arch/x86/kernel/vsmp_64.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  * 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
  32 static 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 }
  40 PV_CALLEE_SAVE_REGS_THUNK(vsmp_save_fl);
  41
  42 static 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 }
  50 PV_CALLEE_SAVE_REGS_THUNK(vsmp_restore_fl);
  51
  52 static 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 }
  58 PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_disable);
  59
  60 static 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 }
  66 PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_enable);
  67
  68 static 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
  83 static 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
 112 static void __init set_vsmp_pv_ops(void)
 113 {
 114 }
 115 #endif
 116
 117 #ifdef CONFIG_PCI
 118 static int is_vsmp = -1;
 119
 120 static 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
 133 int 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
 144 static void __init detect_vsmp_box(void)
 145 {
 146 }
 147 int is_vsmp_box(void)
 148 {
 149         return 0;
 150 }
 151 #endif
 152 void __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 }