[PATCH v3 2/3] powerpc/powernv: Fundamental reset for PCI bus reset
From: Gavin Shan <hidden>
Date: 2015-03-24 00:40:44
Subsystem:
linux for powerpc (32-bit and 64-bit), pci enhanced error handling (eeh) for powerpc, the rest · Maintainers:
Madhavan Srinivasan, Mahesh J Salgaonkar, Linus Torvalds
Function pnv_pci_reset_secondary_bus() is used to reset specified PCI bus, which is leaded by root complex or PCI bridge. That means the function shouldn't be called on PCI root bus and the patch removes the logic for that case. Also, some adapters beneath the indicated PCI bus may require fundamental reset in order to successfully reload their firmwares after the reset. The patch translates hot reset to fundamental reset for that case. Signed-off-by: Gavin Shan <redacted> --- arch/powerpc/platforms/powernv/eeh-powernv.c | 35 +++++++++++++++++++++------- 1 file changed, 26 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 79208cd..0f1e5ba 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c@@ -888,18 +888,35 @@ static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option) return (rc == OPAL_SUCCESS) ? 0 : -EIO; } -void pnv_pci_reset_secondary_bus(struct pci_dev *dev) +static int pnv_pci_dev_reset_type(struct pci_dev *pdev, void *data) { - struct pci_controller *hose; + int *freset = data; - if (pci_is_root_bus(dev->bus)) { - hose = pci_bus_to_host(dev->bus); - pnv_eeh_phb_reset(hose, EEH_RESET_HOT); - pnv_eeh_phb_reset(hose, EEH_RESET_DEACTIVATE); - } else { - pnv_eeh_bridge_reset(dev, EEH_RESET_HOT); - pnv_eeh_bridge_reset(dev, EEH_RESET_DEACTIVATE); + /* + * Stop the iteration immediately if there is any + * one PCI device requesting fundamental reset + */ + *freset |= pdev->needs_freset; + return *freset; +} + +void pnv_pci_reset_secondary_bus(struct pci_dev *pdev) +{ + int option = EEH_RESET_HOT; + int freset = 0; + + /* Check if there're any PCI devices asking for fundamental reset */ + if (pdev->subordinate) { + pci_walk_bus(pdev->subordinate, + pnv_pci_dev_reset_type, + &freset); + if (freset) + option = EEH_RESET_FUNDAMENTAL; } + + /* Issue the requested type of reset */ + pnv_eeh_bridge_reset(pdev, option); + pnv_eeh_bridge_reset(pdev, EEH_RESET_DEACTIVATE); } /**
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1.8.3.2