1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_S390_MEM_DETECT_H
3#define _ASM_S390_MEM_DETECT_H
4
5#include <linux/types.h>
6#include <asm/page.h>
7
8enum physmem_info_source {
9	MEM_DETECT_NONE = 0,
10	MEM_DETECT_SCLP_STOR_INFO,
11	MEM_DETECT_DIAG260,
12	MEM_DETECT_SCLP_READ_INFO,
13	MEM_DETECT_BIN_SEARCH
14};
15
16struct physmem_range {
17	u64 start;
18	u64 end;
19};
20
21enum reserved_range_type {
22	RR_DECOMPRESSOR,
23	RR_INITRD,
24	RR_VMLINUX,
25	RR_AMODE31,
26	RR_IPLREPORT,
27	RR_CERT_COMP_LIST,
28	RR_MEM_DETECT_EXTENDED,
29	RR_VMEM,
30	RR_MAX
31};
32
33struct reserved_range {
34	unsigned long start;
35	unsigned long end;
36	struct reserved_range *chain;
37};
38
39/*
40 * Storage element id is defined as 1 byte (up to 256 storage elements).
41 * In practise only storage element id 0 and 1 are used).
42 * According to architecture one storage element could have as much as
43 * 1020 subincrements. 255 physmem_ranges are embedded in physmem_info.
44 * If more physmem_ranges are required, a block of memory from already
45 * known physmem_range is taken (online_extended points to it).
46 */
47#define MEM_INLINED_ENTRIES 255 /* (PAGE_SIZE - 16) / 16 */
48
49struct physmem_info {
50	u32 range_count;
51	u8 info_source;
52	unsigned long usable;
53	struct reserved_range reserved[RR_MAX];
54	struct physmem_range online[MEM_INLINED_ENTRIES];
55	struct physmem_range *online_extended;
56};
57
58extern struct physmem_info physmem_info;
59
60void add_physmem_online_range(u64 start, u64 end);
61
62static inline int __get_physmem_range(u32 n, unsigned long *start,
63				      unsigned long *end, bool respect_usable_limit)
64{
65	if (n >= physmem_info.range_count) {
66		*start = 0;
67		*end = 0;
68		return -1;
69	}
70
71	if (n < MEM_INLINED_ENTRIES) {
72		*start = (unsigned long)physmem_info.online[n].start;
73		*end = (unsigned long)physmem_info.online[n].end;
74	} else {
75		*start = (unsigned long)physmem_info.online_extended[n - MEM_INLINED_ENTRIES].start;
76		*end = (unsigned long)physmem_info.online_extended[n - MEM_INLINED_ENTRIES].end;
77	}
78
79	if (respect_usable_limit && physmem_info.usable) {
80		if (*start >= physmem_info.usable)
81			return -1;
82		if (*end > physmem_info.usable)
83			*end = physmem_info.usable;
84	}
85	return 0;
86}
87
88/**
89 * for_each_physmem_usable_range - early online memory range iterator
90 * @i: an integer used as loop variable
91 * @p_start: ptr to unsigned long for start address of the range
92 * @p_end: ptr to unsigned long for end address of the range
93 *
94 * Walks over detected online memory ranges below usable limit.
95 */
96#define for_each_physmem_usable_range(i, p_start, p_end)		\
97	for (i = 0; !__get_physmem_range(i, p_start, p_end, true); i++)
98
99/* Walks over all detected online memory ranges disregarding usable limit. */
100#define for_each_physmem_online_range(i, p_start, p_end)		\
101	for (i = 0; !__get_physmem_range(i, p_start, p_end, false); i++)
102
103static inline const char *get_physmem_info_source(void)
104{
105	switch (physmem_info.info_source) {
106	case MEM_DETECT_SCLP_STOR_INFO:
107		return "sclp storage info";
108	case MEM_DETECT_DIAG260:
109		return "diag260";
110	case MEM_DETECT_SCLP_READ_INFO:
111		return "sclp read info";
112	case MEM_DETECT_BIN_SEARCH:
113		return "binary search";
114	}
115	return "none";
116}
117
118#define RR_TYPE_NAME(t) case RR_ ## t: return #t
119static inline const char *get_rr_type_name(enum reserved_range_type t)
120{
121	switch (t) {
122	RR_TYPE_NAME(DECOMPRESSOR);
123	RR_TYPE_NAME(INITRD);
124	RR_TYPE_NAME(VMLINUX);
125	RR_TYPE_NAME(AMODE31);
126	RR_TYPE_NAME(IPLREPORT);
127	RR_TYPE_NAME(CERT_COMP_LIST);
128	RR_TYPE_NAME(MEM_DETECT_EXTENDED);
129	RR_TYPE_NAME(VMEM);
130	default:
131		return "UNKNOWN";
132	}
133}
134
135#define for_each_physmem_reserved_type_range(t, range, p_start, p_end)				\
136	for (range = &physmem_info.reserved[t], *p_start = range->start, *p_end = range->end;	\
137	     range && range->end; range = range->chain ? __va(range->chain) : NULL,		\
138	     *p_start = range ? range->start : 0, *p_end = range ? range->end : 0)
139
140static inline struct reserved_range *__physmem_reserved_next(enum reserved_range_type *t,
141							     struct reserved_range *range)
142{
143	if (!range) {
144		range = &physmem_info.reserved[*t];
145		if (range->end)
146			return range;
147	}
148	if (range->chain)
149		return __va(range->chain);
150	while (++*t < RR_MAX) {
151		range = &physmem_info.reserved[*t];
152		if (range->end)
153			return range;
154	}
155	return NULL;
156}
157
158#define for_each_physmem_reserved_range(t, range, p_start, p_end)			\
159	for (t = 0, range = __physmem_reserved_next(&t, NULL),			\
160	    *p_start = range ? range->start : 0, *p_end = range ? range->end : 0;	\
161	     range; range = __physmem_reserved_next(&t, range),			\
162	    *p_start = range ? range->start : 0, *p_end = range ? range->end : 0)
163
164static inline unsigned long get_physmem_reserved(enum reserved_range_type type,
165						 unsigned long *addr, unsigned long *size)
166{
167	*addr = physmem_info.reserved[type].start;
168	*size = physmem_info.reserved[type].end - physmem_info.reserved[type].start;
169	return *size;
170}
171
172#endif
173