#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;
-/*
- * tpm_chip_find_get - return tpm_chip for a given chip number
- * @chip_num the device number for the chip
+/**
+ * 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.
*/
-struct tpm_chip *tpm_chip_find_get(int chip_num)
+int tpm_try_get_ops(struct tpm_chip *chip)
{
- struct tpm_chip *pos, *chip = NULL;
+ int rc = -EIO;
- 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;
+ get_device(&chip->dev);
- if (try_module_get(pos->pdev->driver->owner)) {
- chip = pos;
- break;
- }
+ 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;
}
- rcu_read_unlock();
- return chip;
+
+ mutex_unlock(&idr_lock);
+
+ return res;
}
/**
{
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);
}
/**
- * tpmm_chip_alloc() - allocate a new struct tpm_chip instance
- * @dev: device to which the chip is associated
+ * 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. Caller does not have to worry about
- * freeing the allocated resources. When the devices is removed
- * devres calls tpmm_chip_remove() to do the job.
+ * device number for it. Must be paired with put_device(&chip->dev).
*/
-struct tpm_chip *tpmm_chip_alloc(struct device *dev,
- const struct tpm_class_ops *ops)
+struct tpm_chip *tpm_chip_alloc(struct device *dev,
+ const struct tpm_class_ops *ops)
{
struct tpm_chip *chip;
int rc;
return ERR_PTR(-ENOMEM);
mutex_init(&chip->tpm_mutex);
- INIT_LIST_HEAD(&chip->list);
+ init_rwsem(&chip->ops_sem);
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);
}
+ chip->dev_num = rc;
- set_bit(chip->dev_num, dev_mask);
-
- scnprintf(chip->devname, sizeof(chip->devname), "tpm%d", chip->dev_num);
-
- chip->pdev = dev;
-
- dev_set_drvdata(dev, chip);
+ device_initialize(&chip->dev);
chip->dev.class = tpm_class;
chip->dev.release = tpm_dev_release;
- chip->dev.parent = chip->pdev;
+ chip->dev.parent = dev;
#ifdef CONFIG_ACPI
chip->dev.groups = chip->groups;
#endif
else
chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num);
- dev_set_name(&chip->dev, "%s", chip->devname);
-
- device_initialize(&chip->dev);
+ rc = dev_set_name(&chip->dev, "tpm%d", chip->dev_num);
+ if (rc)
+ goto out;
cdev_init(&chip->cdev, &tpm_fops);
- chip->cdev.owner = chip->pdev->driver->owner;
+ chip->cdev.owner = THIS_MODULE;
chip->cdev.kobj.parent = &chip->dev.kobj;
- rc = devm_add_action(dev, (void (*)(void *)) put_device, &chip->dev);
+ 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);
if (rc) {
dev_err(&chip->dev,
"unable to cdev_add() %s, major %d, minor %d, err=%d\n",
- chip->devname, MAJOR(chip->dev.devt),
+ dev_name(&chip->dev), MAJOR(chip->dev.devt),
MINOR(chip->dev.devt), rc);
return rc;
if (rc) {
dev_err(&chip->dev,
"unable to device_register() %s, major %d, minor %d, err=%d\n",
- chip->devname, MAJOR(chip->dev.devt),
+ 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;
}
{
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)
if (rc)
return rc;
- chip->bios_dir = tpm_bios_log_setup(chip->devname);
+ chip->bios_dir = tpm_bios_log_setup(dev_name(&chip->dev));
return 0;
}
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)) {
- rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj,
- &chip->dev.kobj,
- "ppi");
+ 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;
* 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.
*/
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->pdev->kobj, "ppi");
+ sysfs_remove_link(&chip->dev.parent->kobj, "ppi");
tpm1_chip_unregister(chip);
tpm_del_char_device(chip);
projects / linux-2.6-microblaze.git / blobdiff