indirect_pci.c

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/*
 * Support for indirect PCI bridges.
 *
 * Copyright (C) 1998 Gabriel Paubert.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>

#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>

static int
indirect_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
             int len, u32 *val)
{
    struct pci_controller *hose = pci_bus_to_host(bus);
    volatile void __iomem *cfg_data;
    u8 cfg_type = 0;
    u32 bus_no, reg;

    if (hose->indirect_type & INDIRECT_TYPE_NO_PCIE_LINK) {
        if (bus->number != hose->first_busno)
            return PCIBIOS_DEVICE_NOT_FOUND;
        if (devfn != 0)
            return PCIBIOS_DEVICE_NOT_FOUND;
    }

    if (hose->indirect_type & INDIRECT_TYPE_SET_CFG_TYPE)
        if (bus->number != hose->first_busno)
            cfg_type = 1;

    bus_no = (bus->number == hose->first_busno) ?
            hose->self_busno : bus->number;

    if (hose->indirect_type & INDIRECT_TYPE_EXT_REG)
        reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
    else
        reg = offset & 0xfc; /* Only 3 bits for function */

    if (hose->indirect_type & INDIRECT_TYPE_BIG_ENDIAN)
        out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
             (devfn << 8) | reg | cfg_type));
    else
        out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
             (devfn << 8) | reg | cfg_type));

    /*
     * Note: the caller has already checked that offset is
     * suitably aligned and that len is 1, 2 or 4.
     */
    cfg_data = hose->cfg_data + (offset & 3); /* Only 3 bits for function */
    switch (len) {
    case 1:
        *val = in_8(cfg_data);
        break;
    case 2:
        *val = in_le16(cfg_data);
        break;
    default:
        *val = in_le32(cfg_data);
        break;
    }
    return PCIBIOS_SUCCESSFUL;
}

static int
indirect_write_config(struct pci_bus *bus, unsigned int devfn, int offset,
              int len, u32 val)
{
    struct pci_controller *hose = pci_bus_to_host(bus);
    volatile void __iomem *cfg_data;
    u8 cfg_type = 0;
    u32 bus_no, reg;

    if (hose->indirect_type & INDIRECT_TYPE_NO_PCIE_LINK) {
        if (bus->number != hose->first_busno)
            return PCIBIOS_DEVICE_NOT_FOUND;
        if (devfn != 0)
            return PCIBIOS_DEVICE_NOT_FOUND;
    }

    if (hose->indirect_type & INDIRECT_TYPE_SET_CFG_TYPE)
        if (bus->number != hose->first_busno)
            cfg_type = 1;

    bus_no = (bus->number == hose->first_busno) ?
            hose->self_busno : bus->number;

    if (hose->indirect_type & INDIRECT_TYPE_EXT_REG)
        reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
    else
        reg = offset & 0xfc;

    if (hose->indirect_type & INDIRECT_TYPE_BIG_ENDIAN)
        out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
             (devfn << 8) | reg | cfg_type));
    else
        out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
             (devfn << 8) | reg | cfg_type));

    /* suppress setting of PCI_PRIMARY_BUS */
    if (hose->indirect_type & INDIRECT_TYPE_SURPRESS_PRIMARY_BUS)
        if ((offset == PCI_PRIMARY_BUS) &&
            (bus->number == hose->first_busno))
            val &= 0xffffff00;

    /* Workaround for PCI_28 Errata in 440EPx/GRx */
    if ((hose->indirect_type & INDIRECT_TYPE_BROKEN_MRM) &&
            offset == PCI_CACHE_LINE_SIZE) {
        val = 0;
    }

    /*
     * Note: the caller has already checked that offset is
     * suitably aligned and that len is 1, 2 or 4.
     */
    cfg_data = hose->cfg_data + (offset & 3);
    switch (len) {
    case 1:
        out_8(cfg_data, val);
        break;
    case 2:
        out_le16(cfg_data, val);
        break;
    default:
        out_le32(cfg_data, val);
        break;
    }

    return PCIBIOS_SUCCESSFUL;
}

static struct pci_ops indirect_pci_ops = {
    .read = indirect_read_config,
    .write = indirect_write_config,
};

void __init
setup_indirect_pci(struct pci_controller *hose,
           resource_size_t cfg_addr,
           resource_size_t cfg_data, u32 flags)
{
    resource_size_t base = cfg_addr & PAGE_MASK;
    void __iomem *mbase;

    mbase = ioremap(base, PAGE_SIZE);
    hose->cfg_addr = mbase + (cfg_addr & ~PAGE_MASK);
    if ((cfg_data & PAGE_MASK) != base)
        mbase = ioremap(cfg_data & PAGE_MASK, PAGE_SIZE);
    hose->cfg_data = mbase + (cfg_data & ~PAGE_MASK);
    hose->ops = &indirect_pci_ops;
    hose->indirect_type = flags;
}