Re: [PATCH v4 03/13] tpm: add kernel doc to buffer handling functions

["Jarkko Sakkinen" <jarkko@kernel.org>]

On Tue Apr 4, 2023 at 12:39 AM EEST, James Bottomley wrote:
> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
> ---
>  drivers/char/tpm/tpm-buf.c | 65 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 65 insertions(+)
>
> diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
> index baa4866d53a9..3351db515e6b 100644
> --- a/drivers/char/tpm/tpm-buf.c
> +++ b/drivers/char/tpm/tpm-buf.c
> @@ -6,6 +6,16 @@
>  #include <linux/module.h>
>  #include <linux/tpm.h>
>  
> +/**
> + * tpm_buf_init - initialize a TPM command buffer
> + * @buf: pointer to a tpm_buf structure (usually on stack)
> + * @tag: command tag
> + * @ordinal: command ordinal
> + *
> + * Allocates a 4k buffer to hold the command structure.
> + *
> + * @return: 0 on success or -ENOMEM
> + */
>  int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
>  {
>  	buf->data = (u8 *)__get_free_page(GFP_KERNEL);
> @@ -18,6 +28,16 @@ int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
>  }
>  EXPORT_SYMBOL_GPL(tpm_buf_init);
>  
> +/**
> + * tpm_buf_reset - reset an initialized TPM command buffer
> + * @buf: pointer to a tpm_buf structure (usually on stack)
> + * @tag: command tag
> + * @ordinal: command ordinal
> + *
> + * Repurposes an already allocated @buf for a new command.
> + * Identical to calling tpm_buf_destroy/tpm_buf_init except it keeps
> + * the 4k allocated page and cannot fail.
> + */
>  void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal)
>  {
>  	struct tpm_header *head = (struct tpm_header *) buf->data;
> @@ -28,12 +48,24 @@ void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal)
>  }
>  EXPORT_SYMBOL_GPL(tpm_buf_reset);
>  
> +/**
> + * tpm_buf_destroy - destroy an initialized TPM command buffer
> + * @buf: pointer to a tpm_buf structure (usually on stack)
> + *
> + * Frees the memory allocated to @buf.
> + */
>  void tpm_buf_destroy(struct tpm_buf *buf)
>  {
>  	free_page((unsigned long)buf->data);
>  }
>  EXPORT_SYMBOL_GPL(tpm_buf_destroy);
>  
> +/**
> + * tpm_buf_length - get the current length of a TPM command
> + * @buf: pointer to a tpm_buf structure (usually on stack)
> + *
> + * @return: the current length of the @buf.
> + */
>  u32 tpm_buf_length(struct tpm_buf *buf)
>  {
>  	struct tpm_header *head = (struct tpm_header *)buf->data;
> @@ -42,6 +74,15 @@ u32 tpm_buf_length(struct tpm_buf *buf)
>  }
>  EXPORT_SYMBOL_GPL(tpm_buf_length);
>  
> +/**
> + * tpm_buf_append - append data to an initialized TPM command buffer
> + * @buf: pointer to a tpm_buf structure (usually on stack)
> + * @new_data: pointer to the added data
> + * @new_len: length of the added data
> + *
> + * Appends @new_data to the end of the current @buf and updates the
> + * length.
> + */
>  void tpm_buf_append(struct tpm_buf *buf,
>  		    const unsigned char *new_data,
>  		    unsigned int new_len)
> @@ -64,12 +105,28 @@ void tpm_buf_append(struct tpm_buf *buf,
>  }
>  EXPORT_SYMBOL_GPL(tpm_buf_append);
>  
> +/**
> + * tpm_buf_append_u8 - append u8 data to an initialized TPM command buffer
> + * @buf: pointer to a tpm_buf structure (usually on stack)
> + * @value: the value of the data to append
> + *
> + * Appends @value as a byte to the end of the current @buf and updates
> + * the length.
> + */
>  void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value)
>  {
>  	tpm_buf_append(buf, &value, 1);
>  }
>  EXPORT_SYMBOL_GPL(tpm_buf_append_u8);
>  
> +/**
> + * tpm_buf_append_u16 - append u16 data to an initialized TPM command buffer
> + * @buf: pointer to a tpm_buf structure (usually on stack)
> + * @value: the value of the data to append
> + *
> + * Appends @value as a big endian short to the end of the current @buf
> + * and updates the length.
> + */
>  void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value)
>  {
>  	__be16 value2 = cpu_to_be16(value);
> @@ -78,6 +135,14 @@ void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value)
>  }
>  EXPORT_SYMBOL_GPL(tpm_buf_append_u16);
>  
> +/**
> + * tpm_buf_append_u32 - append u32 data to an initialized TPM command buffer
> + * @buf: pointer to a tpm_buf structure (usually on stack)
> + * @value: the value of the data to append
> + *
> + * Appends @value as a big endian word to the end of the current @buf
> + * and updates the length.
> + */
>  void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value)
>  {
>  	__be32 value2 = cpu_to_be32(value);
> -- 
> 2.35.3

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

BR, Jarkko