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

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
...@@ -29,9 +29,8 @@ ...@@ -29,9 +29,8 @@
#include "tpm.h" #include "tpm.h"
#include "tpm_eventlog.h" #include "tpm_eventlog.h"
static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES); DEFINE_IDR(dev_nums_idr);
static LIST_HEAD(tpm_chip_list); static DEFINE_MUTEX(idr_lock);
static DEFINE_SPINLOCK(driver_lock);
struct class *tpm_class; struct class *tpm_class;
dev_t tpm_devt; dev_t tpm_devt;
...@@ -88,20 +87,30 @@ EXPORT_SYMBOL_GPL(tpm_put_ops); ...@@ -88,20 +87,30 @@ EXPORT_SYMBOL_GPL(tpm_put_ops);
*/ */
struct tpm_chip *tpm_chip_find_get(int chip_num) 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;
rcu_read_lock();
list_for_each_entry_rcu(pos, &tpm_chip_list, list) { mutex_lock(&idr_lock);
if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
continue; if (chip_num == TPM_ANY_NUM) {
chip_num = 0;
/* rcu prevents chip from being free'd */ do {
if (!tpm_try_get_ops(pos)) chip_prev = chip_num;
chip = pos; chip = idr_get_next(&dev_nums_idr, &chip_num);
if (chip && !tpm_try_get_ops(chip)) {
res = chip;
break; break;
} }
rcu_read_unlock(); } while (chip_prev != chip_num);
return chip; } 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) ...@@ -114,9 +123,10 @@ static void tpm_dev_release(struct device *dev)
{ {
struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev); struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
spin_lock(&driver_lock); mutex_lock(&idr_lock);
clear_bit(chip->dev_num, dev_mask); idr_remove(&dev_nums_idr, chip->dev_num);
spin_unlock(&driver_lock); mutex_unlock(&idr_lock);
kfree(chip); kfree(chip);
} }
...@@ -142,21 +152,18 @@ struct tpm_chip *tpm_chip_alloc(struct device *dev, ...@@ -142,21 +152,18 @@ struct tpm_chip *tpm_chip_alloc(struct device *dev,
mutex_init(&chip->tpm_mutex); mutex_init(&chip->tpm_mutex);
init_rwsem(&chip->ops_sem); init_rwsem(&chip->ops_sem);
INIT_LIST_HEAD(&chip->list);
chip->ops = ops; chip->ops = ops;
spin_lock(&driver_lock); mutex_lock(&idr_lock);
chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES); rc = idr_alloc(&dev_nums_idr, NULL, 0, TPM_NUM_DEVICES, GFP_KERNEL);
spin_unlock(&driver_lock); mutex_unlock(&idr_lock);
if (rc < 0) {
if (chip->dev_num >= TPM_NUM_DEVICES) {
dev_err(dev, "No available tpm device numbers\n"); dev_err(dev, "No available tpm device numbers\n");
kfree(chip); kfree(chip);
return ERR_PTR(-ENOMEM); return ERR_PTR(rc);
} }
chip->dev_num = rc;
set_bit(chip->dev_num, dev_mask);
device_initialize(&chip->dev); device_initialize(&chip->dev);
...@@ -242,19 +249,28 @@ static int tpm_add_char_device(struct tpm_chip *chip) ...@@ -242,19 +249,28 @@ static int tpm_add_char_device(struct tpm_chip *chip)
return rc; 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; return rc;
} }
static void tpm_del_char_device(struct tpm_chip *chip) static void tpm_del_char_device(struct tpm_chip *chip)
{ {
cdev_del(&chip->cdev); 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. */ /* Make the driver uncallable. */
down_write(&chip->ops_sem); down_write(&chip->ops_sem);
chip->ops = NULL; chip->ops = NULL;
up_write(&chip->ops_sem); up_write(&chip->ops_sem);
device_del(&chip->dev);
} }
static int tpm1_chip_register(struct tpm_chip *chip) static int tpm1_chip_register(struct tpm_chip *chip)
...@@ -309,11 +325,6 @@ int tpm_chip_register(struct tpm_chip *chip) ...@@ -309,11 +325,6 @@ int tpm_chip_register(struct tpm_chip *chip)
if (rc) if (rc)
goto out_err; 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; chip->flags |= TPM_CHIP_FLAG_REGISTERED;
if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
...@@ -350,11 +361,6 @@ void tpm_chip_unregister(struct tpm_chip *chip) ...@@ -350,11 +361,6 @@ void tpm_chip_unregister(struct tpm_chip *chip)
if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED)) if (!(chip->flags & TPM_CHIP_FLAG_REGISTERED))
return; return;
spin_lock(&driver_lock);
list_del_rcu(&chip->list);
spin_unlock(&driver_lock);
synchronize_rcu();
if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
sysfs_remove_link(&chip->dev.parent->kobj, "ppi"); sysfs_remove_link(&chip->dev.parent->kobj, "ppi");
......
...@@ -1139,6 +1139,7 @@ static int __init tpm_init(void) ...@@ -1139,6 +1139,7 @@ static int __init tpm_init(void)
static void __exit tpm_exit(void) static void __exit tpm_exit(void)
{ {
idr_destroy(&dev_nums_idr);
class_destroy(tpm_class); class_destroy(tpm_class);
unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES); unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
} }
......
...@@ -34,7 +34,7 @@ ...@@ -34,7 +34,7 @@
enum tpm_const { enum tpm_const {
TPM_MINOR = 224, /* officially assigned */ TPM_MINOR = 224, /* officially assigned */
TPM_BUFSIZE = 4096, TPM_BUFSIZE = 4096,
TPM_NUM_DEVICES = 256, TPM_NUM_DEVICES = 65536,
TPM_RETRY = 50, /* 5 seconds */ TPM_RETRY = 50, /* 5 seconds */
}; };
...@@ -195,8 +195,6 @@ struct tpm_chip { ...@@ -195,8 +195,6 @@ struct tpm_chip {
acpi_handle acpi_dev_handle; acpi_handle acpi_dev_handle;
char ppi_version[TPM_PPI_VERSION_LEN + 1]; char ppi_version[TPM_PPI_VERSION_LEN + 1];
#endif /* CONFIG_ACPI */ #endif /* CONFIG_ACPI */
struct list_head list;
}; };
#define to_tpm_chip(d) container_of(d, struct tpm_chip, dev) #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) ...@@ -492,6 +490,7 @@ static inline void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value)
extern struct class *tpm_class; extern struct class *tpm_class;
extern dev_t tpm_devt; extern dev_t tpm_devt;
extern const struct file_operations tpm_fops; 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_getcap(struct device *, __be32, cap_t *, const char *);
ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf, ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
......
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