pci_of_scan.c

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/*
 * Helper routines to scan the device tree for PCI devices and busses
 *
 * Migrated out of PowerPC architecture pci_64.c file by Grant Likely
 * <[email protected]> so that these routines are available for
 * 32 bit also.
 *
 * Copyright (C) 2003 Anton Blanchard <[email protected]>, 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 <linux/export.h>
#include <asm/pci-bridge.h>
#include <asm/prom.h>

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;
}

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;
}

static void of_pci_parse_addrs(struct device_node *node, struct pci_dev *dev)
{
    u64 base, size;
    unsigned int flags;
    struct pci_bus_region region;
    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->flags = flags;
        res->name = pci_name(dev);
        region.start = base;
        region.end = base + size - 1;
        pcibios_bus_to_resource(dev, res, &region);
    }
}

struct pci_dev *of_create_pci_dev(struct device_node *node,
                 struct pci_bus *bus, int devfn)
{
    struct pci_dev *dev;
    const char *type;
    struct pci_slot *slot;

    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->dev.of_node = of_node_get(node);
    dev->dev.parent = bus->bridge;
    dev->dev.bus = &pci_bus_type;
    dev->devfn = devfn;
    dev->multifunction = 0;     /* maybe a lie? */
    dev->needs_freset = 0;      /* pcie fundamental reset required */
    set_pcie_port_type(dev);

    list_for_each_entry(slot, &dev->bus->slots, list)
        if (PCI_SLOT(dev->devfn) == slot->number)
            dev->slot = slot;

    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;

    /* Early fixups, before probing the BARs */
    pci_fixup_device(pci_fixup_early, dev);

    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;
        set_pcie_hotplug_bridge(dev);
    } 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);

void __devinit of_scan_pci_bridge(struct pci_dev *dev)
{
    struct device_node *node = dev->dev.of_node;
    struct pci_bus *bus;
    const u32 *busrange, *ranges;
    int len, i, mode;
    struct pci_bus_region region;
    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;
    pci_bus_insert_busn_res(bus, busrange[0], busrange[1]);
    bus->bridge_ctl = 0;

    /* 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->flags = flags;
        region.start = of_read_number(&ranges[1], 2);
        region.end = region.start + size - 1;
        pcibios_bus_to_resource(dev, res, &region);
    }
    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);

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);
        if (!of_device_is_available(child))
            continue;
        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) {
            of_scan_pci_bridge(dev);
        }
    }
}

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);

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);