> -----Original Message-----
> From: Zhang, Tianfei <tianfei.zhang@xxxxxxxxx>
> Sent: Tuesday, March 1, 2022 2:21 PM
> To: Wu, Hao <hao.wu@xxxxxxxxx>; trix@xxxxxxxxxx; mdf@xxxxxxxxxx; Xu, Yilun
> <yilun.xu@xxxxxxxxx>; linux-fpga@xxxxxxxxxxxxxxx; linux-doc@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx; corbet@xxxxxxx; Matthew Gerlach
> <matthew.gerlach@xxxxxxxxxxxxxxx>; Zhang, Tianfei <tianfei.zhang@xxxxxxxxx>
> Subject: [PATCH v3 4/5] fpga: dfl: Handle dfl's starting with AFU
>
> From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
>
> Allow for a Device Feature List (DFL) to start with
> a Device Feature Header (DFH) of type Accelerator Function Unit (AFU)
> by doing nothing. This allows for PCIe VFs to be created.
Why this is related to VFs creation? We don't have AFU in PF in OFS case, right?
>
> Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
> Signed-off-by: Tianfei Zhang <tianfei.zhang@xxxxxxxxx>
> ---
> drivers/fpga/dfl-pci.c | 7 ++++++-
> drivers/fpga/dfl.c | 22 +++++++++++++---------
> 2 files changed, 19 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
> index 33545c999c06..e7d58e7b1bbd 100644
> --- a/drivers/fpga/dfl-pci.c
> +++ b/drivers/fpga/dfl-pci.c
> @@ -275,7 +275,12 @@ static int find_dfls_by_default(struct pci_dev *pcidev,
>
> dfl_fpga_enum_info_add_dfl(info, start, len);
> } else {
Can be something like else if dfl_feature_is_afu(base) following the same style.
> - ret = -ENODEV;
> + v = readq(base + DFH);
> + if (FIELD_GET(DFH_TYPE, v) != DFH_TYPE_AFU) {
> + dev_info(&pcidev->dev, "Unknown feature type 0x%llx
> id 0x%llx\n",
> + FIELD_GET(DFH_TYPE, v), FIELD_GET(DFH_ID,
> v));
> + ret = -ENODEV;
> + }
But nothing else done for AFU so far? How it works? Sounds like more patches
are required.
> }
>
> /* release I/O mappings for next step enumeration */
> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> index fd04ef5c8b03..e30bbb3039cd 100644
> --- a/drivers/fpga/dfl.c
> +++ b/drivers/fpga/dfl.c
> @@ -900,9 +900,11 @@ static void build_info_free(struct
> build_feature_devs_info *binfo)
> dfl_id_free(feature_dev_id_type(binfo->feature_dev),
> binfo->feature_dev->id);
>
> - list_for_each_entry_safe(finfo, p, &binfo->sub_features, node)
> {
> - list_del(&finfo->node);
> - kfree(finfo);
> + if (!list_empty(&binfo->sub_features)) {
> + list_for_each_entry_safe(finfo, p, &binfo-
> >sub_features, node) {
> + list_del(&finfo->node);
> + kfree(finfo);
> + }
> }
> }
>
> @@ -1439,12 +1441,14 @@ dfl_fpga_feature_devs_enumerate(struct
> dfl_fpga_enum_info *info)
> * start enumeration for all feature devices based on Device Feature
> * Lists.
> */
> - list_for_each_entry(dfl, &info->dfls, node) {
> - ret = parse_feature_list(binfo, dfl->start, dfl->len);
> - if (ret) {
> - remove_feature_devs(cdev);
> - build_info_free(binfo);
> - goto unregister_region_exit;
> + if (!list_empty(&info->dfls)) {
> + list_for_each_entry(dfl, &info->dfls, node) {
> + ret = parse_feature_list(binfo, dfl->start, dfl->len);
> + if (ret) {
> + remove_feature_devs(cdev);
> + build_info_free(binfo);
> + goto unregister_region_exit;
> + }
> }
> }
>
> --
> 2.26.2
