diff options
| -rw-r--r-- | arch/powerpc/kernel/pci-hotplug.c | 3 | ||||
| -rw-r--r-- | drivers/pci/hotplug/pnv_php.c | 110 |
2 files changed, 110 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c index 9ea74973d78d..6f444d0822d8 100644 --- a/arch/powerpc/kernel/pci-hotplug.c +++ b/arch/powerpc/kernel/pci-hotplug.c @@ -141,6 +141,9 @@ void pci_hp_add_devices(struct pci_bus *bus) struct pci_controller *phb; struct device_node *dn = pci_bus_to_OF_node(bus); + if (!dn) + return; + phb = pci_bus_to_host(bus); mode = PCI_PROBE_NORMAL; diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c index 5476c9e7760d..4f85e7fe29ec 100644 --- a/drivers/pci/hotplug/pnv_php.c +++ b/drivers/pci/hotplug/pnv_php.c @@ -4,12 +4,14 @@ * * Copyright Gavin Shan, IBM Corporation 2016. * Copyright (C) 2025 Raptor Engineering, LLC + * Copyright (C) 2025 Raptor Computing Systems, LLC */ #include <linux/bitfield.h> #include <linux/libfdt.h> #include <linux/module.h> #include <linux/pci.h> +#include <linux/delay.h> #include <linux/pci_hotplug.h> #include <linux/of_fdt.h> @@ -469,6 +471,61 @@ static int pnv_php_set_attention_state(struct hotplug_slot *slot, u8 state) return 0; } +static int pnv_php_activate_slot(struct pnv_php_slot *php_slot, + struct hotplug_slot *slot) +{ + int ret, i; + + /* + * Issue initial slot activation command to firmware + * + * Firmware will power slot on, attempt to train the link, and + * discover any downstream devices. If this process fails, firmware + * will return an error code and an invalid device tree. Failure + * can be caused for multiple reasons, including a faulty + * downstream device, poor connection to the downstream device, or + * a previously latched PHB fence. On failure, issue fundamental + * reset up to three times before aborting. + */ + ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_ON); + if (ret) { + SLOT_WARN( + php_slot, + "PCI slot activation failed with error code %d, possible frozen PHB", + ret); + SLOT_WARN( + php_slot, + "Attempting complete PHB reset before retrying slot activation\n"); + for (i = 0; i < 3; i++) { + /* + * Slot activation failed, PHB may be fenced from a + * prior device failure. + * + * Use the OPAL fundamental reset call to both try a + * device reset and clear any potentially active PHB + * fence / freeze. + */ + SLOT_WARN(php_slot, "Try %d...\n", i + 1); + pci_set_pcie_reset_state(php_slot->pdev, + pcie_warm_reset); + msleep(250); + pci_set_pcie_reset_state(php_slot->pdev, + pcie_deassert_reset); + + ret = pnv_php_set_slot_power_state( + slot, OPAL_PCI_SLOT_POWER_ON); + if (!ret) + break; + } + + if (i >= 3) + SLOT_WARN(php_slot, + "Failed to bring slot online, aborting!\n"); + } + + return ret; +} + static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan) { struct hotplug_slot *slot = &php_slot->slot; @@ -531,7 +588,7 @@ static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan) goto scan; /* Power is off, turn it on and then scan the slot */ - ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_ON); + ret = pnv_php_activate_slot(php_slot, slot); if (ret) return ret; @@ -838,16 +895,63 @@ static int pnv_php_enable_msix(struct pnv_php_slot *php_slot) return entry.vector; } +static void +pnv_php_detect_clear_suprise_removal_freeze(struct pnv_php_slot *php_slot) +{ + struct pci_dev *pdev = php_slot->pdev; + struct eeh_dev *edev; + struct eeh_pe *pe; + int i, rc; + + /* + * When a device is surprise removed from a downstream bridge slot, + * the upstream bridge port can still end up frozen due to related EEH + * events, which will in turn block the MSI interrupts for slot hotplug + * detection. + * + * Detect and thaw any frozen upstream PE after slot deactivation. + */ + edev = pci_dev_to_eeh_dev(pdev); + pe = edev ? edev->pe : NULL; + rc = eeh_pe_get_state(pe); + if ((rc == -ENODEV) || (rc == -ENOENT)) { + SLOT_WARN( + php_slot, + "Upstream bridge PE state unknown, hotplug detect may fail\n"); + } else { + if (pe->state & EEH_PE_ISOLATED) { + SLOT_WARN( + php_slot, + "Upstream bridge PE %02x frozen, thawing...\n", + pe->addr); + for (i = 0; i < 3; i++) + if (!eeh_unfreeze_pe(pe)) + break; + if (i >= 3) + SLOT_WARN( + php_slot, + "Unable to thaw PE %02x, hotplug detect will fail!\n", + pe->addr); + else + SLOT_WARN(php_slot, + "PE %02x thawed successfully\n", + pe->addr); + } + } +} + static void pnv_php_event_handler(struct work_struct *work) { struct pnv_php_event *event = container_of(work, struct pnv_php_event, work); struct pnv_php_slot *php_slot = event->php_slot; - if (event->added) + if (event->added) { pnv_php_enable_slot(&php_slot->slot); - else + } else { pnv_php_disable_slot(&php_slot->slot); + pnv_php_detect_clear_suprise_removal_freeze(php_slot); + } kfree(event); } |