xref: /linux/arch/x86/xen/setup.c (revision 2b8232ce512105e28453f301d1510de8363bccd1)
1 /*
2  * Machine specific setup for xen
3  *
4  * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
5  */
6 
7 #include <linux/module.h>
8 #include <linux/sched.h>
9 #include <linux/mm.h>
10 #include <linux/pm.h>
11 
12 #include <asm/elf.h>
13 #include <asm/e820.h>
14 #include <asm/setup.h>
15 #include <asm/xen/hypervisor.h>
16 #include <asm/xen/hypercall.h>
17 
18 #include <xen/interface/physdev.h>
19 #include <xen/features.h>
20 
21 #include "xen-ops.h"
22 #include "vdso.h"
23 
24 /* These are code, but not functions.  Defined in entry.S */
25 extern const char xen_hypervisor_callback[];
26 extern const char xen_failsafe_callback[];
27 
28 unsigned long *phys_to_machine_mapping;
29 EXPORT_SYMBOL(phys_to_machine_mapping);
30 
31 /**
32  * machine_specific_memory_setup - Hook for machine specific memory setup.
33  **/
34 
35 char * __init xen_memory_setup(void)
36 {
37 	unsigned long max_pfn = xen_start_info->nr_pages;
38 
39 	e820.nr_map = 0;
40 	add_memory_region(0, PFN_PHYS(max_pfn), E820_RAM);
41 
42 	return "Xen";
43 }
44 
45 static void xen_idle(void)
46 {
47 	local_irq_disable();
48 
49 	if (need_resched())
50 		local_irq_enable();
51 	else {
52 		current_thread_info()->status &= ~TS_POLLING;
53 		smp_mb__after_clear_bit();
54 		safe_halt();
55 		current_thread_info()->status |= TS_POLLING;
56 	}
57 }
58 
59 /*
60  * Set the bit indicating "nosegneg" library variants should be used.
61  */
62 static void fiddle_vdso(void)
63 {
64 	extern u32 VDSO_NOTE_MASK; /* See ../kernel/vsyscall-note.S.  */
65 	extern char vsyscall_int80_start;
66 	u32 *mask = (u32 *) ((unsigned long) &VDSO_NOTE_MASK - VDSO_PRELINK +
67 			     &vsyscall_int80_start);
68 	*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
69 }
70 
71 void __init xen_arch_setup(void)
72 {
73 	struct physdev_set_iopl set_iopl;
74 	int rc;
75 
76 	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
77 	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
78 
79 	if (!xen_feature(XENFEAT_auto_translated_physmap))
80 		HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_pae_extended_cr3);
81 
82 	HYPERVISOR_set_callbacks(__KERNEL_CS, (unsigned long)xen_hypervisor_callback,
83 				 __KERNEL_CS, (unsigned long)xen_failsafe_callback);
84 
85 	set_iopl.iopl = 1;
86 	rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
87 	if (rc != 0)
88 		printk(KERN_INFO "physdev_op failed %d\n", rc);
89 
90 #ifdef CONFIG_ACPI
91 	if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
92 		printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
93 		disable_acpi();
94 	}
95 #endif
96 
97 	memcpy(boot_command_line, xen_start_info->cmd_line,
98 	       MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
99 	       COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
100 
101 	pm_idle = xen_idle;
102 
103 #ifdef CONFIG_SMP
104 	/* fill cpus_possible with all available cpus */
105 	xen_fill_possible_map();
106 #endif
107 
108 	paravirt_disable_iospace();
109 
110 	fiddle_vdso();
111 }
112