On 2022-09-23 at 05:17:43 -0700, 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
With this patchset, it's not 'current version' anymore.
> * 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));
> + switch (v) {
> + case 0:
> + break;
In last version, you mentioned that there will be no quirk for DFLv1, so
how about:
v = FIELD_GET(DFH_VERSION, readq(base));
if (v == 0) {
/* quirks */
} else {
/* parse PARAM MSIX */
}
No need to check specific feature ids again.
Thanks,
Yilun
> +
> + case 1:
> + v = readq(base + DFHv1_CSR_SIZE_GRP);
> + 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) {
> + 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;
> @@ -1879,6 +1908,27 @@ long dfl_feature_ioctl_set_irq(struct platform_device *pdev,
> }
> EXPORT_SYMBOL_GPL(dfl_feature_ioctl_set_irq);
>
> +int dfl_find_param(void __iomem *base, resource_size_t max, int param)
> +{
> + int off = 0;
> + u64 v, next;
> +
> + while (off < max) {
> + v = readq(base + off);
> + if (param == FIELD_GET(DFHv1_PARAM_HDR_ID, v))
> + return off;
> +
> + next = FIELD_GET(DFHv1_PARAM_HDR_NEXT_OFFSET, v);
> + if (!next)
> + break;
> +
> + off += next;
> + }
> +
> + return -ENOENT;
> +}
> +EXPORT_SYMBOL_GPL(dfl_find_param);
> +
> static void __exit dfl_fpga_exit(void)
> {
> dfl_chardev_uinit();
> diff --git a/include/linux/dfl.h b/include/linux/dfl.h
> index 1e53468ba8d8..33e21c360671 100644
> --- a/include/linux/dfl.h
> +++ b/include/linux/dfl.h
> @@ -63,6 +63,10 @@
> #define DFHv1_PARAM_HDR_VERSION GENMASK_ULL(31, 16) /* Version Param */
> #define DFHv1_PARAM_HDR_NEXT_OFFSET GENMASK_ULL(63, 32) /* Offset of next Param */
>
> +#define DFHv1_PARAM_ID_MSIX 0x1
> +#define DFHv1_PARAM_MSIX_STARTV 0x8
> +#define DFHv1_PARAM_MSIX_NUMV 0xc
> +
> /**
> * enum dfl_id_type - define the DFL FIU types
> */
> @@ -136,4 +140,14 @@ void dfl_driver_unregister(struct dfl_driver *dfl_drv);
> module_driver(__dfl_driver, dfl_driver_register, \
> dfl_driver_unregister)
>
> +/**
> + * dfl_find_param() - find the offset of the given parameter
> + * @base: base pointer to start of dfl parameters in DFH
> + * @max: maximum offset to search
> + * @param: id of dfl parameter
> + *
> + * Return: positive offset on success, negative error code otherwise.
> + */
> +int dfl_find_param(void __iomem *base, resource_size_t max, int param);
> +
> #endif /* __LINUX_DFL_H */
> --
> 2.25.1
>
