tpm: Fix cancellation of TPM commands (polling mode)

On one of my machines the cancellation of TPM commands does not work.
The reason is that by writing into sysfs 'cancel' the tpm_tis_ready
call causes the status flag TPM_STS_VALID to be set in the statusregister.
However, the TIS driver seems to wait for TPM_STS_COMMAND_READY.
Once a 2nd time sysfs 'cancel' is written to, the TPM_STS_COMMAND_READY flag
also gets set, resulting in TPM_STS_VALID|TPM_STS_COMMAND_READY to be
read from the status register.

This patch now converts req_canceled into a function to enable more complex
comparisons against possible cancellation status codes.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>

drivers/char/tpm/tpm.c

@@ -393,7 +393,7 @@ static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 		    chip->vendor.req_complete_val)
 			goto out_recv;
 
-		if ((status == chip->vendor.req_canceled)) {
+		if (chip->vendor.req_canceled(chip, status)) {
 			dev_err(chip->dev, "Operation Canceled\n");
 			rc = -ECANCELED;
 			goto out;

drivers/char/tpm/tpm.h

@@ -78,7 +78,7 @@ struct tpm_chip;
 struct tpm_vendor_specific {
 	const u8 req_complete_mask;
 	const u8 req_complete_val;
-	const u8 req_canceled;
+	bool (*req_canceled)(struct tpm_chip *chip, u8 status);
 	void __iomem *iobase;		/* ioremapped address */
 	unsigned long base;		/* TPM base address */
 
@@ -112,6 +112,8 @@ struct tpm_vendor_specific {
 #define TPM_VPRIV(c)	(c)->vendor.priv
 
 #define TPM_VID_INTEL    0x8086
+#define TPM_VID_WINBOND  0x1050
+#define TPM_VID_STM      0x104A
 
 struct tpm_chip {
 	struct device *dev;	/* Device stuff */

drivers/char/tpm/tpm_atmel.c

@@ -116,6 +116,11 @@ static u8 tpm_atml_status(struct tpm_chip *chip)
 	return ioread8(chip->vendor.iobase + 1);
 }
 
+static bool tpm_atml_req_canceled(struct tpm_chip *chip, u8 status)
+{
+	return (status == ATML_STATUS_READY);
+}
+
 static const struct file_operations atmel_ops = {
 	.owner = THIS_MODULE,
 	.llseek = no_llseek,
@@ -147,7 +152,7 @@ static const struct tpm_vendor_specific tpm_atmel = {
 	.status = tpm_atml_status,
 	.req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
 	.req_complete_val = ATML_STATUS_DATA_AVAIL,
-	.req_canceled = ATML_STATUS_READY,
+	.req_canceled = tpm_atml_req_canceled,
 	.attr_group = &atmel_attr_grp,
 	.miscdev = { .fops = &atmel_ops, },
 };

drivers/char/tpm/tpm_i2c_infineon.c

@@ -505,6 +505,11 @@ static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
 	return rc;
 }
 
+static bool tpm_tis_i2c_req_canceled(struct tpm_chip *chip, u8 status)
+{
+	return (status == TPM_STS_COMMAND_READY);
+}
+
 static const struct file_operations tis_ops = {
 	.owner = THIS_MODULE,
 	.llseek = no_llseek,
@@ -550,7 +555,7 @@ static struct tpm_vendor_specific tpm_tis_i2c = {
 	.cancel = tpm_tis_i2c_ready,
 	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
-	.req_canceled = TPM_STS_COMMAND_READY,
+	.req_canceled = tpm_tis_i2c_req_canceled,
 	.attr_group = &tis_attr_grp,
 	.miscdev.fops = &tis_ops,
 };

drivers/char/tpm/tpm_i2c_stm_st33.c

@@ -587,6 +587,11 @@ static int tpm_stm_i2c_recv(struct tpm_chip *chip, unsigned char *buf,
 	return size;
 }
 
+static bool tpm_st33_i2c_req_canceled(struct tpm_chip *chip, u8 status)
+{
+       return (status == TPM_STS_COMMAND_READY);
+}
+
 static const struct file_operations tpm_st33_i2c_fops = {
 	.owner = THIS_MODULE,
 	.llseek = no_llseek,
@@ -627,7 +632,7 @@ static struct tpm_vendor_specific st_i2c_tpm = {
 	.status = tpm_stm_i2c_status,
 	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
-	.req_canceled = TPM_STS_COMMAND_READY,
+	.req_canceled = tpm_st33_i2c_req_canceled,
 	.attr_group = &stm_tpm_attr_grp,
 	.miscdev = {.fops = &tpm_st33_i2c_fops,},
 };

drivers/char/tpm/tpm_ibmvtpm.c

@@ -398,6 +398,11 @@ static int tpm_ibmvtpm_resume(struct device *dev)
 	return rc;
 }
 
+static bool tpm_ibmvtpm_req_canceled(struct tpm_chip *chip, u8 status)
+{
+	return (status == 0);
+}
+
 static const struct file_operations ibmvtpm_ops = {
 	.owner = THIS_MODULE,
 	.llseek = no_llseek,
@@ -441,7 +446,7 @@ static const struct tpm_vendor_specific tpm_ibmvtpm = {
 	.status = tpm_ibmvtpm_status,
 	.req_complete_mask = 0,
 	.req_complete_val = 0,
-	.req_canceled = 0,
+	.req_canceled = tpm_ibmvtpm_req_canceled,
 	.attr_group = &ibmvtpm_attr_grp,
 	.miscdev = { .fops = &ibmvtpm_ops, },
 };

drivers/char/tpm/tpm_nsc.c

@@ -227,6 +227,11 @@ static u8 tpm_nsc_status(struct tpm_chip *chip)
 	return inb(chip->vendor.base + NSC_STATUS);
 }
 
+static bool tpm_nsc_req_canceled(struct tpm_chip *chip, u8 status)
+{
+	return (status == NSC_STATUS_RDY);
+}
+
 static const struct file_operations nsc_ops = {
 	.owner = THIS_MODULE,
 	.llseek = no_llseek,
@@ -258,7 +263,7 @@ static const struct tpm_vendor_specific tpm_nsc = {
 	.status = tpm_nsc_status,
 	.req_complete_mask = NSC_STATUS_OBF,
 	.req_complete_val = NSC_STATUS_OBF,
-	.req_canceled = NSC_STATUS_RDY,
+	.req_canceled = tpm_nsc_req_canceled,
 	.attr_group = &nsc_attr_grp,
 	.miscdev = { .fops = &nsc_ops, },
 };

drivers/char/tpm/tpm_tis.c

@@ -400,6 +400,19 @@ static int probe_itpm(struct tpm_chip *chip)
 	return rc;
 }
 
+static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
+{
+	switch (chip->vendor.manufacturer_id) {
+	case TPM_VID_WINBOND:
+		return ((status == TPM_STS_VALID) ||
+			(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
+	case TPM_VID_STM:
+		return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
+	default:
+		return (status == TPM_STS_COMMAND_READY);
+	}
+}
+
 static const struct file_operations tis_ops = {
 	.owner = THIS_MODULE,
 	.llseek = no_llseek,
@@ -445,7 +458,7 @@ static struct tpm_vendor_specific tpm_tis = {
 	.cancel = tpm_tis_ready,
 	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
-	.req_canceled = TPM_STS_COMMAND_READY,
+	.req_canceled = tpm_tis_req_canceled,
 	.attr_group = &tis_attr_grp,
 	.miscdev = {
 		    .fops = &tis_ops,},