On Mon, 26 Sep 2022, matthew.gerlach@linux.intel.com wrote:

On Fri, 23 Sep 2022, Ilpo Järvinen wrote:

quoted

On Fri, 23 Sep 2022, matthew.gerlach@linux.intel.com wrote:

quoted

From: Matthew Gerlach <redacted>

Define and use a DFHv1 parameter to add generic support for MSIX
interrupts for DFL devices.

Signed-off-by: Matthew Gerlach <redacted>
---
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 :-)).

quoted

quoted

+			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.

quoted

quoted

+					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;