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.
> + switch (v) {
> + case 0:
> + break;
> +
> + case 1:
> + v = readq(base + DFHv1_CSR_SIZE_GRP);
Extra space.
> + 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.
> + 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;
> +
> + default:
> + dev_warn(binfo->dev, "unexpected DFH version %lld\n", v);
> + break;
> + }
> + }
> +
> if (!inr) {
> *irq_base = 0;
> *nr_irqs = 0;
--
i.
