LXR linux/arch/x86/kernel/vsmp

   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 * Paravirt ops integration: Glauber de Oliveira Costa <gcosta@redhat.com>,
  12 *                           Ravikiran Thirumalai <kiran@scalemp.com>
  13 */
  14
  15#include <linux/init.h>
  16#include <linux/pci_ids.h>
  17#include <linux/pci_regs.h>
  18
  19#include <asm/apic.h>
  20#include <asm/pci-direct.h>
  21#include <asm/io.h>
  22#include <asm/paravirt.h>
  23#include <asm/setup.h>
  24
  25#if defined CONFIG_PCI && defined CONFIG_PARAVIRT
  26/*
  27 * Interrupt control on vSMPowered systems:
  28 * ~AC is a shadow of IF.  If IF is 'on' AC should be 'off'
  29 * and vice versa.
  30 */
  31
  32static unsigned long vsmp_save_fl(void)
  33{
  34        unsigned long flags = native_save_fl();
  35
  36        if (!(flags & X86_EFLAGS_IF) || (flags & X86_EFLAGS_AC))
  37                flags &= ~X86_EFLAGS_IF;
  38        return flags;
  39}
  40PV_CALLEE_SAVE_REGS_THUNK(vsmp_save_fl);
  41
  42static void vsmp_restore_fl(unsigned long flags)
  43{
  44        if (flags & X86_EFLAGS_IF)
  45                flags &= ~X86_EFLAGS_AC;
  46        else
  47                flags |= X86_EFLAGS_AC;
  48        native_restore_fl(flags);
  49}
  50PV_CALLEE_SAVE_REGS_THUNK(vsmp_restore_fl);
  51
  52static void vsmp_irq_disable(void)
  53{
  54        unsigned long flags = native_save_fl();
  55
  56        native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC);
  57}
  58PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_disable);
  59
  60static void vsmp_irq_enable(void)
  61{
  62        unsigned long flags = native_save_fl();
  63
  64        native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC));
  65}
  66PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_enable);
  67
  68static unsigned __init_or_module vsmp_patch(u8 type, u16 clobbers, void *ibuf,
  69                                  unsigned long addr, unsigned len)
  70{
  71        switch (type) {
  72        case PARAVIRT_PATCH(pv_irq_ops.irq_enable):
  73        case PARAVIRT_PATCH(pv_irq_ops.irq_disable):
  74        case PARAVIRT_PATCH(pv_irq_ops.save_fl):
  75        case PARAVIRT_PATCH(pv_irq_ops.restore_fl):
  76                return paravirt_patch_default(type, clobbers, ibuf, addr, len);
  77        default:
  78                return native_patch(type, clobbers, ibuf, addr, len);
  79        }
  80
  81}
  82
  83static void __init set_vsmp_pv_ops(void)
  84{
  85        void __iomem *address;
  86        unsigned int cap, ctl, cfg;
  87
  88        /* set vSMP magic bits to indicate vSMP capable kernel */
  89        cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0);
  90        address = early_ioremap(cfg, 8);
  91        cap = readl(address);
  92        ctl = readl(address + 4);
  93        printk(KERN_INFO "vSMP CTL: capabilities:0x%08x  control:0x%08x\n",
  94               cap, ctl);
  95        if (cap & ctl & (1 << 4)) {
  96                /* Setup irq ops and turn on vSMP  IRQ fastpath handling */
  97                pv_irq_ops.irq_disable = PV_CALLEE_SAVE(vsmp_irq_disable);
  98                pv_irq_ops.irq_enable  = PV_CALLEE_SAVE(vsmp_irq_enable);
  99                pv_irq_ops.save_fl  = PV_CALLEE_SAVE(vsmp_save_fl);
 100                pv_irq_ops.restore_fl  = PV_CALLEE_SAVE(vsmp_restore_fl);
 101                pv_init_ops.patch = vsmp_patch;
 102
 103                ctl &= ~(1 << 4);
 104                writel(ctl, address + 4);
 105                ctl = readl(address + 4);
 106                printk(KERN_INFO "vSMP CTL: control set to:0x%08x\n", ctl);
 107        }
 108
 109        early_iounmap(address, 8);
 110}
 111#else
 112static void __init set_vsmp_pv_ops(void)
 113{
 114}
 115#endif
 116
 117#ifdef CONFIG_PCI
 118static int is_vsmp = -1;
 119
 120static void __init detect_vsmp_box(void)
 121{
 122        is_vsmp = 0;
 123
 124        if (!early_pci_allowed())
 125                return;
 126
 127        /* Check if we are running on a ScaleMP vSMPowered box */
 128        if (read_pci_config(0, 0x1f, 0, PCI_VENDOR_ID) ==
 129             (PCI_VENDOR_ID_SCALEMP | (PCI_DEVICE_ID_SCALEMP_VSMP_CTL << 16)))
 130                is_vsmp = 1;
 131}
 132
 133int is_vsmp_box(void)
 134{
 135        if (is_vsmp != -1)
 136                return is_vsmp;
 137        else {
 138                WARN_ON_ONCE(1);
 139                return 0;
 140        }
 141}
 142
 143#else
 144static void __init detect_vsmp_box(void)
 145{
 146}
 147int is_vsmp_box(void)
 148{
 149        return 0;
 150}
 151#endif
 152void __init vsmp_init(void)
 153{
 154        detect_vsmp_box();
 155        if (!is_vsmp_box())
 156                return;
 157
 158        set_vsmp_pv_ops();
 159        return;
 160}
 161