1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * definition for paravirtual devices on s390
4 *
5 * Copyright IBM Corp. 2008
6 *
7 *    Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
8 */
9/*
10 * Hypercalls for KVM on s390. The calling convention is similar to the
11 * s390 ABI, so we use R2-R6 for parameters 1-5. In addition we use R1
12 * as hypercall number and R7 as parameter 6. The return value is
13 * written to R2. We use the diagnose instruction as hypercall. To avoid
14 * conflicts with existing diagnoses for LPAR and z/VM, we do not use
15 * the instruction encoded number, but specify the number in R1 and
16 * use 0x500 as KVM hypercall
17 *
18 * Copyright IBM Corp. 2007,2008
19 * Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
20 */
21#ifndef __S390_KVM_PARA_H
22#define __S390_KVM_PARA_H
23
24#include <uapi/asm/kvm_para.h>
25#include <asm/diag.h>
26
27#define HYPERCALL_FMT_0
28#define HYPERCALL_FMT_1 , "0" (r2)
29#define HYPERCALL_FMT_2 , "d" (r3) HYPERCALL_FMT_1
30#define HYPERCALL_FMT_3 , "d" (r4) HYPERCALL_FMT_2
31#define HYPERCALL_FMT_4 , "d" (r5) HYPERCALL_FMT_3
32#define HYPERCALL_FMT_5 , "d" (r6) HYPERCALL_FMT_4
33#define HYPERCALL_FMT_6 , "d" (r7) HYPERCALL_FMT_5
34
35#define HYPERCALL_PARM_0
36#define HYPERCALL_PARM_1 , unsigned long arg1
37#define HYPERCALL_PARM_2 HYPERCALL_PARM_1, unsigned long arg2
38#define HYPERCALL_PARM_3 HYPERCALL_PARM_2, unsigned long arg3
39#define HYPERCALL_PARM_4 HYPERCALL_PARM_3, unsigned long arg4
40#define HYPERCALL_PARM_5 HYPERCALL_PARM_4, unsigned long arg5
41#define HYPERCALL_PARM_6 HYPERCALL_PARM_5, unsigned long arg6
42
43#define HYPERCALL_REGS_0
44#define HYPERCALL_REGS_1						\
45	register unsigned long r2 asm("2") = arg1
46#define HYPERCALL_REGS_2						\
47	HYPERCALL_REGS_1;						\
48	register unsigned long r3 asm("3") = arg2
49#define HYPERCALL_REGS_3						\
50	HYPERCALL_REGS_2;						\
51	register unsigned long r4 asm("4") = arg3
52#define HYPERCALL_REGS_4						\
53	HYPERCALL_REGS_3;						\
54	register unsigned long r5 asm("5") = arg4
55#define HYPERCALL_REGS_5						\
56	HYPERCALL_REGS_4;						\
57	register unsigned long r6 asm("6") = arg5
58#define HYPERCALL_REGS_6						\
59	HYPERCALL_REGS_5;						\
60	register unsigned long r7 asm("7") = arg6
61
62#define HYPERCALL_ARGS_0
63#define HYPERCALL_ARGS_1 , arg1
64#define HYPERCALL_ARGS_2 HYPERCALL_ARGS_1, arg2
65#define HYPERCALL_ARGS_3 HYPERCALL_ARGS_2, arg3
66#define HYPERCALL_ARGS_4 HYPERCALL_ARGS_3, arg4
67#define HYPERCALL_ARGS_5 HYPERCALL_ARGS_4, arg5
68#define HYPERCALL_ARGS_6 HYPERCALL_ARGS_5, arg6
69
70#define GENERATE_KVM_HYPERCALL_FUNC(args)				\
71static inline								\
72long __kvm_hypercall##args(unsigned long nr HYPERCALL_PARM_##args)	\
73{									\
74	register unsigned long __nr asm("1") = nr;			\
75	register long __rc asm("2");					\
76	HYPERCALL_REGS_##args;						\
77									\
78	asm volatile (							\
79		"	diag	2,4,0x500\n"				\
80		: "=d" (__rc)						\
81		: "d" (__nr) HYPERCALL_FMT_##args			\
82		: "memory", "cc");					\
83	return __rc;							\
84}									\
85									\
86static inline								\
87long kvm_hypercall##args(unsigned long nr HYPERCALL_PARM_##args)	\
88{									\
89	diag_stat_inc(DIAG_STAT_X500);					\
90	return __kvm_hypercall##args(nr HYPERCALL_ARGS_##args);		\
91}
92
93GENERATE_KVM_HYPERCALL_FUNC(0)
94GENERATE_KVM_HYPERCALL_FUNC(1)
95GENERATE_KVM_HYPERCALL_FUNC(2)
96GENERATE_KVM_HYPERCALL_FUNC(3)
97GENERATE_KVM_HYPERCALL_FUNC(4)
98GENERATE_KVM_HYPERCALL_FUNC(5)
99GENERATE_KVM_HYPERCALL_FUNC(6)
100
101/* kvm on s390 is always paravirtualization enabled */
102static inline int kvm_para_available(void)
103{
104	return 1;
105}
106
107/* No feature bits are currently assigned for kvm on s390 */
108static inline unsigned int kvm_arch_para_features(void)
109{
110	return 0;
111}
112
113static inline unsigned int kvm_arch_para_hints(void)
114{
115	return 0;
116}
117
118static inline bool kvm_check_and_clear_guest_paused(void)
119{
120	return false;
121}
122
123#endif /* __S390_KVM_PARA_H */
124