xref: /openbmc/linux/arch/x86/kernel/vsmp_64.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2  * vSMPowered(tm) systems specific initialization
3  * Copyright (C) 2005 ScaleMP Inc.
4  *
5  * Use of this code is subject to the terms and conditions of the
6  * GNU general public license version 2. See "COPYING" or
7  * http://www.gnu.org/licenses/gpl.html
8  *
9  * Ravikiran Thirumalai <kiran@scalemp.com>,
10  * Shai Fultheim <shai@scalemp.com>
11  */
12 
13 #include <linux/init.h>
14 #include <linux/pci_ids.h>
15 #include <linux/pci_regs.h>
16 #include <asm/pci-direct.h>
17 #include <asm/io.h>
18 
19 static int __init vsmp_init(void)
20 {
21 	void *address;
22 	unsigned int cap, ctl;
23 
24 	if (!early_pci_allowed())
25 		return 0;
26 
27 	/* Check if we are running on a ScaleMP vSMP box */
28 	if ((read_pci_config_16(0, 0x1f, 0, PCI_VENDOR_ID) != PCI_VENDOR_ID_SCALEMP) ||
29 	    (read_pci_config_16(0, 0x1f, 0, PCI_DEVICE_ID) != PCI_DEVICE_ID_SCALEMP_VSMP_CTL))
30 		return 0;
31 
32 	/* set vSMP magic bits to indicate vSMP capable kernel */
33 	address = ioremap(read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0), 8);
34 	cap = readl(address);
35 	ctl = readl(address + 4);
36 	printk("vSMP CTL: capabilities:0x%08x  control:0x%08x\n", cap, ctl);
37 	if (cap & ctl & (1 << 4)) {
38 		/* Turn on vSMP IRQ fastpath handling (see system.h) */
39 		ctl &= ~(1 << 4);
40 		writel(ctl, address + 4);
41 		ctl = readl(address + 4);
42 		printk("vSMP CTL: control set to:0x%08x\n", ctl);
43 	}
44 
45 	iounmap(address);
46 	return 0;
47 }
48 
49 core_initcall(vsmp_init);
50