Patch "PCI: Use preserve_config in place of pci_flags" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    PCI: Use preserve_config in place of pci_flags

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     pci-use-preserve_config-in-place-of-pci_flags.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 07740f70454bad39bb230cfacb932b8608ab4b3c
Author: Vidya Sagar <vidyas@xxxxxxxxxx>
Date:   Sun Jul 28 12:09:36 2024 -0400

    PCI: Use preserve_config in place of pci_flags
    
    [ Upstream commit 7246a4520b4bf1494d7d030166a11b5226f6d508 ]
    
    Use preserve_config in place of checking for PCI_PROBE_ONLY flag to enable
    support for "linux,pci-probe-only" on a per host bridge basis.
    
    This also obviates the use of adding PCI_REASSIGN_ALL_BUS flag if
    !PCI_PROBE_ONLY, as pci_assign_unassigned_root_bus_resources() takes care
    of reassigning the resources that are not already claimed.
    
    Link: https://lore.kernel.org/r/20240508174138.3630283-5-vidyas@xxxxxxxxxx
    Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
    Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/pci/controller/pci-host-common.c b/drivers/pci/controller/pci-host-common.c
index 6ce34a1deecb..2525bd043261 100644
--- a/drivers/pci/controller/pci-host-common.c
+++ b/drivers/pci/controller/pci-host-common.c
@@ -71,10 +71,6 @@ int pci_host_common_probe(struct platform_device *pdev)
 	if (IS_ERR(cfg))
 		return PTR_ERR(cfg);
 
-	/* Do not reassign resources if probe only */
-	if (!pci_has_flag(PCI_PROBE_ONLY))
-		pci_add_flags(PCI_REASSIGN_ALL_BUS);
-
 	bridge->sysdata = cfg;
 	bridge->ops = (struct pci_ops *)&ops->pci_ops;
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 02a75f3b5920..b0ac721e047d 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -3018,20 +3018,18 @@ int pci_host_probe(struct pci_host_bridge *bridge)
 
 	bus = bridge->bus;
 
+	/* If we must preserve the resource configuration, claim now */
+	if (bridge->preserve_config)
+		pci_bus_claim_resources(bus);
+
 	/*
-	 * We insert PCI resources into the iomem_resource and
-	 * ioport_resource trees in either pci_bus_claim_resources()
-	 * or pci_bus_assign_resources().
+	 * Assign whatever was left unassigned. If we didn't claim above,
+	 * this will reassign everything.
 	 */
-	if (pci_has_flag(PCI_PROBE_ONLY)) {
-		pci_bus_claim_resources(bus);
-	} else {
-		pci_bus_size_bridges(bus);
-		pci_bus_assign_resources(bus);
+	pci_assign_unassigned_root_bus_resources(bus);
 
-		list_for_each_entry(child, &bus->children, node)
-			pcie_bus_configure_settings(child);
-	}
+	list_for_each_entry(child, &bus->children, node)
+		pcie_bus_configure_settings(child);
 
 	pci_bus_add_devices(bus);
 	return 0;