Re: [PATCH v2 4/6] fpga: dfl: add generic support for MSIX interrupts
From: matthew . gerlach
Date: Tue Sep 27 2022 - 08:17:20 EST
On Tue, 27 Sep 2022, Ilpo Järvinen wrote:
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 understand now. This is a good suggestion because the resulting
indentation is better.
Thanks,
Matthew
--
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;