On Thu, Apr 08, 2021 at 06:23:40PM +0000, Raphael Norwitz wrote: > Slot resets are bus resets with additional logic to prevent a device > from being removed during the reset. Currently slot and bus resets have > separate implementations in pci.c, complicating higher level logic. As > discussed on the mailing list, they should be combined into a generic > function which performs an SBR. This change adds a function, > pci_reset_bus_function(), which first attempts a slot reset and then > attempts a bus reset if -ENOTTY is returned, such that there is now a > single device agnostic function to perform an SBR. > > This new function is also needed to add SBR reset quirks and therefore > is exposed in pci.h. I dropped this exposure in pci.h because there's no user yet. We can expose it when we add the user. > Link: https://lkml.org/lkml/2021/3/23/911 > > Suggested-by: Alex Williamson <alex.williamson@xxxxxxxxxx> > Signed-off-by: Amey Narkhede <ameynarkhede03@xxxxxxxxx> > Signed-off-by: Raphael Norwitz <raphael.norwitz@xxxxxxxxxxx> Applied to pci/reset for v5.14 with subject "PCI: Add pci_reset_bus_function() Secondary Bus Reset interface" I attached the patch as applied. > --- > drivers/pci/pci.c | 19 +++++++++++-------- > include/linux/pci.h | 1 + > 2 files changed, 12 insertions(+), 8 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 16a17215f633..a8f8dd588d15 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -4982,6 +4982,15 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) > return pci_reset_hotplug_slot(dev->slot->hotplug, probe); > } > > +int pci_reset_bus_function(struct pci_dev *dev, int probe) > +{ > + int 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); > @@ -5102,10 +5111,7 @@ 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); > > @@ -5135,13 +5141,10 @@ 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); > } > > /** > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 86c799c97b77..979d54335ac1 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1228,6 +1228,7 @@ int pci_probe_reset_bus(struct pci_bus *bus); > int pci_reset_bus(struct pci_dev *dev); > void pci_reset_secondary_bus(struct pci_dev *dev); > void pcibios_reset_secondary_bus(struct pci_dev *dev); > +int pci_reset_bus_function(struct pci_dev *dev, int probe); > void pci_update_resource(struct pci_dev *dev, int resno); > int __must_check pci_assign_resource(struct pci_dev *dev, int i); > int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align); > -- > 2.20.1 commit 0dad3ce523c2 ("PCI: Add pci_reset_bus_function() Secondary Bus Reset interface") Author: Raphael Norwitz <raphael.norwitz@xxxxxxxxxxx> Date: Thu Apr 8 18:23:40 2021 +0000 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 <alex.williamson@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210323100625.0021a943@xxxxxxxxxxxxxxxxxxxxx/ Link: https://lore.kernel.org/r/20210408182328.12323-1-raphael.norwitz@xxxxxxxxxxx Signed-off-by: Amey Narkhede <ameynarkhede03@xxxxxxxxx> Signed-off-by: Raphael Norwitz <raphael.norwitz@xxxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx> 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); } /**
