[PATCH] tpm_crb: request and relinquish locality 0

[Jarkko Sakkinen]

Added two new callbacks to struct tpm_class_ops:

- request_locality
- relinquish_locality

These are called before sending and receiving data from the TPM.

Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
---
 drivers/char/tpm/tpm-interface.c |  9 +++++++++
 drivers/char/tpm/tpm_crb.c       | 41 +++++++++++++++++++++++++++++++++++++++-
 include/linux/tpm.h              |  3 ++-
 3 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index bd2128e..ae6aafa 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -369,6 +369,12 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, 
size_t bufsiz,
        if (chip->dev.parent)
                pm_runtime_get_sync(chip->dev.parent);
 
+       if (chip->ops->request_locality)  {
+               rc = chip->ops->request_locality(chip);
+               if (rc)
+                       goto out;
+       }
+
        rc = chip->ops->send(chip, (u8 *) buf, count);
        if (rc < 0) {
                dev_err(&chip->dev,
@@ -410,6 +416,9 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, 
size_t bufsiz,
                dev_err(&chip->dev,
                        "tpm_transmit: tpm_recv: error %zd\n", rc);
 out:
+       if (chip->ops->relinquish_locality)
+               chip->ops->relinquish_locality(chip);
+
        if (chip->dev.parent)
                pm_runtime_put_sync(chip->dev.parent);
 
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 3245618..89dc8a176 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -34,6 +34,15 @@ enum crb_defaults {
        CRB_ACPI_START_INDEX = 1,
 };
 
+enum crb_loc_ctrl {
+       CRB_LOC_CTRL_REQUEST_ACCESS     = BIT(0),
+       CRB_LOC_CTRL_RELINQUISH         = BIT(1),
+};
+
+enum crb_loc_state {
+       CRB_LOC_STATE_LOC_ASSIGNED      = BIT(1),
+};
+
 enum crb_ctrl_req {
        CRB_CTRL_REQ_CMD_READY  = BIT(0),
        CRB_CTRL_REQ_GO_IDLE    = BIT(1),
@@ -172,6 +181,35 @@ static int __maybe_unused crb_cmd_ready(struct device *dev,
        return 0;
 }
 
+static int crb_request_locality(struct tpm_chip *chip)
+{
+       struct crb_priv *priv = dev_get_drvdata(&chip->dev);
+
+       if (!priv->regs_h)
+               return 0;
+
+       iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl);
+       if (!crb_wait_for_reg_32(&priv->regs_h->loc_state,
+                                CRB_LOC_STATE_LOC_ASSIGNED, /* mask */
+                                CRB_LOC_STATE_LOC_ASSIGNED, /* value */
+                                TPM2_TIMEOUT_C)) {
+               dev_warn(&chip->dev, "TPM_LOC_STATE_x.requestAccess timed 
out\n");
+               return -ETIME;
+       }
+
+       return 0;
+}
+
+static void crb_relinquish_locality(struct tpm_chip *chip)
+{
+       struct crb_priv *priv = dev_get_drvdata(&chip->dev);
+
+       if (!priv->regs_h)
+               return;
+
+       iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl);
+}
+
 static u8 crb_status(struct tpm_chip *chip)
 {
        struct crb_priv *priv = dev_get_drvdata(&chip->dev);
@@ -198,7 +236,6 @@ static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t 
count)
 
        memcpy_fromio(buf, priv->rsp, 6);
        expected = be32_to_cpup((__be32 *) &buf[2]);
-
        if (expected > count)
                return -EIO;
 
@@ -279,6 +316,8 @@ static const struct tpm_class_ops tpm_crb = {
        .send = crb_send,
        .cancel = crb_cancel,
        .req_canceled = crb_req_canceled,
+       .request_locality = crb_request_locality,
+       .relinquish_locality = crb_relinquish_locality,
        .req_complete_mask = CRB_DRV_STS_COMPLETE,
        .req_complete_val = CRB_DRV_STS_COMPLETE,
 };
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index da158f0..0ac6ea6 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -48,7 +48,8 @@ struct tpm_class_ops {
        u8 (*status) (struct tpm_chip *chip);
        bool (*update_timeouts)(struct tpm_chip *chip,
                                unsigned long *timeout_cap);
-
+       int (*request_locality)(struct tpm_chip *chip);
+       void (*relinquish_locality)(struct tpm_chip *chip);
 };
 
 #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)
-- 
2.9.3