xref: /openbmc/linux/arch/x86/kernel/vsmp_64.c (revision a1e58bbd)
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) !=
29 	     PCI_VENDOR_ID_SCALEMP) ||
30 	    (read_pci_config_16(0, 0x1f, 0, PCI_DEVICE_ID) !=
31 	     PCI_DEVICE_ID_SCALEMP_VSMP_CTL))
32 		return 0;
33 
34 	/* set vSMP magic bits to indicate vSMP capable kernel */
35 	address = ioremap(read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0), 8);
36 	cap = readl(address);
37 	ctl = readl(address + 4);
38 	printk(KERN_INFO "vSMP CTL: capabilities:0x%08x  control:0x%08x\n",
39 	       cap, ctl);
40 	if (cap & ctl & (1 << 4)) {
41 		/* Turn on vSMP IRQ fastpath handling (see system.h) */
42 		ctl &= ~(1 << 4);
43 		writel(ctl, address + 4);
44 		ctl = readl(address + 4);
45 		printk(KERN_INFO "vSMP CTL: control set to:0x%08x\n", ctl);
46 	}
47 
48 	iounmap(address);
49 	return 0;
50 }
51 
52 core_initcall(vsmp_init);
53