Re: [PATCH 2/3] dfl: add dfl bus support to MODULE_DEVICE_TABLE()

[Tom Rix <trix@redhat.com>]

On 9/7/20 10:48 PM, Xu Yilun wrote:
> Device Feature List (DFL) is a linked list of feature headers within the
> device MMIO space. It is used by FPGA to enumerate multiple sub features
Do you mean a linked list in the pci config space ?
> within it. Each feature can be uniquely identified by DFL type and
> feature id, which can be read out from feature headers.
>
> A dfl bus helps DFL framework modularize DFL device drivers for different
> sub features. The dfl bus matches its devices and drivers by DFL type and
> feature id.
>
> This patch add dfl bus support to MODULE_DEVICE_TABLE() by adding info
> about struct dfl_device_id in devicetable-offsets.c and add a dfl entry
> point in file2alias.c.
>
> Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> Signed-off-by: Wu Hao <hao.wu@intel.com>
> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> ---
>  scripts/mod/devicetable-offsets.c |  4 ++++
>  scripts/mod/file2alias.c          | 13 +++++++++++++
>  2 files changed, 17 insertions(+)
>
> diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c
> index 27007c1..d8350ee 100644
> --- a/scripts/mod/devicetable-offsets.c
> +++ b/scripts/mod/devicetable-offsets.c
> @@ -243,5 +243,9 @@ int main(void)
>  	DEVID(mhi_device_id);
>  	DEVID_FIELD(mhi_device_id, chan);
>  
> +	DEVID(dfl_device_id);
> +	DEVID_FIELD(dfl_device_id, type);
> +	DEVID_FIELD(dfl_device_id, feature_id);
> +
>  	return 0;
>  }
> diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
> index 2417dd1..0753fc2 100644
> --- a/scripts/mod/file2alias.c
> +++ b/scripts/mod/file2alias.c
> @@ -1368,6 +1368,18 @@ static int do_mhi_entry(const char *filename, void *symval, char *alias)
>  	return 1;
>  }
>  
> +/* Looks like: dfl:tNfN */
> +static int do_dfl_entry(const char *filename, void *symval, char *alias)
> +{
> +	DEF_FIELD(symval, dfl_device_id, type);
> +	DEF_FIELD(symval, dfl_device_id, feature_id);
> +
> +	sprintf(alias, "dfl:t%01Xf%03X", type, feature_id);

Is it necessary to constrain the output here ?

If you do not want to use the full width of the types,

a comment would be helpful.

Tom

> +
> +	add_wildcard(alias);
> +	return 1;
> +}
> +
>  /* Does namelen bytes of name exactly match the symbol? */
>  static bool sym_is(const char *name, unsigned namelen, const char *symbol)
>  {
> @@ -1442,6 +1454,7 @@ static const struct devtable devtable[] = {
>  	{"tee", SIZE_tee_client_device_id, do_tee_entry},
>  	{"wmi", SIZE_wmi_device_id, do_wmi_entry},
>  	{"mhi", SIZE_mhi_device_id, do_mhi_entry},
> +	{"dfl", SIZE_dfl_device_id, do_dfl_entry},
>  };
>  
>  /* Create MODULE_ALIAS() statements.