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 */