aboutsummaryrefslogtreecommitdiff
path: root/arch/s390/mm/init.c
blob: ad446b0c55b6076d5aaf7f095f1ddc91b5e38bf4 (plain)
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
/*
 *  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/bootmem.h>
#include <linux/memory.h>
#include <linux/pfn.h>
#include <linux/poison.h>
#include <linux/initrd.h>
#include <linux/export.h>
#include <linux/gfp.h>
#include <asm/processor.h>
#include <asm/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>

pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));

unsigned long empty_zero_page, zero_page_mask;
EXPORT_SYMBOL(empty_zero_page);

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

	get_cpu_id(&cpu_id);
	switch (cpu_id.machine) {
	case 0x9672:	/* g5 */
	case 0x2064:	/* z900 */
	case 0x2066:	/* z900 */
	case 0x2084:	/* z990 */
	case 0x2086:	/* z990 */
	case 0x2094:	/* z9-109 */
	case 0x2096:	/* z9-109 */
		order = 0;
		break;
	case 0x2097:	/* z10 */
	case 0x2098:	/* z10 */
	case 0x2817:	/* z196 */
	case 0x2818:	/* z196 */
		order = 2;
		break;
	case 0x2827:	/* zEC12 */
	case 0x2828:	/* zEC12 */
	default:
		order = 5;
		break;
	}
	/* Limit number of empty zero pages for small memory sizes */
	if (order > 2 && totalram_pages <= 16384)
		order = 2;

	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;

	init_mm.pgd = swapper_pg_dir;
#ifdef CONFIG_64BIT
	if (VMALLOC_END > (1UL << 42)) {
		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;
	}
#else
	asce_bits = _ASCE_TABLE_LENGTH;
	pgd_type = _SEGMENT_ENTRY_EMPTY;
#endif
	S390_lowcore.kernel_asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
	clear_table((unsigned long *) init_mm.pgd, pgd_type,
		    sizeof(unsigned long)*2048);
	vmem_map_init();

        /* 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);
	arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));

	atomic_set(&init_mm.context.attach_count, 1);

	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 __init mem_init(void)
{
        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 */
	free_all_bootmem();
	setup_zero_pages();	/* Setup zeroed pages. */

	mem_init_print_info(NULL);
	printk("Write protected kernel read-only data: %#lx - %#lx\n",
	       (unsigned long)&_stext,
	       PFN_ALIGN((unsigned long)&_eshared) - 1);
}

void free_initmem(void)
{
	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

#ifdef CONFIG_MEMORY_HOTPLUG
int arch_add_memory(int nid, u64 start, u64 size)
{
	unsigned long zone_start_pfn, zone_end_pfn, nr_pages;
	unsigned long start_pfn = PFN_DOWN(start);
	unsigned long size_pages = PFN_DOWN(size);
	struct zone *zone;
	int rc;

	rc = vmem_add_mapping(start, size);
	if (rc)
		return rc;
	for_each_zone(zone) {
		if (zone_idx(zone) != ZONE_MOVABLE) {
			/* Add range within existing zone limits */
			zone_start_pfn = zone->zone_start_pfn;
			zone_end_pfn = zone->zone_start_pfn +
				       zone->spanned_pages;
		} else {
			/* Add remaining range to ZONE_MOVABLE */
			zone_start_pfn = start_pfn;
			zone_end_pfn = start_pfn + size_pages;
		}
		if (start_pfn < zone_start_pfn || start_pfn >= zone_end_pfn)
			continue;
		nr_pages = (start_pfn + size_pages > zone_end_pfn) ?
			   zone_end_pfn - start_pfn : size_pages;
		rc = __add_pages(nid, zone, start_pfn, nr_pages);
		if (rc)
			break;
		start_pfn += nr_pages;
		size_pages -= nr_pages;
		if (!size_pages)
			break;
	}
	if (rc)
		vmem_remove_mapping(start, size);
	return rc;
}

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_get_rzm());
}

#ifdef CONFIG_MEMORY_HOTREMOVE
int arch_remove_memory(u64 start, u64 size)
{
	/*
	 * 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 */