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