aboutsummaryrefslogtreecommitdiffstats
path: root/arch/s390/mm/init.c
blob: 50388190b39302470e609d43bed992ad0c3e7fa4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
// SPDX-License-Identifier: GPL-2.0
/*
 *  S390 version
 *    Copyright IBM Corp. 1999
 *    Author(s): Hartmut Penner (hp@de.ibm.com)
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1995  Linus Torvalds
 */

#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/memblock.h>
#include <linux/memory.h>
#include <linux/pfn.h>
#include <linux/poison.h>
#include <linux/initrd.h>
#include <linux/export.h>
#include <linux/cma.h>
#include <linux/gfp.h>
#include <asm/processor.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/lowcore.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/ctl_reg.h>
#include <asm/sclp.h>
#include <asm/set_memory.h>
#include <asm/kasan.h>

pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);

unsigned long empty_zero_page, zero_page_mask;
EXPORT_SYMBOL(empty_zero_page);
EXPORT_SYMBOL(zero_page_mask);

static void __init setup_zero_pages(void)
{
	unsigned int order;
	struct page *page;
	int i;

	/* Latest machines require a mapping granularity of 512KB */
	order = 7;

	/* Limit number of empty zero pages for small memory sizes */
	while (order > 2 && (totalram_pages() >> 10) < (1UL << order))
		order--;

	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
	if (!empty_zero_page)
		panic("Out of memory in setup_zero_pages");

	page = virt_to_page((void *) empty_zero_page);
	split_page(page, order);
	for (i = 1 << order; i > 0; i--) {
		mark_page_reserved(page);
		page++;
	}

	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
}

/*
 * paging_init() sets up the page tables
 */
void __init paging_init(void)
{
	unsigned long max_zone_pfns[MAX_NR_ZONES];
	unsigned long pgd_type, asce_bits;
	psw_t psw;

	init_mm.pgd = swapper_pg_dir;
	if (VMALLOC_END > _REGION2_SIZE) {
		asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
		pgd_type = _REGION2_ENTRY_EMPTY;
	} else {
		asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
		pgd_type = _REGION3_ENTRY_EMPTY;
	}
	init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
	S390_lowcore.kernel_asce = init_mm.context.asce;
	S390_lowcore.user_asce = S390_lowcore.kernel_asce;
	crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
	vmem_map_init();
	kasan_copy_shadow(init_mm.pgd);

	/* enable virtual mapping in kernel mode */
	__ctl_load(S390_lowcore.kernel_asce, 1, 1);
	__ctl_load(S390_lowcore.kernel_asce, 7, 7);
	__ctl_load(S390_lowcore.kernel_asce, 13, 13);
	psw.mask = __extract_psw();
	psw_bits(psw).dat = 1;
	psw_bits(psw).as = PSW_BITS_AS_HOME;
	__load_psw_mask(psw.mask);
	kasan_free_early_identity();

	sparse_memory_present_with_active_regions(MAX_NUMNODES);
	sparse_init();
	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
	max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
	free_area_init_nodes(max_zone_pfns);
}

void mark_rodata_ro(void)
{
	unsigned long size = __end_ro_after_init - __start_ro_after_init;

	set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
	pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
}

void __init mem_init(void)
{
	cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
	cpumask_set_cpu(0, mm_cpumask(&init_mm));

	set_max_mapnr(max_low_pfn);
        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);

	/* Setup guest page hinting */
	cmma_init();

	/* this will put all low memory onto the freelists */
	memblock_free_all();
	setup_zero_pages();	/* Setup zeroed pages. */

	cmma_init_nodat();

	mem_init_print_info(NULL);
}

void free_initmem(void)
{
	__set_memory((unsigned long)_sinittext,
		     (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
		     SET_MEMORY_RW | SET_MEMORY_NX);
	free_initmem_default(POISON_FREE_INITMEM);
}

#ifdef CONFIG_BLK_DEV_INITRD
void __init free_initrd_mem(unsigned long start, unsigned long end)
{
	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
			   "initrd");
}
#endif

unsigned long memory_block_size_bytes(void)
{
	/*
	 * Make sure the memory block size is always greater
	 * or equal than the memory increment size.
	 */
	return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
}

#ifdef CONFIG_MEMORY_HOTPLUG

#ifdef CONFIG_CMA

/* Prevent memory blocks which contain cma regions from going offline */

struct s390_cma_mem_data {
	unsigned long start;
	unsigned long end;
};

static int s390_cma_check_range(struct cma *cma, void *data)
{
	struct s390_cma_mem_data *mem_data;
	unsigned long start, end;

	mem_data = data;
	start = cma_get_base(cma);
	end = start + cma_get_size(cma);
	if (end < mem_data->start)
		return 0;
	if (start >= mem_data->end)
		return 0;
	return -EBUSY;
}

static int s390_cma_mem_notifier(struct notifier_block *nb,
				 unsigned long action, void *data)
{
	struct s390_cma_mem_data mem_data;
	struct memory_notify *arg;
	int rc = 0;

	arg = data;
	mem_data.start = arg->start_pfn << PAGE_SHIFT;
	mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
	if (action == MEM_GOING_OFFLINE)
		rc = cma_for_each_area(s390_cma_check_range, &mem_data);
	return notifier_from_errno(rc);
}

static struct notifier_block s390_cma_mem_nb = {
	.notifier_call = s390_cma_mem_notifier,
};

static int __init s390_cma_mem_init(void)
{
	return register_memory_notifier(&s390_cma_mem_nb);
}
device_initcall(s390_cma_mem_init);

#endif /* CONFIG_CMA */

int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
		bool want_memblock)
{
	unsigned long start_pfn = PFN_DOWN(start);
	unsigned long size_pages = PFN_DOWN(size);
	int rc;

	rc = vmem_add_mapping(start, size);
	if (rc)
		return rc;

	rc = __add_pages(nid, start_pfn, size_pages, altmap, want_memblock);
	if (rc)
		vmem_remove_mapping(start, size);
	return rc;
}

#ifdef CONFIG_MEMORY_HOTREMOVE
int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
{
	/*
	 * There is no hardware or firmware interface which could trigger a
	 * hot memory remove on s390. So there is nothing that needs to be
	 * implemented.
	 */
	return -EBUSY;
}
#endif
#endif /* CONFIG_MEMORY_HOTPLUG */