powerpc/pci: move pci_64.c device tree scanning code into pci-common.c

The PCI device tree scanning code in pci_64.c is some useful functionality.
It allows PCI devices to be described in the device tree instead of being
probed for, which in turn allows pci devices to use all of the device tree
facilities to describe complex PCI bus architectures like GPIO and IRQ
routing (perhaps not a common situation for desktop or server systems,
but useful for embedded systems with on-board PCI devices).

This patch moves the device tree scanning into pci-common.c so it is
available for 32-bit powerpc machines too.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 358 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/pci_of_scan.c b/arch/powerpc/kernel/pci_of_scan.c
new file mode 100644
index 000000000000..72c31bcb7aa4
--- /dev/null
+++ b/arch/powerpc/kernel/pci_of_scan.c
@@ -0,0 +1,358 @@
+/*
+ * Helper routines to scan the device tree for PCI devices and busses
+ *
+ * Migrated out of PowerPC architecture pci_64.c file by Grant Likely
+ * <grant.likely@secretlab.ca> so that these routines are available for
+ * 32 bit also.
+ *
+ * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
+ *   Rework, based on alpha PCI code.
+ * Copyright (c) 2009 Secret Lab Technologies Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/pci.h>
+#include <asm/pci-bridge.h>
+#include <asm/prom.h>
+
+/**
+ * get_int_prop - Decode a u32 from a device tree property
+ */
+static u32 get_int_prop(struct device_node *np, const char *name, u32 def)
+{
+	const u32 *prop;
+	int len;
+
+	prop = of_get_property(np, name, &len);
+	if (prop && len >= 4)
+		return *prop;
+	return def;
+}
+
+/**
+ * pci_parse_of_flags - Parse the flags cell of a device tree PCI address
+ * @addr0: value of 1st cell of a device tree PCI address.
+ * @bridge: Set this flag if the address is from a bridge 'ranges' property
+ */
+unsigned int pci_parse_of_flags(u32 addr0, int bridge)
+{
+	unsigned int flags = 0;
+
+	if (addr0 & 0x02000000) {
+		flags = IORESOURCE_MEM | PCI_BASE_ADDRESS_SPACE_MEMORY;
+		flags |= (addr0 >> 22) & PCI_BASE_ADDRESS_MEM_TYPE_64;
+		flags |= (addr0 >> 28) & PCI_BASE_ADDRESS_MEM_TYPE_1M;
+		if (addr0 & 0x40000000)
+			flags |= IORESOURCE_PREFETCH
+				 | PCI_BASE_ADDRESS_MEM_PREFETCH;
+		/* Note: We don't know whether the ROM has been left enabled
+		 * by the firmware or not. We mark it as disabled (ie, we do
+		 * not set the IORESOURCE_ROM_ENABLE flag) for now rather than
+		 * do a config space read, it will be force-enabled if needed
+		 */
+		if (!bridge && (addr0 & 0xff) == 0x30)
+			flags |= IORESOURCE_READONLY;
+	} else if (addr0 & 0x01000000)
+		flags = IORESOURCE_IO | PCI_BASE_ADDRESS_SPACE_IO;
+	if (flags)
+		flags |= IORESOURCE_SIZEALIGN;
+	return flags;
+}
+
+/**
+ * of_pci_parse_addrs - Parse PCI addresses assigned in the device tree node
+ * @node: device tree node for the PCI device
+ * @dev: pci_dev structure for the device
+ *
+ * This function parses the 'assigned-addresses' property of a PCI devices'
+ * device tree node and writes them into the associated pci_dev structure.
+ */
+static void of_pci_parse_addrs(struct device_node *node, struct pci_dev *dev)
+{
+	u64 base, size;
+	unsigned int flags;
+	struct resource *res;
+	const u32 *addrs;
+	u32 i;
+	int proplen;
+
+	addrs = of_get_property(node, "assigned-addresses", &proplen);
+	if (!addrs)
+		return;
+	pr_debug("    parse addresses (%d bytes) @ %p\n", proplen, addrs);
+	for (; proplen >= 20; proplen -= 20, addrs += 5) {
+		flags = pci_parse_of_flags(addrs[0], 0);
+		if (!flags)
+			continue;
+		base = of_read_number(&addrs[1], 2);
+		size = of_read_number(&addrs[3], 2);
+		if (!size)
+			continue;
+		i = addrs[0] & 0xff;
+		pr_debug("  base: %llx, size: %llx, i: %x\n",
+			 (unsigned long long)base,
+			 (unsigned long long)size, i);
+
+		if (PCI_BASE_ADDRESS_0 <= i && i <= PCI_BASE_ADDRESS_5) {
+			res = &dev->resource[(i - PCI_BASE_ADDRESS_0) >> 2];
+		} else if (i == dev->rom_base_reg) {
+			res = &dev->resource[PCI_ROM_RESOURCE];
+			flags |= IORESOURCE_READONLY | IORESOURCE_CACHEABLE;
+		} else {
+			printk(KERN_ERR "PCI: bad cfg reg num 0x%x\n", i);
+			continue;
+		}
+		res->start = base;
+		res->end = base + size - 1;
+		res->flags = flags;
+		res->name = pci_name(dev);
+	}
+}
+
+/**
+ * of_create_pci_dev - Given a device tree node on a pci bus, create a pci_dev
+ * @node: device tree node pointer
+ * @bus: bus the device is sitting on
+ * @devfn: PCI function number, extracted from device tree by caller.
+ */
+struct pci_dev *of_create_pci_dev(struct device_node *node,
+				 struct pci_bus *bus, int devfn)
+{
+	struct pci_dev *dev;
+	const char *type;
+
+	dev = alloc_pci_dev();
+	if (!dev)
+		return NULL;
+	type = of_get_property(node, "device_type", NULL);
+	if (type == NULL)
+		type = "";
+
+	pr_debug("    create device, devfn: %x, type: %s\n", devfn, type);
+
+	dev->bus = bus;
+	dev->sysdata = node;
+	dev->dev.parent = bus->bridge;
+	dev->dev.bus = &pci_bus_type;
+	dev->devfn = devfn;
+	dev->multifunction = 0;		/* maybe a lie? */
+
+	dev->vendor = get_int_prop(node, "vendor-id", 0xffff);
+	dev->device = get_int_prop(node, "device-id", 0xffff);
+	dev->subsystem_vendor = get_int_prop(node, "subsystem-vendor-id", 0);
+	dev->subsystem_device = get_int_prop(node, "subsystem-id", 0);
+
+	dev->cfg_size = pci_cfg_space_size(dev);
+
+	dev_set_name(&dev->dev, "%04x:%02x:%02x.%d", pci_domain_nr(bus),
+		dev->bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn));
+	dev->class = get_int_prop(node, "class-code", 0);
+	dev->revision = get_int_prop(node, "revision-id", 0);
+
+	pr_debug("    class: 0x%x\n", dev->class);
+	pr_debug("    revision: 0x%x\n", dev->revision);
+
+	dev->current_state = 4;		/* unknown power state */
+	dev->error_state = pci_channel_io_normal;
+	dev->dma_mask = 0xffffffff;
+
+	if (!strcmp(type, "pci") || !strcmp(type, "pciex")) {
+		/* a PCI-PCI bridge */
+		dev->hdr_type = PCI_HEADER_TYPE_BRIDGE;
+		dev->rom_base_reg = PCI_ROM_ADDRESS1;
+	} else if (!strcmp(type, "cardbus")) {
+		dev->hdr_type = PCI_HEADER_TYPE_CARDBUS;
+	} else {
+		dev->hdr_type = PCI_HEADER_TYPE_NORMAL;
+		dev->rom_base_reg = PCI_ROM_ADDRESS;
+		/* Maybe do a default OF mapping here */
+		dev->irq = NO_IRQ;
+	}
+
+	of_pci_parse_addrs(node, dev);
+
+	pr_debug("    adding to system ...\n");
+
+	pci_device_add(dev, bus);
+
+	return dev;
+}
+EXPORT_SYMBOL(of_create_pci_dev);
+
+/**
+ * of_scan_pci_bridge - Set up a PCI bridge and scan for child nodes
+ * @node: device tree node of bridge
+ * @dev: pci_dev structure for the bridge
+ *
+ * of_scan_bus() calls this routine for each PCI bridge that it finds, and
+ * this routine in turn call of_scan_bus() recusively to scan for more child
+ * devices.
+ */
+void __devinit of_scan_pci_bridge(struct device_node *node,
+				  struct pci_dev *dev)
+{
+	struct pci_bus *bus;
+	const u32 *busrange, *ranges;
+	int len, i, mode;
+	struct resource *res;
+	unsigned int flags;
+	u64 size;
+
+	pr_debug("of_scan_pci_bridge(%s)\n", node->full_name);
+
+	/* parse bus-range property */
+	busrange = of_get_property(node, "bus-range", &len);
+	if (busrange == NULL || len != 8) {
+		printk(KERN_DEBUG "Can't get bus-range for PCI-PCI bridge %s\n",
+		       node->full_name);
+		return;
+	}
+	ranges = of_get_property(node, "ranges", &len);
+	if (ranges == NULL) {
+		printk(KERN_DEBUG "Can't get ranges for PCI-PCI bridge %s\n",
+		       node->full_name);
+		return;
+	}
+
+	bus = pci_add_new_bus(dev->bus, dev, busrange[0]);
+	if (!bus) {
+		printk(KERN_ERR "Failed to create pci bus for %s\n",
+		       node->full_name);
+		return;
+	}
+
+	bus->primary = dev->bus->number;
+	bus->subordinate = busrange[1];
+	bus->bridge_ctl = 0;
+	bus->sysdata = node;
+
+	/* parse ranges property */
+	/* PCI #address-cells == 3 and #size-cells == 2 always */
+	res = &dev->resource[PCI_BRIDGE_RESOURCES];
+	for (i = 0; i < PCI_NUM_RESOURCES - PCI_BRIDGE_RESOURCES; ++i) {
+		res->flags = 0;
+		bus->resource[i] = res;
+		++res;
+	}
+	i = 1;
+	for (; len >= 32; len -= 32, ranges += 8) {
+		flags = pci_parse_of_flags(ranges[0], 1);
+		size = of_read_number(&ranges[6], 2);
+		if (flags == 0 || size == 0)
+			continue;
+		if (flags & IORESOURCE_IO) {
+			res = bus->resource[0];
+			if (res->flags) {
+				printk(KERN_ERR "PCI: ignoring extra I/O range"
+				       " for bridge %s\n", node->full_name);
+				continue;
+			}
+		} else {
+			if (i >= PCI_NUM_RESOURCES - PCI_BRIDGE_RESOURCES) {
+				printk(KERN_ERR "PCI: too many memory ranges"
+				       " for bridge %s\n", node->full_name);
+				continue;
+			}
+			res = bus->resource[i];
+			++i;
+		}
+		res->start = of_read_number(&ranges[1], 2);
+		res->end = res->start + size - 1;
+		res->flags = flags;
+	}
+	sprintf(bus->name, "PCI Bus %04x:%02x", pci_domain_nr(bus),
+		bus->number);
+	pr_debug("    bus name: %s\n", bus->name);
+
+	mode = PCI_PROBE_NORMAL;
+	if (ppc_md.pci_probe_mode)
+		mode = ppc_md.pci_probe_mode(bus);
+	pr_debug("    probe mode: %d\n", mode);
+
+	if (mode == PCI_PROBE_DEVTREE)
+		of_scan_bus(node, bus);
+	else if (mode == PCI_PROBE_NORMAL)
+		pci_scan_child_bus(bus);
+}
+EXPORT_SYMBOL(of_scan_pci_bridge);
+
+/**
+ * __of_scan_bus - given a PCI bus node, setup bus and scan for child devices
+ * @node: device tree node for the PCI bus
+ * @bus: pci_bus structure for the PCI bus
+ * @rescan_existing: Flag indicating bus has already been set up
+ */
+static void __devinit __of_scan_bus(struct device_node *node,
+				    struct pci_bus *bus, int rescan_existing)
+{
+	struct device_node *child;
+	const u32 *reg;
+	int reglen, devfn;
+	struct pci_dev *dev;
+
+	pr_debug("of_scan_bus(%s) bus no %d... \n",
+		 node->full_name, bus->number);
+
+	/* Scan direct children */
+	for_each_child_of_node(node, child) {
+		pr_debug("  * %s\n", child->full_name);
+		reg = of_get_property(child, "reg", &reglen);
+		if (reg == NULL || reglen < 20)
+			continue;
+		devfn = (reg[0] >> 8) & 0xff;
+
+		/* create a new pci_dev for this device */
+		dev = of_create_pci_dev(child, bus, devfn);
+		if (!dev)
+			continue;
+		pr_debug("    dev header type: %x\n", dev->hdr_type);
+	}
+
+	/* Apply all fixups necessary. We don't fixup the bus "self"
+	 * for an existing bridge that is being rescanned
+	 */
+	if (!rescan_existing)
+		pcibios_setup_bus_self(bus);
+	pcibios_setup_bus_devices(bus);
+
+	/* Now scan child busses */
+	list_for_each_entry(dev, &bus->devices, bus_list) {
+		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
+		    dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
+			struct device_node *child = pci_device_to_OF_node(dev);
+			if (dev)
+				of_scan_pci_bridge(child, dev);
+		}
+	}
+}
+
+/**
+ * of_scan_bus - given a PCI bus node, setup bus and scan for child devices
+ * @node: device tree node for the PCI bus
+ * @bus: pci_bus structure for the PCI bus
+ */
+void __devinit of_scan_bus(struct device_node *node,
+			   struct pci_bus *bus)
+{
+	__of_scan_bus(node, bus, 0);
+}
+EXPORT_SYMBOL_GPL(of_scan_bus);
+
+/**
+ * of_rescan_bus - given a PCI bus node, scan for child devices
+ * @node: device tree node for the PCI bus
+ * @bus: pci_bus structure for the PCI bus
+ *
+ * Same as of_scan_bus, but for a pci_bus structure that has already been
+ * setup.
+ */
+void __devinit of_rescan_bus(struct device_node *node,
+			     struct pci_bus *bus)
+{
+	__of_scan_bus(node, bus, 1);
+}
+EXPORT_SYMBOL_GPL(of_rescan_bus);
+