Messages in this thread | | | From | "Sean V Kelley" <> | Subject | Re: [RFC PATCH 3/9] PCI/portdrv: Add pcie_walk_rcec() to walk RCiEPs associated with RCEC | Date | Mon, 27 Jul 2020 08:21:15 -0700 |
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Hi,
Comments below:
On 27 Jul 2020, at 3:49, Jonathan Cameron wrote:
> On Fri, 24 Jul 2020 10:22:17 -0700 > Sean V Kelley <sean.v.kelley@intel.com> wrote: > >> From: Qiuxu Zhuo <qiuxu.zhuo@intel.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. >> >> Co-developed-by: Sean V Kelley <sean.v.kelley@intel.com> >> Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com> >> Signed-off-by: Sean V Kelley <sean.v.kelley@intel.com> > > A few trivial points inline. With those tidied up. > > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.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 50a9522ab07d..bdcbb34764c2 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. > > /** > * pcie...
Will correct.
> >> + * @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 + 1); bnr++) { > > Why not bnr <= lastbusn? Seems more intuitive way of making it clear > the > range is inclusive.
Good suggestion. Will change.
Thanks,
Sean
> > >> + 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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