diff mbox series

[v1] fpga: dfl: Allow Port to be linked to FME's DFL

Message ID 20220413091519.317735-1-tianfei.zhang@intel.com (mailing list archive)
State New
Headers show
Series [v1] fpga: dfl: Allow Port to be linked to FME's DFL | expand

Commit Message

Zhang, Tianfei April 13, 2022, 9:15 a.m. UTC 
From: Matthew Gerlach <matthew.gerlach@linux.intel.com>

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.

Link: https://lore.kernel.org/linux-fpga/20220316070814.1916017-2-tianfei.zhang@intel.com/
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com>
---
 drivers/fpga/dfl-pci.c | 7 +++++++
 drivers/fpga/dfl.h     | 1 +
 2 files changed, 8 insertions(+)

Comments

Xu Yilun April 16, 2022, 4:18 p.m. UTC | #1 
On Wed, Apr 13, 2022 at 05:15:19AM -0400, Tianfei Zhang wrote:
> From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> 
> 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.
> 
> Link: https://lore.kernel.org/linux-fpga/20220316070814.1916017-2-tianfei.zhang@intel.com/
> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com>
> ---
>  drivers/fpga/dfl-pci.c | 7 +++++++
>  drivers/fpga/dfl.h     | 1 +
>  2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
> index 717ac9715970..6347f31058f0 100644
> --- a/drivers/fpga/dfl-pci.c
> +++ b/drivers/fpga/dfl-pci.c
> @@ -259,6 +259,13 @@ 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 >= PCI_STD_NUM_BARS ||
> +			    bar == FME_PORT_OFST_BAR_SKIP) {

Seems the second judgement will never be triggered?

Thanks
Yilun

> +				dev_dbg(&pcidev->dev, "skipping search DFL for port %d on BAR %d\n",
> +					i, bar);
> +				continue;
> +			}
> +
>  			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
Zhang, Tianfei April 18, 2022, 1:18 a.m. UTC | #2 
> -----Original Message-----
> From: Xu, Yilun <yilun.xu@intel.com>
> Sent: Sunday, April 17, 2022 12:18 AM
> To: Zhang, Tianfei <tianfei.zhang@intel.com>
> Cc: Wu, Hao <hao.wu@intel.com>; trix@redhat.com; mdf@kernel.org; linux-
> fpga@vger.kernel.org; Matthew Gerlach <matthew.gerlach@linux.intel.com>
> Subject: Re: [PATCH v1] fpga: dfl: Allow Port to be linked to FME's DFL
> 
> On Wed, Apr 13, 2022 at 05:15:19AM -0400, Tianfei Zhang wrote:
> > From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> >
> > 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.
> >
> > Link:
> > https://lore.kernel.org/linux-fpga/20220316070814.1916017-2-tianfei.zh
> > ang@intel.com/
> > Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> > Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com>
> > ---
> >  drivers/fpga/dfl-pci.c | 7 +++++++
> >  drivers/fpga/dfl.h     | 1 +
> >  2 files changed, 8 insertions(+)
> >
> > diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c index
> > 717ac9715970..6347f31058f0 100644
> > --- a/drivers/fpga/dfl-pci.c
> > +++ b/drivers/fpga/dfl-pci.c
> > @@ -259,6 +259,13 @@ 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 >= PCI_STD_NUM_BARS ||
> > +			    bar == FME_PORT_OFST_BAR_SKIP) {
> 
> Seems the second judgement will never be triggered?

The value is overlap, but there are different meaning, " bar >= PCI_STD_NUM_BARS" means that the bar was invalid during the PCIe spec,
"bar == FME_PORT_OFST_BAR_SKIP" means that the HW tell us that the SW should skip searching the DFL for the port.

> 
> Thanks
> Yilun
> 
> > +				dev_dbg(&pcidev->dev, "skipping search DFL
> for port %d on BAR %d\n",
> > +					i, bar);
> > +				continue;
> > +			}
> > +
> >  			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
Wu, Hao April 18, 2022, 1:56 a.m. UTC | #3 
> > -----Original Message-----
> > From: Xu, Yilun <yilun.xu@intel.com>
> > Sent: Sunday, April 17, 2022 12:18 AM
> > To: Zhang, Tianfei <tianfei.zhang@intel.com>
> > Cc: Wu, Hao <hao.wu@intel.com>; trix@redhat.com; mdf@kernel.org; linux-
> > fpga@vger.kernel.org; Matthew Gerlach <matthew.gerlach@linux.intel.com>
> > Subject: Re: [PATCH v1] fpga: dfl: Allow Port to be linked to FME's DFL
> >
> > On Wed, Apr 13, 2022 at 05:15:19AM -0400, Tianfei Zhang wrote:
> > > From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> > >
> > > 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.
> > >
> > > Link:
> > > https://lore.kernel.org/linux-fpga/20220316070814.1916017-2-tianfei.zh
> > > ang@intel.com/
> > > Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> > > Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com>
> > > ---
> > >  drivers/fpga/dfl-pci.c | 7 +++++++
> > >  drivers/fpga/dfl.h     | 1 +
> > >  2 files changed, 8 insertions(+)
> > >
> > > diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c index
> > > 717ac9715970..6347f31058f0 100644
> > > --- a/drivers/fpga/dfl-pci.c
> > > +++ b/drivers/fpga/dfl-pci.c
> > > @@ -259,6 +259,13 @@ 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 >= PCI_STD_NUM_BARS ||
> > > +			    bar == FME_PORT_OFST_BAR_SKIP) {
> >
> > Seems the second judgement will never be triggered?
> 
> The value is overlap, but there are different meaning, " bar >=
> PCI_STD_NUM_BARS" means that the bar was invalid during the PCIe spec,
> "bar == FME_PORT_OFST_BAR_SKIP" means that the HW tell us that the SW
> should skip searching the DFL for the port.

So first case is a HW bug we should return error, and second case is a valid
case to skip searching DFL, right?

> 
> >
> > Thanks
> > Yilun
> >
> > > +				dev_dbg(&pcidev->dev, "skipping search DFL
> > for port %d on BAR %d\n",
> > > +					i, bar);
> > > +				continue;
> > > +			}
> > > +
> > >  			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
Zhang, Tianfei April 18, 2022, 2:36 a.m. UTC | #4 
> -----Original Message-----
> From: Wu, Hao <hao.wu@intel.com>
> Sent: Monday, April 18, 2022 9:56 AM
> To: Zhang, Tianfei <tianfei.zhang@intel.com>; Xu, Yilun <yilun.xu@intel.com>
> Cc: trix@redhat.com; mdf@kernel.org; linux-fpga@vger.kernel.org; Matthew
> Gerlach <matthew.gerlach@linux.intel.com>
> Subject: RE: [PATCH v1] fpga: dfl: Allow Port to be linked to FME's DFL
> 
> > > -----Original Message-----
> > > From: Xu, Yilun <yilun.xu@intel.com>
> > > Sent: Sunday, April 17, 2022 12:18 AM
> > > To: Zhang, Tianfei <tianfei.zhang@intel.com>
> > > Cc: Wu, Hao <hao.wu@intel.com>; trix@redhat.com; mdf@kernel.org;
> > > linux- fpga@vger.kernel.org; Matthew Gerlach
> > > <matthew.gerlach@linux.intel.com>
> > > Subject: Re: [PATCH v1] fpga: dfl: Allow Port to be linked to FME's
> > > DFL
> > >
> > > On Wed, Apr 13, 2022 at 05:15:19AM -0400, Tianfei Zhang wrote:
> > > > From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> > > >
> > > > 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.
> > > >
> > > > Link:
> > > > https://lore.kernel.org/linux-fpga/20220316070814.1916017-2-tianfe
> > > > i.zh
> > > > ang@intel.com/
> > > > Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> > > > Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com>
> > > > ---
> > > >  drivers/fpga/dfl-pci.c | 7 +++++++
> > > >  drivers/fpga/dfl.h     | 1 +
> > > >  2 files changed, 8 insertions(+)
> > > >
> > > > diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c index
> > > > 717ac9715970..6347f31058f0 100644
> > > > --- a/drivers/fpga/dfl-pci.c
> > > > +++ b/drivers/fpga/dfl-pci.c
> > > > @@ -259,6 +259,13 @@ 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 >= PCI_STD_NUM_BARS ||
> > > > +			    bar == FME_PORT_OFST_BAR_SKIP) {
> > >
> > > Seems the second judgement will never be triggered?
> >
> > The value is overlap, but there are different meaning, " bar >=
> > PCI_STD_NUM_BARS" means that the bar was invalid during the PCIe spec,
> > "bar == FME_PORT_OFST_BAR_SKIP" means that the HW tell us that the SW
> > should skip searching the DFL for the port.
> 
> So first case is a HW bug we should return error, and second case is a valid case
> to skip searching DFL, right?

Yes, if "bar >= PCI_STD_NUM_BARS" return error is better.

> 
> >
> > >
> > > Thanks
> > > Yilun
> > >
> > > > +				dev_dbg(&pcidev->dev, "skipping search DFL
> > > for port %d on BAR %d\n",
> > > > +					i, bar);
> > > > +				continue;
> > > > +			}
> > > > +
> > > >  			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
diff mbox series

Patch

diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
index 717ac9715970..6347f31058f0 100644
--- a/drivers/fpga/dfl-pci.c
+++ b/drivers/fpga/dfl-pci.c
@@ -259,6 +259,13 @@  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 >= PCI_STD_NUM_BARS ||
+			    bar == FME_PORT_OFST_BAR_SKIP) {
+				dev_dbg(&pcidev->dev, "skipping search DFL for port %d on BAR %d\n",
+					i, bar);
+				continue;
+			}
+
 			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 */