Pileus Git - ~andy/linux/blob - 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 <linux/smp.h>
  19
  20 #include <asm/apic.h>
  21 #include <asm/pci-direct.h>
  22 #include <asm/io.h>
  23 #include <asm/paravirt.h>
  24 #include <asm/setup.h>
  25
  26 #define TOPOLOGY_REGISTER_OFFSET 0x10
  27
  28 #if defined CONFIG_PCI && defined CONFIG_PARAVIRT
  29 /*
  30  * Interrupt control on vSMPowered systems:
  31  * ~AC is a shadow of IF.  If IF is 'on' AC should be 'off'
  32  * and vice versa.
  33  */
  34
  35 static unsigned long vsmp_save_fl(void)
  36 {
  37         unsigned long flags = native_save_fl();
  38
  39         if (!(flags & X86_EFLAGS_IF) || (flags & X86_EFLAGS_AC))
  40                 flags &= ~X86_EFLAGS_IF;
  41         return flags;
  42 }
  43 PV_CALLEE_SAVE_REGS_THUNK(vsmp_save_fl);
  44
  45 static void vsmp_restore_fl(unsigned long flags)
  46 {
  47         if (flags & X86_EFLAGS_IF)
  48                 flags &= ~X86_EFLAGS_AC;
  49         else
  50                 flags |= X86_EFLAGS_AC;
  51         native_restore_fl(flags);
  52 }
  53 PV_CALLEE_SAVE_REGS_THUNK(vsmp_restore_fl);
  54
  55 static void vsmp_irq_disable(void)
  56 {
  57         unsigned long flags = native_save_fl();
  58
  59         native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC);
  60 }
  61 PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_disable);
  62
  63 static void vsmp_irq_enable(void)
  64 {
  65         unsigned long flags = native_save_fl();
  66
  67         native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC));
  68 }
  69 PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_enable);
  70
  71 static unsigned __init_or_module vsmp_patch(u8 type, u16 clobbers, void *ibuf,
  72                                   unsigned long addr, unsigned len)
  73 {
  74         switch (type) {
  75         case PARAVIRT_PATCH(pv_irq_ops.irq_enable):
  76         case PARAVIRT_PATCH(pv_irq_ops.irq_disable):
  77         case PARAVIRT_PATCH(pv_irq_ops.save_fl):
  78         case PARAVIRT_PATCH(pv_irq_ops.restore_fl):
  79                 return paravirt_patch_default(type, clobbers, ibuf, addr, len);
  80         default:
  81                 return native_patch(type, clobbers, ibuf, addr, len);
  82         }
  83
  84 }
  85
  86 static void __init set_vsmp_pv_ops(void)
  87 {
  88         void __iomem *address;
  89         unsigned int cap, ctl, cfg;
  90
  91         /* set vSMP magic bits to indicate vSMP capable kernel */
  92         cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0);
  93         address = early_ioremap(cfg, 8);
  94         cap = readl(address);
  95         ctl = readl(address + 4);
  96         printk(KERN_INFO "vSMP CTL: capabilities:0x%08x  control:0x%08x\n",
  97                cap, ctl);
  98         if (cap & ctl & (1 << 4)) {
  99                 /* Setup irq ops and turn on vSMP  IRQ fastpath handling */
 100                 pv_irq_ops.irq_disable = PV_CALLEE_SAVE(vsmp_irq_disable);
 101                 pv_irq_ops.irq_enable  = PV_CALLEE_SAVE(vsmp_irq_enable);
 102                 pv_irq_ops.save_fl  = PV_CALLEE_SAVE(vsmp_save_fl);
 103                 pv_irq_ops.restore_fl  = PV_CALLEE_SAVE(vsmp_restore_fl);
 104                 pv_init_ops.patch = vsmp_patch;
 105
 106                 ctl &= ~(1 << 4);
 107                 writel(ctl, address + 4);
 108                 ctl = readl(address + 4);
 109                 printk(KERN_INFO "vSMP CTL: control set to:0x%08x\n", ctl);
 110         }
 111
 112         early_iounmap(address, 8);
 113 }
 114 #else
 115 static void __init set_vsmp_pv_ops(void)
 116 {
 117 }
 118 #endif
 119
 120 #ifdef CONFIG_PCI
 121 static int is_vsmp = -1;
 122
 123 static void __init detect_vsmp_box(void)
 124 {
 125         is_vsmp = 0;
 126
 127         if (!early_pci_allowed())
 128                 return;
 129
 130         /* Check if we are running on a ScaleMP vSMPowered box */
 131         if (read_pci_config(0, 0x1f, 0, PCI_VENDOR_ID) ==
 132              (PCI_VENDOR_ID_SCALEMP | (PCI_DEVICE_ID_SCALEMP_VSMP_CTL << 16)))
 133                 is_vsmp = 1;
 134 }
 135
 136 int is_vsmp_box(void)
 137 {
 138         if (is_vsmp != -1)
 139                 return is_vsmp;
 140         else {
 141                 WARN_ON_ONCE(1);
 142                 return 0;
 143         }
 144 }
 145
 146 #else
 147 static void __init detect_vsmp_box(void)
 148 {
 149 }
 150 int is_vsmp_box(void)
 151 {
 152         return 0;
 153 }
 154 #endif
 155
 156 static void __init vsmp_cap_cpus(void)
 157 {
 158 #if !defined(CONFIG_X86_VSMP) && defined(CONFIG_SMP)
 159         void __iomem *address;
 160         unsigned int cfg, topology, node_shift, maxcpus;
 161
 162         /*
 163          * CONFIG_X86_VSMP is not configured, so limit the number CPUs to the
 164          * ones present in the first board, unless explicitly overridden by
 165          * setup_max_cpus
 166          */
 167         if (setup_max_cpus != NR_CPUS)
 168                 return;
 169
 170         /* Read the vSMP Foundation topology register */
 171         cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0);
 172         address = early_ioremap(cfg + TOPOLOGY_REGISTER_OFFSET, 4);
 173         if (WARN_ON(!address))
 174                 return;
 175
 176         topology = readl(address);
 177         node_shift = (topology >> 16) & 0x7;
 178         if (!node_shift)
 179                 /* The value 0 should be decoded as 8 */
 180                 node_shift = 8;
 181         maxcpus = (topology & ((1 << node_shift) - 1)) + 1;
 182
 183         pr_info("vSMP CTL: Capping CPUs to %d (CONFIG_X86_VSMP is unset)\n",
 184                 maxcpus);
 185         setup_max_cpus = maxcpus;
 186         early_iounmap(address, 4);
 187 #endif
 188 }
 189
 190 void __init vsmp_init(void)
 191 {
 192         detect_vsmp_box();
 193         if (!is_vsmp_box())
 194                 return;
 195
 196         vsmp_cap_cpus();
 197
 198         set_vsmp_pv_ops();
 199         return;
 200 }