// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 Imagination Technologies
 * Author: Paul Burton <paul.burton@mips.com>
 *
 * pcibios_align_resource taken from arch/arm/kernel/bios32.c.
 */

#include <linux/pci.h>

/*
 * 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.
 *
 * Why? Because some silly external IO cards only decode
 * the low 10 bits of the IO address. The 0x00-0xff region
 * is reserved for motherboard devices that decode all 16
 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
 * but we want to try to avoid allocating at 0x2900-0x2bff
 * which might have be mirrored at 0x0100-0x03ff..
 */
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;
        resource_size_t start = res->start;
        struct pci_host_bridge *host_bridge;

        if (res->flags & IORESOURCE_IO && start & 0x300)
                start = (start + 0x3ff) & ~0x3ff;

        start = (start + align - 1) & ~(align - 1);

        host_bridge = pci_find_host_bridge(dev->bus);

        if (host_bridge->align_resource)
                return host_bridge->align_resource(dev, res,
                                start, size, align);

        return start;
}

void pcibios_fixup_bus(struct pci_bus *bus)
{
        pci_read_bridge_bases(bus);
}

#ifdef pci_remap_iospace
int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
{
        unsigned long vaddr;

        if (res->start != 0) {
                WARN_ONCE(1, "resource start address is not zero\n");
                return -ENODEV;
        }

        vaddr = (unsigned long)ioremap(phys_addr, resource_size(res));
        set_io_port_base(vaddr);
        return 0;
}
#endif