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Message-ID: <faa5535d194d0238217aaed118d1db40e841ee3a.camel@intel.com>
Date: Wed, 26 Aug 2020 11:37:27 -0700
From: sean.v.kelley@...el.com
To: "Kuppuswamy, Sathyanarayanan"
<sathyanarayanan.kuppuswamy@...ux.intel.com>, bhelgaas@...gle.com,
Jonathan.Cameron@...wei.com, rjw@...ysocki.net,
ashok.raj@...el.com, tony.luck@...el.com
Cc: linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
Qiuxu Zhuo <qiuxu.zhuo@...el.com>
Subject: Re: [PATCH V2 3/9] PCI/portdrv: Add pcie_walk_rcec() to walk RCiEPs
associated with RCEC
Hi Sathya,
On Wed, 2020-08-26 at 09:20 -0700, Kuppuswamy, Sathyanarayanan wrote:
>
> On 8/4/20 12:40 PM, Sean V Kelley wrote:
> > From: Qiuxu Zhuo <qiuxu.zhuo@...el.com>
> >
> > When an RCEC device signals error(s) to a CPU core, the CPU core
> > needs to walk all the RCiEPs associated with that RCEC to check
> > errors. So add the function pcie_walk_rcec() to walk all RCiEPs
> > associated with the RCEC device.
> I think its better if you merge the usage patch and API
> (pcie_walk_rcec) patch together.
Good suggestion, I'll have a look to see if that works well merged.
>
> Did you not get unused function warning with this patch?
The latest patches are below (v3) and they were built on top of
pci/master (prior to the release of 5.9.0-rc1 btw). I did not get a
warning with that but will double check...
https://lore.kernel.org/linux-pci/20200812164659.1118946-1-sean.v.kelley@intel.com/
Thanks!
Sean
Co-developed-by: Sean V Kelley <sean.v.kelley@...el.com>
> > Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@...el.com>
> > Signed-off-by: Sean V Kelley <sean.v.kelley@...el.com>
> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>
> > ---
> > drivers/pci/pcie/portdrv.h | 2 +
> > drivers/pci/pcie/portdrv_core.c | 82
> > +++++++++++++++++++++++++++++++++
> > 2 files changed, 84 insertions(+)
> >
> > diff --git a/drivers/pci/pcie/portdrv.h
> > b/drivers/pci/pcie/portdrv.h
> > index af7cf237432a..c11d5ecbad76 100644
> > --- a/drivers/pci/pcie/portdrv.h
> > +++ b/drivers/pci/pcie/portdrv.h
> > @@ -116,6 +116,8 @@ void pcie_port_service_unregister(struct
> > pcie_port_service_driver *new);
> >
> > extern struct bus_type pcie_port_bus_type;
> > int pcie_port_device_register(struct pci_dev *dev);
> > +void pcie_walk_rcec(struct pci_dev *rcec, int (*cb)(struct pci_dev
> > *, void *),
> > + void *userdata);
> > #ifdef CONFIG_PM
> > int pcie_port_device_suspend(struct device *dev);
> > int pcie_port_device_resume_noirq(struct device *dev);
> > diff --git a/drivers/pci/pcie/portdrv_core.c
> > b/drivers/pci/pcie/portdrv_core.c
> > index 5d4a400094fc..daa2dfa83a0b 100644
> > --- a/drivers/pci/pcie/portdrv_core.c
> > +++ b/drivers/pci/pcie/portdrv_core.c
> > @@ -14,6 +14,7 @@
> > #include <linux/pm_runtime.h>
> > #include <linux/string.h>
> > #include <linux/slab.h>
> > +#include <linux/bitops.h>
> > #include <linux/aer.h>
> >
> > #include "../pci.h"
> > @@ -365,6 +366,87 @@ int pcie_port_device_register(struct pci_dev
> > *dev)
> > return status;
> > }
> >
> > +static int pcie_walk_rciep_devfn(struct pci_bus *pbus, int
> > (*cb)(struct pci_dev *, void *),
> > + void *userdata, unsigned long bitmap)
> > +{
> > + unsigned int dev, fn;
> > + struct pci_dev *pdev;
> > + int retval;
> > +
> > + for_each_set_bit(dev, &bitmap, 32) {
> > + for (fn = 0; fn < 8; fn++) {
> > + pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
> > +
> > + if (!pdev || pci_pcie_type(pdev) !=
> > PCI_EXP_TYPE_RC_END)
> > + continue;
> > +
> > + retval = cb(pdev, userdata);
> > + if (retval)
> > + return retval;
> > + }
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * pcie_walk_rcec - Walk RCiEP devices associating with RCEC and
> > call callback.
> > + * @rcec RCEC whose RCiEP devices should be walked.
> > + * @cb Callback to be called for each RCiEP device found.
> > + * @userdata Arbitrary pointer to be passed to callback.
> > + *
> > + * Walk the given RCEC. Call the provided callback on each RCiEP
> > device found.
> > + *
> > + * We check the return of @cb each time. If it returns anything
> > + * other than 0, we break out.
> > + */
> > +void pcie_walk_rcec(struct pci_dev *rcec, int (*cb)(struct pci_dev
> > *, void *),
> > + void *userdata)
> > +{
> > + u32 pos, bitmap, hdr, busn;
> > + u8 ver, nextbusn, lastbusn;
> > + struct pci_bus *pbus;
> > + unsigned int bnr;
> > +
> > + pos = pci_find_ext_capability(rcec, PCI_EXT_CAP_ID_RCEC);
> > + if (!pos)
> > + return;
> > +
> > + pbus = pci_find_bus(pci_domain_nr(rcec->bus), rcec->bus-
> > >number);
> > + if (!pbus)
> > + return;
> > +
> > + pci_read_config_dword(rcec, pos + PCI_RCEC_RCIEP_BITMAP,
> > &bitmap);
> > +
> > + /* Find RCiEP devices on the same bus as the RCEC */
> > + if (pcie_walk_rciep_devfn(pbus, cb, userdata, (unsigned
> > long)bitmap))
> > + return;
> > +
> > + /* Check whether RCEC BUSN register is present */
> > + pci_read_config_dword(rcec, pos, &hdr);
> > + ver = PCI_EXT_CAP_VER(hdr);
> > + if (ver < PCI_RCEC_BUSN_REG_VER)
> > + return;
> > +
> > + pci_read_config_dword(rcec, pos + PCI_RCEC_BUSN, &busn);
> > + nextbusn = PCI_RCEC_BUSN_NEXT(busn);
> > + lastbusn = PCI_RCEC_BUSN_LAST(busn);
> > +
> > + /* All RCiEP devices are on the same bus as the RCEC */
> > + if (nextbusn == 0xff && lastbusn == 0x00)
> > + return;
> > +
> > + for (bnr = nextbusn; bnr <= lastbusn; bnr++) {
> > + pbus = pci_find_bus(pci_domain_nr(rcec->bus), bnr);
> > + if (!pbus)
> > + continue;
> > +
> > + /* Find RCiEP devices on the given bus */
> > + if (pcie_walk_rciep_devfn(pbus, cb, userdata,
> > 0xffffffff))
> > + return;
> > + }
> > +}
> > +
> > #ifdef CONFIG_PM
> > typedef int (*pcie_pm_callback_t)(struct pcie_device *);
> >
> >
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