cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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pci.c (2233B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * arch/xtensa/kernel/pci.c
      4 *
      5 * PCI bios-type initialisation for PCI machines
      6 *
      7 * Copyright (C) 2001-2005 Tensilica Inc.
      8 *
      9 * Based largely on work from Cort (ppc/kernel/pci.c)
     10 * IO functions copied from sparc.
     11 *
     12 * Chris Zankel <chris@zankel.net>
     13 */
     14
     15#include <linux/kernel.h>
     16#include <linux/pci.h>
     17#include <linux/delay.h>
     18#include <linux/string.h>
     19#include <linux/init.h>
     20#include <linux/sched.h>
     21#include <linux/errno.h>
     22#include <linux/memblock.h>
     23
     24#include <asm/pci-bridge.h>
     25#include <asm/platform.h>
     26
     27/*
     28 * We need to avoid collisions with `mirrored' VGA ports
     29 * and other strange ISA hardware, so we always want the
     30 * addresses to be allocated in the 0x000-0x0ff region
     31 * modulo 0x400.
     32 *
     33 * Why? Because some silly external IO cards only decode
     34 * the low 10 bits of the IO address. The 0x00-0xff region
     35 * is reserved for motherboard devices that decode all 16
     36 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
     37 * but we want to try to avoid allocating at 0x2900-0x2bff
     38 * which might have be mirrored at 0x0100-0x03ff..
     39 */
     40resource_size_t
     41pcibios_align_resource(void *data, const struct resource *res,
     42		       resource_size_t size, resource_size_t align)
     43{
     44	struct pci_dev *dev = data;
     45	resource_size_t start = res->start;
     46
     47	if (res->flags & IORESOURCE_IO) {
     48		if (size > 0x100) {
     49			pr_err("PCI: I/O Region %s/%d too large (%u bytes)\n",
     50					pci_name(dev), dev->resource - res,
     51					size);
     52		}
     53
     54		if (start & 0x300)
     55			start = (start + 0x3ff) & ~0x3ff;
     56	}
     57
     58	return start;
     59}
     60
     61void pcibios_fixup_bus(struct pci_bus *bus)
     62{
     63	if (bus->parent) {
     64		/* This is a subordinate bridge */
     65		pci_read_bridge_bases(bus);
     66	}
     67}
     68
     69/*
     70 * Platform support for /proc/bus/pci/X/Y mmap()s.
     71 *  -- paulus.
     72 */
     73
     74int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma)
     75{
     76	struct pci_controller *pci_ctrl = (struct pci_controller*) pdev->sysdata;
     77	resource_size_t ioaddr = pci_resource_start(pdev, bar);
     78
     79	if (!pci_ctrl)
     80		return -EINVAL;		/* should never happen */
     81
     82	/* Convert to an offset within this PCI controller */
     83	ioaddr -= (unsigned long)pci_ctrl->io_space.base;
     84
     85	vma->vm_pgoff += (ioaddr + pci_ctrl->io_space.start) >> PAGE_SHIFT;
     86	return 0;
     87}