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@xxxxxxxxx> > > > > 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@xxxxxxxxx/ Thanks! Sean Co-developed-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx> > > Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx> > > Signed-off-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx> > > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > > --- > > 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 *); > > > >
