On Mon, 26 Sep 2022, matthew.gerlach@xxxxxxxxxxxxxxx wrote:
>
>
> On Fri, 23 Sep 2022, Ilpo Järvinen wrote:
>
> > On Fri, 23 Sep 2022, matthew.gerlach@xxxxxxxxxxxxxxx wrote:
> >
> > > From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
> > >
> > > Define and use a DFHv1 parameter to add generic support for MSIX
> > > interrupts for DFL devices.
> > >
> > > Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
> > > ---
> > > v2: fix kernel doc
> > > clarify use of DFH_VERSION field
> > > ---
> > > drivers/fpga/dfl.c | 60 +++++++++++++++++++++++++++++++++++++++++----
> > > include/linux/dfl.h | 14 +++++++++++
> > > 2 files changed, 69 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> > > index 1132f3c10440..dfd3f563c92d 100644
> > > --- a/drivers/fpga/dfl.c
> > > +++ b/drivers/fpga/dfl.c
> > > @@ -941,23 +941,22 @@ static int parse_feature_irqs(struct
> > > build_feature_devs_info *binfo,
> > > void __iomem *base = binfo->ioaddr + ofst;
> > > unsigned int i, ibase, inr = 0;
> > > enum dfl_id_type type;
> > > - int virq;
> > > + int virq, off;
> > > u64 v;
> > >
> > > type = feature_dev_id_type(binfo->feature_dev);
> > >
> > > /*
> > > * Ideally DFL framework should only read info from DFL header, but
> > > - * current version DFL only provides mmio resources information for
> > > + * current version, DFHv0, only provides mmio resources information
> > > for
> > > * each feature in DFL Header, no field for interrupt resources.
> > > * Interrupt resource information is provided by specific mmio
> > > * registers of each private feature which supports interrupt. So in
> > > * order to parse and assign irq resources, DFL framework has to look
> > > * into specific capability registers of these private features.
> > > *
> > > - * Once future DFL version supports generic interrupt resource
> > > - * information in common DFL headers, the generic interrupt parsing
> > > - * code will be added. But in order to be compatible to old version
> > > + * DFHv1 supports generic interrupt resource information in DFHv1
> > > + * parameter blocks. But in order to be compatible to old version
> > > * DFL, the driver may still fall back to these quirks.
> > > */
> > > if (type == PORT_ID) {
> > > @@ -981,6 +980,36 @@ static int parse_feature_irqs(struct
> > > build_feature_devs_info *binfo,
> > > }
> > > }
> > >
> > > + if (fid != FEATURE_ID_AFU && fid != PORT_FEATURE_ID_ERROR &&
> > > + fid != PORT_FEATURE_ID_UINT && fid != FME_FEATURE_ID_GLOBAL_ERR) {
> > > +
> > > + v = FIELD_GET(DFH_VERSION, readq(base));
> >
> > I'd call this variable version (or ver) if you want to store it but it
> > would also fit to switch () line so that no extra variable is needed.
>
> I will change the v to dfh_ver to be clearer. I want to store the value
> because it is used in the default case in the error message. The error
> message helps to debug broken FPGA images.
Right, I missed that (or didn't think it too much and all being called
"v" didn't help either :-)).
> > > + if (FIELD_GET(DFHv1_CSR_SIZE_GRP_HAS_PARAMS, v)) {
> > > + off = dfl_find_param(base + DFHv1_PARAM_HDR,
> > > ofst,
> > > + DFHv1_PARAM_ID_MSIX);
> > > + if (off >= 0) {
> >
> > I'd reverse these 2 conditions and break when there's nothing to do.
>
> I'm not sure what you mean by reversing these conditions because a DFHv1 may
> or may not have parameters (the first condition), and a DFHv1 may have
> parameters but may not have a MSI-X parameter (the second condition).
This is what I meant:
if (!FIELD_GET(DFHv1_CSR_SIZE_GRP_HAS_PARAMS, v))
break;
off = dfl_find_param(...);
if (off < 0)
break;
ibase = ...
--
i.
> > > + ibase = readl(base + DFHv1_PARAM_HDR +
> > > + off +
> > > DFHv1_PARAM_MSIX_STARTV);
> > > + inr = readl(base + DFHv1_PARAM_HDR +
> > > + off +
> > > DFHv1_PARAM_MSIX_NUMV);
> > > + dev_dbg(binfo->dev, "start %d num %d
> > > fid 0x%x\n",
> > > + ibase, inr, fid);
> > > + }
> > > + }
> > > + break;
