On Tue, Apr 19, 2022 at 03:52:24AM -0400, Tianfei Zhang wrote:
> From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
>
> Currently we use PORTn_OFFSET to locate PORT DFLs, and PORT DFLs are not
> connected FME DFL. But for some cases (e.g. Intel Open FPGA Stack device),
> PORT DFLs are connected to FME DFL directly, so we don't need to search
> PORT DFLs via PORTn_OFFSET again. If BAR value of PORTn_OFFSET is 0x7
> (FME_PORT_OFST_BAR_SKIP) then driver will skip searching the DFL for that
> port. If BAR value is invalid, return -EINVAL.
>
> Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
> Signed-off-by: Tianfei Zhang <tianfei.zhang@xxxxxxxxx>
> ---
> v2: return -EINVAL if bar number invalid.
> ---
> drivers/fpga/dfl-pci.c | 11 +++++++++++
> drivers/fpga/dfl.h | 1 +
> 2 files changed, 12 insertions(+)
>
> diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
> index 86ed9e4223d3..5bd6ef231ccc 100644
> --- a/drivers/fpga/dfl-pci.c
> +++ b/drivers/fpga/dfl-pci.c
> @@ -263,6 +263,17 @@ static int find_dfls_by_default(struct pci_dev *pcidev,
> */
> bar = FIELD_GET(FME_PORT_OFST_BAR_ID, v);
> offset = FIELD_GET(FME_PORT_OFST_DFH_OFST, v);
> + if (bar == FME_PORT_OFST_BAR_SKIP) {
> + dev_dbg(&pcidev->dev, "skipping search DFL for port %d on BAR %d\n",
> + i, bar);
I suggest we remove the dev_dbg, it's a normal case in DFL walking.
> + continue;
> + } else if (bar >= PCI_STD_NUM_BARS) {
> + dev_err(&pcidev->dev, "bad BAR %d for port %d\n",
> + bar, i);
> + ret = -EINVAL;
> + break;
The code is workable, but I suggest we use goto instead of break for
error out.
Thanks,
Yilun
> + }
> +
> start = pci_resource_start(pcidev, bar) + offset;
> len = pci_resource_len(pcidev, bar) - offset;
>
> diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
> index 53572c7aced0..e0f0abfbeb8c 100644
> --- a/drivers/fpga/dfl.h
> +++ b/drivers/fpga/dfl.h
> @@ -91,6 +91,7 @@
> #define FME_HDR_PORT_OFST(n) (0x38 + ((n) * 0x8))
> #define FME_HDR_BITSTREAM_ID 0x60
> #define FME_HDR_BITSTREAM_MD 0x68
> +#define FME_PORT_OFST_BAR_SKIP 7
>
> /* FME Fab Capability Register Bitfield */
> #define FME_CAP_FABRIC_VERID GENMASK_ULL(7, 0) /* Fabric version ID */
> --
> 2.26.2
