Re: [PATCH] drm/panthor: Display FW version information

[Boris Brezillon <boris.brezillon@collabora.com>]

On Thu,  5 Sep 2024 16:51:44 +0100
Steven Price <steven.price@arm.com> wrote:

> The firmware binary has a git SHA embedded into it which can be used to
> identify which firmware binary is being loaded. Output this as a
> drm_info() so that it's obvious from a dmesg log which firmware binary
> is being used.
> 
> Signed-off-by: Steven Price <steven.price@arm.com>

Just one formatting issue mentioned below, looks good otherwise.

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

> ---
>  drivers/gpu/drm/panthor/panthor_fw.c | 55 ++++++++++++++++++++++++++++
>  1 file changed, 55 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
> index 857f3f11258a..ef007287575c 100644
> --- a/drivers/gpu/drm/panthor/panthor_fw.c
> +++ b/drivers/gpu/drm/panthor/panthor_fw.c
> @@ -78,6 +78,12 @@ enum panthor_fw_binary_entry_type {
>  
>  	/** @CSF_FW_BINARY_ENTRY_TYPE_TIMELINE_METADATA: Timeline metadata interface. */
>  	CSF_FW_BINARY_ENTRY_TYPE_TIMELINE_METADATA = 4,
> +
> +	/**
> +	 * @CSF_FW_BINARY_ENTRY_TYPE_BUILD_INFO_METADATA: Metadata about how
> +	 * the FW binary was built.
> +	 */
> +	CSF_FW_BINARY_ENTRY_TYPE_BUILD_INFO_METADATA = 6
>  };
>  
>  #define CSF_FW_BINARY_ENTRY_TYPE(ehdr)					((ehdr) & 0xff)
> @@ -132,6 +138,13 @@ struct panthor_fw_binary_section_entry_hdr {
>  	} data;
>  };
>  
> +struct panthor_fw_build_info_hdr {
> +	/** @meta_start: Offset of the build info data in the FW binary */
> +	u32 meta_start;
> +	/** @meta_size: Size of the build info data in the FW binary */
> +	u32 meta_size;
> +};
> +
>  /**
>   * struct panthor_fw_binary_iter - Firmware binary iterator
>   *
> @@ -628,6 +641,46 @@ static int panthor_fw_load_section_entry(struct panthor_device *ptdev,
>  	return 0;
>  }
>  
> +static int panthor_fw_read_build_info(struct panthor_device *ptdev,
> +				      const struct firmware *fw,
> +				      struct panthor_fw_binary_iter *iter,
> +				      u32 ehdr)
> +{
> +	struct panthor_fw_build_info_hdr hdr;
> +	char header[9];
> +	const char git_sha_header[sizeof(header)] = "git_sha: ";
> +	int ret;
> +
> +	ret = panthor_fw_binary_iter_read(ptdev, iter, &hdr, sizeof(hdr));
> +	if (ret)
> +		return ret;
> +
> +	if (hdr.meta_start > fw->size ||
> +	    hdr.meta_start + hdr.meta_size > fw->size) {
> +		drm_err(&ptdev->base, "Firmware build info corrupt\n");
> +		/* We don't need the build info, so continue */
> +		return 0;
> +	}
> +
> +	if (memcmp(git_sha_header, fw->data + hdr.meta_start,
> +	    sizeof(git_sha_header))) {

Indentation seems broken here:

	if (memcmp(git_sha_header, fw->data + hdr.meta_start,
		   sizeof(git_sha_header))) {

> +		/* Not the expected header, this isn't metadata we understand */
> +		return 0;
> +	}
> +
> +	/* Check that the git SHA is NULL terminated as expected */
> +	if (fw->data[hdr.meta_start + hdr.meta_size - 1] != '\0') {
> +		drm_warn(&ptdev->base, "Firmware's git sha is not NULL terminated\n");
> +		/* Don't treat as fatal */
> +		return 0;
> +	}
> +
> +	drm_info(&ptdev->base, "Firmware git sha: %s\n",
> +		 fw->data + hdr.meta_start + sizeof(git_sha_header));

Maybe we should also change the "FW vX.Y.Z" message into "FW interface
vX.Y.Z" to clarify things.

> +
> +	return 0;
> +}
> +
>  static void
>  panthor_reload_fw_sections(struct panthor_device *ptdev, bool full_reload)
>  {
> @@ -672,6 +725,8 @@ static int panthor_fw_load_entry(struct panthor_device *ptdev,
>  	switch (CSF_FW_BINARY_ENTRY_TYPE(ehdr)) {
>  	case CSF_FW_BINARY_ENTRY_TYPE_IFACE:
>  		return panthor_fw_load_section_entry(ptdev, fw, &eiter, ehdr);
> +	case CSF_FW_BINARY_ENTRY_TYPE_BUILD_INFO_METADATA:
> +		return panthor_fw_read_build_info(ptdev, fw, &eiter, ehdr);
>  
>  	/* FIXME: handle those entry types? */
>  	case CSF_FW_BINARY_ENTRY_TYPE_CONFIG: