[04/10] tpm: Manage itpm workaround with tis specific data_expect bit

Commit Message

Christophe Ricard April 10, 2016, 9:23 p.m. UTC

In order to keep this itpm workaround available after the tpm_tis rework,
we are changing the way it is managed by using a tpm_tis_phy_ops structure
allowing to manage TPM_STS_EXPECT_DATA bit behavior according to different
TPM vendor.

Those 2 fields might be used only for tpm_tis (lpc) phy in the future.

Signed-off-by: Christophe Ricard <[e-mail]>
---
 drivers/char/tpm/tpm_tis.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

Comments

Jason Gunthorpe April 10, 2016, 11:42 p.m. UTC | #1

On Sun, Apr 10, 2016 at 11:23:00PM +0200, Christophe Ricard wrote:
>  	itpm = true;
> +	priv->phy_ops->data_expect_mask = 0;
> +	priv->phy_ops->data_expect_val = 0;

> +static struct tpm_tis_phy_ops tis_phy_ops = {
> +	.data_expect_mask = TPM_STS_DATA_EXPECT,
> +	.data_expect_val = TPM_STS_DATA_EXPECT,
> +};
> +
>  static int tpm_mem_read_bytes(struct tpm_chip *chip, u32 addr, u16 len,
>  			      u8 *result)
>  {
> @@ -844,6 +864,7 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info,
>  	chip->timeout_b = TIS_TIMEOUT_B_MAX;
>  	chip->timeout_c = TIS_TIMEOUT_C_MAX;
>  	chip->timeout_d = TIS_TIMEOUT_D_MAX;
> +	priv->phy_ops = &tis_phy_ops;

That writes to a global static, for all probes. Don't do that.

Why is something called 'ops' having variant data? Just stick it in priv.

Jason

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Patch

diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index ee5851e..5b3eb26 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -93,6 +93,11 @@  struct tpm_info {
 #define	TPM_DID_VID(l)			(0x0F00 | ((l) << 12))
 #define	TPM_RID(l)			(0x0F04 | ((l) << 12))
 
+struct tpm_tis_phy_ops {
+	u8 data_expect_mask;
+	u8 data_expect_val;
+};
+
 struct priv_data {
 	void __iomem *iobase;
 	u16 manufacturer_id;
@@ -101,6 +106,7 @@  struct priv_data {
 	bool irq_tested;
 	wait_queue_head_t int_queue;
 	wait_queue_head_t read_queue;
+	struct tpm_tis_phy_ops *phy_ops;
 };
 
 #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
@@ -381,7 +387,8 @@  static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
 		wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
 				  &priv->int_queue, false);
 		status = tpm_tis_status(chip);
-		if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) {
+		if ((status & priv->phy_ops->data_expect_mask) !=
+			      priv->phy_ops->data_expect_val) {
 			rc = -EIO;
 			goto out_err;
 		}
@@ -395,7 +402,8 @@  static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
 	wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
 			  &priv->int_queue, false);
 	status = tpm_tis_status(chip);
-	if ((status & TPM_STS_DATA_EXPECT) != 0) {
+	if ((status & priv->phy_ops->data_expect_mask) ==
+		      priv->phy_ops->data_expect_mask) {
 		rc = -EIO;
 		goto out_err;
 	}
@@ -532,6 +540,8 @@  static bool tpm_tis_update_timeouts(struct tpm_chip *chip,
 static int probe_itpm(struct tpm_chip *chip)
 {
 	struct priv_data *priv = dev_get_drvdata(&chip->dev);
+	u8 data_expect_mask = priv->phy_ops->data_expect_mask;
+	u8 data_expect_val = priv->phy_ops->data_expect_val;
 	int rc = 0;
 	u8 cmd_getticks[] = {
 		0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a,
@@ -559,13 +569,18 @@  static int probe_itpm(struct tpm_chip *chip)
 	release_locality(chip, priv->locality, 0);
 
 	itpm = true;
+	priv->phy_ops->data_expect_mask = 0;
+	priv->phy_ops->data_expect_val = 0;
 
 	rc = tpm_tis_send_data(chip, cmd_getticks, len);
 	if (rc == 0) {
 		dev_info(&chip->dev, "Detected an iTPM.\n");
 		rc = 1;
-	} else
+	} else {
+		priv->phy_ops->data_expect_mask = data_expect_mask;
+		priv->phy_ops->data_expect_val = data_expect_val;
 		rc = -EFAULT;
+	}
 
 out:
 	itpm = rem_itpm;
@@ -601,6 +616,11 @@  static const struct tpm_class_ops tpm_tis = {
 	.req_canceled = tpm_tis_req_canceled,
 };
 
+static struct tpm_tis_phy_ops tis_phy_ops = {
+	.data_expect_mask = TPM_STS_DATA_EXPECT,
+	.data_expect_val = TPM_STS_DATA_EXPECT,
+};
+
 static int tpm_mem_read_bytes(struct tpm_chip *chip, u32 addr, u16 len,
 			      u8 *result)
 {
@@ -844,6 +864,7 @@  static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info,
 	chip->timeout_b = TIS_TIMEOUT_B_MAX;
 	chip->timeout_c = TIS_TIMEOUT_C_MAX;
 	chip->timeout_d = TIS_TIMEOUT_D_MAX;
+	priv->phy_ops = &tis_phy_ops;
 
 	dev_set_drvdata(&chip->dev, priv);