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1/* SPDX-License-Identifier: GPL-2.0 */
2
3/*
4 * Linux-specific definitions for managing interactions with Microsoft's
5 * Hyper-V hypervisor. The definitions in this file are architecture
6 * independent. See arch/<arch>/include/asm/mshyperv.h for definitions
7 * that are specific to architecture <arch>.
8 *
9 * Definitions that are specified in the Hyper-V Top Level Functional
10 * Spec (TLFS) should not go in this file, but should instead go in
11 * hyperv-tlfs.h.
12 *
13 * Copyright (C) 2019, Microsoft, Inc.
14 *
15 * Author : Michael Kelley <mikelley@microsoft.com>
16 */
17
18#ifndef _ASM_GENERIC_MSHYPERV_H
19#define _ASM_GENERIC_MSHYPERV_H
20
21#include <linux/types.h>
22#include <linux/atomic.h>
23#include <linux/bitops.h>
24#include <linux/cpumask.h>
25#include <asm/ptrace.h>
26#include <asm/hyperv-tlfs.h>
27
28struct ms_hyperv_info {
29 u32 features;
30 u32 misc_features;
31 u32 hints;
32 u32 nested_features;
33 u32 max_vp_index;
34 u32 max_lp_index;
35};
36extern struct ms_hyperv_info ms_hyperv;
37
38extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
39extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
40
41
42/* Generate the guest OS identifier as described in the Hyper-V TLFS */
43static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
44 __u64 d_info2)
45{
46 __u64 guest_id = 0;
47
48 guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
49 guest_id |= (d_info1 << 48);
50 guest_id |= (kernel_version << 16);
51 guest_id |= d_info2;
52
53 return guest_id;
54}
55
56
57/* Free the message slot and signal end-of-message if required */
58static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
59{
60 /*
61 * On crash we're reading some other CPU's message page and we need
62 * to be careful: this other CPU may already had cleared the header
63 * and the host may already had delivered some other message there.
64 * In case we blindly write msg->header.message_type we're going
65 * to lose it. We can still lose a message of the same type but
66 * we count on the fact that there can only be one
67 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
68 * on crash.
69 */
70 if (cmpxchg(&msg->header.message_type, old_msg_type,
71 HVMSG_NONE) != old_msg_type)
72 return;
73
74 /*
75 * The cmxchg() above does an implicit memory barrier to
76 * ensure the write to MessageType (ie set to
77 * HVMSG_NONE) happens before we read the
78 * MessagePending and EOMing. Otherwise, the EOMing
79 * will not deliver any more messages since there is
80 * no empty slot
81 */
82 if (msg->header.message_flags.msg_pending) {
83 /*
84 * This will cause message queue rescan to
85 * possibly deliver another msg from the
86 * hypervisor
87 */
88 hv_signal_eom();
89 }
90}
91
92int hv_setup_vmbus_irq(int irq, void (*handler)(void));
93void hv_remove_vmbus_irq(void);
94void hv_enable_vmbus_irq(void);
95void hv_disable_vmbus_irq(void);
96
97void hv_setup_kexec_handler(void (*handler)(void));
98void hv_remove_kexec_handler(void);
99void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
100void hv_remove_crash_handler(void);
101
102extern int vmbus_interrupt;
103
104#if IS_ENABLED(CONFIG_HYPERV)
105/*
106 * Hypervisor's notion of virtual processor ID is different from
107 * Linux' notion of CPU ID. This information can only be retrieved
108 * in the context of the calling CPU. Setup a map for easy access
109 * to this information.
110 */
111extern u32 *hv_vp_index;
112extern u32 hv_max_vp_index;
113
114/* Sentinel value for an uninitialized entry in hv_vp_index array */
115#define VP_INVAL U32_MAX
116
117/**
118 * hv_cpu_number_to_vp_number() - Map CPU to VP.
119 * @cpu_number: CPU number in Linux terms
120 *
121 * This function returns the mapping between the Linux processor
122 * number and the hypervisor's virtual processor number, useful
123 * in making hypercalls and such that talk about specific
124 * processors.
125 *
126 * Return: Virtual processor number in Hyper-V terms
127 */
128static inline int hv_cpu_number_to_vp_number(int cpu_number)
129{
130 return hv_vp_index[cpu_number];
131}
132
133static inline int cpumask_to_vpset(struct hv_vpset *vpset,
134 const struct cpumask *cpus)
135{
136 int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
137
138 /* valid_bank_mask can represent up to 64 banks */
139 if (hv_max_vp_index / 64 >= 64)
140 return 0;
141
142 /*
143 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
144 * structs are not cleared between calls, we risk flushing unneeded
145 * vCPUs otherwise.
146 */
147 for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
148 vpset->bank_contents[vcpu_bank] = 0;
149
150 /*
151 * Some banks may end up being empty but this is acceptable.
152 */
153 for_each_cpu(cpu, cpus) {
154 vcpu = hv_cpu_number_to_vp_number(cpu);
155 if (vcpu == VP_INVAL)
156 return -1;
157 vcpu_bank = vcpu / 64;
158 vcpu_offset = vcpu % 64;
159 __set_bit(vcpu_offset, (unsigned long *)
160 &vpset->bank_contents[vcpu_bank]);
161 if (vcpu_bank >= nr_bank)
162 nr_bank = vcpu_bank + 1;
163 }
164 vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
165 return nr_bank;
166}
167
168void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
169void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
170bool hv_is_hyperv_initialized(void);
171bool hv_is_hibernation_supported(void);
172void hyperv_cleanup(void);
173#else /* CONFIG_HYPERV */
174static inline bool hv_is_hyperv_initialized(void) { return false; }
175static inline bool hv_is_hibernation_supported(void) { return false; }
176static inline void hyperv_cleanup(void) {}
177#endif /* CONFIG_HYPERV */
178
179#if IS_ENABLED(CONFIG_HYPERV)
180extern int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void));
181extern void hv_remove_stimer0_irq(int irq);
182#endif
183
184#endif