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
  41 static void vsmp_restore_fl(unsigned long flags)
  42 {
  43         if (flags & X86_EFLAGS_IF)
  44                 flags &= ~X86_EFLAGS_AC;
  45         else
  46                 flags |= X86_EFLAGS_AC;
  47         native_restore_fl(flags);
  48 }
  49
  50 static void vsmp_irq_disable(void)
  51 {
  52         unsigned long flags = native_save_fl();
  53
  54         native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC);
  55 }
  56
  57 static void vsmp_irq_enable(void)
  58 {
  59         unsigned long flags = native_save_fl();
  60
  61         native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC));
  62 }
  63
  64 static unsigned __init_or_module vsmp_patch(u8 type, u16 clobbers, void *ibuf,
  65                                   unsigned long addr, unsigned len)
  66 {
  67         switch (type) {
  68         case PARAVIRT_PATCH(pv_irq_ops.irq_enable):
  69         case PARAVIRT_PATCH(pv_irq_ops.irq_disable):
  70         case PARAVIRT_PATCH(pv_irq_ops.save_fl):
  71         case PARAVIRT_PATCH(pv_irq_ops.restore_fl):
  72                 return paravirt_patch_default(type, clobbers, ibuf, addr, len);
  73         default:
  74                 return native_patch(type, clobbers, ibuf, addr, len);
  75         }
  76
  77 }
  78
  79 static void __init set_vsmp_pv_ops(void)
  80 {
  81         void __iomem *address;
  82         unsigned int cap, ctl, cfg;
  83
  84         /* set vSMP magic bits to indicate vSMP capable kernel */
  85         cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0);
  86         address = early_ioremap(cfg, 8);
  87         cap = readl(address);
  88         ctl = readl(address + 4);
  89         printk(KERN_INFO "vSMP CTL: capabilities:0x%08x  control:0x%08x\n",
  90                cap, ctl);
  91         if (cap & ctl & (1 << 4)) {
  92                 /* Setup irq ops and turn on vSMP  IRQ fastpath handling */
  93                 pv_irq_ops.irq_disable = vsmp_irq_disable;
  94                 pv_irq_ops.irq_enable  = vsmp_irq_enable;
  95                 pv_irq_ops.save_fl  = vsmp_save_fl;
  96                 pv_irq_ops.restore_fl  = vsmp_restore_fl;
  97                 pv_init_ops.patch = vsmp_patch;
  98
  99                 ctl &= ~(1 << 4);
 100                 writel(ctl, address + 4);
 101                 ctl = readl(address + 4);
 102                 printk(KERN_INFO "vSMP CTL: control set to:0x%08x\n", ctl);
 103         }
 104
 105         early_iounmap(address, 8);
 106 }
 107 #else
 108 static void __init set_vsmp_pv_ops(void)
 109 {
 110 }
 111 #endif
 112
 113 #ifdef CONFIG_PCI
 114 static int is_vsmp = -1;
 115
 116 static void __init detect_vsmp_box(void)
 117 {
 118         is_vsmp = 0;
 119
 120         if (!early_pci_allowed())
 121                 return;
 122
 123         /* Check if we are running on a ScaleMP vSMPowered box */
 124         if (read_pci_config(0, 0x1f, 0, PCI_VENDOR_ID) ==
 125              (PCI_VENDOR_ID_SCALEMP | (PCI_DEVICE_ID_SCALEMP_VSMP_CTL << 16)))
 126                 is_vsmp = 1;
 127 }
 128
 129 int is_vsmp_box(void)
 130 {
 131         if (is_vsmp != -1)
 132                 return is_vsmp;
 133         else {
 134                 WARN_ON_ONCE(1);
 135                 return 0;
 136         }
 137 }
 138 #else
 139 static void __init detect_vsmp_box(void)
 140 {
 141 }
 142 int is_vsmp_box(void)
 143 {
 144         return 0;
 145 }
 146 #endif
 147
 148 void __init vsmp_init(void)
 149 {
 150         detect_vsmp_box();
 151         if (!is_vsmp_box())
 152                 return;
 153
 154         set_vsmp_pv_ops();
 155         return;
 156 }