53 lines
1.6 KiB
C
53 lines
1.6 KiB
C
/*
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* Copyright (C) 2016 Imagination Technologies
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* Author: Paul Burton <paul.burton@mips.com>
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*
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* pcibios_align_resource taken from arch/arm/kernel/bios32.c.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/pci.h>
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/*
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* We need to avoid collisions with `mirrored' VGA ports
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* and other strange ISA hardware, so we always want the
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* addresses to be allocated in the 0x000-0x0ff region
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* modulo 0x400.
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*
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* Why? Because some silly external IO cards only decode
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* the low 10 bits of the IO address. The 0x00-0xff region
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* is reserved for motherboard devices that decode all 16
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* bits, so it's ok to allocate at, say, 0x2800-0x28ff,
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* but we want to try to avoid allocating at 0x2900-0x2bff
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* which might have be mirrored at 0x0100-0x03ff..
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*/
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resource_size_t pcibios_align_resource(void *data, const struct resource *res,
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resource_size_t size, resource_size_t align)
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{
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struct pci_dev *dev = data;
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resource_size_t start = res->start;
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struct pci_host_bridge *host_bridge;
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if (res->flags & IORESOURCE_IO && start & 0x300)
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start = (start + 0x3ff) & ~0x3ff;
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start = (start + align - 1) & ~(align - 1);
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host_bridge = pci_find_host_bridge(dev->bus);
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if (host_bridge->align_resource)
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return host_bridge->align_resource(dev, res,
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start, size, align);
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return start;
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}
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void pcibios_fixup_bus(struct pci_bus *bus)
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{
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pci_read_bridge_bases(bus);
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}
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