Re: [PATCH 1/4] perf/dwc_pcie: Move common DWC struct definitions to 'pcie-dwc.h'

[Manivannan Sadhasivam]

On Tue, Feb 18, 2025 at 06:31:02PM +0200, Dmitry Baryshkov wrote:
> On Tue, Feb 18, 2025 at 08:06:40PM +0530, Manivannan Sadhasivam via B4 Relay wrote:
> > From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > 
> > Since these are common to all Desginware PCIe IPs, move them to a new
> > header, 'pcie-dwc.h' so that other drivers could make use of them.
> 
> Which drivers are going to use it? Please provide an explanation.
> 

I can certainly add reference as 'upcoming pcie-designware-sysfs' driver.

> > 
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > ---
> >  MAINTAINERS                 |  1 +
> >  drivers/perf/dwc_pcie_pmu.c | 23 ++---------------------
> >  include/linux/pcie-dwc.h    | 34 ++++++++++++++++++++++++++++++++++
> >  3 files changed, 37 insertions(+), 21 deletions(-)
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 896a307fa065..b4d09d52a750 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -18123,6 +18123,7 @@ S:	Maintained
> >  F:	Documentation/devicetree/bindings/pci/snps,dw-pcie-ep.yaml
> >  F:	Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml
> >  F:	drivers/pci/controller/dwc/*designware*
> > +F:	include/linux/pcie-dwc.h
> >  
> >  PCI DRIVER FOR TI DRA7XX/J721E
> >  M:	Vignesh Raghavendra <vigneshr@xxxxxx>
> > diff --git a/drivers/perf/dwc_pcie_pmu.c b/drivers/perf/dwc_pcie_pmu.c
> > index cccecae9823f..05b37ea7cf16 100644
> > --- a/drivers/perf/dwc_pcie_pmu.c
> > +++ b/drivers/perf/dwc_pcie_pmu.c
> > @@ -13,6 +13,7 @@
> >  #include <linux/errno.h>
> >  #include <linux/kernel.h>
> >  #include <linux/list.h>
> > +#include <linux/pcie-dwc.h>
> >  #include <linux/perf_event.h>
> >  #include <linux/pci.h>
> >  #include <linux/platform_device.h>
> > @@ -99,26 +100,6 @@ struct dwc_pcie_dev_info {
> >  	struct list_head dev_node;
> >  };
> >  
> > -struct dwc_pcie_pmu_vsec_id {
> > -	u16 vendor_id;
> > -	u16 vsec_id;
> > -	u8 vsec_rev;
> > -};
> > -
> > -/*
> > - * VSEC IDs are allocated by the vendor, so a given ID may mean different
> > - * things to different vendors.  See PCIe r6.0, sec 7.9.5.2.
> > - */
> > -static const struct dwc_pcie_pmu_vsec_id dwc_pcie_pmu_vsec_ids[] = {
> > -	{ .vendor_id = PCI_VENDOR_ID_ALIBABA,
> > -	  .vsec_id = 0x02, .vsec_rev = 0x4 },
> > -	{ .vendor_id = PCI_VENDOR_ID_AMPERE,
> > -	  .vsec_id = 0x02, .vsec_rev = 0x4 },
> > -	{ .vendor_id = PCI_VENDOR_ID_QCOM,
> > -	  .vsec_id = 0x02, .vsec_rev = 0x4 },
> > -	{} /* terminator */
> > -};
> > -
> >  static ssize_t cpumask_show(struct device *dev,
> >  					 struct device_attribute *attr,
> >  					 char *buf)
> > @@ -529,7 +510,7 @@ static void dwc_pcie_unregister_pmu(void *data)
> >  
> >  static u16 dwc_pcie_des_cap(struct pci_dev *pdev)
> >  {
> > -	const struct dwc_pcie_pmu_vsec_id *vid;
> > +	const struct dwc_pcie_vsec_id *vid;
> >  	u16 vsec;
> >  	u32 val;
> >  
> > diff --git a/include/linux/pcie-dwc.h b/include/linux/pcie-dwc.h
> > new file mode 100644
> > index 000000000000..261ae11d75a4
> > --- /dev/null
> > +++ b/include/linux/pcie-dwc.h
> > @@ -0,0 +1,34 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright (C) 2021-2023 Alibaba Inc.
> > + *
> > + * Copyright 2025 Linaro Ltd.
> > + * Author: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > + */
> > +
> > +#ifndef LINUX_PCIE_DWC_H
> > +#define LINUX_PCIE_DWC_H
> > +
> > +#include <linux/pci_ids.h>
> > +
> > +struct dwc_pcie_vsec_id {
> > +	u16 vendor_id;
> > +	u16 vsec_id;
> > +	u8 vsec_rev;
> > +};
> > +
> > +/*
> > + * VSEC IDs are allocated by the vendor, so a given ID may mean different
> > + * things to different vendors.  See PCIe r6.0, sec 7.9.5.2.
> > + */
> > +static const struct dwc_pcie_vsec_id dwc_pcie_pmu_vsec_ids[] = {
> 
> Having it in the header means that there are going to be several
> copies of this data. Is that expected?
> 

Yes. I wanted to consolidate these ids in a single file to make it easy to track
them. Otherwise, these are spread across different subsystems, making it harder
to maintain.

- Mani

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