[PATCH v5 6/7] tpm_crb: Factor crb_send()/crb_recv() bodies into helpers

[Arun Menon <armenon@redhat.com>]

From: Arun Menon <armenon@redhat.com>

A later patch adds CRB chunking, which needs its own send/receive
loops alongside the existing single-shot transfer. Move the body of
crb_send() into tpm_crb_send_no_chunks() and the body of crb_recv()
into tpm_crb_recv_no_chunks().

Pure code motion, no behavior change. Also fix the block comment to the
kernel's preferred multi-line style.

Signed-off-by: Arun Menon <armenon@redhat.com>
---
 drivers/char/tpm/tpm_crb.c | 71 ++++++++++++++++++++++++--------------
 1 file changed, 45 insertions(+), 26 deletions(-)

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 30ca8192d3a8..f0bac9e1f1e8 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -369,24 +369,13 @@ static u8 crb_status(struct tpm_chip *chip)
 	return sts;
 }
 
-static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
+static int tpm_crb_recv_no_chunks(struct tpm_chip *chip, u8 *buf, size_t count)
 {
 	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 	unsigned int expected;
 
-	/* A sanity check that the upper layer wants to get at least the header
-	 * as that is the minimum size for any TPM response.
-	 */
-	if (count < TPM_HEADER_SIZE)
-		return -EIO;
-
-	/* If this bit is set, according to the spec, the TPM is in
-	 * unrecoverable condition.
-	 */
-	if (ioread32(&priv->regs_t->ctrl_sts) & CRB_CTRL_STS_ERROR)
-		return -EIO;
-
-	/* Read the first 8 bytes in order to get the length of the response.
+	/*
+	 * Read the first 8 bytes in order to get the length of the response.
 	 * We read exactly a quad word in order to make sure that the remaining
 	 * reads will be aligned.
 	 */
@@ -399,6 +388,28 @@ static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	memcpy_fromio(&buf[8], &priv->rsp[8], expected - 8);
 
 	return expected;
+
+}
+
+static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
+
+	/*
+	 * A sanity check that the upper layer wants to get at least the header
+	 * as that is the minimum size for any TPM response.
+	 */
+	if (count < TPM_HEADER_SIZE)
+		return -EIO;
+
+	/*
+	 * If this bit is set, according to the spec, the TPM is in
+	 * unrecoverable condition.
+	 */
+	if (ioread32(&priv->regs_t->ctrl_sts) & CRB_CTRL_STS_ERROR)
+		return -EIO;
+
+	return tpm_crb_recv_no_chunks(chip, buf, count);
 }
 
 static int crb_do_acpi_start(struct tpm_chip *chip)
@@ -474,12 +485,29 @@ static int tpm_crb_start(struct tpm_chip *chip, u32 start_cmd)
 	return rc;
 }
 
-static int crb_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz, size_t len)
+static int tpm_crb_send_no_chunks(struct tpm_chip *chip, u8 *buf, size_t len)
 {
 	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 	int rc = 0;
 
-	/* Zero the cancel register so that the next command will not get
+	memcpy_toio(priv->cmd, buf, len);
+
+	/* Make sure that cmd is populated before issuing start. */
+	wmb();
+
+	rc = tpm_crb_start(chip, CRB_START_INVOKE);
+	if (rc)
+		return rc;
+
+	return crb_try_pluton_doorbell(priv, false);
+}
+
+static int crb_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz, size_t len)
+{
+	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
+
+	/*
+	 * Zero the cancel register so that the next command will not get
 	 * canceled.
 	 */
 	iowrite32(0, &priv->regs_t->ctrl_cancel);
@@ -494,16 +522,7 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz, size_t len)
 	if (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON)
 		__crb_cmd_ready(&chip->dev, priv, chip->locality);
 
-	memcpy_toio(priv->cmd, buf, len);
-
-	/* Make sure that cmd is populated before issuing start. */
-	wmb();
-
-	rc = tpm_crb_start(chip, CRB_START_INVOKE);
-	if (rc)
-		return rc;
-
-	return crb_try_pluton_doorbell(priv, false);
+	return tpm_crb_send_no_chunks(chip, buf, len);
 }
 
 static void crb_cancel(struct tpm_chip *chip)
-- 
2.56.0