From 0dad3ce523c2917b1912fbde047207533e9f1eeb Mon Sep 17 00:00:00 2001 From: Raphael Norwitz Date: Thu, 8 Apr 2021 18:23:40 +0000 Subject: [PATCH] PCI: Add pci_reset_bus_function() Secondary Bus Reset interface pci_parent_bus_reset() resets a device by performing a Secondary Bus Reset on a PCI-to-PCI bridge leading to the device. pci_dev_reset_slot_function() does the same, except that it uses a hotplug driver to keep the reset from looking like a hot-remove followed by a hot-add. Add a pci_reset_bus_function() wrapper, which attempts the hotplug driver slot reset and falls back to the parent bus reset if that fails. This provides a single interface for performing a Secondary Bus Reset. [bhelgaas: commit log, don't expose yet] Suggested-by: Alex Williamson Link: https://lore.kernel.org/r/20210323100625.0021a943@omen.home.shazbot.org/ Link: https://lore.kernel.org/r/20210408182328.12323-1-raphael.norwitz@nutanix.com Signed-off-by: Amey Narkhede Signed-off-by: Raphael Norwitz Signed-off-by: Bjorn Helgaas Reviewed-by: Leon Romanovsky --- drivers/pci/pci.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b717680377a9..452351025a09 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5020,6 +5020,16 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) return pci_reset_hotplug_slot(dev->slot->hotplug, probe); } +static int pci_reset_bus_function(struct pci_dev *dev, int probe) +{ + int rc; + + rc = pci_dev_reset_slot_function(dev, probe); + if (rc != -ENOTTY) + return rc; + return pci_parent_bus_reset(dev, probe); +} + static void pci_dev_lock(struct pci_dev *dev) { pci_cfg_access_lock(dev); @@ -5140,10 +5150,7 @@ int __pci_reset_function_locked(struct pci_dev *dev) rc = pci_pm_reset(dev, 0); if (rc != -ENOTTY) return rc; - rc = pci_dev_reset_slot_function(dev, 0); - if (rc != -ENOTTY) - return rc; - return pci_parent_bus_reset(dev, 0); + return pci_reset_bus_function(dev, 0); } EXPORT_SYMBOL_GPL(__pci_reset_function_locked); @@ -5173,13 +5180,10 @@ int pci_probe_reset_function(struct pci_dev *dev) if (rc != -ENOTTY) return rc; rc = pci_pm_reset(dev, 1); - if (rc != -ENOTTY) - return rc; - rc = pci_dev_reset_slot_function(dev, 1); if (rc != -ENOTTY) return rc; - return pci_parent_bus_reset(dev, 1); + return pci_reset_bus_function(dev, 1); } /** -- 2.20.1