1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef LINUX_KEXEC_HANDOVER_H
3#define LINUX_KEXEC_HANDOVER_H
4
5#include <linux/err.h>
6#include <linux/errno.h>
7#include <linux/types.h>
8
9struct kho_scratch {
10 phys_addr_t addr;
11 phys_addr_t size;
12};
13
14struct folio;
15struct page;
16
17#define DECLARE_KHOSER_PTR(name, type) \
18 union { \
19 phys_addr_t phys; \
20 type ptr; \
21 } name
22#define KHOSER_STORE_PTR(dest, val) \
23 ({ \
24 typeof(val) v = val; \
25 typecheck(typeof((dest).ptr), v); \
26 (dest).phys = virt_to_phys(v); \
27 })
28#define KHOSER_LOAD_PTR(src) \
29 ({ \
30 typeof(src) s = src; \
31 (typeof((s).ptr))((s).phys ? phys_to_virt((s).phys) : NULL); \
32 })
33
34struct kho_vmalloc_chunk;
35struct kho_vmalloc {
36 DECLARE_KHOSER_PTR(first, struct kho_vmalloc_chunk *);
37 unsigned int total_pages;
38 unsigned short flags;
39 unsigned short order;
40};
41
42#ifdef CONFIG_KEXEC_HANDOVER
43bool kho_is_enabled(void);
44bool is_kho_boot(void);
45
46int kho_preserve_folio(struct folio *folio);
47void kho_unpreserve_folio(struct folio *folio);
48int kho_preserve_pages(struct page *page, unsigned int nr_pages);
49void kho_unpreserve_pages(struct page *page, unsigned int nr_pages);
50int kho_preserve_vmalloc(void *ptr, struct kho_vmalloc *preservation);
51void kho_unpreserve_vmalloc(struct kho_vmalloc *preservation);
52void *kho_alloc_preserve(size_t size);
53void kho_unpreserve_free(void *mem);
54void kho_restore_free(void *mem);
55struct folio *kho_restore_folio(phys_addr_t phys);
56struct page *kho_restore_pages(phys_addr_t phys, unsigned int nr_pages);
57void *kho_restore_vmalloc(const struct kho_vmalloc *preservation);
58int kho_add_subtree(const char *name, void *fdt);
59void kho_remove_subtree(void *fdt);
60int kho_retrieve_subtree(const char *name, phys_addr_t *phys);
61
62void kho_memory_init(void);
63
64void kho_populate(phys_addr_t fdt_phys, u64 fdt_len, phys_addr_t scratch_phys,
65 u64 scratch_len);
66#else
67static inline bool kho_is_enabled(void)
68{
69 return false;
70}
71
72static inline bool is_kho_boot(void)
73{
74 return false;
75}
76
77static inline int kho_preserve_folio(struct folio *folio)
78{
79 return -EOPNOTSUPP;
80}
81
82static inline void kho_unpreserve_folio(struct folio *folio) { }
83
84static inline int kho_preserve_pages(struct page *page, unsigned int nr_pages)
85{
86 return -EOPNOTSUPP;
87}
88
89static inline void kho_unpreserve_pages(struct page *page, unsigned int nr_pages) { }
90
91static inline int kho_preserve_vmalloc(void *ptr,
92 struct kho_vmalloc *preservation)
93{
94 return -EOPNOTSUPP;
95}
96
97static inline void kho_unpreserve_vmalloc(struct kho_vmalloc *preservation) { }
98
99static inline void *kho_alloc_preserve(size_t size)
100{
101 return ERR_PTR(error: -EOPNOTSUPP);
102}
103
104static inline void kho_unpreserve_free(void *mem) { }
105static inline void kho_restore_free(void *mem) { }
106
107static inline struct folio *kho_restore_folio(phys_addr_t phys)
108{
109 return NULL;
110}
111
112static inline struct page *kho_restore_pages(phys_addr_t phys,
113 unsigned int nr_pages)
114{
115 return NULL;
116}
117
118static inline void *kho_restore_vmalloc(const struct kho_vmalloc *preservation)
119{
120 return NULL;
121}
122
123static inline int kho_add_subtree(const char *name, void *fdt)
124{
125 return -EOPNOTSUPP;
126}
127
128static inline void kho_remove_subtree(void *fdt) { }
129
130static inline int kho_retrieve_subtree(const char *name, phys_addr_t *phys)
131{
132 return -EOPNOTSUPP;
133}
134
135static inline void kho_memory_init(void) { }
136
137static inline void kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
138 phys_addr_t scratch_phys, u64 scratch_len)
139{
140}
141#endif /* CONFIG_KEXEC_HANDOVER */
142
143#endif /* LINUX_KEXEC_HANDOVER_H */
144

source code of linux/include/linux/kexec_handover.h