arch/x86_64/kernel/vsmp.c

   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);