From a131bfc69bc868083a6c7f9b5dad1331902a3534 Mon Sep 17 00:00:00 2001 From: Oliver O'Halloran Date: Sat, 25 Jul 2020 18:12:31 +1000 Subject: powerpc/eeh: Move PE tree setup into the platform The EEH core has a concept of a "PE tree" to support PowerNV. The PE tree follows the PCI bus structures because a reset asserted on an upstream bridge will be propagated to the downstream bridges. On pseries there's a 1-1 correspondence between what the guest sees are a PHB and a PE so the "tree" is really just a single node. Current the EEH core is reponsible for setting up this PE tree which it does by traversing the pci_dn tree. The structure of the pci_dn tree matches the bus tree on PowerNV which leads to the PE tree being "correct" this setup method doesn't make a whole lot of sense and it's actively confusing for the pseries case where it doesn't really do anything. We want to remove the dependence on pci_dn anyway so this patch move choosing where to insert a new PE into the platform code rather than being part of the generic EEH code. For PowerNV this simplifies the tree building logic and removes the use of pci_dn. For pseries we keep the existing logic. I'm not really convinced it does anything due to the 1-1 PE-to-PHB correspondence so every device under that PHB should be in the same PE, but I'd rather not remove it entirely until we've had a chance to look at it more deeply. Signed-off-by: Oliver O'Halloran Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200725081231.39076-14-oohall@gmail.com --- arch/powerpc/platforms/pseries/eeh_pseries.c | 67 +++++++++++++++++++++++----- 1 file changed, 57 insertions(+), 10 deletions(-) (limited to 'arch/powerpc/platforms/pseries') diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c index 69650d8dc705..cb2d9a970b7b 100644 --- a/arch/powerpc/platforms/pseries/eeh_pseries.c +++ b/arch/powerpc/platforms/pseries/eeh_pseries.c @@ -69,11 +69,16 @@ void pseries_pcibios_bus_add_device(struct pci_dev *pdev) pseries_eeh_init_edev(pdn); #ifdef CONFIG_PCI_IOV if (pdev->is_virtfn) { + /* + * FIXME: This really should be handled by choosing the right + * parent PE in in pseries_eeh_init_edev(). + */ + struct eeh_pe *physfn_pe = pci_dev_to_eeh_dev(pdev->physfn)->pe; struct eeh_dev *edev = pdn_to_eeh_dev(pdn); edev->pe_config_addr = (pdn->busno << 16) | (pdn->devfn << 8); eeh_pe_tree_remove(edev); /* Remove as it is adding to bus pe */ - eeh_pe_tree_insert(edev); /* Add as VF PE type */ + eeh_pe_tree_insert(edev, physfn_pe); /* Add as VF PE type */ } #endif eeh_probe_device(pdev); @@ -385,6 +390,43 @@ static int pseries_eeh_find_ecap(struct pci_dn *pdn, int cap) return 0; } +/** + * pseries_eeh_pe_get_parent - Retrieve the parent PE + * @edev: EEH device + * + * The whole PEs existing in the system are organized as hierarchy + * tree. The function is used to retrieve the parent PE according + * to the parent EEH device. + */ +static struct eeh_pe *pseries_eeh_pe_get_parent(struct eeh_dev *edev) +{ + struct eeh_dev *parent; + struct pci_dn *pdn = eeh_dev_to_pdn(edev); + + /* + * It might have the case for the indirect parent + * EEH device already having associated PE, but + * the direct parent EEH device doesn't have yet. + */ + if (edev->physfn) + pdn = pci_get_pdn(edev->physfn); + else + pdn = pdn ? pdn->parent : NULL; + while (pdn) { + /* We're poking out of PCI territory */ + parent = pdn_to_eeh_dev(pdn); + if (!parent) + return NULL; + + if (parent->pe) + return parent->pe; + + pdn = pdn->parent; + } + + return NULL; +} + /** * pseries_eeh_init_edev - initialise the eeh_dev and eeh_pe for a pci_dn * @@ -468,6 +510,8 @@ void pseries_eeh_init_edev(struct pci_dn *pdn) if (ret) { eeh_edev_dbg(edev, "EEH failed to enable on device (code %d)\n", ret); } else { + struct eeh_pe *parent; + /* Retrieve PE address */ edev->pe_config_addr = pseries_eeh_get_pe_addr(pdn); pe.addr = edev->pe_config_addr; @@ -480,16 +524,19 @@ void pseries_eeh_init_edev(struct pci_dn *pdn) if (ret > 0 && ret != EEH_STATE_NOT_SUPPORT) enable = 1; - if (enable) { + /* + * This device doesn't support EEH, but it may have an + * EEH parent. In this case any error on the device will + * freeze the PE of it's upstream bridge, so added it to + * the upstream PE. + */ + parent = pseries_eeh_pe_get_parent(edev); + if (parent && !enable) + edev->pe_config_addr = parent->addr; + + if (enable || parent) { eeh_add_flag(EEH_ENABLED); - eeh_pe_tree_insert(edev); - } else if (pdn->parent && pdn_to_eeh_dev(pdn->parent) && - (pdn_to_eeh_dev(pdn->parent))->pe) { - /* This device doesn't support EEH, but it may have an - * EEH parent, in which case we mark it as supported. - */ - edev->pe_config_addr = pdn_to_eeh_dev(pdn->parent)->pe_config_addr; - eeh_pe_tree_insert(edev); + eeh_pe_tree_insert(edev, parent); } eeh_edev_dbg(edev, "EEH is %s on device (code %d)\n", (enable ? "enabled" : "unsupported"), ret); -- cgit v1.2.3