Subject: [PATCH 1/2] powerpc/pci: Allow to disable filling deprecated pci-OF-bus-map

From: Pali Rohár <[email-masked]>
Date: Wed, 17 Aug 2022 18:39:26 +0200

Creating or filling pci-OF-bus-map property in the device-tree is
deprecated since May 2006 [1]. Allow to disable filling this property by
unsetting config option CONFIG_PPC_PCI_OF_BUS_MAP_FILL for remaining chrp
and powermac code.

Disabling of pci-OF-bus-map property allows to enable new option
CONFIG_PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT also for chrp and powermac.

[1] - https://lore.kernel.org/linuxppc-dev/[email-masked]/

Signed-off-by: Pali Rohár <[email-masked]>
---
 arch/powerpc/Kconfig         | 12 +++++++++++-
 arch/powerpc/kernel/pci_32.c |  6 ++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 5881441f7672..df2696c406ad 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -373,9 +373,19 @@ config PPC_DCR
 	depends on PPC_DCR_NATIVE || PPC_DCR_MMIO
 	default y
 
+config PPC_PCI_OF_BUS_MAP_FILL
+	bool "Fill pci-OF-bus-map property in the device-tree"
+	depends on PPC32
+	depends on PPC_PMAC || PPC_CHRP
+	default y
+	help
+	  This option creates and fills pci-OF-bus-map property in the
+	  device-tree which is deprecated and is needed only for old
+	  platforms.
+
 config PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT
 	depends on PPC32
-	depends on !PPC_PMAC && !PPC_CHRP
+	depends on !PPC_PCI_OF_BUS_MAP_FILL
 	bool "Assign PCI bus numbers from zero individually for each PCI domain"
 	help
 	  By default on PPC32 were PCI bus numbers unique across all PCI domains.
diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c
index 433965bf37b4..ffc4e1928c80 100644
--- a/arch/powerpc/kernel/pci_32.c
+++ b/arch/powerpc/kernel/pci_32.c
@@ -64,6 +64,8 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_IBM,	PCI_DEVICE_ID_IBM_CPC710_PCI64,	fixu
 
 #if defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_CHRP)
 
+#ifdef CONFIG_PPC_PCI_OF_BUS_MAP_FILL
+
 static u8* pci_to_OF_bus_map;
 static int pci_bus_count;
 
@@ -223,6 +225,8 @@ pci_create_OF_bus_map(void)
 }
 #endif
 
+#endif /* CONFIG_PPC_PCI_OF_BUS_MAP_FILL */
+
 #endif /* defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_CHRP) */
 
 void pcibios_setup_phb_io_space(struct pci_controller *hose)
@@ -264,6 +268,7 @@ static int __init pcibios_init(void)
 	}
 
 #if defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_CHRP)
+#ifdef CONFIG_PPC_PCI_OF_BUS_MAP_FILL
 	pci_bus_count = next_busno;
 
 	/* OpenFirmware based machines need a map of OF bus
@@ -272,6 +277,7 @@ static int __init pcibios_init(void)
 	 */
 	if (pci_assign_all_buses)
 		pcibios_make_OF_bus_map();
+#endif
 #endif
 
 	/* Call common code to handle resource allocation */
-- 
2.20.1