> -----Original Message-----
> From: Wu, Hao <hao.wu@xxxxxxxxx>
> Sent: Tuesday, March 1, 2022 3:28 PM
> To: Zhang, Tianfei <tianfei.zhang@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>
> Subject: RE: [PATCH v3 4/5] fpga: dfl: Handle dfl's starting with AFU
>
> > -----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?
Yes, in " Multiple VFs per PR slot" model, the AFU was not connected with Port.
>
> >
> > 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.
dfl_feature_is_afu(base) will be better.
>
> > - 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.
In " Multiple VFs per PR slot" model, we access the AFU resource via VFs for example VFIO-PIC driver, and we cannot access the AFU MMIO resource by AFU APIs.
>
> > }
> >
> > /* 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
