tpm: use u32 instead of int for PCR index

The TPM specs defines PCR index as a positive number, and there is
no reason to use a signed number. It is also a possible security
issue as currently no functions check for a negative index,
which may become a large number when converted to u32.

Adjust the API to use u32 instead of int in all PCR related
functions.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.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>
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 4609b94..b49a55c 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -53,8 +53,8 @@ struct tpm_class_ops {
 #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)
 
 extern int tpm_is_tpm2(struct tpm_chip *chip);
-extern int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);
-extern int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash);
+extern int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf);
+extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash);
 extern int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen);
 extern int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max);
 extern int tpm_seal_trusted(struct tpm_chip *chip,
@@ -69,15 +69,18 @@ static inline int tpm_is_tpm2(struct tpm_chip *chip)
 {
 	return -ENODEV;
 }
-static inline int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
+
+static inline int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
 {
 	return -ENODEV;
 }
-static inline int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx,
+
+static inline int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
 				 const u8 *hash)
 {
 	return -ENODEV;
 }
+
 static inline int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
 {
 	return -ENODEV;