[Skiboot] [PATCH 05/14] tpm_i2c_nuvoton: isolate the code that handles the TPM_TIMEOUT_D timeout
Claudio Carvalho
cclaudio at linux.vnet.ibm.com
Mon Nov 28 14:08:05 AEDT 2016
TPM_TIMEOUT_D timeout is only related to burst_count polling.
This moves the burstCount polling code to tpm_read_burst_count() in
order to isolate the code that is related to TPM_TIMEOUT_D.
Signed-off-by: Claudio Carvalho <cclaudio at linux.vnet.ibm.com>
---
libstb/drivers/tpm_i2c_nuvoton.c | 219 +++++++++++++++++----------------------
1 file changed, 95 insertions(+), 124 deletions(-)
diff --git a/libstb/drivers/tpm_i2c_nuvoton.c b/libstb/drivers/tpm_i2c_nuvoton.c
index 05a90fc..eb96f5e 100644
--- a/libstb/drivers/tpm_i2c_nuvoton.c
+++ b/libstb/drivers/tpm_i2c_nuvoton.c
@@ -217,19 +217,51 @@ static int tpm_poll_for_data_avail(void)
static int tpm_read_burst_count(uint8_t* burst_count)
{
- int rc = 0;
- /* In i2C, burstCount is 1 byte */
- rc = tpm_status_read_byte(TPM_BURST_COUNT, burst_count);
- DBG("---- burst_count=%d rc=%d\n", *burst_count, rc);
- if (rc < 0)
- *burst_count = 0;
- return rc;
+ int rc, delay;
+ uint8_t bc;
+
+ delay = 0;
+ *burst_count = 0;
+
+ do {
+ /* In i2C, burstCount is 1 byte */
+ rc = tpm_status_read_byte(TPM_BURST_COUNT, &bc);
+ if (rc == 0 && bc > 0) {
+ DBG("---- burst_count=%d, delay=%d/%d\n",
+ delay, TPM_TIMEOUT_D);
+ *burst_count = bc;
+ return 0;
+ }
+ if (rc < 0) {
+ /**
+ * @fwts-label TPMReadBurstCount
+ * @fwts-advice Either the tpm device or the tpm-i2c
+ * interface doesn't seem to be working properly. Check
+ * the return code (rc) for further details.
+ */
+ prlog(PR_ERR, "NUVOTON: fail to read sts.burstCount, "
+ "rc=%d\n", rc);
+ return STB_DRIVER_ERROR;
+ }
+ time_wait_ms(TPM_TIMEOUT_INTERVAL);
+ delay += TPM_TIMEOUT_INTERVAL;
+
+ } while (delay < TPM_TIMEOUT_D);
+
+ /**
+ * @fwts-label TPMBurstCountTimeout
+ * @fwts-advice The burstcount bit of the tpm status register is
+ * taking longer to be settled. Either the wait time need to be
+ * increased or the TPM device is not functional.
+ */
+ prlog(PR_ERR, "NUVOTON: timeout on sts.burstCount, delay=%d/%d\n",
+ delay, TPM_TIMEOUT_D);
+ return STB_TPM_TIMEOUT;
}
static int tpm_write_fifo(uint8_t* buf, size_t buflen)
{
uint8_t burst_count = 0;
- int delay = 0;
int rc;
size_t curByte = 0;
uint8_t* bytePtr = buf;
@@ -244,14 +276,8 @@ static int tpm_write_fifo(uint8_t* buf, size_t buflen)
do {
rc = tpm_read_burst_count(&burst_count);
- if (rc < 0) {
+ if (rc < 0)
return rc;
- } else if (burst_count == 0) {
- /* Need to delay to allow the TPM time */
- time_wait_ms(TPM_TIMEOUT_INTERVAL);
- delay += TPM_TIMEOUT_INTERVAL;
- continue;
- }
/*
* Send in some data
*/
@@ -263,11 +289,8 @@ static int tpm_write_fifo(uint8_t* buf, size_t buflen)
SMBUS_WRITE, TPM_DATA_FIFO_W,
1, curBytePtr, tx_len);
curByte += tx_len;
- DBG("%s write FIFO sent %zd bytes."
- " burstcount polling delay=%d/%d, rc=%d\n",
- (rc) ? "!!!!" : "----", curByte, delay,
- TPM_TIMEOUT_D, rc);
- delay = 0;
+ DBG("%s write FIFO sent %zd bytes, rc=%d\n",
+ (rc) ? "!!!!" : "----", curByte, TPM_TIMEOUT_D, rc);
if (rc < 0)
return rc;
@@ -281,51 +304,23 @@ static int tpm_write_fifo(uint8_t* buf, size_t buflen)
prlog(PR_ERR, "TPM: write FIFO overflow1\n");
return STB_TPM_OVERFLOW;
}
- /* Everything but the last byte sent? */
- if (curByte >= length)
- break;
- } while (delay < TPM_TIMEOUT_D);
+ } while (curByte < length);
- if (delay < TPM_TIMEOUT_D) {
- /*
- * Send the final byte
- */
- delay = 0;
- do {
- rc = tpm_read_burst_count(&burst_count);
- if (rc < 0) {
- return rc;
- } else if (burst_count == 0) {
- /* Need to delay to allow the TPM time */
- time_wait_ms(TPM_TIMEOUT_INTERVAL);
- delay += TPM_TIMEOUT_INTERVAL;
- continue;
- }
- curBytePtr = &(bytePtr[curByte]);
- rc = tpm_i2c_request_send(tpm_device->bus_id,
- tpm_device->xscom_base,
- SMBUS_WRITE,
- TPM_DATA_FIFO_W, 1,
- curBytePtr, 1);
- DBG("%s write FIFO sent last byte, delay=%d/%d,"
- " rc=%d\n",
- (rc) ? "!!!!" : "----", delay,
- TPM_TIMEOUT_D, rc);
- break;
- } while (delay < TPM_TIMEOUT_D);
- }
+ /*
+ * Send the final byte
+ */
+ rc = tpm_read_burst_count(&burst_count);
+ if (rc < 0)
+ return rc;
+ curBytePtr = &(bytePtr[curByte]);
+ rc = tpm_i2c_request_send(tpm_device->bus_id,
+ tpm_device->xscom_base,
+ SMBUS_WRITE,
+ TPM_DATA_FIFO_W, 1,
+ curBytePtr, 1);
+ DBG("%s write FIFO sent last byte, rc=%d\n",
+ (rc) ? "!!!!" : "----", TPM_TIMEOUT_D, rc);
- if (delay >= TPM_TIMEOUT_D) {
- /**
- * @fwts-label TPMWriteBurstcountBitTimeout
- * @fwts-advice The burstcount bit of the tpm status register is
- * taking longer to be settled. Either the wait time need to be
- * increased or the TPM device is not functional.
- */
- prlog(PR_ERR, "TPM: write FIFO, burstcount polling timeout."
- " delay=%d/%d\n", delay, TPM_TIMEOUT_D);
- return STB_TPM_TIMEOUT;
- }
if (rc == 0) {
if (tpm_is_expecting(&rc)) {
/**
@@ -346,75 +341,51 @@ static int tpm_read_fifo(uint8_t* buf, size_t* buflen)
{
int rc;
uint8_t burst_count;
- int delay = 0;
size_t curByte = 0;
uint8_t* bytePtr = (uint8_t*)buf;
uint8_t* curBytePtr = NULL;
rc = tpm_poll_for_data_avail();
+ if (rc < 0)
+ goto error;
- if (rc == 0) {
- do {
- rc = tpm_read_burst_count(&burst_count);
- if (rc < 0) {
- break;
- } else if (burst_count == 0) {
- /* Need to delay to allow the TPM time */
- time_wait_ms(TPM_TIMEOUT_INTERVAL);
- delay += TPM_TIMEOUT_INTERVAL;
- continue;
- }
- /* Buffer overflow check */
- if (curByte + burst_count > *buflen)
- {
- /**
- * @fwts-label TPMReadFifoOverflow1
- * @fwts-advice The read from TPM FIFO overflowed. It is
- * expecting more data even though we think we are done.
- * This indicates a bug in the TPM device driver.
- */
- prlog(PR_ERR, "TPM: read FIFO overflow1. delay %d/%d\n",
- delay, TPM_TIMEOUT_D);
- rc = STB_TPM_OVERFLOW;
- }
- /*
- * Read some data
+ do {
+ rc = tpm_read_burst_count(&burst_count);
+ if (rc < 0)
+ goto error;
+ /* Buffer overflow check */
+ if (curByte + burst_count > *buflen)
+ {
+ /**
+ * @fwts-label TPMReadFifoOverflow1
+ * @fwts-advice The read from TPM FIFO overflowed. It is
+ * expecting more data even though we think we are done.
+ * This indicates a bug in the TPM device driver.
*/
- curBytePtr = &(bytePtr[curByte]);
- rc = tpm_i2c_request_send(tpm_device->bus_id,
- tpm_device->xscom_base,
- SMBUS_READ,
- TPM_DATA_FIFO_R, 1,
- curBytePtr, burst_count);
- curByte += burst_count;
- DBG("%s read FIFO. received %zd bytes. burstcount"
- " polling delay=%d/%d, rc=%d\n",
- (rc) ? "!!!!" : "----", curByte, delay,
- TPM_TIMEOUT_D, rc);
- delay = 0;
- if (rc < 0)
- break;
- if (!tpm_is_data_avail(&rc))
- break;
- } while (delay < TPM_TIMEOUT_D);
- }
-
- if (rc == 0 && delay >= TPM_TIMEOUT_D) {
- /**
- * @fwts-label TPMReadBurstcountBitTimeout
- * @fwts-advice The burstcount bit of the tpm status register is
- * taking longer to be settled. Either the wait time needs to be
- * increased or the TPM device is not functional.
+ prlog(PR_ERR, "TPM: read FIFO overflow1\n");
+ rc = STB_TPM_OVERFLOW;
+ }
+ /*
+ * Read some data
*/
- prlog(PR_ERR, "TPM: read FIFO, burstcount polling timeout."
- " delay=%d/%d\n",
- delay, TPM_TIMEOUT_D);
- return STB_TPM_TIMEOUT;
- }
- if (rc == 0)
- *buflen = curByte;
- else
- *buflen = 0;
+ curBytePtr = &(bytePtr[curByte]);
+ rc = tpm_i2c_request_send(tpm_device->bus_id,
+ tpm_device->xscom_base,
+ SMBUS_READ,
+ TPM_DATA_FIFO_R, 1,
+ curBytePtr, burst_count);
+ curByte += burst_count;
+ DBG("%s read FIFO. received %zd bytes, rc=%d\n",
+ (rc) ? "!!!!" : "----", curByte, rc);
+ if (rc < 0)
+ goto error;
+ } while (tpm_is_data_avail(&rc));
+
+ *buflen = curByte;
+ return 0;
+
+error:
+ *buflen = 0;
return rc;
}
--
1.9.1
More information about the Skiboot
mailing list