diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c
index fe48150f06d1..2c912ea08166 100644
--- a/drivers/firmware/efi/tpm.c
+++ b/drivers/firmware/efi/tpm.c
@@ -28,6 +28,7 @@ static int tpm2_calc_event_log_size(void *data, int count, void *size_info)
 		if (event_size == 0)
 			return -1;
 		size += event_size;
+		count--;
 	}
 
 	return size;
@@ -41,6 +42,7 @@ int __init efi_tpm_eventlog_init(void)
 	struct linux_efi_tpm_eventlog *log_tbl;
 	struct efi_tcg2_final_events_table *final_tbl;
 	unsigned int tbl_size;
+	int ret = 0;
 
 	if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) {
 		/*
@@ -60,10 +62,9 @@ int __init efi_tpm_eventlog_init(void)
 
 	tbl_size = sizeof(*log_tbl) + log_tbl->size;
 	memblock_reserve(efi.tpm_log, tbl_size);
-	early_memunmap(log_tbl, sizeof(*log_tbl));
 
 	if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR)
-		return 0;
+		goto out;
 
 	final_tbl = early_memremap(efi.tpm_final_log, sizeof(*final_tbl));
 
@@ -71,17 +72,22 @@ int __init efi_tpm_eventlog_init(void)
 		pr_err("Failed to map TPM Final Event Log table @ 0x%lx\n",
 		       efi.tpm_final_log);
 		efi.tpm_final_log = EFI_INVALID_TABLE_ADDR;
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out;
 	}
 
-	tbl_size = tpm2_calc_event_log_size(final_tbl->events,
+	tbl_size = tpm2_calc_event_log_size(efi.tpm_final_log
+					    + sizeof(final_tbl->version)
+					    + sizeof(final_tbl->nr_events),
 					    final_tbl->nr_events,
-					    (void *)efi.tpm_log);
+					    log_tbl->log);
 	memblock_reserve((unsigned long)final_tbl,
 			 tbl_size + sizeof(*final_tbl));
 	early_memunmap(final_tbl, sizeof(*final_tbl));
 	efi_tpm_final_log_size = tbl_size;
 
-	return 0;
+out:
+	early_memunmap(log_tbl, sizeof(*log_tbl));
+	return ret;
 }
 
diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h
index 0ca27bc053af..63238c84dc0b 100644
--- a/include/linux/tpm_eventlog.h
+++ b/include/linux/tpm_eventlog.h
@@ -185,8 +185,12 @@ static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
 			size = 0;
 			goto out;
 		}
+	} else {
+		mapping = marker_start;
 	}
 
+	event = (struct tcg_pcr_event2_head *)mapping;
+
 	efispecid = (struct tcg_efi_specid_event_head *)event_header->event;
 
 	/* Check if event is malformed. */
@@ -201,34 +205,24 @@ static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
 		/* Map the digest's algorithm identifier */
 		if (do_mapping) {
 			TPM_MEMUNMAP(mapping, mapping_size);
-			mapping_size = marker - marker_start + halg_size;
-			mapping = TPM_MEMREMAP((unsigned long)marker_start,
-					       mapping_size);
+			mapping_size = halg_size;
+			mapping = TPM_MEMREMAP((unsigned long)marker,
+					     mapping_size);
 			if (!mapping) {
 				size = 0;
 				goto out;
 			}
+		} else {
+			mapping = marker;
 		}
 
-		memcpy(&halg, marker, halg_size);
+		memcpy(&halg, mapping, halg_size);
 		marker = marker + halg_size;
 
 		for (j = 0; j < efispecid->num_algs; j++) {
 			if (halg == efispecid->digest_sizes[j].alg_id) {
 				marker +=
 					efispecid->digest_sizes[j].digest_size;
-
-				/* Map the digest content itself */
-				if (do_mapping) {
-					TPM_MEMUNMAP(mapping, mapping_size);
-					mapping_size = marker - marker_start;
-					mapping = TPM_MEMREMAP((unsigned long)marker_start,
-							       mapping_size);
-					if (!mapping) {
-						size = 0;
-						goto out;
-					}
-				}
 				break;
 			}
 		}
@@ -239,23 +233,25 @@ static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
 		}
 	}
 
-	event_field = (struct tcg_event_field *)marker;
-
 	/*
 	 * Map the event size - we don't read from the event itself, so
 	 * we don't need to map it
 	 */
 	if (do_mapping) {
-		TPM_MEMUNMAP(marker_start, mapping_size);
+		TPM_MEMUNMAP(mapping, mapping_size);
 		mapping_size += sizeof(event_field->event_size);
-		mapping = TPM_MEMREMAP((unsigned long)marker_start,
+		mapping = TPM_MEMREMAP((unsigned long)marker,
 				       mapping_size);
 		if (!mapping) {
 			size = 0;
 			goto out;
 		}
+	} else {
+		mapping = marker;
 	}
 
+	event_field = (struct tcg_event_field *)mapping;
+
 	marker = marker + sizeof(event_field->event_size)
 		+ event_field->event_size;
 	size = marker - marker_start;