Re: [PATCH v4 1/2] tpm: Refactor tpm_transmit pulling out tpm_transfer function

From: Stefan Berger
Date: Mon May 15 2017 - 12:07:11 EST


On 05/15/2017 12:04 PM, Stefan Berger wrote:
On 05/15/2017 08:40 AM, Jarkko Sakkinen wrote:
On Wed, May 10, 2017 at 07:54:21PM -0400, Stefan Berger wrote:
Refactor tpm_transmit and pull out code sending the command
and receiving the response and put this into tpm_transfer.

Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm-interface.c | 121 +++++++++++++++++++++++----------------
1 file changed, 73 insertions(+), 48 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 158c1db..263b6d1 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -370,67 +370,29 @@ static bool tpm_validate_command(struct tpm_chip *chip,
}
/**
- * tmp_transmit - Internal kernel interface to transmit TPM commands.
+ * tmp_transfer - Send a TPM command to the TPM and receive response
*
* @chip: TPM chip to use
* @buf: TPM command buffer
+ * @count: size of the TPM command
* @bufsiz: length of the TPM command buffer
- * @flags: tpm transmit flags - bitmap
*
* Return:
- * 0 when the operation is successful.
+ * >0 when the operation is successful; returns response length
* A negative number for system errors (errno).
*/
-ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
- u8 *buf, size_t bufsiz, unsigned int flags)
+ssize_t tpm_transfer(struct tpm_chip *chip, u8 *buf, u32 count, size_t bufsiz)
Add instead a flag TPM_TRANSMIT_RAW (this name is just a suggestion)
that skips "prepare" and "commit" parts. That would save us from a
new export.

Better way to make it less messy would be to add static functions
tpm_prepare_command and tpm_commit_command that would be always
called and would return immediately if flags contain TPM_TRANSMIT_RAW.

I'll do that then, modifying the code to skip tpm_validate_command as well.


But we don't want to recurse (in the 2nd patch) into chip->ops->request_locality(). Any suggestions ?

Stefan