[PATCH v9 7/8] tpm-buf: Remove chip parameter from tpm_buf_append_handle

Jarkko Sakkinen
2025-11-28T02:54:52Z

Remove @chip from tpm_buf_append_handle() in order to decouple it from
driver. This allows tpm-buf.c to be compiled as part of early boot code,
thus providing a mechanism to build and parse TPM data.

E.g., Trenchboot can use this to manage TPM2_PcrExtend protocol data as
part of its early boot blob simply by compiling and linking the object
file.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@opinsys.com>
Reviewed-by: Jonathan McDowell <noodles@meta.com>
---
v6:
- Rewrote the commit message.
v5:
- No changes.
v4:
- No changes.
v3:
- No changes.
v2:
- No changes.
---
drivers/char/tpm/tpm-buf.c | 5 ++---
drivers/char/tpm/tpm2-cmd.c | 2 +-
drivers/char/tpm/tpm2-sessions.c | 2 +-
include/linux/tpm.h | 2 +-
4 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
index 69ee77400539..1b9dee0d0681 100644
--- a/drivers/char/tpm/tpm-buf.c
+++ b/drivers/char/tpm/tpm-buf.c
@@ -147,20 +147,19 @@ EXPORT_SYMBOL_GPL(tpm_buf_append_u32);

/**
* tpm_buf_append_handle() - Add a handle
- * @chip: &tpm_chip instance
* @buf: &tpm_buf instance
* @handle: a TPM object handle
*
* Add a handle to the buffer, and increase the count tracking the number of
* handles in the command buffer. Works only for command buffers.
*/
-void tpm_buf_append_handle(struct tpm_chip *chip, struct tpm_buf *buf, u32 handle)
+void tpm_buf_append_handle(struct tpm_buf *buf, u32 handle)
{
if (buf->flags & TPM_BUF_INVALID)
return;

if (buf->flags & TPM_BUF_TPM2B) {
- dev_err(&chip->dev, "Invalid buffer type (TPM2B)\n");
+ WARN(1, "tpm-buf: invalid type: TPM2B\n");
buf->flags |= TPM_BUF_INVALID;
return;
}
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index a121c518ff6f..b7dc9c3dd15f 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -202,7 +202,7 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
tpm_buf_append_name(chip, &buf, pcr_idx, NULL);
tpm_buf_append_hmac_session(chip, &buf, 0, NULL, 0);
} else {
- tpm_buf_append_handle(chip, &buf, pcr_idx);
+ tpm_buf_append_handle(&buf, pcr_idx);
tpm_buf_append_auth(chip, &buf, NULL, 0);
}

diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c
index 13f019d1312a..bbc05f0997a8 100644
--- a/drivers/char/tpm/tpm2-sessions.c
+++ b/drivers/char/tpm/tpm2-sessions.c
@@ -232,7 +232,7 @@ void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf,
#endif

if (!tpm2_chip_auth(chip)) {
- tpm_buf_append_handle(chip, buf, handle);
+ tpm_buf_append_handle(buf, handle);
return;
}

diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 2796bac2a114..a52334c36855 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -426,7 +426,7 @@ void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value);
u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset);
u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset);
u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset);
-void tpm_buf_append_handle(struct tpm_chip *chip, struct tpm_buf *buf, u32 handle);
+void tpm_buf_append_handle(struct tpm_buf *buf, u32 handle);

/*
* Check if TPM device is in the firmware upgrade mode.
--
2.52.0