Re: [PATCH net-next 10/11] net: enetc: add preliminary support for i.MX95 ENETC PF

[Frank Li <Frank.li@nxp.com>]

On Fri, Oct 11, 2024 at 02:02:03AM +0000, Wei Fang wrote:
> > -----Original Message-----
> > From: Frank Li <frank.li@nxp.com>
> > Sent: 2024年10月10日 23:22
> > To: Wei Fang <wei.fang@nxp.com>
> > Cc: davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> > pabeni@redhat.com; robh@kernel.org; krzk+dt@kernel.org;
> > conor+dt@kernel.org; Vladimir Oltean <vladimir.oltean@nxp.com>; Claudiu
> > Manoil <claudiu.manoil@nxp.com>; Clark Wang <xiaoning.wang@nxp.com>;
> > christophe.leroy@csgroup.eu; linux@armlinux.org.uk; bhelgaas@google.com;
> > imx@lists.linux.dev; netdev@vger.kernel.org; devicetree@vger.kernel.org;
> > linux-kernel@vger.kernel.org; linux-pci@vger.kernel.org
> > Subject: Re: [PATCH net-next 10/11] net: enetc: add preliminary support for
> > i.MX95 ENETC PF
> >
> > On Thu, Oct 10, 2024 at 04:59:45AM +0000, Wei Fang wrote:
> > > > On Wed, Oct 09, 2024 at 05:51:15PM +0800, Wei Fang wrote:
> > > > > The i.MX95 ENETC has been upgraded to revision 4.1, which is very
> > > > > different from the LS1028A ENETC (revision 1.0) except for the SI
> > > > > part. Therefore, the fsl-enetc driver is incompatible with i.MX95
> > > > > ENETC PF. So we developed the nxp-enetc4 driver for i.MX95 ENETC
> > > >             So add new nxp-enetc4 driver for i.MX95 ENETC PF with
> > > > major revision 4.
> > > >
> > > > > PF, and this driver will be used to support the ENETC PF with
> > > > > major revision 4 in the future.
> > > > >
> > > > > diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h
> > > > b/drivers/net/ethernet/freescale/enetc/enetc.h
> > > > > index 97524dfa234c..7f1ea11c33a0 100644
> > > > > --- a/drivers/net/ethernet/freescale/enetc/enetc.h
> > > > > +++ b/drivers/net/ethernet/freescale/enetc/enetc.h
> > > > > @@ -14,6 +14,7 @@
> > > > >  #include <net/xdp.h>
> > > > >
> > > > >  #include "enetc_hw.h"
> > > > > +#include "enetc4_hw.h"
> > > > >
> > > > >  #define ENETC_SI_ALIGN	32
> > > > >
> > > > > +static inline bool is_enetc_rev1(struct enetc_si *si) {
> > > > > +	return si->pdev->revision == ENETC_REV1; }
> > > > > +
> > > > > +static inline bool is_enetc_rev4(struct enetc_si *si) {
> > > > > +	return si->pdev->revision == ENETC_REV4; }
> > > > > +
> > > >
> > > > Actually, I suggest you check features, instead of check version number.
> > > >
> > > This is mainly used to distinguish between ENETC v1 and ENETC v4 in
> > > the general interfaces. See enetc_ethtool.c.
> >
> > Suggest use flags, such as, IS_SUPPORT_ETHTOOL.
> >
> > otherwise, your check may become complex in future.
> >
> > If use flags, you just change id table in future.
>
> enetc_ethtool just is an example, I meant that the ENETCv4 and ENETCv1
> use some common drivers, like enect_pf_common, enetc-core, so different
> hardware versions have different logic, that's all.

My means is that avoid use v1\v2 to distingiush it and use supported
features in difference version for example:

ENETC_FEATURE_1, ENETC_FEATURE_2, ENETC_FEATURE_3, ENETC_FEATURE_4.

{ PCI_DEVICE(PCI_VENDOR_ID_NXP2, PCI_DEVICE_ID_NXP2_ENETC_PF)
  .driver_data = ENETC_FEATURE_1 |  ENETC_FEATURE_2 | ENETC_FEATURE_4
  PCI_DEVICE(....)
  .driver_data = ENETC_FEATURE_1 | ENETC_FEATURE_3,
  PCI_DEVICE(...)
  .driver_data = ENETC_FEATURE_4,
)

It will be easy to know the difference between difference version. Your if
check logic will be simple.

if (driver_data & ENETC_FEATURE_1)
  ....

otherwise
   if (vers == 1 || vers == 2 || ver == 5), which distribute to difference
places in whole code.

It is real hard to know hardware differences between version in future.

You can ref drivers/misc/pci_endpoint_test.c

Frank

>
> >
> > { PCI_DEVICE(PCI_VENDOR_ID_NXP2, PCI_DEVICE_ID_NXP2_ENETC_PF),
> >   .driver_data = IS_SUPPORT_ETHTOOL | .... },
> >
> > Frank
> > >
> > > > > diff --git a/drivers/net/ethernet/freescale/enetc/enetc4_pf.c
> > > > b/drivers/net/ethernet/freescale/enetc/enetc4_pf.c
> > > > > new file mode 100644
> > > > > index 000000000000..e38ade76260b
> > > > > --- /dev/null
> > > > > +++ b/drivers/net/ethernet/freescale/enetc/enetc4_pf.c
> > > > > @@ -0,0 +1,761 @@
> > > > > +// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
> > > > > +/* Copyright 2024 NXP */
> > > > > +#include <linux/unaligned.h>
> > > > > +#include <linux/module.h>
> > > > > +#include <linux/of_net.h>
> > > > > +#include <linux/of_platform.h>
> > > > > +#include <linux/clk.h>
> > > > > +#include <linux/pinctrl/consumer.h> #include
> > > > > +<linux/fsl/netc_global.h>
> > > >
> > > > sort headers.
> > > >
> > >
> > > Sure
> > >
> > > > > +static int enetc4_pf_probe(struct pci_dev *pdev,
> > > > > +			   const struct pci_device_id *ent) {
> > > > > +	struct device *dev = &pdev->dev;
> > > > > +	struct enetc_si *si;
> > > > > +	struct enetc_pf *pf;
> > > > > +	int err;
> > > > > +
> > > > > +	err = enetc_pci_probe(pdev, KBUILD_MODNAME, sizeof(*pf));
> > > > > +	if (err) {
> > > > > +		dev_err(dev, "PCIe probing failed\n");
> > > > > +		return err;
> > > >
> > > > use dev_err_probe()
> > > >
> > >
> > > Okay
> > >
> > > > > +	}
> > > > > +
> > > > > +	/* si is the private data. */
> > > > > +	si = pci_get_drvdata(pdev);
> > > > > +	if (!si->hw.port || !si->hw.global) {
> > > > > +		err = -ENODEV;
> > > > > +		dev_err(dev, "Couldn't map PF only space!\n");
> > > > > +		goto err_enetc_pci_probe;
> > > > > +	}
> > > > > +
> > > > > +	err = enetc4_pf_struct_init(si);
> > > > > +	if (err)
> > > > > +		goto err_pf_struct_init;
> > > > > +
> > > > > +	pf = enetc_si_priv(si);
> > > > > +	err = enetc4_pf_init(pf);
> > > > > +	if (err)
> > > > > +		goto err_pf_init;
> > > > > +
> > > > > +	pinctrl_pm_select_default_state(dev);
> > > > > +	enetc_get_si_caps(si);
> > > > > +	err = enetc4_pf_netdev_create(si);
> > > > > +	if (err)
> > > > > +		goto err_netdev_create;
> > > > > +
> > > > > +	return 0;
> > > > > +
> > > > > +err_netdev_create:
> > > > > +err_pf_init:
> > > > > +err_pf_struct_init:
> > > > > +err_enetc_pci_probe:
> > > > > +	enetc_pci_remove(pdev);
> > > >
> > > > you can use devm_add_action_or_reset() to remove these goto labels.
> > > >
> > > Subsequent patches will have corresponding processing for these
> > > labels, so I don't want to add too many devm_add_action_or_reset ().