pci.c

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/*
 * New-style PCI core.
 *
 * Copyright (c) 2004 - 2009  Paul Mundt
 * Copyright (c) 2002  M. R. Brown
 *
 * Modelled after arch/mips/pci/pci.c:
 *  Copyright (C) 2003, 04 Ralf Baechle ([email protected])
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/dma-debug.h>
#include <linux/io.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/export.h>

unsigned long PCIBIOS_MIN_IO = 0x0000;
unsigned long PCIBIOS_MIN_MEM = 0;

/*
 * The PCI controller list.
 */
static struct pci_channel *hose_head, **hose_tail = &hose_head;

static int pci_initialized;

static void __devinit pcibios_scanbus(struct pci_channel *hose)
{
    static int next_busno;
    static int need_domain_info;
    LIST_HEAD(resources);
    struct resource *res;
    resource_size_t offset;
    int i;
    struct pci_bus *bus;

    for (i = 0; i < hose->nr_resources; i++) {
        res = hose->resources + i;
        offset = 0;
        if (res->flags & IORESOURCE_IO)
            offset = hose->io_offset;
        else if (res->flags & IORESOURCE_MEM)
            offset = hose->mem_offset;
        pci_add_resource_offset(&resources, res, offset);
    }

    bus = pci_scan_root_bus(NULL, next_busno, hose->pci_ops, hose,
                &resources);
    hose->bus = bus;

    need_domain_info = need_domain_info || hose->index;
    hose->need_domain_info = need_domain_info;
    if (bus) {
        next_busno = bus->busn_res.end + 1;
        /* Don't allow 8-bit bus number overflow inside the hose -
           reserve some space for bridges. */
        if (next_busno > 224) {
            next_busno = 0;
            need_domain_info = 1;
        }

        pci_bus_size_bridges(bus);
        pci_bus_assign_resources(bus);
        pci_enable_bridges(bus);
    } else {
        pci_free_resource_list(&resources);
    }
}

/*
 * This interrupt-safe spinlock protects all accesses to PCI
 * configuration space.
 */
DEFINE_RAW_SPINLOCK(pci_config_lock);
static DEFINE_MUTEX(pci_scan_mutex);

int __devinit register_pci_controller(struct pci_channel *hose)
{
    int i;

    for (i = 0; i < hose->nr_resources; i++) {
        struct resource *res = hose->resources + i;

        if (res->flags & IORESOURCE_IO) {
            if (request_resource(&ioport_resource, res) < 0)
                goto out;
        } else {
            if (request_resource(&iomem_resource, res) < 0)
                goto out;
        }
    }

    *hose_tail = hose;
    hose_tail = &hose->next;

    /*
     * Do not panic here but later - this might happen before console init.
     */
    if (!hose->io_map_base) {
        printk(KERN_WARNING
               "registering PCI controller with io_map_base unset\n");
    }

    /*
     * Setup the ERR/PERR and SERR timers, if available.
     */
    pcibios_enable_timers(hose);

    /*
     * Scan the bus if it is register after the PCI subsystem
     * initialization.
     */
    if (pci_initialized) {
        mutex_lock(&pci_scan_mutex);
        pcibios_scanbus(hose);
        mutex_unlock(&pci_scan_mutex);
    }

    return 0;

out:
    for (--i; i >= 0; i--)
        release_resource(&hose->resources[i]);

    printk(KERN_WARNING "Skipping PCI bus scan due to resource conflict\n");
    return -1;
}

static int __init pcibios_init(void)
{
    struct pci_channel *hose;

    /* Scan all of the recorded PCI controllers.  */
    for (hose = hose_head; hose; hose = hose->next)
        pcibios_scanbus(hose);

    pci_fixup_irqs(pci_common_swizzle, pcibios_map_platform_irq);

    dma_debug_add_bus(&pci_bus_type);

    pci_initialized = 1;

    return 0;
}
subsys_initcall(pcibios_init);

/*
 *  Called after each bus is probed, but before its children
 *  are examined.
 */
void __devinit pcibios_fixup_bus(struct pci_bus *bus)
{
}

/*
 * We need to avoid collisions with `mirrored' VGA ports
 * and other strange ISA hardware, so we always want the
 * addresses to be allocated in the 0x000-0x0ff region
 * modulo 0x400.
 */
resource_size_t pcibios_align_resource(void *data, const struct resource *res,
                resource_size_t size, resource_size_t align)
{
    struct pci_dev *dev = data;
    struct pci_channel *hose = dev->sysdata;
    resource_size_t start = res->start;

    if (res->flags & IORESOURCE_IO) {
        if (start < PCIBIOS_MIN_IO + hose->resources[0].start)
            start = PCIBIOS_MIN_IO + hose->resources[0].start;

        /*
                 * Put everything into 0x00-0xff region modulo 0x400.
         */
        if (start & 0x300)
            start = (start + 0x3ff) & ~0x3ff;
    }

    return start;
}

int pcibios_enable_device(struct pci_dev *dev, int mask)
{
    return pci_enable_resources(dev, mask);
}

static void __init
pcibios_bus_report_status_early(struct pci_channel *hose,
                int top_bus, int current_bus,
                unsigned int status_mask, int warn)
{
    unsigned int pci_devfn;
    u16 status;
    int ret;

    for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
        if (PCI_FUNC(pci_devfn))
            continue;
        ret = early_read_config_word(hose, top_bus, current_bus,
                         pci_devfn, PCI_STATUS, &status);
        if (ret != PCIBIOS_SUCCESSFUL)
            continue;
        if (status == 0xffff)
            continue;

        early_write_config_word(hose, top_bus, current_bus,
                    pci_devfn, PCI_STATUS,
                    status & status_mask);
        if (warn)
            printk("(%02x:%02x: %04X) ", current_bus,
                   pci_devfn, status);
    }
}

/*
 * We can't use pci_find_device() here since we are
 * called from interrupt context.
 */
static void __init_refok
pcibios_bus_report_status(struct pci_bus *bus, unsigned int status_mask,
              int warn)
{
    struct pci_dev *dev;

    list_for_each_entry(dev, &bus->devices, bus_list) {
        u16 status;

        /*
         * ignore host bridge - we handle
         * that separately
         */
        if (dev->bus->number == 0 && dev->devfn == 0)
            continue;

        pci_read_config_word(dev, PCI_STATUS, &status);
        if (status == 0xffff)
            continue;

        if ((status & status_mask) == 0)
            continue;

        /* clear the status errors */
        pci_write_config_word(dev, PCI_STATUS, status & status_mask);

        if (warn)
            printk("(%s: %04X) ", pci_name(dev), status);
    }

    list_for_each_entry(dev, &bus->devices, bus_list)
        if (dev->subordinate)
            pcibios_bus_report_status(dev->subordinate, status_mask, warn);
}

void __init_refok pcibios_report_status(unsigned int status_mask, int warn)
{
    struct pci_channel *hose;

    for (hose = hose_head; hose; hose = hose->next) {
        if (unlikely(!hose->bus))
            pcibios_bus_report_status_early(hose, hose_head->index,
                    hose->index, status_mask, warn);
        else
            pcibios_bus_report_status(hose->bus, status_mask, warn);
    }
}

int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
            enum pci_mmap_state mmap_state, int write_combine)
{
    /*
     * I/O space can be accessed via normal processor loads and stores on
     * this platform but for now we elect not to do this and portable
     * drivers should not do this anyway.
     */
    if (mmap_state == pci_mmap_io)
        return -EINVAL;

    /*
     * Ignore write-combine; for now only return uncached mappings.
     */
    vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

    return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
                   vma->vm_end - vma->vm_start,
                   vma->vm_page_prot);
}

#ifndef CONFIG_GENERIC_IOMAP

void __iomem *__pci_ioport_map(struct pci_dev *dev,
                   unsigned long port, unsigned int nr)
{
    struct pci_channel *chan = dev->sysdata;

    if (unlikely(!chan->io_map_base)) {
        chan->io_map_base = sh_io_port_base;

        if (pci_domains_supported)
            panic("To avoid data corruption io_map_base MUST be "
                  "set with multiple PCI domains.");
    }

    return (void __iomem *)(chan->io_map_base + port);
}

void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
{
    iounmap(addr);
}
EXPORT_SYMBOL(pci_iounmap);

#endif /* CONFIG_GENERIC_IOMAP */

#ifdef CONFIG_HOTPLUG
EXPORT_SYMBOL(PCIBIOS_MIN_IO);
EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
#endif