physmem_info.h

  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_DIAG500_STOR_LIMIT,
 13	MEM_DETECT_SCLP_READ_INFO,
 14	MEM_DETECT_BIN_SEARCH
 15};
 16
 17struct physmem_range {
 18	u64 start;
 19	u64 end;
 20};
 21
 22enum reserved_range_type {
 23	RR_DECOMPRESSOR,
 24	RR_INITRD,
 25	RR_VMLINUX,
 26	RR_AMODE31,
 27	RR_IPLREPORT,
 28	RR_CERT_COMP_LIST,
 29	RR_MEM_DETECT_EXT,
 30	RR_VMEM,
 31	RR_MAX
 32};
 33
 34struct reserved_range {
 35	unsigned long start;
 36	unsigned long end;
 37	struct reserved_range *chain;
 38};
 39
 40/*
 41 * Storage element id is defined as 1 byte (up to 256 storage elements).
 42 * In practise only storage element id 0 and 1 are used).
 43 * According to architecture one storage element could have as much as
 44 * 1020 subincrements. 255 physmem_ranges are embedded in physmem_info.
 45 * If more physmem_ranges are required, a block of memory from already
 46 * known physmem_range is taken (online_extended points to it).
 47 */
 48#define MEM_INLINED_ENTRIES 255 /* (PAGE_SIZE - 16) / 16 */
 49
 50struct physmem_info {
 51	u32 range_count;
 52	u8 info_source;
 53	unsigned long usable;
 54	struct reserved_range reserved[RR_MAX];
 55	struct physmem_range online[MEM_INLINED_ENTRIES];
 56	struct physmem_range *online_extended;
 57};
 58
 59extern struct physmem_info physmem_info;
 60
 61void add_physmem_online_range(u64 start, u64 end);
 62
 63static inline int __get_physmem_range(u32 n, unsigned long *start,
 64				      unsigned long *end, bool respect_usable_limit)
 65{
 66	if (n >= physmem_info.range_count) {
 67		*start = 0;
 68		*end = 0;
 69		return -1;
 70	}
 71
 72	if (n < MEM_INLINED_ENTRIES) {
 73		*start = (unsigned long)physmem_info.online[n].start;
 74		*end = (unsigned long)physmem_info.online[n].end;
 75	} else {
 76		*start = (unsigned long)physmem_info.online_extended[n - MEM_INLINED_ENTRIES].start;
 77		*end = (unsigned long)physmem_info.online_extended[n - MEM_INLINED_ENTRIES].end;
 78	}
 79
 80	if (respect_usable_limit && physmem_info.usable) {
 81		if (*start >= physmem_info.usable)
 82			return -1;
 83		if (*end > physmem_info.usable)
 84			*end = physmem_info.usable;
 85	}
 86	return 0;
 87}
 88
 89/**
 90 * for_each_physmem_usable_range - early online memory range iterator
 91 * @i: an integer used as loop variable
 92 * @p_start: ptr to unsigned long for start address of the range
 93 * @p_end: ptr to unsigned long for end address of the range
 94 *
 95 * Walks over detected online memory ranges below usable limit.
 96 */
 97#define for_each_physmem_usable_range(i, p_start, p_end)		\
 98	for (i = 0; !__get_physmem_range(i, p_start, p_end, true); i++)
 99
100/* Walks over all detected online memory ranges disregarding usable limit. */
101#define for_each_physmem_online_range(i, p_start, p_end)		\
102	for (i = 0; !__get_physmem_range(i, p_start, p_end, false); i++)
103
104static inline const char *get_physmem_info_source(void)
105{
106	switch (physmem_info.info_source) {
107	case MEM_DETECT_SCLP_STOR_INFO:
108		return "sclp storage info";
109	case MEM_DETECT_DIAG260:
110		return "diag260";
111	case MEM_DETECT_DIAG500_STOR_LIMIT:
112		return "diag500 storage limit";
113	case MEM_DETECT_SCLP_READ_INFO:
114		return "sclp read info";
115	case MEM_DETECT_BIN_SEARCH:
116		return "binary search";
117	}
118	return "none";
119}
120
121#define RR_TYPE_NAME(t) case RR_ ## t: return #t
122static inline const char *get_rr_type_name(enum reserved_range_type t)
123{
124	switch (t) {
125	RR_TYPE_NAME(DECOMPRESSOR);
126	RR_TYPE_NAME(INITRD);
127	RR_TYPE_NAME(VMLINUX);
128	RR_TYPE_NAME(AMODE31);
129	RR_TYPE_NAME(IPLREPORT);
130	RR_TYPE_NAME(CERT_COMP_LIST);
131	RR_TYPE_NAME(MEM_DETECT_EXT);
132	RR_TYPE_NAME(VMEM);
133	default:
134		return "UNKNOWN";
135	}
136}
137
138#define for_each_physmem_reserved_type_range(t, range, p_start, p_end)				\
139	for (range = &physmem_info.reserved[t], *p_start = range->start, *p_end = range->end;	\
140	     range && range->end; range = range->chain ? __va(range->chain) : NULL,		\
141	     *p_start = range ? range->start : 0, *p_end = range ? range->end : 0)
142
143static inline struct reserved_range *__physmem_reserved_next(enum reserved_range_type *t,
144							     struct reserved_range *range)
145{
146	if (!range) {
147		range = &physmem_info.reserved[*t];
148		if (range->end)
149			return range;
150	}
151	if (range->chain)
152		return __va(range->chain);
153	while (++*t < RR_MAX) {
154		range = &physmem_info.reserved[*t];
155		if (range->end)
156			return range;
157	}
158	return NULL;
159}
160
161#define for_each_physmem_reserved_range(t, range, p_start, p_end)			\
162	for (t = 0, range = __physmem_reserved_next(&t, NULL),			\
163	    *p_start = range ? range->start : 0, *p_end = range ? range->end : 0;	\
164	     range; range = __physmem_reserved_next(&t, range),			\
165	    *p_start = range ? range->start : 0, *p_end = range ? range->end : 0)
166
167static inline unsigned long get_physmem_reserved(enum reserved_range_type type,
168						 unsigned long *addr, unsigned long *size)
169{
170	*addr = physmem_info.reserved[type].start;
171	*size = physmem_info.reserved[type].end - physmem_info.reserved[type].start;
172	return *size;
173}
174
175#define AMODE31_START	(physmem_info.reserved[RR_AMODE31].start)
176#define AMODE31_END	(physmem_info.reserved[RR_AMODE31].end)
177
178#endif