x86: introduce vsmp paravirt helpers
[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 /*
23  * Interrupt control on vSMPowered systems:
24  * ~AC is a shadow of IF.  If IF is 'on' AC should be 'off'
25  * and vice versa.
26  */
27
28 static unsigned long vsmp_save_fl(void)
29 {
30         unsigned long flags = native_save_fl();
31
32         if (!(flags & X86_EFLAGS_IF) || (flags & X86_EFLAGS_AC))
33                 flags &= ~X86_EFLAGS_IF;
34         return flags;
35 }
36
37 static void vsmp_restore_fl(unsigned long flags)
38 {
39         if (flags & X86_EFLAGS_IF)
40                 flags &= ~X86_EFLAGS_AC;
41         else
42                 flags |= X86_EFLAGS_AC;
43         native_restore_fl(flags);
44 }
45
46 static void vsmp_irq_disable(void)
47 {
48         unsigned long flags = native_save_fl();
49
50         native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC);
51 }
52
53 static void vsmp_irq_enable(void)
54 {
55         unsigned long flags = native_save_fl();
56
57         native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC));
58 }
59
60 static unsigned __init vsmp_patch(u8 type, u16 clobbers, void *ibuf,
61                                   unsigned long addr, unsigned len)
62 {
63         switch (type) {
64         case PARAVIRT_PATCH(pv_irq_ops.irq_enable):
65         case PARAVIRT_PATCH(pv_irq_ops.irq_disable):
66         case PARAVIRT_PATCH(pv_irq_ops.save_fl):
67         case PARAVIRT_PATCH(pv_irq_ops.restore_fl):
68                 return paravirt_patch_default(type, clobbers, ibuf, addr, len);
69         default:
70                 return native_patch(type, clobbers, ibuf, addr, len);
71         }
72
73 }
74
75 void __init vsmp_init(void)
76 {
77         void *address;
78         unsigned int cap, ctl, cfg;
79
80         if (!early_pci_allowed())
81                 return;
82
83         /* Check if we are running on a ScaleMP vSMP box */
84         if ((read_pci_config_16(0, 0x1f, 0, PCI_VENDOR_ID) !=
85              PCI_VENDOR_ID_SCALEMP) ||
86             (read_pci_config_16(0, 0x1f, 0, PCI_DEVICE_ID) !=
87              PCI_DEVICE_ID_SCALEMP_VSMP_CTL))
88                 return;
89
90         /* set vSMP magic bits to indicate vSMP capable kernel */
91         cfg = read_pci_config(0, 0x1f, 0, PCI_BASE_ADDRESS_0);
92         address = early_ioremap(cfg, 8);
93         cap = readl(address);
94         ctl = readl(address + 4);
95         printk(KERN_INFO "vSMP CTL: capabilities:0x%08x  control:0x%08x\n",
96                cap, ctl);
97         if (cap & ctl & (1 << 4)) {
98                 /* Turn on vSMP IRQ fastpath handling (see system.h) */
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         return;
107 }