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From: Vidya Sagar <vidyas@nvidia.com>
To: <bhelgaas@google.com>, <rafael@kernel.org>, <lenb@kernel.org>,
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Subject: [PATCH V7 4/4] PCI: Use preserve_config in place of pci_flags
Date: Wed, 8 May 2024 23:11:38 +0530
Message-ID: <20240508174138.3630283-5-vidyas@nvidia.com>
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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 patch 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.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
 drivers/pci/controller/pci-host-common.c |  4 ----
 drivers/pci/probe.c                      | 20 +++++++++-----------
 2 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/drivers/pci/controller/pci-host-common.c b/drivers/pci/controller/pci-host-common.c
index 45b71806182d..c96b2de163b5 100644
--- a/drivers/pci/controller/pci-host-common.c
+++ b/drivers/pci/controller/pci-host-common.c
@@ -73,10 +73,6 @@ 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;
 	bridge->msi_domain = true;
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 2c232c22d6af..b4adc33f88cf 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -3088,20 +3088,18 @@ 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;
-- 
2.25.1