1 files changed, 7 insertions, 18 deletions

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 160dc080d580..6889e7db3aff 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -32,7 +32,6 @@ enum tpm_const {
         TPM_MINOR = 224,        /* officially assigned */
         TPM_BUFSIZE = 2048,
         TPM_NUM_DEVICES = 256,
-        TPM_NUM_MASK_ENTRIES = TPM_NUM_DEVICES / (8 * sizeof(int))
 };
 
 enum tpm_duration {
@@ -48,7 +47,7 @@ enum tpm_duration {
 
 static LIST_HEAD(tpm_chip_list);
 static DEFINE_SPINLOCK(driver_lock);
-static int dev_mask[TPM_NUM_MASK_ENTRIES];
+static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
 
 /*
  * Array with one entry per ordinal defining the maximum amount
@@ -1038,8 +1037,7 @@ void tpm_remove_hardware(struct device *dev)
         sysfs_remove_group(&dev->kobj, chip->vendor.attr_group);
         tpm_bios_log_teardown(chip->bios_dir);
 
-        dev_mask[chip->dev_num / TPM_NUM_MASK_ENTRIES] &=
-            ~(1 << (chip->dev_num % TPM_NUM_MASK_ENTRIES));
+        clear_bit(chip->dev_num, dev_mask);
 
         kfree(chip);
 
@@ -1097,7 +1095,6 @@ struct tpm_chip *tpm_register_hardware(struct device *dev, const struct tpm_vend
 
         char *devname;
         struct tpm_chip *chip;
-        int i, j;
 
         /* Driver specific per-device data */
         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
@@ -1116,19 +1113,9 @@ struct tpm_chip *tpm_register_hardware(struct device *dev, const struct tpm_vend
 
         memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
 
-        chip->dev_num = -1;
+        chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
 
-        for (i = 0; i < TPM_NUM_MASK_ENTRIES; i++)
-                for (j = 0; j < 8 * sizeof(int); j++)
-                        if ((dev_mask[i] & (1 << j)) == 0) {
-                                chip->dev_num =
-                                    i * TPM_NUM_MASK_ENTRIES + j;
-                                dev_mask[i] |= 1 << j;
-                                goto dev_num_search_complete;
-                        }
-
-dev_num_search_complete:
-        if (chip->dev_num < 0) {
+        if (chip->dev_num >= TPM_NUM_DEVICES) {
                 dev_err(dev, "No available tpm device numbers\n");
                 kfree(chip);
                 return NULL;
@@ -1137,6 +1124,8 @@ dev_num_search_complete:
         else
                 chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;
 
+        set_bit(chip->dev_num, dev_mask);
+
         devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
         scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
         chip->vendor.miscdev.name = devname;
@@ -1150,8 +1139,8 @@ dev_num_search_complete:
                         chip->vendor.miscdev.name,
                         chip->vendor.miscdev.minor);
                 put_device(dev);
+                clear_bit(chip->dev_num, dev_mask);
                 kfree(chip);
-                dev_mask[i] &= !(1 << j);
                 return NULL;
         }