xref: /openbmc/linux/arch/x86/include/asm/xen/hypervisor.h (revision 8957261c)
1 /******************************************************************************
2  * hypervisor.h
3  *
4  * Linux-specific hypervisor handling.
5  *
6  * Copyright (c) 2002-2004, K A Fraser
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License version 2
10  * as published by the Free Software Foundation; or, when distributed
11  * separately from the Linux kernel or incorporated into other
12  * software packages, subject to the following license:
13  *
14  * Permission is hereby granted, free of charge, to any person obtaining a copy
15  * of this source file (the "Software"), to deal in the Software without
16  * restriction, including without limitation the rights to use, copy, modify,
17  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
18  * and to permit persons to whom the Software is furnished to do so, subject to
19  * the following conditions:
20  *
21  * The above copyright notice and this permission notice shall be included in
22  * all copies or substantial portions of the Software.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
25  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
26  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
27  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
28  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
29  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
30  * IN THE SOFTWARE.
31  */
32 
33 #ifndef _ASM_X86_XEN_HYPERVISOR_H
34 #define _ASM_X86_XEN_HYPERVISOR_H
35 
36 extern struct shared_info *HYPERVISOR_shared_info;
37 extern struct start_info *xen_start_info;
38 
39 #include <asm/bug.h>
40 #include <asm/processor.h>
41 
42 #define XEN_SIGNATURE "XenVMMXenVMM"
43 
44 static inline uint32_t xen_cpuid_base(void)
45 {
46 	return hypervisor_cpuid_base(XEN_SIGNATURE, 2);
47 }
48 
49 struct pci_dev;
50 
51 #ifdef CONFIG_XEN_PV_DOM0
52 bool xen_initdom_restore_msi(struct pci_dev *dev);
53 #else
54 static inline bool xen_initdom_restore_msi(struct pci_dev *dev) { return true; }
55 #endif
56 
57 #ifdef CONFIG_HOTPLUG_CPU
58 void xen_arch_register_cpu(int num);
59 void xen_arch_unregister_cpu(int num);
60 #endif
61 
62 #ifdef CONFIG_PVH
63 void __init xen_pvh_init(struct boot_params *boot_params);
64 void __init mem_map_via_hcall(struct boot_params *boot_params_p);
65 #endif
66 
67 /* Lazy mode for batching updates / context switch */
68 enum xen_lazy_mode {
69 	XEN_LAZY_NONE,
70 	XEN_LAZY_MMU,
71 	XEN_LAZY_CPU,
72 };
73 
74 DECLARE_PER_CPU(enum xen_lazy_mode, xen_lazy_mode);
75 DECLARE_PER_CPU(unsigned int, xen_lazy_nesting);
76 
77 static inline void enter_lazy(enum xen_lazy_mode mode)
78 {
79 	enum xen_lazy_mode old_mode = this_cpu_read(xen_lazy_mode);
80 
81 	if (mode == old_mode) {
82 		this_cpu_inc(xen_lazy_nesting);
83 		return;
84 	}
85 
86 	BUG_ON(old_mode != XEN_LAZY_NONE);
87 
88 	this_cpu_write(xen_lazy_mode, mode);
89 }
90 
91 static inline void leave_lazy(enum xen_lazy_mode mode)
92 {
93 	BUG_ON(this_cpu_read(xen_lazy_mode) != mode);
94 
95 	if (this_cpu_read(xen_lazy_nesting) == 0)
96 		this_cpu_write(xen_lazy_mode, XEN_LAZY_NONE);
97 	else
98 		this_cpu_dec(xen_lazy_nesting);
99 }
100 
101 enum xen_lazy_mode xen_get_lazy_mode(void);
102 
103 #endif /* _ASM_X86_XEN_HYPERVISOR_H */
104