linux/arch/xtensa/kernel/pci.c

88 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* arch/xtensa/kernel/pci.c
*
* PCI bios-type initialisation for PCI machines
*
* Copyright (C) 2001-2005 Tensilica Inc.
*
* Based largely on work from Cort (ppc/kernel/pci.c)
* IO functions copied from sparc.
*
* Chris Zankel <chris@zankel.net>
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/memblock.h>
#include <asm/pci-bridge.h>
#include <asm/platform.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;
if (res->flags & IORESOURCE_IO) {
if (size > 0x100) {
pr_err("PCI: I/O Region %s/%d too large (%u bytes)\n",
pci_name(dev), dev->resource - res,
size);
}
if (start & 0x300)
start = (start + 0x3ff) & ~0x3ff;
}
return start;
}
void pcibios_fixup_bus(struct pci_bus *bus)
{
if (bus->parent) {
/* This is a subordinate bridge */
pci_read_bridge_bases(bus);
}
}
/*
* Platform support for /proc/bus/pci/X/Y mmap()s.
* -- paulus.
*/
int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma)
{
struct pci_controller *pci_ctrl = (struct pci_controller*) pdev->sysdata;
resource_size_t ioaddr = pci_resource_start(pdev, bar);
if (pci_ctrl == 0)
return -EINVAL; /* should never happen */
/* Convert to an offset within this PCI controller */
ioaddr -= (unsigned long)pci_ctrl->io_space.base;
vma->vm_pgoff += (ioaddr + pci_ctrl->io_space.start) >> PAGE_SHIFT;
return 0;
}