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// 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);
}
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