aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arc/mm/init.c
blob: e2ed355438c96ca18c7bbe37f50763898320e4c2 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
 */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#ifdef CONFIG_BLK_DEV_INITRD
#include <linux/initrd.h>
#endif
#include <linux/of_fdt.h>
#include <linux/swap.h>
#include <linux/module.h>
#include <linux/highmem.h>
#include <asm/page.h>
#include <asm/sections.h>
#include <asm/arcregs.h>

pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
EXPORT_SYMBOL(empty_zero_page);

static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
static unsigned long low_mem_sz;

#ifdef CONFIG_HIGHMEM
static unsigned long min_high_pfn, max_high_pfn;
static phys_addr_t high_mem_start;
static phys_addr_t high_mem_sz;
unsigned long arch_pfn_offset;
EXPORT_SYMBOL(arch_pfn_offset);
#endif

#ifdef CONFIG_DISCONTIGMEM
struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
EXPORT_SYMBOL(node_data);
#endif

long __init arc_get_mem_sz(void)
{
	return low_mem_sz;
}

/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
static int __init setup_mem_sz(char *str)
{
	low_mem_sz = memparse(str, NULL) & PAGE_MASK;

	/* early console might not be setup yet - it will show up later */
	pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));

	return 0;
}
early_param("mem", setup_mem_sz);

void __init early_init_dt_add_memory_arch(u64 base, u64 size)
{
	int in_use = 0;

	if (!low_mem_sz) {
		if (base != low_mem_start)
			panic("CONFIG_LINUX_RAM_BASE != DT memory { }");

		low_mem_sz = size;
		in_use = 1;
		memblock_add_node(base, size, 0);
	} else {
#ifdef CONFIG_HIGHMEM
		high_mem_start = base;
		high_mem_sz = size;
		in_use = 1;
		memblock_add_node(base, size, 1);
		memblock_reserve(base, size);
#endif
	}

	pr_info("Memory @ %llx [%lldM] %s\n",
		base, TO_MB(size), !in_use ? "Not used":"");
}

bool arch_has_descending_max_zone_pfns(void)
{
	return !IS_ENABLED(CONFIG_ARC_HAS_PAE40);
}

/*
 * First memory setup routine called from setup_arch()
 * 1. setup swapper's mm @init_mm
 * 2. Count the pages we have and setup bootmem allocator
 * 3. zone setup
 */
void __init setup_arch_memory(void)
{
	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };

	init_mm.start_code = (unsigned long)_text;
	init_mm.end_code = (unsigned long)_etext;
	init_mm.end_data = (unsigned long)_edata;
	init_mm.brk = (unsigned long)_end;

	/* first page of system - kernel .vector starts here */
	min_low_pfn = virt_to_pfn(CONFIG_LINUX_RAM_BASE);

	/* Last usable page of low mem */
	max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);

	/*------------- bootmem allocator setup -----------------------*/

	/*
	 * seed the bootmem allocator after any DT memory node parsing or
	 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
	 *
	 * Only low mem is added, otherwise we have crashes when allocating
	 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
	 * avail memory, ending in highmem with a > 32-bit address. However
	 * it then tries to memset it with a truncaed 32-bit handle, causing
	 * the crash
	 */

	memblock_reserve(CONFIG_LINUX_LINK_BASE,
			 __pa(_end) - CONFIG_LINUX_LINK_BASE);

#ifdef CONFIG_BLK_DEV_INITRD
	if (phys_initrd_size) {
		memblock_reserve(phys_initrd_start, phys_initrd_size);
		initrd_start = (unsigned long)__va(phys_initrd_start);
		initrd_end = initrd_start + phys_initrd_size;
	}
#endif

	early_init_fdt_reserve_self();
	early_init_fdt_scan_reserved_mem();

	memblock_dump_all();

	/*----------------- node/zones setup --------------------------*/
	max_zone_pfn[ZONE_NORMAL] = max_low_pfn;

#ifdef CONFIG_HIGHMEM
	/*
	 * Populate a new node with highmem
	 *
	 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
	 * than addresses in normal ala low memory (0x8000_0000 based).
	 * Even with PAE, the huge peripheral space hole would waste a lot of
	 * mem with single mem_map[]. This warrants a mem_map per region design.
	 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
	 *
	 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
	 * populated with normal memory zone while node 1 only has highmem
	 */
#ifdef CONFIG_DISCONTIGMEM
	node_set_online(1);
#endif

	min_high_pfn = PFN_DOWN(high_mem_start);
	max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);

	/*
	 * max_high_pfn should be ok here for both HIGHMEM and HIGHMEM+PAE.
	 * For HIGHMEM without PAE max_high_pfn should be less than
	 * min_low_pfn to guarantee that these two regions don't overlap.
	 * For PAE case highmem is greater than lowmem, so it is natural
	 * to use max_high_pfn.
	 *
	 * In both cases, holes should be handled by pfn_valid().
	 */
	max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn;

	high_memory = (void *)(min_high_pfn << PAGE_SHIFT);

	arch_pfn_offset = min(min_low_pfn, min_high_pfn);
	kmap_init();

#else /* CONFIG_HIGHMEM */
	/* pfn_valid() uses this when FLATMEM=y and HIGHMEM=n */
	max_mapnr = max_low_pfn - min_low_pfn;

#endif /* CONFIG_HIGHMEM */

	free_area_init(max_zone_pfn);
}

static void __init highmem_init(void)
{
#ifdef CONFIG_HIGHMEM
	unsigned long tmp;

	memblock_free(high_mem_start, high_mem_sz);
	for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
		free_highmem_page(pfn_to_page(tmp));
#endif
}

/*
 * mem_init - initializes memory
 *
 * Frees up bootmem
 * Calculates and displays memory available/used
 */
void __init mem_init(void)
{
	memblock_free_all();
	highmem_init();
}

#ifdef CONFIG_HIGHMEM
int pfn_valid(unsigned long pfn)
{
	return (pfn >= min_high_pfn && pfn <= max_high_pfn) ||
		(pfn >= min_low_pfn && pfn <= max_low_pfn);
}
EXPORT_SYMBOL(pfn_valid);
#endif