diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 96c8261d0f04..eb7c79ca8a94 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -451,11 +451,12 @@ EXPORT_SYMBOL_GPL(tpm_is_tpm2);
  * tpm_pcr_read - read a PCR value from SHA1 bank
  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
  * @pcr_idx:	the PCR to be retrieved
- * @res_buf:	the value of the PCR
+ * @digest:	the PCR bank and buffer current PCR value is written to
  *
  * Return: same as with tpm_transmit_cmd()
  */
-int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
+int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
+		 struct tpm_digest *digest)
 {
 	int rc;
 
@@ -464,9 +465,9 @@ int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
 		return -ENODEV;
 
 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
-		rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
+		rc = tpm2_pcr_read(chip, pcr_idx, digest, NULL);
 	else
-		rc = tpm1_pcr_read(chip, pcr_idx, res_buf);
+		rc = tpm1_pcr_read(chip, pcr_idx, digest->digest);
 
 	tpm_put_ops(chip);
 	return rc;
@@ -479,9 +480,8 @@ EXPORT_SYMBOL_GPL(tpm_pcr_read);
  * @pcr_idx:	the PCR to be retrieved
  * @hash:	the hash value used to extend the PCR value
  *
- * Note: with TPM 2.0 extends also those banks with a known digest size to the
- * cryto subsystem in order to prevent malicious use of those PCR banks. In the
- * future we should dynamically determine digest sizes.
+ * Note: with TPM 2.0 extends also those banks for which no digest was
+ * specified in order to prevent malicious use of those PCR banks.
  *
  * Return: same as with tpm_transmit_cmd()
  */
@@ -502,7 +502,7 @@ int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash)
 			return -ENOMEM;
 
 		for (i = 0; i < chip->nr_allocated_banks; i++) {
-			digest_list[i].alg_id = chip->allocated_banks[i];
+			digest_list[i].alg_id = chip->allocated_banks[i].alg_id;
 			memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
 		}
 
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index e961e5c5d197..64d93d26087f 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -247,7 +247,7 @@ struct tpm_chip {
 	unsigned int groups_cnt;
 
 	u32 nr_allocated_banks;
-	u16 *allocated_banks;
+	struct tpm_bank_info *allocated_banks;
 #ifdef CONFIG_ACPI
 	acpi_handle acpi_dev_handle;
 	char ppi_version[TPM_PPI_VERSION_LEN + 1];
@@ -548,7 +548,8 @@ static inline u32 tpm2_rc_value(u32 rc)
 }
 
 int tpm2_get_timeouts(struct tpm_chip *chip);
-int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf);
+int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
+		  struct tpm_digest *digest, u16 *digest_size_ptr);
 int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
 		    struct tpm_digest *digests);
 int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max);
diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
index ec4f197bae0a..8b70a7f884a7 100644
--- a/drivers/char/tpm/tpm1-cmd.c
+++ b/drivers/char/tpm/tpm1-cmd.c
@@ -716,7 +716,9 @@ int tpm1_auto_startup(struct tpm_chip *chip)
 		goto out;
 	}
 
-	chip->allocated_banks[0] = TPM_ALG_SHA1;
+	chip->allocated_banks[0].alg_id = TPM_ALG_SHA1;
+	chip->allocated_banks[0].digest_size = hash_digest_size[HASH_ALGO_SHA1];
+	chip->allocated_banks[0].crypto_id = HASH_ALGO_SHA1;
 	chip->nr_allocated_banks = 1;
 
 	return rc;
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index db8e05c8dad3..760893957f13 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -171,20 +171,36 @@ struct tpm2_pcr_read_out {
  * tpm2_pcr_read() - read a PCR value
  * @chip:	TPM chip to use.
  * @pcr_idx:	index of the PCR to read.
- * @res_buf:	buffer to store the resulting hash.
+ * @digest:	PCR bank and buffer current PCR value is written to.
+ * @digest_size_ptr:	pointer to variable that stores the digest size.
  *
  * Return: Same as with tpm_transmit_cmd.
  */
-int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
+int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
+		  struct tpm_digest *digest, u16 *digest_size_ptr)
 {
+	int i;
 	int rc;
 	struct tpm_buf buf;
 	struct tpm2_pcr_read_out *out;
 	u8 pcr_select[TPM2_PCR_SELECT_MIN] = {0};
+	u16 digest_size;
+	u16 expected_digest_size = 0;
 
 	if (pcr_idx >= TPM2_PLATFORM_PCR)
 		return -EINVAL;
 
+	if (!digest_size_ptr) {
+		for (i = 0; i < chip->nr_allocated_banks &&
+		     chip->allocated_banks[i].alg_id != digest->alg_id; i++)
+			;
+
+		if (i == chip->nr_allocated_banks)
+			return -EINVAL;
+
+		expected_digest_size = chip->allocated_banks[i].digest_size;
+	}
+
 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_PCR_READ);
 	if (rc)
 		return rc;
@@ -192,18 +208,29 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
 	pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
 
 	tpm_buf_append_u32(&buf, 1);
-	tpm_buf_append_u16(&buf, TPM_ALG_SHA1);
+	tpm_buf_append_u16(&buf, digest->alg_id);
 	tpm_buf_append_u8(&buf, TPM2_PCR_SELECT_MIN);
 	tpm_buf_append(&buf, (const unsigned char *)pcr_select,
 		       sizeof(pcr_select));
 
 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
-			res_buf ? "attempting to read a pcr value" : NULL);
-	if (rc == 0 && res_buf) {
-		out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
-		memcpy(res_buf, out->digest, SHA1_DIGEST_SIZE);
+			      "attempting to read a pcr value");
+	if (rc)
+		goto out;
+
+	out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
+	digest_size = be16_to_cpu(out->digest_size);
+	if (digest_size > sizeof(digest->digest) ||
+	    (!digest_size_ptr && digest_size != expected_digest_size)) {
+		rc = -EINVAL;
+		goto out;
 	}
 
+	if (digest_size_ptr)
+		*digest_size_ptr = digest_size;
+
+	memcpy(digest->digest, out->digest, digest_size);
+out:
 	tpm_buf_destroy(&buf);
 	return rc;
 }
@@ -232,7 +259,6 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
 	struct tpm2_null_auth_area auth_area;
 	int rc;
 	int i;
-	int j;
 
 	if (count > chip->nr_allocated_banks)
 		return -EINVAL;
@@ -254,14 +280,9 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
 	tpm_buf_append_u32(&buf, count);
 
 	for (i = 0; i < count; i++) {
-		for (j = 0; j < ARRAY_SIZE(tpm2_hash_map); j++) {
-			if (digests[i].alg_id != tpm2_hash_map[j].tpm_id)
-				continue;
-			tpm_buf_append_u16(&buf, digests[i].alg_id);
-			tpm_buf_append(&buf, (const unsigned char
-					      *)&digests[i].digest,
-			       hash_digest_size[tpm2_hash_map[j].crypto_id]);
-		}
+		tpm_buf_append_u16(&buf, digests[i].alg_id);
+		tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest,
+			       chip->allocated_banks[i].digest_size);
 	}
 
 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
@@ -812,6 +833,30 @@ int tpm2_probe(struct tpm_chip *chip)
 }
 EXPORT_SYMBOL_GPL(tpm2_probe);
 
+static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index)
+{
+	struct tpm_bank_info *bank = chip->allocated_banks + bank_index;
+	struct tpm_digest digest = { .alg_id = bank->alg_id };
+	int i;
+
+	/*
+	 * Avoid unnecessary PCR read operations to reduce overhead
+	 * and obtain identifiers of the crypto subsystem.
+	 */
+	for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
+		enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id;
+
+		if (bank->alg_id != tpm2_hash_map[i].tpm_id)
+			continue;
+
+		bank->digest_size = hash_digest_size[crypto_algo];
+		bank->crypto_id = crypto_algo;
+		return 0;
+	}
+
+	return tpm2_pcr_read(chip, 0, &digest, &bank->digest_size);
+}
+
 struct tpm2_pcr_selection {
 	__be16  hash_alg;
 	u8  size_of_select;
@@ -876,7 +921,12 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
 		pcr_select_offset = memchr_inv(pcr_selection.pcr_select, 0,
 					       pcr_selection.size_of_select);
 		if (pcr_select_offset) {
-			chip->allocated_banks[nr_alloc_banks] = hash_alg;
+			chip->allocated_banks[nr_alloc_banks].alg_id = hash_alg;
+
+			rc = tpm2_init_bank_info(chip, nr_alloc_banks);
+			if (rc < 0)
+				break;
+
 			nr_alloc_banks++;
 		}
 
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 330c0a481581..72df8d4252ef 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -46,6 +46,12 @@ struct tpm_digest {
 	u8 digest[SHA512_DIGEST_SIZE];
 } __packed;
 
+struct tpm_bank_info {
+	u16 alg_id;
+	u16 digest_size;
+	u16 crypto_id;
+};
+
 enum TPM_OPS_FLAGS {
 	TPM_OPS_AUTO_STARTUP = BIT(0),
 };
@@ -71,7 +77,8 @@ 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, u32 pcr_idx, u8 *res_buf);
+extern int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
+			struct tpm_digest *digest);
 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);
@@ -88,7 +95,8 @@ static inline int tpm_is_tpm2(struct tpm_chip *chip)
 	return -ENODEV;
 }
 
-static inline int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
+static inline int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx,
+			       struct tpm_digest *digest)
 {
 	return -ENODEV;
 }
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index acf2c7df7145..16a4f45863b1 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -643,12 +643,12 @@ int ima_calc_buffer_hash(const void *buf, loff_t len,
 	return calc_buffer_shash(buf, len, hash);
 }
 
-static void __init ima_pcrread(u32 idx, u8 *pcr)
+static void __init ima_pcrread(u32 idx, struct tpm_digest *d)
 {
 	if (!ima_tpm_chip)
 		return;
 
-	if (tpm_pcr_read(ima_tpm_chip, idx, pcr) != 0)
+	if (tpm_pcr_read(ima_tpm_chip, idx, d) != 0)
 		pr_err("Error Communicating to TPM chip\n");
 }
 
@@ -658,7 +658,7 @@ static void __init ima_pcrread(u32 idx, u8 *pcr)
 static int __init ima_calc_boot_aggregate_tfm(char *digest,
 					      struct crypto_shash *tfm)
 {
-	u8 pcr_i[TPM_DIGEST_SIZE];
+	struct tpm_digest d = { .alg_id = TPM_ALG_SHA1, .digest = {0} };
 	int rc;
 	u32 i;
 	SHASH_DESC_ON_STACK(shash, tfm);
@@ -672,9 +672,9 @@ static int __init ima_calc_boot_aggregate_tfm(char *digest,
 
 	/* cumulative sha1 over tpm registers 0-7 */
 	for (i = TPM_PCR0; i < TPM_PCR8; i++) {
-		ima_pcrread(i, pcr_i);
+		ima_pcrread(i, &d);
 		/* now accumulate with current aggregate */
-		rc = crypto_shash_update(shash, pcr_i, TPM_DIGEST_SIZE);
+		rc = crypto_shash_update(shash, d.digest, TPM_DIGEST_SIZE);
 	}
 	if (!rc)
 		crypto_shash_final(shash, digest);
