2022-03-01 07:15:18

by Zhang, Tianfei

[permalink] [raw]
Subject: [PATCH v3 4/5] fpga: dfl: Handle dfl's starting with AFU

From: Matthew Gerlach <[email protected]>

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.

Signed-off-by: Matthew Gerlach <[email protected]>
Signed-off-by: Tianfei Zhang <[email protected]>
---
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 {
- 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;
+ }
}

/* 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


2022-03-01 08:12:58

by Wu Hao

[permalink] [raw]
Subject: RE: [PATCH v3 4/5] fpga: dfl: Handle dfl's starting with AFU

> -----Original Message-----
> From: Zhang, Tianfei <[email protected]>
> Sent: Tuesday, March 1, 2022 2:21 PM
> To: Wu, Hao <[email protected]>; [email protected]; [email protected]; Xu, Yilun
> <[email protected]>; [email protected]; [email protected]
> Cc: [email protected]; [email protected]; Matthew Gerlach
> <[email protected]>; Zhang, Tianfei <[email protected]>
> Subject: [PATCH v3 4/5] fpga: dfl: Handle dfl's starting with AFU
>
> From: Matthew Gerlach <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Tianfei Zhang <[email protected]>
> ---
> 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

2022-03-02 13:55:52

by Zhang, Tianfei

[permalink] [raw]
Subject: RE: [PATCH v3 4/5] fpga: dfl: Handle dfl's starting with AFU



> -----Original Message-----
> From: Wu, Hao <[email protected]>
> Sent: Tuesday, March 1, 2022 3:28 PM
> To: Zhang, Tianfei <[email protected]>; [email protected];
> [email protected]; Xu, Yilun <[email protected]>; [email protected];
> [email protected]
> Cc: [email protected]; [email protected]; Matthew Gerlach
> <[email protected]>
> Subject: RE: [PATCH v3 4/5] fpga: dfl: Handle dfl's starting with AFU
>
> > -----Original Message-----
> > From: Zhang, Tianfei <[email protected]>
> > Sent: Tuesday, March 1, 2022 2:21 PM
> > To: Wu, Hao <[email protected]>; [email protected]; [email protected]; Xu,
> > Yilun <[email protected]>; [email protected];
> > [email protected]
> > Cc: [email protected]; [email protected]; Matthew Gerlach
> > <[email protected]>; Zhang, Tianfei
> > <[email protected]>
> > Subject: [PATCH v3 4/5] fpga: dfl: Handle dfl's starting with AFU
> >
> > From: Matthew Gerlach <[email protected]>
> >
> > 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 <[email protected]>
> > Signed-off-by: Tianfei Zhang <[email protected]>
> > ---
> > 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