linux/arch/x86_64/kernel/vsmp.c
Andi Kleen 0637a70a5d [PATCH] x86: Allow disabling early pci scans with pci=noearly or disallowing conf1
Some buggy systems can machine check when config space accesses
happen for some non existent devices.  i386/x86-64 do some early
device scans that might trigger this. Allow pci=noearly to disable
this. Also when type 1 is disabling also don't do any early
accesses which are always type1.

This moves the pci= configuration parsing to be a early parameter.
I don't think this can break anything because it only changes
a single global that is only used by PCI.

Cc: gregkh@suse.de
Cc: Trammell Hudson <hudson@osresearch.net>

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:41 +02:00

49 lines
1.3 KiB
C

/*
* vSMPowered(tm) systems specific initialization
* Copyright (C) 2005 ScaleMP Inc.
*
* Use of this code is subject to the terms and conditions of the
* GNU general public license version 2. See "COPYING" or
* http://www.gnu.org/licenses/gpl.html
*
* Ravikiran Thirumalai <kiran@scalemp.com>,
* Shai Fultheim <shai@scalemp.com>
*/
#include <linux/init.h>
#include <linux/pci_ids.h>
#include <linux/pci_regs.h>
#include <asm/pci-direct.h>
static int __init vsmp_init(void)
{
void *address;
unsigned int cap, ctl;
if (!early_pci_allowed())
return 0;
/* Check if we are running on a ScaleMP vSMP box */
if ((read_pci_config_16(0, 0x1f, 0, PCI_VENDOR_ID) != PCI_VENDOR_ID_SCALEMP) ||
(read_pci_config_16(0, 0x1f, 0, PCI_DEVICE_ID) != PCI_DEVICE_ID_SCALEMP_VSMP_CTL))
return 0;
/* set vSMP magic bits to indicate vSMP capable kernel */
address = ioremap(read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0), 8);
cap = readl(address);
ctl = readl(address + 4);
printk("vSMP CTL: capabilities:0x%08x control:0x%08x\n", cap, ctl);
if (cap & ctl & (1 << 4)) {
/* Turn on vSMP IRQ fastpath handling (see system.h) */
ctl &= ~(1 << 4);
writel(ctl, address + 4);
ctl = readl(address + 4);
printk("vSMP CTL: control set to:0x%08x\n", ctl);
}
iounmap(address);
return 0;
}
core_initcall(vsmp_init);