[PATCH] tpm: reorganize sysfs files

Many of the sysfs files were calling the TPM_GetCapability command with array.
Since for 1.2 more sysfs files of this type are coming I am generalizing the
array so there can be one array and the unique parts can be filled in just
before the command is called.
Signed-off-by: Kylene Hall <kjhall@us.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/char/tpm/tpm.c

@@ -119,17 +119,57 @@ out:
 }
 
 #define TPM_DIGEST_SIZE 20
-#define CAP_PCR_RESULT_SIZE 18
-static const u8 cap_pcr[] = {
+#define TPM_ERROR_SIZE 10
+#define TPM_RET_CODE_IDX 6
+#define TPM_GET_CAP_RET_SIZE_IDX 10
+#define TPM_GET_CAP_RET_UINT32_1_IDX 14
+#define TPM_GET_CAP_RET_UINT32_2_IDX 18
+#define TPM_GET_CAP_RET_UINT32_3_IDX 22
+#define TPM_GET_CAP_RET_UINT32_4_IDX 26
+
+#define TPM_CAP_IDX 13
+#define TPM_CAP_SUBCAP_IDX 21
+
+enum tpm_capabilities {
+	TPM_CAP_PROP = 5,
+};
+
+enum tpm_sub_capabilities {
+	TPM_CAP_PROP_PCR = 0x1,
+	TPM_CAP_PROP_MANUFACTURER = 0x3,
+};
+
+/*
+ * This is a semi generic GetCapability command for use
+ * with the capability type TPM_CAP_PROP or TPM_CAP_FLAG
+ * and their associated sub_capabilities.
+ */
+
+static const u8 tpm_cap[] = {
 	0, 193,			/* TPM_TAG_RQU_COMMAND */
 	0, 0, 0, 22,		/* length */
 	0, 0, 0, 101,		/* TPM_ORD_GetCapability */
-	0, 0, 0, 5,
-	0, 0, 0, 4,
-	0, 0, 1, 1
+	0, 0, 0, 0,		/* TPM_CAP_<TYPE> */
+	0, 0, 0, 4,		/* TPM_CAP_SUB_<TYPE> size */
+	0, 0, 1, 0		/* TPM_CAP_SUB_<TYPE> */
 };
 
-#define READ_PCR_RESULT_SIZE 30
+static ssize_t transmit_cmd(struct tpm_chip *chip, u8 *data, int len,
+			    char *desc)
+{
+	int err;
+
+	len = tpm_transmit(chip, data, len);
+	if (len <  0)
+		return len;
+	if (len == TPM_ERROR_SIZE) {
+		err = be32_to_cpu(*((__be32 *) (data + TPM_RET_CODE_IDX)));
+		dev_dbg(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
+		return err;
+	}
+	return 0;
+}
+
 static const u8 pcrread[] = {
 	0, 193,			/* TPM_TAG_RQU_COMMAND */
 	0, 0, 0, 14,		/* length */
@@ -140,8 +180,8 @@ static const u8 pcrread[] = {
 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
 		      char *buf)
 {
-	u8 data[READ_PCR_RESULT_SIZE];
-	ssize_t len;
+	u8 data[30];
+	ssize_t rc;
 	int i, j, num_pcrs;
 	__be32 index;
 	char *str = buf;
@@ -150,29 +190,24 @@ ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
 	if (chip == NULL)
 		return -ENODEV;
 
-	memcpy(data, cap_pcr, sizeof(cap_pcr));
-	if ((len = tpm_transmit(chip, data, sizeof(data)))
-	    < CAP_PCR_RESULT_SIZE) {
-		dev_dbg(chip->dev, "A TPM error (%d) occurred "
-				"attempting to determine the number of PCRS\n",
-			be32_to_cpu(*((__be32 *) (data + 6))));
+	memcpy(data, tpm_cap, sizeof(tpm_cap));
+	data[TPM_CAP_IDX] = TPM_CAP_PROP;
+	data[TPM_CAP_SUBCAP_IDX] = TPM_CAP_PROP_PCR;
+
+	rc = transmit_cmd(chip, data, sizeof(data),
+			"attempting to determine the number of PCRS");
+	if (rc)
 		return 0;
-	}
 
 	num_pcrs = be32_to_cpu(*((__be32 *) (data + 14)));
-
 	for (i = 0; i < num_pcrs; i++) {
 		memcpy(data, pcrread, sizeof(pcrread));
 		index = cpu_to_be32(i);
 		memcpy(data + 10, &index, 4);
-		if ((len = tpm_transmit(chip, data, sizeof(data)))
-		    < READ_PCR_RESULT_SIZE){
-			dev_dbg(chip->dev, "A TPM error (%d) occurred"
-				" attempting to read PCR %d of %d\n",
-				be32_to_cpu(*((__be32 *) (data + 6))),
-				i, num_pcrs);
+		rc = transmit_cmd(chip, data, sizeof(data),
+				"attempting to read a PCR");
+		if (rc)
 			goto out;
-		}
 		str += sprintf(str, "PCR-%02d: ", i);
 		for (j = 0; j < TPM_DIGEST_SIZE; j++)
 			str += sprintf(str, "%02X ", *(data + 10 + j));
@@ -194,7 +229,7 @@ ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
 		       char *buf)
 {
 	u8 *data;
-	ssize_t len;
+	ssize_t err;
 	int i, rc;
 	char *str = buf;
 
@@ -208,14 +243,10 @@ ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
 
 	memcpy(data, readpubek, sizeof(readpubek));
 
-	if ((len = tpm_transmit(chip, data, READ_PUBEK_RESULT_SIZE)) <
-	    READ_PUBEK_RESULT_SIZE) {
-		dev_dbg(chip->dev, "A TPM error (%d) occurred "
-				"attempting to read the PUBEK\n",
-			    be32_to_cpu(*((__be32 *) (data + 6))));
-		rc = 0;
+	err = transmit_cmd(chip, data, READ_PUBEK_RESULT_SIZE,
+			"attempting to read the PUBEK");
+	if (err)
 		goto out;
-	}
 
 	/* 
 	   ignore header 10 bytes
@@ -245,63 +276,59 @@ ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
 		if ((i + 1) % 16 == 0)
 			str += sprintf(str, "\n");
 	}
-	rc = str - buf;
 out:
+	rc = str - buf;
 	kfree(data);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_show_pubek);
 
-#define CAP_VER_RESULT_SIZE 18
+#define CAP_VERSION_1_1 6
+#define CAP_VERSION_IDX 13
 static const u8 cap_version[] = {
 	0, 193,			/* TPM_TAG_RQU_COMMAND */
 	0, 0, 0, 18,		/* length */
 	0, 0, 0, 101,		/* TPM_ORD_GetCapability */
-	0, 0, 0, 6,
+	0, 0, 0, 0,
 	0, 0, 0, 0
 };
 
-#define CAP_MANUFACTURER_RESULT_SIZE 18
-static const u8 cap_manufacturer[] = {
-	0, 193,			/* TPM_TAG_RQU_COMMAND */
-	0, 0, 0, 22,		/* length */
-	0, 0, 0, 101,		/* TPM_ORD_GetCapability */
-	0, 0, 0, 5,
-	0, 0, 0, 4,
-	0, 0, 1, 3
-};
-
 ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
 		      char *buf)
 {
-	u8 data[sizeof(cap_manufacturer)];
-	ssize_t len;
+	u8 data[30];
+	ssize_t rc;
 	char *str = buf;
 
 	struct tpm_chip *chip = dev_get_drvdata(dev);
 	if (chip == NULL)
 		return -ENODEV;
 
-	memcpy(data, cap_manufacturer, sizeof(cap_manufacturer));
+	memcpy(data, tpm_cap, sizeof(tpm_cap));
+	data[TPM_CAP_IDX] = TPM_CAP_PROP;
+	data[TPM_CAP_SUBCAP_IDX] = TPM_CAP_PROP_MANUFACTURER;
 
-	if ((len = tpm_transmit(chip, data, sizeof(data))) <
-	    CAP_MANUFACTURER_RESULT_SIZE)
-		return len;
+	rc = transmit_cmd(chip, data, sizeof(data),
+			"attempting to determine the manufacturer");
+	if (rc)
+		return 0;
 
 	str += sprintf(str, "Manufacturer: 0x%x\n",
-		       be32_to_cpu(*((__be32 *) (data + 14))));
+		       be32_to_cpu(*((__be32 *) (data + TPM_GET_CAP_RET_UINT32_1_IDX))));
 
 	memcpy(data, cap_version, sizeof(cap_version));
+	data[CAP_VERSION_IDX] = CAP_VERSION_1_1;
+	rc = transmit_cmd(chip, data, sizeof(data),
+			"attempting to determine the 1.1 version");
+	if (rc)
+		goto out;
 
-	if ((len = tpm_transmit(chip, data, sizeof(data))) <
-	    CAP_VER_RESULT_SIZE)
-		return len;
-
-	str +=
-	    sprintf(str, "TCG version: %d.%d\nFirmware version: %d.%d\n",
+	str += sprintf(str,
+		       "TCG version: %d.%d\nFirmware version: %d.%d\n",
 		       (int) data[14], (int) data[15], (int) data[16],
 		       (int) data[17]);
 
+out:
 	return str - buf;
 }
 EXPORT_SYMBOL_GPL(tpm_show_caps);