1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2017, Anshuman Khandual, IBM Corp.
4 *
5 * Works on architectures which support 128TB virtual
6 * address range and beyond.
7 */
8#include <stdio.h>
9#include <stdlib.h>
10#include <string.h>
11#include <unistd.h>
12#include <errno.h>
13#include <sys/mman.h>
14#include <sys/time.h>
15
16/*
17 * Maximum address range mapped with a single mmap()
18 * call is little bit more than 1GB. Hence 1GB is
19 * chosen as the single chunk size for address space
20 * mapping.
21 */
22
23#define SZ_1GB	(1024 * 1024 * 1024UL)
24#define SZ_1TB	(1024 * 1024 * 1024 * 1024UL)
25
26#define MAP_CHUNK_SIZE	SZ_1GB
27
28/*
29 * Address space till 128TB is mapped without any hint
30 * and is enabled by default. Address space beyond 128TB
31 * till 512TB is obtained by passing hint address as the
32 * first argument into mmap() system call.
33 *
34 * The process heap address space is divided into two
35 * different areas one below 128TB and one above 128TB
36 * till it reaches 512TB. One with size 128TB and the
37 * other being 384TB.
38 *
39 * On Arm64 the address space is 256TB and support for
40 * high mappings up to 4PB virtual address space has
41 * been added.
42 */
43
44#define NR_CHUNKS_128TB   ((128 * SZ_1TB) / MAP_CHUNK_SIZE) /* Number of chunks for 128TB */
45#define NR_CHUNKS_256TB   (NR_CHUNKS_128TB * 2UL)
46#define NR_CHUNKS_384TB   (NR_CHUNKS_128TB * 3UL)
47#define NR_CHUNKS_3840TB  (NR_CHUNKS_128TB * 30UL)
48
49#define ADDR_MARK_128TB  (1UL << 47) /* First address beyond 128TB */
50#define ADDR_MARK_256TB  (1UL << 48) /* First address beyond 256TB */
51
52#ifdef __aarch64__
53#define HIGH_ADDR_MARK  ADDR_MARK_256TB
54#define HIGH_ADDR_SHIFT 49
55#define NR_CHUNKS_LOW   NR_CHUNKS_256TB
56#define NR_CHUNKS_HIGH  NR_CHUNKS_3840TB
57#else
58#define HIGH_ADDR_MARK  ADDR_MARK_128TB
59#define HIGH_ADDR_SHIFT 48
60#define NR_CHUNKS_LOW   NR_CHUNKS_128TB
61#define NR_CHUNKS_HIGH  NR_CHUNKS_384TB
62#endif
63
64static char *hind_addr(void)
65{
66	int bits = HIGH_ADDR_SHIFT + rand() % (63 - HIGH_ADDR_SHIFT);
67
68	return (char *) (1UL << bits);
69}
70
71static int validate_addr(char *ptr, int high_addr)
72{
73	unsigned long addr = (unsigned long) ptr;
74
75	if (high_addr) {
76		if (addr < HIGH_ADDR_MARK) {
77			printf("Bad address %lx\n", addr);
78			return 1;
79		}
80		return 0;
81	}
82
83	if (addr > HIGH_ADDR_MARK) {
84		printf("Bad address %lx\n", addr);
85		return 1;
86	}
87	return 0;
88}
89
90static int validate_lower_address_hint(void)
91{
92	char *ptr;
93
94	ptr = mmap((void *) (1UL << 45), MAP_CHUNK_SIZE, PROT_READ |
95			PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
96
97	if (ptr == MAP_FAILED)
98		return 0;
99
100	return 1;
101}
102
103int main(int argc, char *argv[])
104{
105	char *ptr[NR_CHUNKS_LOW];
106	char **hptr;
107	char *hint;
108	unsigned long i, lchunks, hchunks;
109
110	for (i = 0; i < NR_CHUNKS_LOW; i++) {
111		ptr[i] = mmap(NULL, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE,
112					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
113
114		if (ptr[i] == MAP_FAILED) {
115			if (validate_lower_address_hint())
116				return 1;
117			break;
118		}
119
120		if (validate_addr(ptr[i], 0))
121			return 1;
122	}
123	lchunks = i;
124	hptr = (char **) calloc(NR_CHUNKS_HIGH, sizeof(char *));
125	if (hptr == NULL)
126		return 1;
127
128	for (i = 0; i < NR_CHUNKS_HIGH; i++) {
129		hint = hind_addr();
130		hptr[i] = mmap(hint, MAP_CHUNK_SIZE, PROT_READ | PROT_WRITE,
131					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
132
133		if (hptr[i] == MAP_FAILED)
134			break;
135
136		if (validate_addr(hptr[i], 1))
137			return 1;
138	}
139	hchunks = i;
140
141	for (i = 0; i < lchunks; i++)
142		munmap(ptr[i], MAP_CHUNK_SIZE);
143
144	for (i = 0; i < hchunks; i++)
145		munmap(hptr[i], MAP_CHUNK_SIZE);
146
147	free(hptr);
148	return 0;
149}
150