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authorStefan Berger <stefanb@linux.vnet.ibm.com>2016-02-29 08:53:02 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-06 19:19:43 -0700
commitf7e0f7f86ce0cf83e3e352399eec5d3b23566824 (patch)
tree8c4289d6a81503bdb0aac09e89ed80d982382a46 /drivers/char
parent7e789223932762e1e7ffdb63f3fd1b42dbeeb789 (diff)
tpm: Replace device number bitmap with IDR
commit 15516788e581eb32ec1c50e5f00aba3faf95d817 upstream. 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: Stefan Berger <stefanb@linux.vnet.ibm.com> Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/tpm-chip.c85
-rw-r--r--drivers/char/tpm/tpm-interface.c1
-rw-r--r--drivers/char/tpm/tpm.h5
3 files changed, 49 insertions, 42 deletions
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 6d56877b2e0a..a0d9ac6b6cc9 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -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;
@@ -92,20 +91,30 @@ EXPORT_SYMBOL_GPL(tpm_put_ops);
*/
struct tpm_chip *tpm_chip_find_get(int chip_num)
{
- struct tpm_chip *pos, *chip = NULL;
+ 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;
+ }
- 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;
+ mutex_unlock(&idr_lock);
- /* rcu prevents chip from being free'd */
- if (!tpm_try_get_ops(pos))
- chip = pos;
- break;
- }
- rcu_read_unlock();
- return chip;
+ return res;
}
/**
@@ -118,9 +127,10 @@ 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);
}
@@ -173,6 +183,7 @@ struct tpm_chip *tpmm_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)
@@ -180,21 +191,18 @@ struct tpm_chip *tpmm_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;
scnprintf(chip->devname, sizeof(chip->devname), "tpm%d", chip->dev_num);
@@ -252,19 +260,28 @@ 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)
@@ -319,11 +336,6 @@ 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)) {
@@ -360,11 +372,6 @@ 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");
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 8588f2e4b9af..aaa5fa95dede 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -1127,6 +1127,7 @@ 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);
}
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index e21e2c599e66..772d99b3a8e4 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -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 */
};
@@ -200,8 +200,6 @@ 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)
@@ -497,6 +495,7 @@ 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;
enum tpm_transmit_flags {
TPM_TRANSMIT_UNLOCKED = BIT(0),