On Fri, Nov 20, 2020 at 04:10:33PM -0800, Sean V Kelley wrote: > From: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx> > > When attempting error recovery for an RCiEP associated with an RCEC device, > there needs to be a way to update the Root Error Status, the Uncorrectable > Error Status and the Uncorrectable Error Severity of the parent RCEC. In > some non-native cases in which there is no OS-visible device associated > with the RCiEP, there is nothing to act upon as the firmware is acting > before the OS. > > Add handling for the linked RCEC in AER/ERR while taking into account > non-native cases. > > Co-developed-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx> > Link: https://lore.kernel.org/r/20201002184735.1229220-12-seanvk.dev@xxxxxxxxxxxxxxxx > Signed-off-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx> > Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx> > Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > --- > drivers/pci/pcie/aer.c | 46 +++++++++++++++++++++++++++++++----------- > drivers/pci/pcie/err.c | 20 +++++++++--------- > 2 files changed, 44 insertions(+), 22 deletions(-) > > diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c > index 0ba0b47ae751..51389a6ee4ca 100644 > --- a/drivers/pci/pcie/aer.c > +++ b/drivers/pci/pcie/aer.c > @@ -1358,29 +1358,51 @@ static int aer_probe(struct pcie_device *dev) > */ > static pci_ers_result_t aer_root_reset(struct pci_dev *dev) > { > - int aer = dev->aer_cap; > + int type = pci_pcie_type(dev); > + struct pci_dev *root; > + int aer = 0; > + int rc = 0; > u32 reg32; > - int rc; > > - if (pcie_aer_is_native(dev)) { > + if (type == PCI_EXP_TYPE_RC_END) > + /* > + * The reset should only clear the Root Error Status > + * of the RCEC. Only perform this for the > + * native case, i.e., an RCEC is present. > + */ > + root = dev->rcec; > + else > + root = dev; > + > + if (root) > + aer = dev->aer_cap; > + > + if ((aer) && pcie_aer_is_native(dev)) { > /* Disable Root's interrupt in response to error messages */ > - pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, ®32); > + pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, ®32); > reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK; > - pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, reg32); > + pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32); > } > > - rc = pci_bus_error_reset(dev); > - pci_info(dev, "Root Port link has been reset (%d)\n", rc); > + if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) { > + if (pcie_has_flr(dev)) { > + rc = pcie_flr(dev); > + pci_info(dev, "has been reset (%d)\n", rc); Maybe: + } else { + rc = -ENOTTY; + pci_info(dev, "not reset (no FLR support)\n"); Or do we want to pretend the device was reset and return PCI_ERS_RESULT_RECOVERED? > + } else { > + rc = pci_bus_error_reset(dev); > + pci_info(dev, "Root Port link has been reset (%d)\n", rc); > + } > > - if (pcie_aer_is_native(dev)) { > + if ((aer) && pcie_aer_is_native(dev)) { > /* Clear Root Error Status */ > - pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, ®32); > - pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, reg32); > + pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, ®32); > + pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32); > > /* Enable Root Port's interrupt in response to error messages */ > - pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, ®32); > + pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, ®32); > reg32 |= ROOT_PORT_INTR_ON_MESG_MASK; > - pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, reg32); > + pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32); > } > > return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED; > diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c > index 7883c9791562..cbc5abfe767b 100644 > --- a/drivers/pci/pcie/err.c > +++ b/drivers/pci/pcie/err.c > @@ -148,10 +148,10 @@ static int report_resume(struct pci_dev *dev, void *data) > > /** > * pci_walk_bridge - walk bridges potentially AER affected > - * @bridge: bridge which may be a Port, an RCEC with associated RCiEPs, > - * or an RCiEP associated with an RCEC > - * @cb: callback to be called for each device found > - * @userdata: arbitrary pointer to be passed to callback > + * @bridge bridge which may be an RCEC with associated RCiEPs, > + * or a Port. > + * @cb callback to be called for each device found > + * @userdata arbitrary pointer to be passed to callback. > * > * If the device provided is a bridge, walk the subordinate bus, including > * any bridged devices on buses under this bus. Call the provided callback > @@ -164,8 +164,14 @@ static void pci_walk_bridge(struct pci_dev *bridge, > int (*cb)(struct pci_dev *, void *), > void *userdata) > { > + /* > + * In a non-native case where there is no OS-visible reporting > + * device the bridge will be NULL, i.e., no RCEC, no Downstream Port. I don't quite understand this comment. I see that in the non-native case, the reporting device may not be OS-visible. But I don't understand why the comment is *here*. If "bridge" can be NULL here, we should test that before dereferencing "bridge->subordinate". > if (bridge->subordinate) > pci_walk_bus(bridge->subordinate, cb, userdata); > + else if (bridge->rcec) > + cb(bridge->rcec, userdata); And I don't understand what's going on here. In this case, I *think* "bridge" is an RCiEP and "bridge->rcec" is the related RCEC, so it looks like we'll call report_frozen_detected(), report_mmio_enabled(), etc for the RCEC driver. I would think we'd want the RCiEP driver. Sorry if I'm missing the obvious. > else > cb(bridge, userdata); > } > @@ -194,12 +200,6 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, > pci_dbg(bridge, "broadcast error_detected message\n"); > if (state == pci_channel_io_frozen) { > pci_walk_bridge(bridge, report_frozen_detected, &status); > - if (type == PCI_EXP_TYPE_RC_END) { > - pci_warn(dev, "subordinate device reset not possible for RCiEP\n"); > - status = PCI_ERS_RESULT_NONE; > - goto failed; > - } > - > status = reset_subordinates(bridge); > if (status != PCI_ERS_RESULT_RECOVERED) { > pci_warn(bridge, "subordinate device reset failed\n"); > -- > 2.29.2 >
