x86: fix build breakage when PCI is define and PARAVIRT is not
[sfrench/cifs-2.6.git] / 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         pv_irq_ops.irq_disable = vsmp_irq_disable;
82         pv_irq_ops.irq_enable  = vsmp_irq_enable;
83         pv_irq_ops.save_fl  = vsmp_save_fl;
84         pv_irq_ops.restore_fl  = vsmp_restore_fl;
85         pv_init_ops.patch = vsmp_patch;
86
87         /* set vSMP magic bits to indicate vSMP capable kernel */
88         cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0);
89         address = early_ioremap(cfg, 8);
90         cap = readl(address);
91         ctl = readl(address + 4);
92         printk(KERN_INFO "vSMP CTL: capabilities:0x%08x  control:0x%08x\n",
93                cap, ctl);
94         if (cap & ctl & (1 << 4)) {
95                 /* Turn on vSMP IRQ fastpath handling (see system.h) */
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 vsmp = -1;
112
113 int is_vsmp_box(void)
114 {
115         if (vsmp != -1)
116                 return vsmp;
117
118         vsmp = 0;
119         if (!early_pci_allowed())
120                 return vsmp;
121
122         /* Check if we are running on a ScaleMP vSMP box */
123         if ((read_pci_config_16(0, 0x1f, 0, PCI_VENDOR_ID) ==
124              PCI_VENDOR_ID_SCALEMP) &&
125             (read_pci_config_16(0, 0x1f, 0, PCI_DEVICE_ID) ==
126             PCI_DEVICE_ID_SCALEMP_VSMP_CTL))
127                 vsmp = 1;
128
129         return vsmp;
130 }
131 #else
132 int is_vsmp_box(void)
133 {
134         return 0;
135 }
136 #endif
137
138 void __init vsmp_init(void)
139 {
140         if (!is_vsmp_box())
141                 return;
142
143         set_vsmp_pv_ops();
144         return;
145 }