From: Stefan Berger Date: Mon, 29 Feb 2016 13:53:02 +0000 (-0500) Subject: tpm: Replace device number bitmap with IDR X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=15516788e581eb32ec1c50e5f00aba3faf95d817;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git 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: Stefan Berger Reviewed-by: Jason Gunthorpe Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 588037733107..f62c8518cd68 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; @@ -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; + 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; } /** @@ -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"); diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 5caf15421ef7..5397b64b6c96 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -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); } diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 5fcf7885a4b9..928b47f58771 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 */ }; @@ -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,