drivers/char/tpm/tpm-chip.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (C) 2004 IBM Corporation
  * Copyright (C) 2014 Intel Corporation
  *
  * Authors:
  * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
  * Leendert van Doorn <leendert@watson.ibm.com>
  * Dave Safford <safford@watson.ibm.com>
  * Reiner Sailer <sailer@watson.ibm.com>
  * Kylene Hall <kjhall@us.ibm.com>
  *
  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  *
  * TPM chip management routines.
  *
  * 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/poll.h>
 #include <linux/slab.h>
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
 #include <linux/freezer.h>
 #include <linux/major.h>
 #include "tpm.h"
 #include "tpm_eventlog.h"

 DEFINE_IDR(dev_nums_idr);
 static DEFINE_MUTEX(idr_lock);

 struct class *tpm_class;
 dev_t tpm_devt;

 /**
  * tpm_try_get_ops() - Get a ref to the tpm_chip
  * @chip: Chip to ref
  *
  * The caller must already have some kind of locking to ensure that chip is
  * valid. This function will lock the chip so that the ops member can be
  * accessed safely. The locking prevents tpm_chip_unregister from
  * completing, so it should not be held for long periods.
  *
  * Returns -ERRNO if the chip could not be got.
  */
 int tpm_try_get_ops(struct tpm_chip *chip)
 {
 	int rc = -EIO;

 	get_device(&chip->dev);

 	down_read(&chip->ops_sem);
 	if (!chip->ops)
 		goto out_lock;

 	return 0;
 out_lock:
 	up_read(&chip->ops_sem);
 	put_device(&chip->dev);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_try_get_ops);

 /**
  * tpm_put_ops() - Release a ref to the tpm_chip
  * @chip: Chip to put
  *
  * This is the opposite pair to tpm_try_get_ops(). After this returns chip may
  * be kfree'd.
  */
 void tpm_put_ops(struct tpm_chip *chip)
 {
 	up_read(&chip->ops_sem);
 	put_device(&chip->dev);
 }
 EXPORT_SYMBOL_GPL(tpm_put_ops);

 /**
  * tpm_chip_find_get() - return tpm_chip for a given chip number
  * @chip_num: id to find
  *
  * The return'd chip has been tpm_try_get_ops'd and must be released via
  * tpm_put_ops
   */
 struct tpm_chip *tpm_chip_find_get(int chip_num)
 {
 	struct tpm_chip *chip, *res = NULL;
 	int chip_prev;

 	mutex_lock(&idr_lock);

 	if (chip_num == TPM_ANY_NUM) {
 		chip_num = 0;
 		do {
 			chip_prev = chip_num;
 			chip = idr_get_next(&dev_nums_idr, &chip_num);
 			if (chip && !tpm_try_get_ops(chip)) {
 				res = chip;
 				break;
 			}
 		} while (chip_prev != chip_num);
 	} else {
 		chip = idr_find_slowpath(&dev_nums_idr, chip_num);
 		if (chip && !tpm_try_get_ops(chip))
 			res = chip;
 	}

 	mutex_unlock(&idr_lock);

 	return res;
 }

 /**
  * tpm_dev_release() - free chip memory and the device number
  * @dev: the character device for the TPM chip
  *
  * This is used as the release function for the character device.
  */
 static void tpm_dev_release(struct device *dev)
 {
 	struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);

 	mutex_lock(&idr_lock);
 	idr_remove(&dev_nums_idr, chip->dev_num);
 	mutex_unlock(&idr_lock);

 	kfree(chip);
 }

 /**
  * tpm_chip_alloc() - allocate a new struct tpm_chip instance
  * @pdev: device to which the chip is associated
  *        At this point pdev mst be initialized, but does not have to
  *        be registered
  * @ops: struct tpm_class_ops instance
  *
  * Allocates a new struct tpm_chip instance and assigns a free
  * device number for it. Must be paired with put_device(&chip->dev).
  */
 struct tpm_chip *tpm_chip_alloc(struct device *dev,
 				const struct tpm_class_ops *ops)
 {
 	struct tpm_chip *chip;
 	int rc;

 	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 	if (chip == NULL)
 		return ERR_PTR(-ENOMEM);

 	mutex_init(&chip->tpm_mutex);
 	init_rwsem(&chip->ops_sem);

 	chip->ops = ops;

 	mutex_lock(&idr_lock);
 	rc = idr_alloc(&dev_nums_idr, NULL, 0, TPM_NUM_DEVICES, GFP_KERNEL);
 	mutex_unlock(&idr_lock);
 	if (rc < 0) {
 		dev_err(dev, "No available tpm device numbers\n");
 		kfree(chip);
 		return ERR_PTR(rc);
 	}
 	chip->dev_num = rc;

 	device_initialize(&chip->dev);

 	chip->dev.class = tpm_class;
 	chip->dev.release = tpm_dev_release;
 	chip->dev.parent = dev;
 #ifdef CONFIG_ACPI
 	chip->dev.groups = chip->groups;
 #endif

 	if (chip->dev_num == 0)
 		chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR);
 	else
 		chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num);

 	rc = dev_set_name(&chip->dev, "tpm%d", chip->dev_num);
 	if (rc)
 		goto out;

 	cdev_init(&chip->cdev, &tpm_fops);
 	chip->cdev.owner = THIS_MODULE;
 	chip->cdev.kobj.parent = &chip->dev.kobj;

 	return chip;

 out:
 	put_device(&chip->dev);
 	return ERR_PTR(rc);
 }
 EXPORT_SYMBOL_GPL(tpm_chip_alloc);

 /**
  * tpmm_chip_alloc() - allocate a new struct tpm_chip instance
  * @pdev: parent device to which the chip is associated
  * @ops: struct tpm_class_ops instance
  *
  * Same as tpm_chip_alloc except devm is used to do the put_device
  */
 struct tpm_chip *tpmm_chip_alloc(struct device *pdev,
 				 const struct tpm_class_ops *ops)
 {
 	struct tpm_chip *chip;
 	int rc;

 	chip = tpm_chip_alloc(pdev, ops);
 	if (IS_ERR(chip))
 		return chip;

 	rc = devm_add_action(pdev, (void (*)(void *)) put_device, &chip->dev);
 	if (rc) {
 		put_device(&chip->dev);
 		return ERR_PTR(rc);
 	}

 	dev_set_drvdata(pdev, chip);

 	return chip;
 }
 EXPORT_SYMBOL_GPL(tpmm_chip_alloc);

 static int tpm_add_char_device(struct tpm_chip *chip)
 {
 	int 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",
 			dev_name(&chip->dev), MAJOR(chip->dev.devt),
 			MINOR(chip->dev.devt), rc);

 		return rc;
 	}

 	rc = device_add(&chip->dev);
 	if (rc) {
 		dev_err(&chip->dev,
 			"unable to device_register() %s, major %d, minor %d, err=%d\n",
 			dev_name(&chip->dev), MAJOR(chip->dev.devt),
 			MINOR(chip->dev.devt), rc);

 		cdev_del(&chip->cdev);
 		return rc;
 	}

 	/* Make the chip available. */
 	mutex_lock(&idr_lock);
 	idr_replace(&dev_nums_idr, chip, chip->dev_num);
 	mutex_unlock(&idr_lock);

 	return rc;
 }

 static void tpm_del_char_device(struct tpm_chip *chip)
 {
 	cdev_del(&chip->cdev);
 	device_del(&chip->dev);

 	/* Make the chip unavailable. */
 	mutex_lock(&idr_lock);
 	idr_replace(&dev_nums_idr, NULL, chip->dev_num);
 	mutex_unlock(&idr_lock);

 	/* Make the driver uncallable. */
 	down_write(&chip->ops_sem);
 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
 		tpm2_shutdown(chip, TPM2_SU_CLEAR);
 	chip->ops = NULL;
 	up_write(&chip->ops_sem);
 }

 static int tpm1_chip_register(struct tpm_chip *chip)
 {
 	int rc;

 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
 		return 0;

 	rc = tpm_sysfs_add_device(chip);
 	if (rc)
 		return rc;

 	chip->bios_dir = tpm_bios_log_setup(dev_name(&chip->dev));

 	return 0;
 }

 static void tpm1_chip_unregister(struct tpm_chip *chip)
 {
 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
 		return;

 	if (chip->bios_dir)
 		tpm_bios_log_teardown(chip->bios_dir);

 	tpm_sysfs_del_device(chip);
 }

 /*
  * tpm_chip_register() - create a character device for the TPM chip
  * @chip: TPM chip to use.
  *
  * Creates a character device for the TPM chip and adds sysfs attributes for
  * the device. As the last step this function adds the chip to the list of TPM
  * chips available for in-kernel use.
  *
  * This function should be only called after the chip initialization is
  * complete.
  */
 int tpm_chip_register(struct tpm_chip *chip)
 {
 	int rc;

 	rc = tpm1_chip_register(chip);
 	if (rc)
 		return rc;

 	tpm_add_ppi(chip);

 	rc = tpm_add_char_device(chip);
 	if (rc)
 		goto out_err;

 	chip->flags |= TPM_CHIP_FLAG_REGISTERED;

 	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
 		rc = __compat_only_sysfs_link_entry_to_kobj(
 		    &chip->dev.parent->kobj, &chip->dev.kobj, "ppi");
 		if (rc && rc != -ENOENT) {
 			tpm_chip_unregister(chip);
 			return rc;
 		}
 	}

 	return 0;
 out_err:
 	tpm1_chip_unregister(chip);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_chip_register);

 /*
  * tpm_chip_unregister() - release the TPM driver
  * @chip: TPM chip to use.
  *
  * Takes the chip first away from the list of available TPM chips and then
  * cleans up all the resources reserved by tpm_chip_register().
  *
  * Once this function returns the driver call backs in 'op's will not be
  * running and will no longer start.
  *
  * NOTE: This function should be only called before deinitializing chip
  * resources.
  */
 void tpm_chip_unregister(struct tpm_chip *chip)
 {
 	if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED))
 		return;

 	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
 		sysfs_remove_link(&chip->dev.parent->kobj, "ppi");

 	tpm1_chip_unregister(chip);
 	tpm_del_char_device(chip);
 }
 EXPORT_SYMBOL_GPL(tpm_chip_unregister);
	/*
	* Copyright (C) 2004 IBM Corporation
	* Copyright (C) 2014 Intel Corporation
	*
	* Authors:
	* Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
	* Leendert van Doorn <leendert@watson.ibm.com>
	* Dave Safford <safford@watson.ibm.com>
	* Reiner Sailer <sailer@watson.ibm.com>
	* Kylene Hall <kjhall@us.ibm.com>
	*
	* Maintained by: <tpmdd-devel@lists.sourceforge.net>
	*
	* TPM chip management routines.
	*
	* 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/poll.h>
	#include <linux/slab.h>
	#include <linux/mutex.h>
	#include <linux/spinlock.h>
	#include <linux/freezer.h>
	#include <linux/major.h>
	#include "tpm.h"
	#include "tpm_eventlog.h"

	DEFINE_IDR(dev_nums_idr);
	static DEFINE_MUTEX(idr_lock);

	struct class *tpm_class;
	dev_t tpm_devt;

	/**
	* tpm_try_get_ops() - Get a ref to the tpm_chip
	* @chip: Chip to ref
	*
	* The caller must already have some kind of locking to ensure that chip is
	* valid. This function will lock the chip so that the ops member can be
	* accessed safely. The locking prevents tpm_chip_unregister from
	* completing, so it should not be held for long periods.
	*
	* Returns -ERRNO if the chip could not be got.
	*/
	int tpm_try_get_ops(struct tpm_chip *chip)
	{
	int rc = -EIO;

	get_device(&chip->dev);

	down_read(&chip->ops_sem);
	if (!chip->ops)
	goto out_lock;

	return 0;
	out_lock:
	up_read(&chip->ops_sem);
	put_device(&chip->dev);
	return rc;
	}
	EXPORT_SYMBOL_GPL(tpm_try_get_ops);

	/**
	* tpm_put_ops() - Release a ref to the tpm_chip
	* @chip: Chip to put
	*
	* This is the opposite pair to tpm_try_get_ops(). After this returns chip may
	* be kfree'd.
	*/
	void tpm_put_ops(struct tpm_chip *chip)
	{
	up_read(&chip->ops_sem);
	put_device(&chip->dev);
	}
	EXPORT_SYMBOL_GPL(tpm_put_ops);

	/**
	* tpm_chip_find_get() - return tpm_chip for a given chip number
	* @chip_num: id to find
	*
	* The return'd chip has been tpm_try_get_ops'd and must be released via
	* tpm_put_ops
	*/
	struct tpm_chip *tpm_chip_find_get(int chip_num)
	{
	struct tpm_chip chip, res = NULL;
	int chip_prev;

	mutex_lock(&idr_lock);

	if (chip_num == TPM_ANY_NUM) {
	chip_num = 0;
	do {
	chip_prev = chip_num;
	chip = idr_get_next(&dev_nums_idr, &chip_num);
	if (chip && !tpm_try_get_ops(chip)) {
	res = chip;
	break;
	}
	} while (chip_prev != chip_num);
	} else {
	chip = idr_find_slowpath(&dev_nums_idr, chip_num);
	if (chip && !tpm_try_get_ops(chip))
	res = chip;
	}

	mutex_unlock(&idr_lock);

	return res;
	}

	/**
	* tpm_dev_release() - free chip memory and the device number
	* @dev: the character device for the TPM chip
	*
	* This is used as the release function for the character device.
	*/
	static void tpm_dev_release(struct device *dev)
	{
	struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);

	mutex_lock(&idr_lock);
	idr_remove(&dev_nums_idr, chip->dev_num);
	mutex_unlock(&idr_lock);

	kfree(chip);
	}

	/**
	* tpm_chip_alloc() - allocate a new struct tpm_chip instance
	* @pdev: device to which the chip is associated
	* At this point pdev mst be initialized, but does not have to
	* be registered
	* @ops: struct tpm_class_ops instance
	*
	* Allocates a new struct tpm_chip instance and assigns a free
	* device number for it. Must be paired with put_device(&chip->dev).
	*/
	struct tpm_chip tpm_chip_alloc(struct device dev,
	const struct tpm_class_ops *ops)
	{
	struct tpm_chip *chip;
	int rc;

	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
	if (chip == NULL)
	return ERR_PTR(-ENOMEM);

	mutex_init(&chip->tpm_mutex);
	init_rwsem(&chip->ops_sem);

	chip->ops = ops;

	mutex_lock(&idr_lock);
	rc = idr_alloc(&dev_nums_idr, NULL, 0, TPM_NUM_DEVICES, GFP_KERNEL);
	mutex_unlock(&idr_lock);
	if (rc < 0) {
	dev_err(dev, "No available tpm device numbers\n");
	kfree(chip);
	return ERR_PTR(rc);
	}
	chip->dev_num = rc;

	device_initialize(&chip->dev);

	chip->dev.class = tpm_class;
	chip->dev.release = tpm_dev_release;
	chip->dev.parent = dev;
	#ifdef CONFIG_ACPI
	chip->dev.groups = chip->groups;
	#endif

	if (chip->dev_num == 0)
	chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR);
	else
	chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num);

	rc = dev_set_name(&chip->dev, "tpm%d", chip->dev_num);
	if (rc)
	goto out;

	cdev_init(&chip->cdev, &tpm_fops);
	chip->cdev.owner = THIS_MODULE;
	chip->cdev.kobj.parent = &chip->dev.kobj;

	return chip;

	out:
	put_device(&chip->dev);
	return ERR_PTR(rc);
	}
	EXPORT_SYMBOL_GPL(tpm_chip_alloc);

	/**
	* tpmm_chip_alloc() - allocate a new struct tpm_chip instance
	* @pdev: parent device to which the chip is associated
	* @ops: struct tpm_class_ops instance
	*
	* Same as tpm_chip_alloc except devm is used to do the put_device
	*/
	struct tpm_chip tpmm_chip_alloc(struct device pdev,
	const struct tpm_class_ops *ops)
	{
	struct tpm_chip *chip;
	int rc;

	chip = tpm_chip_alloc(pdev, ops);
	if (IS_ERR(chip))
	return chip;

	rc = devm_add_action(pdev, (void ()(void )) put_device, &chip->dev);
	if (rc) {
	put_device(&chip->dev);
	return ERR_PTR(rc);
	}

	dev_set_drvdata(pdev, chip);

	return chip;
	}
	EXPORT_SYMBOL_GPL(tpmm_chip_alloc);

	static int tpm_add_char_device(struct tpm_chip *chip)
	{
	int 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",
	dev_name(&chip->dev), MAJOR(chip->dev.devt),
	MINOR(chip->dev.devt), rc);

	return rc;
	}

	rc = device_add(&chip->dev);
	if (rc) {
	dev_err(&chip->dev,
	"unable to device_register() %s, major %d, minor %d, err=%d\n",
	dev_name(&chip->dev), MAJOR(chip->dev.devt),
	MINOR(chip->dev.devt), rc);

	cdev_del(&chip->cdev);
	return rc;
	}

	/* Make the chip available. */
	mutex_lock(&idr_lock);
	idr_replace(&dev_nums_idr, chip, chip->dev_num);
	mutex_unlock(&idr_lock);

	return rc;
	}

	static void tpm_del_char_device(struct tpm_chip *chip)
	{
	cdev_del(&chip->cdev);
	device_del(&chip->dev);

	/* Make the chip unavailable. */
	mutex_lock(&idr_lock);
	idr_replace(&dev_nums_idr, NULL, chip->dev_num);
	mutex_unlock(&idr_lock);

	/* Make the driver uncallable. */
	down_write(&chip->ops_sem);
	if (chip->flags & TPM_CHIP_FLAG_TPM2)
	tpm2_shutdown(chip, TPM2_SU_CLEAR);
	chip->ops = NULL;
	up_write(&chip->ops_sem);
	}

	static int tpm1_chip_register(struct tpm_chip *chip)
	{
	int rc;

	if (chip->flags & TPM_CHIP_FLAG_TPM2)
	return 0;

	rc = tpm_sysfs_add_device(chip);
	if (rc)
	return rc;

	chip->bios_dir = tpm_bios_log_setup(dev_name(&chip->dev));

	return 0;
	}

	static void tpm1_chip_unregister(struct tpm_chip *chip)
	{
	if (chip->flags & TPM_CHIP_FLAG_TPM2)
	return;

	if (chip->bios_dir)
	tpm_bios_log_teardown(chip->bios_dir);

	tpm_sysfs_del_device(chip);
	}

	/*
	* tpm_chip_register() - create a character device for the TPM chip
	* @chip: TPM chip to use.
	*
	* Creates a character device for the TPM chip and adds sysfs attributes for
	* the device. As the last step this function adds the chip to the list of TPM
	* chips available for in-kernel use.
	*
	* This function should be only called after the chip initialization is
	* complete.
	*/
	int tpm_chip_register(struct tpm_chip *chip)
	{
	int rc;

	rc = tpm1_chip_register(chip);
	if (rc)
	return rc;

	tpm_add_ppi(chip);

	rc = tpm_add_char_device(chip);
	if (rc)
	goto out_err;

	chip->flags \|= TPM_CHIP_FLAG_REGISTERED;

	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
	rc = __compat_only_sysfs_link_entry_to_kobj(
	&chip->dev.parent->kobj, &chip->dev.kobj, "ppi");
	if (rc && rc != -ENOENT) {
	tpm_chip_unregister(chip);
	return rc;
	}
	}

	return 0;
	out_err:
	tpm1_chip_unregister(chip);
	return rc;
	}
	EXPORT_SYMBOL_GPL(tpm_chip_register);

	/*
	* tpm_chip_unregister() - release the TPM driver
	* @chip: TPM chip to use.
	*
	* Takes the chip first away from the list of available TPM chips and then
	* cleans up all the resources reserved by tpm_chip_register().
	*
	* Once this function returns the driver call backs in 'op's will not be
	* running and will no longer start.
	*
	* NOTE: This function should be only called before deinitializing chip
	* resources.
	*/
	void tpm_chip_unregister(struct tpm_chip *chip)
	{
	if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED))
	return;

	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
	sysfs_remove_link(&chip->dev.parent->kobj, "ppi");

	tpm1_chip_unregister(chip);
	tpm_del_char_device(chip);
	}
	EXPORT_SYMBOL_GPL(tpm_chip_unregister);