[SLOF] [PATCH v4 19/33] tpm: Implement log related 32 bit endian conversion functions

[Stefan Berger]

Implement log related endian conversion functions for 32 bit
numbers. This is necessary since TPM 1.2 logs are written in
big endian format and TPM 2.0 logs in little endia format.

Use the conversion function when we read or write 32 bit
numbers to/from the 'pcpes' structure.

Signed-off-by Stefan Berger <stefanb at linux.ibm.com>
---
 lib/libtpm/tcgbios.c | 48 ++++++++++++++++++++++++++++++++++++--------
 1 file changed, 40 insertions(+), 8 deletions(-)

diff --git a/lib/libtpm/tcgbios.c b/lib/libtpm/tcgbios.c
index 7554bd3..af29406 100644
--- a/lib/libtpm/tcgbios.c
+++ b/lib/libtpm/tcgbios.c
@@ -62,6 +62,37 @@ typedef uint8_t tpm_ppi_op;
 
 #define TPM_version spapr_get_tpm_version()
 
+/*
+ * TPM 1.2 logs are written in big endian format and TPM 2 logs
+ * are written in little endian format.
+ */
+static inline uint32_t log32_to_cpu(uint32_t val)
+{
+	switch (TPM_version) {
+	case TPM_VERSION_1_2:
+		return be32_to_cpu(val);
+	case TPM_VERSION_2:
+		return le32_to_cpu(val);
+	}
+	return 0;
+}
+
+static inline uint32_t cpu_to_log32(uint32_t val)
+{
+	switch (TPM_version) {
+	case TPM_VERSION_1_2:
+		return cpu_to_be32(val);
+	case TPM_VERSION_2:
+		return cpu_to_le32(val);
+	}
+	return 0;
+}
+
+static inline bool tpm_log_is_be(void)
+{
+	return TPM_version == TPM_VERSION_1_2;
+}
+
 /********************************************************
   Extensions for TCG-enabled BIOS
  *******************************************************/
@@ -256,7 +287,7 @@ static uint32_t tpm_log_event_long(struct pcpes *pcpes,
 		return TCGBIOS_LOGOVERFLOW;
 	}
 
-	pcpes->eventdatasize = event_length;
+	pcpes->eventdatasize = cpu_to_log32(event_length);
 
 	memcpy(tpm_state.log_area_next_entry, pcpes,
 	       offset_of(struct pcpes, event));
@@ -271,7 +302,7 @@ static uint32_t tpm_log_event_long(struct pcpes *pcpes,
 bool tpm_log_event(struct pcpes *pcpes)
 {
 	const char *event = NULL;
-	uint32_t event_length = pcpes->eventdatasize;
+	uint32_t event_length = log32_to_cpu(pcpes->eventdatasize);
 
 	if (event_length)
 		event = (void *)pcpes + offset_of(struct pcpes, event);
@@ -411,13 +442,13 @@ static uint32_t hash_log_extend(struct pcpes *pcpes,
 {
 	int ret;
 
-	if (pcpes->pcrindex >= 24)
+	if (log32_to_cpu(pcpes->pcrindex) >= 24)
 		return TCGBIOS_INVALID_INPUT_PARA;
 	if (hashdata)
 		tpm_hash_all(hashdata, hashdata_length, pcpes->digest);
 
 	if (extend) {
-		ret = tpm_extend(pcpes->digest, pcpes->pcrindex);
+		ret = tpm_extend(pcpes->digest, log32_to_cpu(pcpes->pcrindex));
 		if (ret)
 			return TCGBIOS_COMMAND_ERROR;
 	}
@@ -448,8 +479,8 @@ static uint32_t tpm_add_measurement_to_log(uint32_t pcrindex,
 {
 	struct pcpes pcpes;
 
-	pcpes.pcrindex	= pcrindex;
-	pcpes.eventtype = eventtype;
+	pcpes.pcrindex	= cpu_to_log32(pcrindex);
+	pcpes.eventtype = cpu_to_log32(eventtype);
 	memset(&pcpes.digest, 0, sizeof(pcpes.digest));
 
 	return hash_log_extend(&pcpes, hashdata, hashdatalen,
@@ -462,7 +493,7 @@ static uint32_t tpm_add_measurement_to_log(uint32_t pcrindex,
 uint32_t tpm_hash_log_extend_event(struct pcpes *pcpes)
 {
 	const char *event = NULL;
-	uint32_t event_length = pcpes->eventdatasize;
+	uint32_t event_length = log32_to_cpu(pcpes->eventdatasize);
 
 	if (!tpm_is_working())
 		return TCGBIOS_GENERAL_ERROR;
@@ -471,7 +502,8 @@ uint32_t tpm_hash_log_extend_event(struct pcpes *pcpes)
 		event = (void *)pcpes + offset_of(struct pcpes, event);
 
 	return hash_log_extend(pcpes,
-			       &pcpes->event, pcpes->eventdatasize,
+			       &pcpes->event,
+			       log32_to_cpu(pcpes->eventdatasize),
 			       event, event_length, true);
 }
 
-- 
2.17.1