From 85dc04136e86680378546afb808357a58c06061c Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Sat, 15 Jun 2019 10:23:59 +1000 Subject: [PATCH] arm64: PCI: Preserve firmware configuration when desired If we must preserve the firmware resource assignments, claim the existing resources rather than reassigning everything. Link: https://lore.kernel.org/r/20190615002359.29577-4-benh@kernel.crashing.org Signed-off-by: Benjamin Herrenschmidt [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas Acked-by: Lorenzo Pieralisi Acked-by: Ard Biesheuvel --- arch/arm64/kernel/pci.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index 1419b1b4e9b9..16fcb8d72553 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -168,6 +168,7 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) struct acpi_pci_generic_root_info *ri; struct pci_bus *bus, *child; struct acpi_pci_root_ops *root_ops; + struct pci_host_bridge *host; ri = kzalloc(sizeof(*ri), GFP_KERNEL); if (!ri) @@ -193,6 +194,15 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) if (!bus) return NULL; + /* If we must preserve the resource configuration, claim now */ + host = pci_find_host_bridge(bus); + if (host->preserve_config) + pci_bus_claim_resources(bus); + + /* + * Assign whatever was left unassigned. If we didn't claim above, + * this will reassign everything. + */ pci_assign_unassigned_root_bus_resources(bus); list_for_each_entry(child, &bus->children, node) -- 2.39.5