PCI: host-common: Convert to library for host controller drivers

This common library will be used as a placeholder for helper functions
shared by the host controller drivers. This avoids placing the host
controller drivers specific helpers in drivers/pci/*.c, to avoid enlarging
the kernel image on platforms that do not use host controller drivers at
all (like x86/ACPI platforms).

Suggested-by: Lukas Wunner <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
Signed-off-by: Krzysztof Wilczyński <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: Mani-Sadhasivam

drivers/pci/controller/Kconfig

@@ -3,6 +3,10 @@
 menu "PCI controller drivers"
 	depends on PCI
 
+config PCI_HOST_COMMON
+	tristate
+	select PCI_ECAM
+
 config PCI_AARDVARK
 	tristate "Aardvark PCIe controller"
 	depends on (ARCH_MVEBU && ARM64) || COMPILE_TEST
@@ -119,10 +123,6 @@ config PCI_FTPCI100
 	depends on OF
 	default ARCH_GEMINI
 
-config PCI_HOST_COMMON
-	tristate
-	select PCI_ECAM
-
 config PCI_HOST_GENERIC
 	tristate "Generic PCI host controller"
 	depends on OF

drivers/pci/controller/dwc/pcie-hisi.c

@@ -15,6 +15,7 @@
 #include <linux/pci-acpi.h>
 #include <linux/pci-ecam.h>
 #include "../../pci.h"
+#include "../pci-host-common.h"
 
 #if defined(CONFIG_PCI_HISI) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
 

drivers/pci/controller/pci-host-common.c

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Generic PCI host driver common code
+ * Common library for PCI host controller drivers
  *
  * Copyright (C) 2014 ARM Limited
  *
@@ -15,6 +15,8 @@
 #include <linux/pci-ecam.h>
 #include <linux/platform_device.h>
 
+#include "pci-host-common.h"
+
 static void gen_pci_unmap_cfg(void *ptr)
 {
 	pci_ecam_free((struct pci_config_window *)ptr);
@@ -94,5 +96,5 @@ void pci_host_common_remove(struct platform_device *pdev)
 }
 EXPORT_SYMBOL_GPL(pci_host_common_remove);
 
-MODULE_DESCRIPTION("Generic PCI host common driver");
+MODULE_DESCRIPTION("Common library for PCI host controller drivers");
 MODULE_LICENSE("GPL v2");

drivers/pci/controller/pci-host-common.h

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common library for PCI host controller drivers
+ *
+ * Copyright (C) 2014 ARM Limited
+ *
+ * Author: Will Deacon <[email protected]>
+ */
+
+#ifndef _PCI_HOST_COMMON_H
+#define _PCI_HOST_COMMON_H
+
+int pci_host_common_probe(struct platform_device *pdev);
+void pci_host_common_remove(struct platform_device *pdev);
+
+#endif

drivers/pci/controller/pci-host-generic.c

@@ -14,6 +14,8 @@
 #include <linux/pci-ecam.h>
 #include <linux/platform_device.h>
 
+#include "pci-host-common.h"
+
 static const struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = {
 	.bus_shift	= 16,
 	.pci_ops	= {

drivers/pci/controller/pci-thunder-ecam.c

@@ -11,6 +11,8 @@
 #include <linux/pci-ecam.h>
 #include <linux/platform_device.h>
 
+#include "pci-host-common.h"
+
 #if defined(CONFIG_PCI_HOST_THUNDER_ECAM) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
 
 static void set_val(u32 v, int where, int size, u32 *val)

drivers/pci/controller/pci-thunder-pem.c

@@ -14,6 +14,7 @@
 #include <linux/platform_device.h>
 #include <linux/io-64-nonatomic-lo-hi.h>
 #include "../pci.h"
+#include "pci-host-common.h"
 
 #if defined(CONFIG_PCI_HOST_THUNDER_PEM) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
 

drivers/pci/controller/pcie-apple.c

@@ -29,6 +29,8 @@
 #include <linux/of_irq.h>
 #include <linux/pci-ecam.h>
 
+#include "pci-host-common.h"
+
 #define CORE_RC_PHYIF_CTL		0x00024
 #define   CORE_RC_PHYIF_CTL_RUN		BIT(0)
 #define CORE_RC_PHYIF_STAT		0x00028

drivers/pci/controller/plda/pcie-microchip-host.c

@@ -23,6 +23,7 @@
 #include <linux/wordpart.h>
 
 #include "../../pci.h"
+#include "../pci-host-common.h"
 #include "pcie-plda.h"
 
 #define MC_MAX_NUM_INBOUND_WINDOWS		8

include/linux/pci-ecam.h

@@ -93,10 +93,4 @@ extern const struct pci_ecam_ops al_pcie_ops;	/* Amazon Annapurna Labs PCIe */
 extern const struct pci_ecam_ops tegra194_pcie_ops; /* Tegra194 PCIe */
 extern const struct pci_ecam_ops loongson_pci_ecam_ops; /* Loongson PCIe */
 #endif
-
-#if IS_ENABLED(CONFIG_PCI_HOST_COMMON)
-/* for DT-based PCI controllers that support ECAM */
-int pci_host_common_probe(struct platform_device *pdev);
-void pci_host_common_remove(struct platform_device *pdev);
-#endif
 #endif