Commit 15516788 authored by Stefan Berger's avatar Stefan Berger Committed by Jarkko Sakkinen
Browse files

tpm: Replace device number bitmap with IDR 



Replace the device number bitmap with IDR. Extend the number of devices we
can create to 64k.
Since an IDR allows us to associate a pointer with an ID, we use this now
to rewrite tpm_chip_find_get() to simply look up the chip pointer by the
given device ID.

Protect the IDR calls with a mutex.

Signed-off-by: default avatarStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: default avatarJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
parent 3897cd9c

drivers/char/tpm/tpm-chip.c

+45 −39
Original line number Diff line number Diff line
@@ -29,9 +29,8 @@ 
#include "tpm.h"

#include "tpm_eventlog.h"



static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);

static LIST_HEAD(tpm_chip_list);

static DEFINE_SPINLOCK(driver_lock);

DEFINE_IDR(dev_nums_idr);

static DEFINE_MUTEX(idr_lock);



struct class *tpm_class;

dev_t tpm_devt;
@@ -88,20 +87,30 @@ EXPORT_SYMBOL_GPL(tpm_put_ops); 
  */

struct tpm_chip *tpm_chip_find_get(int chip_num)

{

	struct tpm_chip *pos, *chip = NULL;



	rcu_read_lock();

	list_for_each_entry_rcu(pos, &tpm_chip_list, list) {

		if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)

			continue;



		/* rcu prevents chip from being free'd */

		if (!tpm_try_get_ops(pos))

			chip = pos;

	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;

			}

	rcu_read_unlock();

	return chip;

		} 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;

}



/**
@@ -114,9 +123,10 @@ static void tpm_dev_release(struct device *dev) 
{

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



	spin_lock(&driver_lock);

	clear_bit(chip->dev_num, dev_mask);

	spin_unlock(&driver_lock);

	mutex_lock(&idr_lock);

	idr_remove(&dev_nums_idr, chip->dev_num);

	mutex_unlock(&idr_lock);



	kfree(chip);

}
@@ -142,21 +152,18 @@ struct tpm_chip *tpm_chip_alloc(struct device *dev, 


	mutex_init(&chip->tpm_mutex);

	init_rwsem(&chip->ops_sem);

	INIT_LIST_HEAD(&chip->list);



	chip->ops = ops;



	spin_lock(&driver_lock);

	chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);

	spin_unlock(&driver_lock);



	if (chip->dev_num >= TPM_NUM_DEVICES) {

	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(-ENOMEM);

		return ERR_PTR(rc);

	}



	set_bit(chip->dev_num, dev_mask);

	chip->dev_num = rc;



	device_initialize(&chip->dev);
@@ -242,19 +249,28 @@ static int tpm_add_char_device(struct tpm_chip *chip) 
		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);

	chip->ops = NULL;

	up_write(&chip->ops_sem);



	device_del(&chip->dev);

}



static int tpm1_chip_register(struct tpm_chip *chip)
@@ -309,11 +325,6 @@ int tpm_chip_register(struct tpm_chip *chip) 
	if (rc)

		goto out_err;



	/* Make the chip available. */

	spin_lock(&driver_lock);

	list_add_tail_rcu(&chip->list, &tpm_chip_list);

	spin_unlock(&driver_lock);



	chip->flags |= TPM_CHIP_FLAG_REGISTERED;



	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
@@ -350,11 +361,6 @@ void tpm_chip_unregister(struct tpm_chip *chip) 
	if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED))

		return;



	spin_lock(&driver_lock);

	list_del_rcu(&chip->list);

	spin_unlock(&driver_lock);

	synchronize_rcu();



	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))

		sysfs_remove_link(&chip->dev.parent->kobj, "ppi");

drivers/char/tpm/tpm-interface.c

+1 −0
Original line number Diff line number Diff line
@@ -1139,6 +1139,7 @@ static int __init tpm_init(void) 


static void __exit tpm_exit(void)

{

	idr_destroy(&dev_nums_idr);

	class_destroy(tpm_class);

	unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);

}

drivers/char/tpm/tpm.h

+2 −3
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ 
enum tpm_const {

	TPM_MINOR = 224,	/* officially assigned */

	TPM_BUFSIZE = 4096,

	TPM_NUM_DEVICES = 256,

	TPM_NUM_DEVICES = 65536,

	TPM_RETRY = 50,		/* 5 seconds */

};
@@ -195,8 +195,6 @@ struct tpm_chip { 
	acpi_handle acpi_dev_handle;

	char ppi_version[TPM_PPI_VERSION_LEN + 1];

#endif /* CONFIG_ACPI */



	struct list_head list;

};



#define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)
@@ -492,6 +490,7 @@ static inline void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value) 
extern struct class *tpm_class;

extern dev_t tpm_devt;

extern const struct file_operations tpm_fops;

extern struct idr dev_nums_idr;



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

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

CRA Git | Maintained and supported by SUSTech CRA and CCSE