[PATCH 12/16] pci: add of_pci_bridge_init()

[Sascha Hauer <s.hauer@pengutronix.de>]

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/pci/Makefile |   1 +
 drivers/pci/of.c     | 102 +++++++++++++++++++++++++++++++++++++++++++
 drivers/pci/pci.c    |   2 +
 include/linux/pci.h  |  10 +++++
 4 files changed, 115 insertions(+)
 create mode 100644 drivers/pci/of.c

diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index c222f77b3b..69649fbcd2 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -3,6 +3,7 @@
 # Makefile for the PCI bus specific drivers.
 #
 obj-y		+= pci.o bus.o pci_iomap.o host-bridge.o
+obj-$(CONFIG_OFDEVICE) += of.o
 
 ccflags-$(CONFIG_PCI_DEBUG) := -DDEBUG
 
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
new file mode 100644
index 0000000000..b1ee3fa938
--- /dev/null
+++ b/drivers/pci/of.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCI <-> OF mapping helpers
+ *
+ * Copyright 2011 IBM Corp.
+ */
+#define pr_fmt(fmt)	"PCI: OF: " fmt
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <of.h>
+#include <of_address.h>
+#include <common.h>
+#include <linux/resource_ext.h>
+
+/**
+ * of_pci_get_host_bridge_resources() - parsing of PCI host bridge resources from DT
+ * @dev: host bridge device
+ * @resources: list where the range of resources will be added after DT parsing
+ *
+ * This function will parse the "ranges" property of a PCI host bridge device
+ * node and setup the resource mapping based on its content. It is expected
+ * that the property conforms with the Power ePAPR document.
+ *
+ * It returns zero if the range parsing has been successful or a standard error
+ * value if it failed.
+ */
+static int of_pci_get_host_bridge_resources(struct device *dev,
+					    struct pci_controller *bridge)
+{
+	struct list_head *resources = &bridge->windows;
+	struct device_node *dev_node = dev->of_node;
+	struct resource *res, tmp_res;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+	const char *range_type;
+	int err;
+
+	dev_dbg(dev, "host bridge %pOF ranges:\n", dev_node);
+
+	/* Check for ranges property */
+	err = of_pci_range_parser_init(&parser, dev_node);
+	if (err)
+		return 0;
+
+	dev_dbg(dev, "Parsing ranges property...\n");
+	for_each_of_pci_range(&parser, &range) {
+		/* Read next ranges element */
+		if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
+			range_type = "IO";
+		else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
+			range_type = "MEM";
+		else
+			range_type = "err";
+		dev_dbg(dev, "  %6s %#012llx..%#012llx -> %#012llx\n",
+			 range_type, range.cpu_addr,
+			 range.cpu_addr + range.size - 1, range.pci_addr);
+
+		/*
+		 * If we failed translation or got a zero-sized region
+		 * then skip this range
+		 */
+		if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
+			continue;
+
+		of_pci_range_to_resource(&range, dev_node, &tmp_res);
+
+		res = kmemdup(&tmp_res, sizeof(tmp_res), GFP_KERNEL);
+		if (!res) {
+			err = -ENOMEM;
+			goto failed;
+		}
+
+		pci_add_resource_offset(resources, res,	res->start - range.pci_addr);
+
+		switch (res->flags & IORESOURCE_TYPE_BITS) {
+		case IORESOURCE_IO:
+			bridge->io_resource = res;
+			break;
+
+		case IORESOURCE_MEM:
+			if (res->flags & IORESOURCE_PREFETCH)
+				bridge->mem_pref_resource = res;
+			else
+				bridge->mem_resource = res;
+			break;
+		}
+	}
+
+	return 0;
+
+failed:
+	return err;
+}
+
+int of_pci_bridge_init(struct device *dev, struct pci_controller *bridge)
+{
+	if (!dev->of_node)
+		return 0;
+
+	return of_pci_get_host_bridge_resources(dev, bridge);
+}
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 0a238cd190..bc083270d9 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -45,6 +45,8 @@ static void pci_bus_register_devices(struct pci_bus *bus)
 void pci_controller_init(struct pci_controller *hose)
 {
 	INIT_LIST_HEAD(&hose->windows);
+
+	of_pci_bridge_init(hose->parent, hose);
 }
 
 void register_pci_controller(struct pci_controller *hose)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 11a60f66a9..f6511e0095 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -414,4 +414,14 @@ void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
 void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
 			     struct pci_bus_region *region);
 
+/* drivers/pci/of.c */
+#ifdef CONFIG_OFDEVICE
+int of_pci_bridge_init(struct device *dev, struct pci_controller *bridge);
+#else
+static inline int of_pci_bridge_init(struct device *dev, struct pci_controller *bridge)
+{
+	return 0;
+}
+#endif
+
 #endif /* LINUX_PCI_H */
-- 
2.39.2