[PATCH v6 0/4] tpm: add support for sync send() and use it in ftpm and svsm drivers

[PATCH v6 0/4] tpm: add support for sync send() and use it in ftpm and svsm drivers

[Stefano Garzarella]

The content of this version is the same of v5, but rebased on current
linux-tpmdd/next (`git range-diff` on v5 is empty) after the merge
window since tpm-svsm patches were merged with another tree, so we
agreed on postpone this series, see
  https://lore.kernel.org/linux-integrity/aDCb-wkHGoLQ-IGg@kernel.org/

This series is a follow-up to the discussion we had about whether or not
to add send_recv() op in tpm_class_ops[1]. Much boilerplate code has
already been removed by Jarkko with commit 980a573621ea ("tpm: Make
chip->{status,cancel,req_canceled} opt"). With this series we try to
avoid also the temporary buffers needed between send() and recv() for
devices that do not support interrupts and provide a single operation
to send the command and receive the response on the same buffer like
tpm_ftpm_tee.

The biggest advantage for this approach is with tpm_ftpm_tee where we
remove the local buffer and extra memory copies. For tpm_svsm it does
not change much since we continue to use the pre-allocated buffer,
to avoid making an allocation for each command.

Introduce a new flag (TPM_CHIP_FLAG_SYNC) to support synchronous send().
If that flag is set by the driver, tpm_try_transmit() will use the send()
callback to send the command and receive the response on the same buffer
synchronously. In that case send() return the number of bytes of the
response on success, or -errno on failure.

Thanks,
Stefano

Changelog
- v5 -> v6
  - rebased on linux-tpmdd/next - commit e271ed52b344 ("Merge tag
    'pm-6.16-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm")
- v4 -> v5: https://lore.kernel.org/linux-integrity/20250514134630.137621-1-sgarzare@redhat.com/
  - changed order and parameter names to match tpm_try_transmit() [Jarkko]
  - rebased on next-20250514
- v3 -> v4: https://lore.kernel.org/linux-integrity/20250509085713.76851-1-sgarzare@redhat.com/
  - reworked commit descriptions [Jarkko]
  - added Jarkko's R-b on patch 2
  - added Sumit's R-b on patch 3
  - rebased on next-20250508
- v2 -> v3: https://lore.kernel.org/linux-integrity/20250414145653.239081-1-sgarzare@redhat.com/
  - fixed comment style [Jarkko]
  - renamend `out_send_sync` label to `out_sync` [Jarkko]
- v1 -> v2: https://lore.kernel.org/linux-integrity/20250408083208.43512-1-sgarzare@redhat.com/
  - changed title since we removed send_recv() op
  - implemented TPM_CHIP_FLAG_SYNC idea [Jarkko]
  - removed Jens' T-b
- RFC -> v1: https://lore.kernel.org/linux-integrity/20250320152433.144083-1-sgarzare@redhat.com/
  - added Jens' T-b on ftpm driver
  - removed last patch since [2] is not yet merged and will require a new version
- RFC: https://lore.kernel.org/linux-integrity/20250311100130.42169-1-sgarzare@redhat.com/

[1] https://lore.kernel.org/linux-integrity/Z8sfiDEhsG6RATiQ@kernel.org/
[2] https://lore.kernel.org/linux-integrity/20250410135118.133240-1-sgarzare@redhat.com/

Stefano Garzarella (4):
  tpm: add bufsiz parameter in the .send callback
  tpm: support devices with synchronous send()
  tpm/tpm_ftpm_tee: support TPM_CHIP_FLAG_SYNC
  tpm/tpm_svsm: support TPM_CHIP_FLAG_SYNC

 drivers/char/tpm/tpm_ftpm_tee.h      |  4 --
 include/linux/tpm.h                  |  4 +-
 drivers/char/tpm/st33zp24/st33zp24.c |  2 +-
 drivers/char/tpm/tpm-interface.c     | 22 ++++++++--
 drivers/char/tpm/tpm_atmel.c         |  3 +-
 drivers/char/tpm/tpm_crb.c           |  2 +-
 drivers/char/tpm/tpm_ftpm_tee.c      | 66 +++++++++-------------------
 drivers/char/tpm/tpm_i2c_atmel.c     |  3 +-
 drivers/char/tpm/tpm_i2c_infineon.c  |  3 +-
 drivers/char/tpm/tpm_i2c_nuvoton.c   |  3 +-
 drivers/char/tpm/tpm_ibmvtpm.c       |  6 ++-
 drivers/char/tpm/tpm_infineon.c      |  3 +-
 drivers/char/tpm/tpm_nsc.c           |  3 +-
 drivers/char/tpm/tpm_svsm.c          | 28 +++++-------
 drivers/char/tpm/tpm_tis_core.c      |  3 +-
 drivers/char/tpm/tpm_tis_i2c_cr50.c  |  6 ++-
 drivers/char/tpm/tpm_vtpm_proxy.c    |  4 +-
 drivers/char/tpm/xen-tpmfront.c      |  3 +-
 18 files changed, 83 insertions(+), 85 deletions(-)

-- 
2.49.0

[PATCH v6 1/4] tpm: add bufsiz parameter in the .send callback

[Stefano Garzarella]

From: Stefano Garzarella <sgarzare@redhat.com>

Add a new `bufsiz` parameter to the `.send` callback in `tpm_class_ops`.
This parameter will allow drivers to differentiate between the actual
command length to send and the total buffer size. Currently `bufsiz` is
not used, but it will be used to implement devices with synchronous send()
to send the command and receive the response on the same buffer.

Also rename the previous parameter `len` to `cmd_len` in the declaration
to make it clear that it contains the length in bytes of the command
stored in the buffer. The semantics don't change and it can be used as
before by drivers. This is an optimization since the drivers could get it
from the header, but let's avoid duplicating code.

While we are here, resolve a checkpatch warning:
  WARNING: Unnecessary space before function pointer arguments
  #66: FILE: include/linux/tpm.h:90:
  +	int (*send) (struct tpm_chip *chip, u8 *buf, size_t bufsiz,

Suggested-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
v5:
- changed order and parameter names to match tpm_try_transmit() [Jarkko]
v4:
- rework the commit description [Jarkko]
---
 include/linux/tpm.h                  | 3 ++-
 drivers/char/tpm/st33zp24/st33zp24.c | 2 +-
 drivers/char/tpm/tpm-interface.c     | 2 +-
 drivers/char/tpm/tpm_atmel.c         | 3 ++-
 drivers/char/tpm/tpm_crb.c           | 2 +-
 drivers/char/tpm/tpm_ftpm_tee.c      | 4 +++-
 drivers/char/tpm/tpm_i2c_atmel.c     | 3 ++-
 drivers/char/tpm/tpm_i2c_infineon.c  | 3 ++-
 drivers/char/tpm/tpm_i2c_nuvoton.c   | 3 ++-
 drivers/char/tpm/tpm_ibmvtpm.c       | 6 ++++--
 drivers/char/tpm/tpm_infineon.c      | 3 ++-
 drivers/char/tpm/tpm_nsc.c           | 3 ++-
 drivers/char/tpm/tpm_svsm.c          | 3 ++-
 drivers/char/tpm/tpm_tis_core.c      | 3 ++-
 drivers/char/tpm/tpm_tis_i2c_cr50.c  | 6 ++++--
 drivers/char/tpm/tpm_vtpm_proxy.c    | 4 +++-
 drivers/char/tpm/xen-tpmfront.c      | 3 ++-
 17 files changed, 37 insertions(+), 19 deletions(-)

diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index a3d8305e88a5..cafe8c283e88 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -87,7 +87,8 @@ struct tpm_class_ops {
 	const u8 req_complete_val;
 	bool (*req_canceled)(struct tpm_chip *chip, u8 status);
 	int (*recv) (struct tpm_chip *chip, u8 *buf, size_t len);
-	int (*send) (struct tpm_chip *chip, u8 *buf, size_t len);
+	int (*send)(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+		    size_t cmd_len);
 	void (*cancel) (struct tpm_chip *chip);
 	u8 (*status) (struct tpm_chip *chip);
 	void (*update_timeouts)(struct tpm_chip *chip,
diff --git a/drivers/char/tpm/st33zp24/st33zp24.c b/drivers/char/tpm/st33zp24/st33zp24.c
index c0771980bc2f..2ed7815e4899 100644
--- a/drivers/char/tpm/st33zp24/st33zp24.c
+++ b/drivers/char/tpm/st33zp24/st33zp24.c
@@ -300,7 +300,7 @@ static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id)
  * send TPM commands through the I2C bus.
  */
 static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf,
-			 size_t len)
+			 size_t bufsiz, size_t len)
 {
 	struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
 	u32 status, i, size, ordinal;
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 8d7e4da6ed53..816b7c690bc9 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -106,7 +106,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
 		return -E2BIG;
 	}
 
-	rc = chip->ops->send(chip, buf, count);
+	rc = chip->ops->send(chip, buf, bufsiz, count);
 	if (rc < 0) {
 		if (rc != -EPIPE)
 			dev_err(&chip->dev,
diff --git a/drivers/char/tpm/tpm_atmel.c b/drivers/char/tpm/tpm_atmel.c
index 54a0360a3c95..f25faf468bba 100644
--- a/drivers/char/tpm/tpm_atmel.c
+++ b/drivers/char/tpm/tpm_atmel.c
@@ -148,7 +148,8 @@ static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	return size;
 }
 
-static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
+static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+			 size_t count)
 {
 	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 	int i;
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 876edf2705ab..ed97344f2324 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -426,7 +426,7 @@ static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
 }
 #endif
 
-static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
+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);
 	int rc = 0;
diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c
index 53ba28ccd5d3..dbad83bf798e 100644
--- a/drivers/char/tpm/tpm_ftpm_tee.c
+++ b/drivers/char/tpm/tpm_ftpm_tee.c
@@ -63,13 +63,15 @@ static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
  * ftpm_tee_tpm_op_send() - send TPM commands through the TEE shared memory.
  * @chip:	the tpm_chip description as specified in driver/char/tpm/tpm.h
  * @buf:	the buffer to send.
+ * @bufsiz:	the size of the buffer.
  * @len:	the number of bytes to send.
  *
  * Return:
  *	In case of success, returns 0.
  *	On failure, -errno
  */
-static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t len)
+static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+				size_t len)
 {
 	struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
 	size_t resp_len;
diff --git a/drivers/char/tpm/tpm_i2c_atmel.c b/drivers/char/tpm/tpm_i2c_atmel.c
index d1d27fdfe523..4f229656a8e2 100644
--- a/drivers/char/tpm/tpm_i2c_atmel.c
+++ b/drivers/char/tpm/tpm_i2c_atmel.c
@@ -37,7 +37,8 @@ struct priv_data {
 	u8 buffer[sizeof(struct tpm_header) + 25];
 };
 
-static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len)
+static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+			  size_t len)
 {
 	struct priv_data *priv = dev_get_drvdata(&chip->dev);
 	struct i2c_client *client = to_i2c_client(chip->dev.parent);
diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c
index 81d8a78dc655..bdf1f329a679 100644
--- a/drivers/char/tpm/tpm_i2c_infineon.c
+++ b/drivers/char/tpm/tpm_i2c_infineon.c
@@ -514,7 +514,8 @@ static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 	return size;
 }
 
-static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
+static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+			    size_t len)
 {
 	int rc, status;
 	ssize_t burstcnt;
diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
index 3c3ee5f551db..d44903b29929 100644
--- a/drivers/char/tpm/tpm_i2c_nuvoton.c
+++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
@@ -350,7 +350,8 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
  * tpm.c can skip polling for the data to be available as the interrupt is
  * waited for here
  */
-static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
+static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+			    size_t len)
 {
 	struct priv_data *priv = dev_get_drvdata(&chip->dev);
 	struct device *dev = chip->dev.parent;
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index 76d048f63d55..4734a69406ce 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.c
+++ b/drivers/char/tpm/tpm_ibmvtpm.c
@@ -191,13 +191,15 @@ static int tpm_ibmvtpm_resume(struct device *dev)
  * tpm_ibmvtpm_send() - Send a TPM command
  * @chip:	tpm chip struct
  * @buf:	buffer contains data to send
- * @count:	size of buffer
+ * @bufsiz:	size of the buffer
+ * @count:	length of the command
  *
  * Return:
  *   0 on success,
  *   -errno on error
  */
-static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
+static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+			    size_t count)
 {
 	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
 	bool retry = true;
diff --git a/drivers/char/tpm/tpm_infineon.c b/drivers/char/tpm/tpm_infineon.c
index 2d2ae37153ba..7638b65b851b 100644
--- a/drivers/char/tpm/tpm_infineon.c
+++ b/drivers/char/tpm/tpm_infineon.c
@@ -312,7 +312,8 @@ static int tpm_inf_recv(struct tpm_chip *chip, u8 * buf, size_t count)
 	return -EIO;
 }
 
-static int tpm_inf_send(struct tpm_chip *chip, u8 * buf, size_t count)
+static int tpm_inf_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+			size_t count)
 {
 	int i;
 	int ret;
diff --git a/drivers/char/tpm/tpm_nsc.c b/drivers/char/tpm/tpm_nsc.c
index 0f62bbc940da..879ac88f5783 100644
--- a/drivers/char/tpm/tpm_nsc.c
+++ b/drivers/char/tpm/tpm_nsc.c
@@ -178,7 +178,8 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
 	return size;
 }
 
-static int tpm_nsc_send(struct tpm_chip *chip, u8 * buf, size_t count)
+static int tpm_nsc_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+			size_t count)
 {
 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
 	u8 data;
diff --git a/drivers/char/tpm/tpm_svsm.c b/drivers/char/tpm/tpm_svsm.c
index 4280edf427d6..0847cbf450b4 100644
--- a/drivers/char/tpm/tpm_svsm.c
+++ b/drivers/char/tpm/tpm_svsm.c
@@ -25,7 +25,8 @@ struct tpm_svsm_priv {
 	void *buffer;
 };
 
-static int tpm_svsm_send(struct tpm_chip *chip, u8 *buf, size_t len)
+static int tpm_svsm_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+			 size_t len)
 {
 	struct tpm_svsm_priv *priv = dev_get_drvdata(&chip->dev);
 	int ret;
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index ed0d3d8449b3..4b12c4b9da8b 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -580,7 +580,8 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
 	return rc;
 }
 
-static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
+static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+			size_t len)
 {
 	int rc, irq;
 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
diff --git a/drivers/char/tpm/tpm_tis_i2c_cr50.c b/drivers/char/tpm/tpm_tis_i2c_cr50.c
index 3b55a7b05c46..fc6891a0b693 100644
--- a/drivers/char/tpm/tpm_tis_i2c_cr50.c
+++ b/drivers/char/tpm/tpm_tis_i2c_cr50.c
@@ -546,13 +546,15 @@ static int tpm_cr50_i2c_tis_recv(struct tpm_chip *chip, u8 *buf, size_t buf_len)
  * tpm_cr50_i2c_tis_send() - TPM transmission callback.
  * @chip:	A TPM chip.
  * @buf:	Buffer to send.
- * @len:	Buffer length.
+ * @bufsiz:	Buffer size.
+ * @len:	Command length.
  *
  * Return:
  * - 0:		Success.
  * - -errno:	A POSIX error code.
  */
-static int tpm_cr50_i2c_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
+static int tpm_cr50_i2c_tis_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+				 size_t len)
 {
 	size_t burstcnt, limit, sent = 0;
 	u8 tpm_go[4] = { TPM_STS_GO };
diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
index 8fe4a01eea12..0818bb517805 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -321,12 +321,14 @@ static int vtpm_proxy_is_driver_command(struct tpm_chip *chip,
  *
  * @chip: tpm chip to use
  * @buf: send buffer
+ * @bufsiz: size of the buffer
  * @count: bytes to send
  *
  * Return:
  *      0 in case of success, negative error value otherwise.
  */
-static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count)
+static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+				  size_t count)
 {
 	struct proxy_dev *proxy_dev = dev_get_drvdata(&chip->dev);
 
diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c
index 80cca3b83b22..556bf2256716 100644
--- a/drivers/char/tpm/xen-tpmfront.c
+++ b/drivers/char/tpm/xen-tpmfront.c
@@ -131,7 +131,8 @@ static size_t shr_data_offset(struct vtpm_shared_page *shr)
 	return struct_size(shr, extra_pages, shr->nr_extra_pages);
 }
 
-static int vtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
+static int vtpm_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
+		     size_t count)
 {
 	struct tpm_private *priv = dev_get_drvdata(&chip->dev);
 	struct vtpm_shared_page *shr = priv->shr;
-- 
2.49.0

Re: [PATCH v6 1/4] tpm: add bufsiz parameter in the .send callback

[Jarkko Sakkinen]

On Fri, Jun 20, 2025 at 03:08:07PM +0200, Stefano Garzarella wrote:
> From: Stefano Garzarella <sgarzare@redhat.com>
> 
> Add a new `bufsiz` parameter to the `.send` callback in `tpm_class_ops`.
> This parameter will allow drivers to differentiate between the actual
> command length to send and the total buffer size. Currently `bufsiz` is
> not used, but it will be used to implement devices with synchronous send()
> to send the command and receive the response on the same buffer.
> 
> Also rename the previous parameter `len` to `cmd_len` in the declaration
> to make it clear that it contains the length in bytes of the command
> stored in the buffer. The semantics don't change and it can be used as
> before by drivers. This is an optimization since the drivers could get it
> from the header, but let's avoid duplicating code.
> 
> While we are here, resolve a checkpatch warning:
>   WARNING: Unnecessary space before function pointer arguments
>   #66: FILE: include/linux/tpm.h:90:
>   +	int (*send) (struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> 
> Suggested-by: Jarkko Sakkinen <jarkko@kernel.org>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
> v5:
> - changed order and parameter names to match tpm_try_transmit() [Jarkko]
> v4:
> - rework the commit description [Jarkko]
> ---
>  include/linux/tpm.h                  | 3 ++-
>  drivers/char/tpm/st33zp24/st33zp24.c | 2 +-
>  drivers/char/tpm/tpm-interface.c     | 2 +-
>  drivers/char/tpm/tpm_atmel.c         | 3 ++-
>  drivers/char/tpm/tpm_crb.c           | 2 +-
>  drivers/char/tpm/tpm_ftpm_tee.c      | 4 +++-
>  drivers/char/tpm/tpm_i2c_atmel.c     | 3 ++-
>  drivers/char/tpm/tpm_i2c_infineon.c  | 3 ++-
>  drivers/char/tpm/tpm_i2c_nuvoton.c   | 3 ++-
>  drivers/char/tpm/tpm_ibmvtpm.c       | 6 ++++--
>  drivers/char/tpm/tpm_infineon.c      | 3 ++-
>  drivers/char/tpm/tpm_nsc.c           | 3 ++-
>  drivers/char/tpm/tpm_svsm.c          | 3 ++-
>  drivers/char/tpm/tpm_tis_core.c      | 3 ++-
>  drivers/char/tpm/tpm_tis_i2c_cr50.c  | 6 ++++--
>  drivers/char/tpm/tpm_vtpm_proxy.c    | 4 +++-
>  drivers/char/tpm/xen-tpmfront.c      | 3 ++-
>  17 files changed, 37 insertions(+), 19 deletions(-)
> 
> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> index a3d8305e88a5..cafe8c283e88 100644
> --- a/include/linux/tpm.h
> +++ b/include/linux/tpm.h
> @@ -87,7 +87,8 @@ struct tpm_class_ops {
>  	const u8 req_complete_val;
>  	bool (*req_canceled)(struct tpm_chip *chip, u8 status);
>  	int (*recv) (struct tpm_chip *chip, u8 *buf, size_t len);
> -	int (*send) (struct tpm_chip *chip, u8 *buf, size_t len);
> +	int (*send)(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +		    size_t cmd_len);
>  	void (*cancel) (struct tpm_chip *chip);
>  	u8 (*status) (struct tpm_chip *chip);
>  	void (*update_timeouts)(struct tpm_chip *chip,
> diff --git a/drivers/char/tpm/st33zp24/st33zp24.c b/drivers/char/tpm/st33zp24/st33zp24.c
> index c0771980bc2f..2ed7815e4899 100644
> --- a/drivers/char/tpm/st33zp24/st33zp24.c
> +++ b/drivers/char/tpm/st33zp24/st33zp24.c
> @@ -300,7 +300,7 @@ static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id)
>   * send TPM commands through the I2C bus.
>   */
>  static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf,
> -			 size_t len)
> +			 size_t bufsiz, size_t len)
>  {
>  	struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
>  	u32 status, i, size, ordinal;
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index 8d7e4da6ed53..816b7c690bc9 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -106,7 +106,7 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
>  		return -E2BIG;
>  	}
>  
> -	rc = chip->ops->send(chip, buf, count);
> +	rc = chip->ops->send(chip, buf, bufsiz, count);
>  	if (rc < 0) {
>  		if (rc != -EPIPE)
>  			dev_err(&chip->dev,
> diff --git a/drivers/char/tpm/tpm_atmel.c b/drivers/char/tpm/tpm_atmel.c
> index 54a0360a3c95..f25faf468bba 100644
> --- a/drivers/char/tpm/tpm_atmel.c
> +++ b/drivers/char/tpm/tpm_atmel.c
> @@ -148,7 +148,8 @@ static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
>  	return size;
>  }
>  
> -static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
> +static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +			 size_t count)
>  {
>  	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
>  	int i;
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> index 876edf2705ab..ed97344f2324 100644
> --- a/drivers/char/tpm/tpm_crb.c
> +++ b/drivers/char/tpm/tpm_crb.c
> @@ -426,7 +426,7 @@ static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
>  }
>  #endif
>  
> -static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
> +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);
>  	int rc = 0;
> diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c
> index 53ba28ccd5d3..dbad83bf798e 100644
> --- a/drivers/char/tpm/tpm_ftpm_tee.c
> +++ b/drivers/char/tpm/tpm_ftpm_tee.c
> @@ -63,13 +63,15 @@ static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
>   * ftpm_tee_tpm_op_send() - send TPM commands through the TEE shared memory.
>   * @chip:	the tpm_chip description as specified in driver/char/tpm/tpm.h
>   * @buf:	the buffer to send.
> + * @bufsiz:	the size of the buffer.
>   * @len:	the number of bytes to send.
>   *
>   * Return:
>   *	In case of success, returns 0.
>   *	On failure, -errno
>   */
> -static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t len)
> +static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +				size_t len)
>  {
>  	struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
>  	size_t resp_len;
> diff --git a/drivers/char/tpm/tpm_i2c_atmel.c b/drivers/char/tpm/tpm_i2c_atmel.c
> index d1d27fdfe523..4f229656a8e2 100644
> --- a/drivers/char/tpm/tpm_i2c_atmel.c
> +++ b/drivers/char/tpm/tpm_i2c_atmel.c
> @@ -37,7 +37,8 @@ struct priv_data {
>  	u8 buffer[sizeof(struct tpm_header) + 25];
>  };
>  
> -static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len)
> +static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +			  size_t len)
>  {
>  	struct priv_data *priv = dev_get_drvdata(&chip->dev);
>  	struct i2c_client *client = to_i2c_client(chip->dev.parent);
> diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c
> index 81d8a78dc655..bdf1f329a679 100644
> --- a/drivers/char/tpm/tpm_i2c_infineon.c
> +++ b/drivers/char/tpm/tpm_i2c_infineon.c
> @@ -514,7 +514,8 @@ static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count)
>  	return size;
>  }
>  
> -static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
> +static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +			    size_t len)
>  {
>  	int rc, status;
>  	ssize_t burstcnt;
> diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
> index 3c3ee5f551db..d44903b29929 100644
> --- a/drivers/char/tpm/tpm_i2c_nuvoton.c
> +++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
> @@ -350,7 +350,8 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
>   * tpm.c can skip polling for the data to be available as the interrupt is
>   * waited for here
>   */
> -static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
> +static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +			    size_t len)
>  {
>  	struct priv_data *priv = dev_get_drvdata(&chip->dev);
>  	struct device *dev = chip->dev.parent;
> diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
> index 76d048f63d55..4734a69406ce 100644
> --- a/drivers/char/tpm/tpm_ibmvtpm.c
> +++ b/drivers/char/tpm/tpm_ibmvtpm.c
> @@ -191,13 +191,15 @@ static int tpm_ibmvtpm_resume(struct device *dev)
>   * tpm_ibmvtpm_send() - Send a TPM command
>   * @chip:	tpm chip struct
>   * @buf:	buffer contains data to send
> - * @count:	size of buffer
> + * @bufsiz:	size of the buffer
> + * @count:	length of the command
>   *
>   * Return:
>   *   0 on success,
>   *   -errno on error
>   */
> -static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
> +static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +			    size_t count)
>  {
>  	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
>  	bool retry = true;
> diff --git a/drivers/char/tpm/tpm_infineon.c b/drivers/char/tpm/tpm_infineon.c
> index 2d2ae37153ba..7638b65b851b 100644
> --- a/drivers/char/tpm/tpm_infineon.c
> +++ b/drivers/char/tpm/tpm_infineon.c
> @@ -312,7 +312,8 @@ static int tpm_inf_recv(struct tpm_chip *chip, u8 * buf, size_t count)
>  	return -EIO;
>  }
>  
> -static int tpm_inf_send(struct tpm_chip *chip, u8 * buf, size_t count)
> +static int tpm_inf_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +			size_t count)
>  {
>  	int i;
>  	int ret;
> diff --git a/drivers/char/tpm/tpm_nsc.c b/drivers/char/tpm/tpm_nsc.c
> index 0f62bbc940da..879ac88f5783 100644
> --- a/drivers/char/tpm/tpm_nsc.c
> +++ b/drivers/char/tpm/tpm_nsc.c
> @@ -178,7 +178,8 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
>  	return size;
>  }
>  
> -static int tpm_nsc_send(struct tpm_chip *chip, u8 * buf, size_t count)
> +static int tpm_nsc_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +			size_t count)
>  {
>  	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
>  	u8 data;
> diff --git a/drivers/char/tpm/tpm_svsm.c b/drivers/char/tpm/tpm_svsm.c
> index 4280edf427d6..0847cbf450b4 100644
> --- a/drivers/char/tpm/tpm_svsm.c
> +++ b/drivers/char/tpm/tpm_svsm.c
> @@ -25,7 +25,8 @@ struct tpm_svsm_priv {
>  	void *buffer;
>  };
>  
> -static int tpm_svsm_send(struct tpm_chip *chip, u8 *buf, size_t len)
> +static int tpm_svsm_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +			 size_t len)
>  {
>  	struct tpm_svsm_priv *priv = dev_get_drvdata(&chip->dev);
>  	int ret;
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index ed0d3d8449b3..4b12c4b9da8b 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -580,7 +580,8 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
>  	return rc;
>  }
>  
> -static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
> +static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +			size_t len)
>  {
>  	int rc, irq;
>  	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> diff --git a/drivers/char/tpm/tpm_tis_i2c_cr50.c b/drivers/char/tpm/tpm_tis_i2c_cr50.c
> index 3b55a7b05c46..fc6891a0b693 100644
> --- a/drivers/char/tpm/tpm_tis_i2c_cr50.c
> +++ b/drivers/char/tpm/tpm_tis_i2c_cr50.c
> @@ -546,13 +546,15 @@ static int tpm_cr50_i2c_tis_recv(struct tpm_chip *chip, u8 *buf, size_t buf_len)
>   * tpm_cr50_i2c_tis_send() - TPM transmission callback.
>   * @chip:	A TPM chip.
>   * @buf:	Buffer to send.
> - * @len:	Buffer length.
> + * @bufsiz:	Buffer size.
> + * @len:	Command length.
>   *
>   * Return:
>   * - 0:		Success.
>   * - -errno:	A POSIX error code.
>   */
> -static int tpm_cr50_i2c_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
> +static int tpm_cr50_i2c_tis_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +				 size_t len)
>  {
>  	size_t burstcnt, limit, sent = 0;
>  	u8 tpm_go[4] = { TPM_STS_GO };
> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
> index 8fe4a01eea12..0818bb517805 100644
> --- a/drivers/char/tpm/tpm_vtpm_proxy.c
> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
> @@ -321,12 +321,14 @@ static int vtpm_proxy_is_driver_command(struct tpm_chip *chip,
>   *
>   * @chip: tpm chip to use
>   * @buf: send buffer
> + * @bufsiz: size of the buffer
>   * @count: bytes to send
>   *
>   * Return:
>   *      0 in case of success, negative error value otherwise.
>   */
> -static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t count)
> +static int vtpm_proxy_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +				  size_t count)
>  {
>  	struct proxy_dev *proxy_dev = dev_get_drvdata(&chip->dev);
>  
> diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c
> index 80cca3b83b22..556bf2256716 100644
> --- a/drivers/char/tpm/xen-tpmfront.c
> +++ b/drivers/char/tpm/xen-tpmfront.c
> @@ -131,7 +131,8 @@ static size_t shr_data_offset(struct vtpm_shared_page *shr)
>  	return struct_size(shr, extra_pages, shr->nr_extra_pages);
>  }
>  
> -static int vtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
> +static int vtpm_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> +		     size_t count)
>  {
>  	struct tpm_private *priv = dev_get_drvdata(&chip->dev);
>  	struct vtpm_shared_page *shr = priv->shr;
> -- 
> 2.49.0
> 

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko

[PATCH v6 2/4] tpm: support devices with synchronous send()

[Stefano Garzarella]

From: Stefano Garzarella <sgarzare@redhat.com>

Some devices do not support interrupts and provide a single synchronous
operation to send the command and receive the response on the same buffer.

Currently, these types of drivers must use an internal buffer where they
temporarily store the response between .send() and .recv() calls.

Introduce a new flag (TPM_CHIP_FLAG_SYNC) to support synchronous send().
If that flag is set by the driver, tpm_try_transmit() will use the send()
callback to send the command and receive the response on the same buffer
synchronously. In that case send() return the number of bytes of the
response on success, or -errno on failure.

Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Suggested-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
v4:
- added Jarkko's R-b
v3:
- fixed comment style [Jarkko]
- renamend `out_send_sync` label to `out_sync` [Jarkko]
---
 include/linux/tpm.h              |  1 +
 drivers/char/tpm/tpm-interface.c | 20 +++++++++++++++++---
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index cafe8c283e88..804fbbe3873d 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -351,6 +351,7 @@ enum tpm_chip_flags {
 	TPM_CHIP_FLAG_SUSPENDED			= BIT(8),
 	TPM_CHIP_FLAG_HWRNG_DISABLED		= BIT(9),
 	TPM_CHIP_FLAG_DISABLE			= BIT(10),
+	TPM_CHIP_FLAG_SYNC			= BIT(11),
 };
 
 #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 816b7c690bc9..512882ac0db1 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -114,8 +114,19 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
 		return rc;
 	}
 
-	/* A sanity check. send() should just return zero on success e.g.
-	 * not the command length.
+	/*
+	 * Synchronous devices return the response directly during the send()
+	 * call in the same buffer.
+	 */
+	if (chip->flags & TPM_CHIP_FLAG_SYNC) {
+		len = rc;
+		rc = 0;
+		goto out_sync;
+	}
+
+	/*
+	 * A sanity check. send() of asynchronous devices should just return
+	 * zero on success e.g. not the command length.
 	 */
 	if (rc > 0) {
 		dev_warn(&chip->dev,
@@ -151,7 +162,10 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
 	if (len < 0) {
 		rc = len;
 		dev_err(&chip->dev, "tpm_transmit: tpm_recv: error %d\n", rc);
-	} else if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
+		return rc;
+	}
+out_sync:
+	if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
 		rc = -EFAULT;
 
 	return rc ? rc : len;
-- 
2.49.0

[PATCH v6 3/4] tpm/tpm_ftpm_tee: support TPM_CHIP_FLAG_SYNC

[Stefano Garzarella]

From: Stefano Garzarella <sgarzare@redhat.com>

This driver does not support interrupts, and receiving the response is
synchronous with sending the command.

Enable synchronous send() with TPM_CHIP_FLAG_SYNC, which implies that
->send() already fills the provided buffer with a response, and ->recv()
is not implemented.

Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
v5:
- changed order and parameter names to match tpm_try_transmit() [Jarkko]
v4:
- added Sumit's R-b
- reworked commit description [Jarkko]
v2:
- set TPM_CHIP_FLAG_SYNC and support it in the new send()
- removed Jens' T-b
v1:
- added Jens' T-b
---
 drivers/char/tpm/tpm_ftpm_tee.h |  4 ---
 drivers/char/tpm/tpm_ftpm_tee.c | 64 ++++++++++-----------------------
 2 files changed, 19 insertions(+), 49 deletions(-)

diff --git a/drivers/char/tpm/tpm_ftpm_tee.h b/drivers/char/tpm/tpm_ftpm_tee.h
index e39903b7ea07..8d5c3f0d2879 100644
--- a/drivers/char/tpm/tpm_ftpm_tee.h
+++ b/drivers/char/tpm/tpm_ftpm_tee.h
@@ -22,16 +22,12 @@
  * struct ftpm_tee_private - fTPM's private data
  * @chip:     struct tpm_chip instance registered with tpm framework.
  * @session:  fTPM TA session identifier.
- * @resp_len: cached response buffer length.
- * @resp_buf: cached response buffer.
  * @ctx:      TEE context handler.
  * @shm:      Memory pool shared with fTPM TA in TEE.
  */
 struct ftpm_tee_private {
 	struct tpm_chip *chip;
 	u32 session;
-	size_t resp_len;
-	u8 resp_buf[MAX_RESPONSE_SIZE];
 	struct tee_context *ctx;
 	struct tee_shm *shm;
 };
diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c
index dbad83bf798e..4e63c30aeaf1 100644
--- a/drivers/char/tpm/tpm_ftpm_tee.c
+++ b/drivers/char/tpm/tpm_ftpm_tee.c
@@ -31,47 +31,19 @@ static const uuid_t ftpm_ta_uuid =
 		  0x82, 0xCB, 0x34, 0x3F, 0xB7, 0xF3, 0x78, 0x96);
 
 /**
- * ftpm_tee_tpm_op_recv() - retrieve fTPM response.
- * @chip:	the tpm_chip description as specified in driver/char/tpm/tpm.h.
- * @buf:	the buffer to store data.
- * @count:	the number of bytes to read.
- *
- * Return:
- *	In case of success the number of bytes received.
- *	On failure, -errno.
- */
-static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
-{
-	struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
-	size_t len;
-
-	len = pvt_data->resp_len;
-	if (count < len) {
-		dev_err(&chip->dev,
-			"%s: Invalid size in recv: count=%zd, resp_len=%zd\n",
-			__func__, count, len);
-		return -EIO;
-	}
-
-	memcpy(buf, pvt_data->resp_buf, len);
-	pvt_data->resp_len = 0;
-
-	return len;
-}
-
-/**
- * ftpm_tee_tpm_op_send() - send TPM commands through the TEE shared memory.
+ * ftpm_tee_tpm_op_send() - send TPM commands through the TEE shared memory
+ * and retrieve the response.
  * @chip:	the tpm_chip description as specified in driver/char/tpm/tpm.h
- * @buf:	the buffer to send.
+ * @buf:	the buffer to send and to store the response.
  * @bufsiz:	the size of the buffer.
- * @len:	the number of bytes to send.
+ * @cmd_len:	the number of bytes to send.
  *
  * Return:
- *	In case of success, returns 0.
+ *	In case of success, returns the number of bytes received.
  *	On failure, -errno
  */
 static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
-				size_t len)
+				size_t cmd_len)
 {
 	struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
 	size_t resp_len;
@@ -82,16 +54,15 @@ static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
 	struct tee_param command_params[4];
 	struct tee_shm *shm = pvt_data->shm;
 
-	if (len > MAX_COMMAND_SIZE) {
+	if (cmd_len > MAX_COMMAND_SIZE) {
 		dev_err(&chip->dev,
 			"%s: len=%zd exceeds MAX_COMMAND_SIZE supported by fTPM TA\n",
-			__func__, len);
+			__func__, cmd_len);
 		return -EIO;
 	}
 
 	memset(&transceive_args, 0, sizeof(transceive_args));
 	memset(command_params, 0, sizeof(command_params));
-	pvt_data->resp_len = 0;
 
 	/* Invoke FTPM_OPTEE_TA_SUBMIT_COMMAND function of fTPM TA */
 	transceive_args = (struct tee_ioctl_invoke_arg) {
@@ -105,7 +76,7 @@ static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
 		.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT,
 		.u.memref = {
 			.shm = shm,
-			.size = len,
+			.size = cmd_len,
 			.shm_offs = 0,
 		},
 	};
@@ -117,7 +88,7 @@ static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
 		return PTR_ERR(temp_buf);
 	}
 	memset(temp_buf, 0, (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE));
-	memcpy(temp_buf, buf, len);
+	memcpy(temp_buf, buf, cmd_len);
 
 	command_params[1] = (struct tee_param) {
 		.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT,
@@ -158,17 +129,20 @@ static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
 			__func__, resp_len);
 		return -EIO;
 	}
+	if (resp_len > bufsiz) {
+		dev_err(&chip->dev,
+			"%s: resp_len=%zd exceeds bufsiz=%zd\n",
+			__func__, resp_len, bufsiz);
+		return -EIO;
+	}
 
-	/* sanity checks look good, cache the response */
-	memcpy(pvt_data->resp_buf, temp_buf, resp_len);
-	pvt_data->resp_len = resp_len;
+	memcpy(buf, temp_buf, resp_len);
 
-	return 0;
+	return resp_len;
 }
 
 static const struct tpm_class_ops ftpm_tee_tpm_ops = {
 	.flags = TPM_OPS_AUTO_STARTUP,
-	.recv = ftpm_tee_tpm_op_recv,
 	.send = ftpm_tee_tpm_op_send,
 };
 
@@ -253,7 +227,7 @@ static int ftpm_tee_probe(struct device *dev)
 	}
 
 	pvt_data->chip = chip;
-	pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2;
+	pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_SYNC;
 
 	/* Create a character device for the fTPM */
 	rc = tpm_chip_register(pvt_data->chip);
-- 
2.49.0

Re: [PATCH v6 3/4] tpm/tpm_ftpm_tee: support TPM_CHIP_FLAG_SYNC

[Jarkko Sakkinen]

On Fri, Jun 20, 2025 at 03:08:09PM +0200, Stefano Garzarella wrote:
> From: Stefano Garzarella <sgarzare@redhat.com>
> 
> This driver does not support interrupts, and receiving the response is
> synchronous with sending the command.
> 
> Enable synchronous send() with TPM_CHIP_FLAG_SYNC, which implies that
> ->send() already fills the provided buffer with a response, and ->recv()
> is not implemented.
> 
> Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
> v5:
> - changed order and parameter names to match tpm_try_transmit() [Jarkko]
> v4:
> - added Sumit's R-b
> - reworked commit description [Jarkko]
> v2:
> - set TPM_CHIP_FLAG_SYNC and support it in the new send()
> - removed Jens' T-b
> v1:
> - added Jens' T-b
> ---
>  drivers/char/tpm/tpm_ftpm_tee.h |  4 ---
>  drivers/char/tpm/tpm_ftpm_tee.c | 64 ++++++++++-----------------------
>  2 files changed, 19 insertions(+), 49 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_ftpm_tee.h b/drivers/char/tpm/tpm_ftpm_tee.h
> index e39903b7ea07..8d5c3f0d2879 100644
> --- a/drivers/char/tpm/tpm_ftpm_tee.h
> +++ b/drivers/char/tpm/tpm_ftpm_tee.h
> @@ -22,16 +22,12 @@
>   * struct ftpm_tee_private - fTPM's private data
>   * @chip:     struct tpm_chip instance registered with tpm framework.
>   * @session:  fTPM TA session identifier.
> - * @resp_len: cached response buffer length.
> - * @resp_buf: cached response buffer.
>   * @ctx:      TEE context handler.
>   * @shm:      Memory pool shared with fTPM TA in TEE.
>   */
>  struct ftpm_tee_private {
>  	struct tpm_chip *chip;
>  	u32 session;
> -	size_t resp_len;
> -	u8 resp_buf[MAX_RESPONSE_SIZE];
>  	struct tee_context *ctx;
>  	struct tee_shm *shm;
>  };
> diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c
> index dbad83bf798e..4e63c30aeaf1 100644
> --- a/drivers/char/tpm/tpm_ftpm_tee.c
> +++ b/drivers/char/tpm/tpm_ftpm_tee.c
> @@ -31,47 +31,19 @@ static const uuid_t ftpm_ta_uuid =
>  		  0x82, 0xCB, 0x34, 0x3F, 0xB7, 0xF3, 0x78, 0x96);
>  
>  /**
> - * ftpm_tee_tpm_op_recv() - retrieve fTPM response.
> - * @chip:	the tpm_chip description as specified in driver/char/tpm/tpm.h.
> - * @buf:	the buffer to store data.
> - * @count:	the number of bytes to read.
> - *
> - * Return:
> - *	In case of success the number of bytes received.
> - *	On failure, -errno.
> - */
> -static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> -{
> -	struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
> -	size_t len;
> -
> -	len = pvt_data->resp_len;
> -	if (count < len) {
> -		dev_err(&chip->dev,
> -			"%s: Invalid size in recv: count=%zd, resp_len=%zd\n",
> -			__func__, count, len);
> -		return -EIO;
> -	}
> -
> -	memcpy(buf, pvt_data->resp_buf, len);
> -	pvt_data->resp_len = 0;
> -
> -	return len;
> -}
> -
> -/**
> - * ftpm_tee_tpm_op_send() - send TPM commands through the TEE shared memory.
> + * ftpm_tee_tpm_op_send() - send TPM commands through the TEE shared memory
> + * and retrieve the response.
>   * @chip:	the tpm_chip description as specified in driver/char/tpm/tpm.h
> - * @buf:	the buffer to send.
> + * @buf:	the buffer to send and to store the response.
>   * @bufsiz:	the size of the buffer.
> - * @len:	the number of bytes to send.
> + * @cmd_len:	the number of bytes to send.
>   *
>   * Return:
> - *	In case of success, returns 0.
> + *	In case of success, returns the number of bytes received.
>   *	On failure, -errno
>   */
>  static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> -				size_t len)
> +				size_t cmd_len)
>  {
>  	struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
>  	size_t resp_len;
> @@ -82,16 +54,15 @@ static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
>  	struct tee_param command_params[4];
>  	struct tee_shm *shm = pvt_data->shm;
>  
> -	if (len > MAX_COMMAND_SIZE) {
> +	if (cmd_len > MAX_COMMAND_SIZE) {
>  		dev_err(&chip->dev,
>  			"%s: len=%zd exceeds MAX_COMMAND_SIZE supported by fTPM TA\n",
> -			__func__, len);
> +			__func__, cmd_len);
>  		return -EIO;
>  	}
>  
>  	memset(&transceive_args, 0, sizeof(transceive_args));
>  	memset(command_params, 0, sizeof(command_params));
> -	pvt_data->resp_len = 0;
>  
>  	/* Invoke FTPM_OPTEE_TA_SUBMIT_COMMAND function of fTPM TA */
>  	transceive_args = (struct tee_ioctl_invoke_arg) {
> @@ -105,7 +76,7 @@ static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
>  		.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT,
>  		.u.memref = {
>  			.shm = shm,
> -			.size = len,
> +			.size = cmd_len,
>  			.shm_offs = 0,
>  		},
>  	};
> @@ -117,7 +88,7 @@ static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
>  		return PTR_ERR(temp_buf);
>  	}
>  	memset(temp_buf, 0, (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE));
> -	memcpy(temp_buf, buf, len);
> +	memcpy(temp_buf, buf, cmd_len);
>  
>  	command_params[1] = (struct tee_param) {
>  		.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT,
> @@ -158,17 +129,20 @@ static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
>  			__func__, resp_len);
>  		return -EIO;
>  	}
> +	if (resp_len > bufsiz) {
> +		dev_err(&chip->dev,
> +			"%s: resp_len=%zd exceeds bufsiz=%zd\n",
> +			__func__, resp_len, bufsiz);
> +		return -EIO;
> +	}
>  
> -	/* sanity checks look good, cache the response */
> -	memcpy(pvt_data->resp_buf, temp_buf, resp_len);
> -	pvt_data->resp_len = resp_len;
> +	memcpy(buf, temp_buf, resp_len);
>  
> -	return 0;
> +	return resp_len;
>  }
>  
>  static const struct tpm_class_ops ftpm_tee_tpm_ops = {
>  	.flags = TPM_OPS_AUTO_STARTUP,
> -	.recv = ftpm_tee_tpm_op_recv,
>  	.send = ftpm_tee_tpm_op_send,
>  };
>  
> @@ -253,7 +227,7 @@ static int ftpm_tee_probe(struct device *dev)
>  	}
>  
>  	pvt_data->chip = chip;
> -	pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2;
> +	pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_SYNC;
>  
>  	/* Create a character device for the fTPM */
>  	rc = tpm_chip_register(pvt_data->chip);
> -- 
> 2.49.0
> 

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko

[PATCH v6 4/4] tpm/tpm_svsm: support TPM_CHIP_FLAG_SYNC

[Stefano Garzarella]

From: Stefano Garzarella <sgarzare@redhat.com>

This driver does not support interrupts, and receiving the response is
synchronous with sending the command.

Enable synchronous send() with TPM_CHIP_FLAG_SYNC, which implies that
->send() already fills the provided buffer with a response, and ->recv()
is not implemented.

Keep using the same pre-allocated buffer to avoid having to allocate
it for each command. We need the buffer to have the header required by
the SVSM protocol and the command contiguous in memory.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
v5:
- changed order and parameter names to match tpm_try_transmit() [Jarkko]
v4:
- reworked commit description [Jarkko]
---
 drivers/char/tpm/tpm_svsm.c | 27 +++++++++++----------------
 1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/drivers/char/tpm/tpm_svsm.c b/drivers/char/tpm/tpm_svsm.c
index 0847cbf450b4..f5ba0f64850b 100644
--- a/drivers/char/tpm/tpm_svsm.c
+++ b/drivers/char/tpm/tpm_svsm.c
@@ -26,37 +26,31 @@ struct tpm_svsm_priv {
 };
 
 static int tpm_svsm_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
-			 size_t len)
+			 size_t cmd_len)
 {
 	struct tpm_svsm_priv *priv = dev_get_drvdata(&chip->dev);
 	int ret;
 
-	ret = svsm_vtpm_cmd_request_fill(priv->buffer, 0, buf, len);
+	ret = svsm_vtpm_cmd_request_fill(priv->buffer, 0, buf, cmd_len);
 	if (ret)
 		return ret;
 
 	/*
 	 * The SVSM call uses the same buffer for the command and for the
-	 * response, so after this call, the buffer will contain the response
-	 * that can be used by .recv() op.
+	 * response, so after this call, the buffer will contain the response.
+	 *
+	 * Note: we have to use an internal buffer because the device in SVSM
+	 * expects the svsm_vtpm header + data to be physically contiguous.
 	 */
-	return snp_svsm_vtpm_send_command(priv->buffer);
-}
-
-static int tpm_svsm_recv(struct tpm_chip *chip, u8 *buf, size_t len)
-{
-	struct tpm_svsm_priv *priv = dev_get_drvdata(&chip->dev);
+	ret = snp_svsm_vtpm_send_command(priv->buffer);
+	if (ret)
+		return ret;
 
-	/*
-	 * The internal buffer contains the response after we send the command
-	 * to SVSM.
-	 */
-	return svsm_vtpm_cmd_response_parse(priv->buffer, buf, len);
+	return svsm_vtpm_cmd_response_parse(priv->buffer, buf, bufsiz);
 }
 
 static struct tpm_class_ops tpm_chip_ops = {
 	.flags = TPM_OPS_AUTO_STARTUP,
-	.recv = tpm_svsm_recv,
 	.send = tpm_svsm_send,
 };
 
@@ -85,6 +79,7 @@ static int __init tpm_svsm_probe(struct platform_device *pdev)
 
 	dev_set_drvdata(&chip->dev, priv);
 
+	chip->flags |= TPM_CHIP_FLAG_SYNC;
 	err = tpm2_probe(chip);
 	if (err)
 		return err;
-- 
2.49.0

Re: [PATCH v6 4/4] tpm/tpm_svsm: support TPM_CHIP_FLAG_SYNC

[Jarkko Sakkinen]

On Fri, Jun 20, 2025 at 03:08:10PM +0200, Stefano Garzarella wrote:
> From: Stefano Garzarella <sgarzare@redhat.com>
> 
> This driver does not support interrupts, and receiving the response is
> synchronous with sending the command.
> 
> Enable synchronous send() with TPM_CHIP_FLAG_SYNC, which implies that
> ->send() already fills the provided buffer with a response, and ->recv()
> is not implemented.
> 
> Keep using the same pre-allocated buffer to avoid having to allocate
> it for each command. We need the buffer to have the header required by
> the SVSM protocol and the command contiguous in memory.
> 
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
> v5:
> - changed order and parameter names to match tpm_try_transmit() [Jarkko]
> v4:
> - reworked commit description [Jarkko]
> ---
>  drivers/char/tpm/tpm_svsm.c | 27 +++++++++++----------------
>  1 file changed, 11 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_svsm.c b/drivers/char/tpm/tpm_svsm.c
> index 0847cbf450b4..f5ba0f64850b 100644
> --- a/drivers/char/tpm/tpm_svsm.c
> +++ b/drivers/char/tpm/tpm_svsm.c
> @@ -26,37 +26,31 @@ struct tpm_svsm_priv {
>  };
>  
>  static int tpm_svsm_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> -			 size_t len)
> +			 size_t cmd_len)
>  {
>  	struct tpm_svsm_priv *priv = dev_get_drvdata(&chip->dev);
>  	int ret;
>  
> -	ret = svsm_vtpm_cmd_request_fill(priv->buffer, 0, buf, len);
> +	ret = svsm_vtpm_cmd_request_fill(priv->buffer, 0, buf, cmd_len);
>  	if (ret)
>  		return ret;
>  
>  	/*
>  	 * The SVSM call uses the same buffer for the command and for the
> -	 * response, so after this call, the buffer will contain the response
> -	 * that can be used by .recv() op.
> +	 * response, so after this call, the buffer will contain the response.
> +	 *
> +	 * Note: we have to use an internal buffer because the device in SVSM
> +	 * expects the svsm_vtpm header + data to be physically contiguous.
>  	 */
> -	return snp_svsm_vtpm_send_command(priv->buffer);
> -}
> -
> -static int tpm_svsm_recv(struct tpm_chip *chip, u8 *buf, size_t len)
> -{
> -	struct tpm_svsm_priv *priv = dev_get_drvdata(&chip->dev);
> +	ret = snp_svsm_vtpm_send_command(priv->buffer);
> +	if (ret)
> +		return ret;
>  
> -	/*
> -	 * The internal buffer contains the response after we send the command
> -	 * to SVSM.
> -	 */
> -	return svsm_vtpm_cmd_response_parse(priv->buffer, buf, len);
> +	return svsm_vtpm_cmd_response_parse(priv->buffer, buf, bufsiz);
>  }
>  
>  static struct tpm_class_ops tpm_chip_ops = {
>  	.flags = TPM_OPS_AUTO_STARTUP,
> -	.recv = tpm_svsm_recv,
>  	.send = tpm_svsm_send,
>  };
>  
> @@ -85,6 +79,7 @@ static int __init tpm_svsm_probe(struct platform_device *pdev)
>  
>  	dev_set_drvdata(&chip->dev, priv);
>  
> +	chip->flags |= TPM_CHIP_FLAG_SYNC;
>  	err = tpm2_probe(chip);
>  	if (err)
>  		return err;
> -- 
> 2.49.0
> 

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko

Re: [PATCH v6 4/4] tpm/tpm_svsm: support TPM_CHIP_FLAG_SYNC

[Jarkko Sakkinen]

On Wed, Jun 25, 2025 at 03:02:54PM +0300, Jarkko Sakkinen wrote:
> On Fri, Jun 20, 2025 at 03:08:10PM +0200, Stefano Garzarella wrote:
> > From: Stefano Garzarella <sgarzare@redhat.com>
> > 
> > This driver does not support interrupts, and receiving the response is
> > synchronous with sending the command.
> > 
> > Enable synchronous send() with TPM_CHIP_FLAG_SYNC, which implies that
> > ->send() already fills the provided buffer with a response, and ->recv()
> > is not implemented.
> > 
> > Keep using the same pre-allocated buffer to avoid having to allocate
> > it for each command. We need the buffer to have the header required by
> > the SVSM protocol and the command contiguous in memory.
> > 
> > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> > ---
> > v5:
> > - changed order and parameter names to match tpm_try_transmit() [Jarkko]
> > v4:
> > - reworked commit description [Jarkko]
> > ---
> >  drivers/char/tpm/tpm_svsm.c | 27 +++++++++++----------------
> >  1 file changed, 11 insertions(+), 16 deletions(-)
> > 
> > diff --git a/drivers/char/tpm/tpm_svsm.c b/drivers/char/tpm/tpm_svsm.c
> > index 0847cbf450b4..f5ba0f64850b 100644
> > --- a/drivers/char/tpm/tpm_svsm.c
> > +++ b/drivers/char/tpm/tpm_svsm.c
> > @@ -26,37 +26,31 @@ struct tpm_svsm_priv {
> >  };
> >  
> >  static int tpm_svsm_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> > -			 size_t len)
> > +			 size_t cmd_len)
> >  {
> >  	struct tpm_svsm_priv *priv = dev_get_drvdata(&chip->dev);
> >  	int ret;
> >  
> > -	ret = svsm_vtpm_cmd_request_fill(priv->buffer, 0, buf, len);
> > +	ret = svsm_vtpm_cmd_request_fill(priv->buffer, 0, buf, cmd_len);
> >  	if (ret)
> >  		return ret;
> >  
> >  	/*
> >  	 * The SVSM call uses the same buffer for the command and for the
> > -	 * response, so after this call, the buffer will contain the response
> > -	 * that can be used by .recv() op.
> > +	 * response, so after this call, the buffer will contain the response.
> > +	 *
> > +	 * Note: we have to use an internal buffer because the device in SVSM
> > +	 * expects the svsm_vtpm header + data to be physically contiguous.
> >  	 */
> > -	return snp_svsm_vtpm_send_command(priv->buffer);
> > -}
> > -
> > -static int tpm_svsm_recv(struct tpm_chip *chip, u8 *buf, size_t len)
> > -{
> > -	struct tpm_svsm_priv *priv = dev_get_drvdata(&chip->dev);
> > +	ret = snp_svsm_vtpm_send_command(priv->buffer);
> > +	if (ret)
> > +		return ret;
> >  
> > -	/*
> > -	 * The internal buffer contains the response after we send the command
> > -	 * to SVSM.
> > -	 */
> > -	return svsm_vtpm_cmd_response_parse(priv->buffer, buf, len);
> > +	return svsm_vtpm_cmd_response_parse(priv->buffer, buf, bufsiz);
> >  }
> >  
> >  static struct tpm_class_ops tpm_chip_ops = {
> >  	.flags = TPM_OPS_AUTO_STARTUP,
> > -	.recv = tpm_svsm_recv,
> >  	.send = tpm_svsm_send,
> >  };
> >  
> > @@ -85,6 +79,7 @@ static int __init tpm_svsm_probe(struct platform_device *pdev)
> >  
> >  	dev_set_drvdata(&chip->dev, priv);
> >  
> > +	chip->flags |= TPM_CHIP_FLAG_SYNC;
> >  	err = tpm2_probe(chip);
> >  	if (err)
> >  		return err;
> > -- 
> > 2.49.0
> > 
> 
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

Applied.

BR, Jarkko

Re: [PATCH v6 4/4] tpm/tpm_svsm: support TPM_CHIP_FLAG_SYNC

[Stefano Garzarella]

On Wed, 25 Jun 2025 at 17:08, Jarkko Sakkinen <jarkko@kernel.org> wrote:
>
> On Wed, Jun 25, 2025 at 03:02:54PM +0300, Jarkko Sakkinen wrote:
> > On Fri, Jun 20, 2025 at 03:08:10PM +0200, Stefano Garzarella wrote:
> > > From: Stefano Garzarella <sgarzare@redhat.com>
> > >
> > > This driver does not support interrupts, and receiving the response is
> > > synchronous with sending the command.
> > >
> > > Enable synchronous send() with TPM_CHIP_FLAG_SYNC, which implies that
> > > ->send() already fills the provided buffer with a response, and ->recv()
> > > is not implemented.
> > >
> > > Keep using the same pre-allocated buffer to avoid having to allocate
> > > it for each command. We need the buffer to have the header required by
> > > the SVSM protocol and the command contiguous in memory.
> > >
> > > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> > > ---
> > > v5:
> > > - changed order and parameter names to match tpm_try_transmit() [Jarkko]
> > > v4:
> > > - reworked commit description [Jarkko]
> > > ---
> > >  drivers/char/tpm/tpm_svsm.c | 27 +++++++++++----------------
> > >  1 file changed, 11 insertions(+), 16 deletions(-)
> > >
> > > diff --git a/drivers/char/tpm/tpm_svsm.c b/drivers/char/tpm/tpm_svsm.c
> > > index 0847cbf450b4..f5ba0f64850b 100644
> > > --- a/drivers/char/tpm/tpm_svsm.c
> > > +++ b/drivers/char/tpm/tpm_svsm.c
> > > @@ -26,37 +26,31 @@ struct tpm_svsm_priv {
> > >  };
> > >
> > >  static int tpm_svsm_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
> > > -                    size_t len)
> > > +                    size_t cmd_len)
> > >  {
> > >     struct tpm_svsm_priv *priv = dev_get_drvdata(&chip->dev);
> > >     int ret;
> > >
> > > -   ret = svsm_vtpm_cmd_request_fill(priv->buffer, 0, buf, len);
> > > +   ret = svsm_vtpm_cmd_request_fill(priv->buffer, 0, buf, cmd_len);
> > >     if (ret)
> > >             return ret;
> > >
> > >     /*
> > >      * The SVSM call uses the same buffer for the command and for the
> > > -    * response, so after this call, the buffer will contain the response
> > > -    * that can be used by .recv() op.
> > > +    * response, so after this call, the buffer will contain the response.
> > > +    *
> > > +    * Note: we have to use an internal buffer because the device in SVSM
> > > +    * expects the svsm_vtpm header + data to be physically contiguous.
> > >      */
> > > -   return snp_svsm_vtpm_send_command(priv->buffer);
> > > -}
> > > -
> > > -static int tpm_svsm_recv(struct tpm_chip *chip, u8 *buf, size_t len)
> > > -{
> > > -   struct tpm_svsm_priv *priv = dev_get_drvdata(&chip->dev);
> > > +   ret = snp_svsm_vtpm_send_command(priv->buffer);
> > > +   if (ret)
> > > +           return ret;
> > >
> > > -   /*
> > > -    * The internal buffer contains the response after we send the command
> > > -    * to SVSM.
> > > -    */
> > > -   return svsm_vtpm_cmd_response_parse(priv->buffer, buf, len);
> > > +   return svsm_vtpm_cmd_response_parse(priv->buffer, buf, bufsiz);
> > >  }
> > >
> > >  static struct tpm_class_ops tpm_chip_ops = {
> > >     .flags = TPM_OPS_AUTO_STARTUP,
> > > -   .recv = tpm_svsm_recv,
> > >     .send = tpm_svsm_send,
> > >  };
> > >
> > > @@ -85,6 +79,7 @@ static int __init tpm_svsm_probe(struct platform_device *pdev)
> > >
> > >     dev_set_drvdata(&chip->dev, priv);
> > >
> > > +   chip->flags |= TPM_CHIP_FLAG_SYNC;
> > >     err = tpm2_probe(chip);
> > >     if (err)
> > >             return err;
> > > --
> > > 2.49.0
> > >
> >
> > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
>
> Applied.

Great, thanks!
Stefano