the device, PPI and TCPA. As the last step this function adds the

 * chip to the list of TPM chips available for use.

 *

drivers/char/tpm/tpm-dev.c

+3 −33
Original line number Diff line number Diff line
@@ -17,7 +17,6 @@ 
 * License.

 *

 */

#include <linux/miscdevice.h>

#include <linux/slab.h>

#include <linux/uaccess.h>

#include "tpm.h"
@@ -54,9 +53,8 @@ static void timeout_work(struct work_struct *work) 


static int tpm_open(struct inode *inode, struct file *file)

{

	struct miscdevice *misc = file->private_data;

	struct tpm_chip *chip = container_of(misc, struct tpm_chip,

					     vendor.miscdev);

	struct tpm_chip *chip =

		container_of(inode->i_cdev, struct tpm_chip, cdev);

	struct file_priv *priv;



	/* It's assured that the chip will be opened just once,
@@ -173,7 +171,7 @@ static int tpm_release(struct inode *inode, struct file *file) 
	return 0;

}



static const struct file_operations tpm_fops = {

const struct file_operations tpm_fops = {

	.owner = THIS_MODULE,

	.llseek = no_llseek,

	.open = tpm_open,
@@ -182,32 +180,4 @@ static const struct file_operations tpm_fops = { 
	.release = tpm_release,

};



int tpm_dev_add_device(struct tpm_chip *chip)

{

	int rc;

	chip->vendor.miscdev.fops = &tpm_fops;

	if (chip->dev_num == 0)

		chip->vendor.miscdev.minor = TPM_MINOR;

	else

		chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;



	chip->vendor.miscdev.name = chip->devname;

	chip->vendor.miscdev.parent = chip->pdev;



	rc = misc_register(&chip->vendor.miscdev);

	if (rc) {

		chip->vendor.miscdev.name = NULL;

		dev_err(chip->pdev,

			"unable to misc_register %s, minor %d err=%d\n",

			chip->vendor.miscdev.name,

			chip->vendor.miscdev.minor, rc);

	}

	return rc;

}



void tpm_dev_del_device(struct tpm_chip *chip)

{

	if (chip->vendor.miscdev.name)

		misc_deregister(&chip->vendor.miscdev);

}

drivers/char/tpm/tpm-interface.c

+29 −0
Original line number Diff line number Diff line
@@ -997,6 +997,35 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max) 
}

EXPORT_SYMBOL_GPL(tpm_get_random);



static int __init tpm_init(void)

{

	int rc;



	tpm_class = class_create(THIS_MODULE, "tpm");

	if (IS_ERR(tpm_class)) {

		pr_err("couldn't create tpm class\n");

		return PTR_ERR(tpm_class);

	}



	rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");

	if (rc < 0) {

		pr_err("tpm: failed to allocate char dev region\n");

		class_destroy(tpm_class);

		return rc;

	}



	return 0;

}



static void __exit tpm_exit(void)

{

	class_destroy(tpm_class);

	unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);

}



subsys_initcall(tpm_init);

module_exit(tpm_exit);



MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");

MODULE_DESCRIPTION("TPM Driver");

MODULE_VERSION("2.0");

drivers/char/tpm/tpm.h

+8 −4
Original line number Diff line number Diff line
@@ -23,11 +23,11 @@ 
#include <linux/fs.h>

#include <linux/mutex.h>

#include <linux/sched.h>

#include <linux/miscdevice.h>

#include <linux/platform_device.h>

#include <linux/io.h>

#include <linux/tpm.h>

#include <linux/acpi.h>

#include <linux/cdev.h>



enum tpm_const {

	TPM_MINOR = 224,	/* officially assigned */
@@ -74,7 +74,6 @@ struct tpm_vendor_specific { 
	int region_size;

	int have_region;



	struct miscdevice miscdev;

	struct list_head list;

	int locality;

	unsigned long timeout_a, timeout_b, timeout_c, timeout_d; /* jiffies */
@@ -104,6 +103,9 @@ enum tpm_chip_flags { 


struct tpm_chip {

	struct device *pdev;	/* Device stuff */

	struct device dev;

	struct cdev cdev;



	const struct tpm_class_ops *ops;

	unsigned int flags;
@@ -326,6 +328,10 @@ struct tpm_cmd_t { 
	tpm_cmd_params	params;

} __packed;



extern struct class *tpm_class;

extern dev_t tpm_devt;

extern const struct file_operations tpm_fops;



ssize_t	tpm_getcap(struct device *, __be32, cap_t *, const char *);

ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,

		     size_t bufsiz);
@@ -346,8 +352,6 @@ extern struct tpm_chip *tpmm_chip_alloc(struct device *dev, 
extern int tpm_chip_register(struct tpm_chip *chip);

extern void tpm_chip_unregister(struct tpm_chip *chip);



int tpm_dev_add_device(struct tpm_chip *chip);

void tpm_dev_del_device(struct tpm_chip *chip);

int tpm_sysfs_add_device(struct tpm_chip *chip);

void tpm_sysfs_del_device(struct tpm_chip *chip);

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