aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arc/mm/init.c
blob: a9305b5a2cd4ba091f7ae18914f6ef5e64d5236c (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
/*
 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#ifdef CONFIG_BLK_DEV_INITRD
#include <linux/initrd.h>
#endif
#include <linux/swap.h>
#include <linux/module.h>
#include <linux/highmem.h>
#include <asm/page.h>
#include <asm/pgalloc.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_LINK_BASE;
static unsigned long low_mem_sz;

#ifdef CONFIG_HIGHMEM
static unsigned long min_high_pfn;
static u64 high_mem_start;
static u64 high_mem_sz;
#endif

/* 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) {
		BUG_ON(base != low_mem_start);
		low_mem_sz = size;
		in_use = 1;
	} else {
#ifdef CONFIG_HIGHMEM
		high_mem_start = base;
		high_mem_sz = size;
		in_use = 1;
#endif
	}

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

#ifdef CONFIG_BLK_DEV_INITRD
static int __init early_initrd(char *p)
{
	unsigned long start, size;
	char *endp;

	start = memparse(p, &endp);
	if (*endp == ',') {
		size = memparse(endp + 1, NULL);

		initrd_start = (unsigned long)__va(start);
		initrd_end = (unsigned long)__va(start + size);
	}
	return 0;
}
early_param("initrd", early_initrd);
#endif

/*
 * 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 zones_size[MAX_NR_ZONES];
	unsigned long zones_holes[MAX_NR_ZONES];

	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 = ARCH_PFN_OFFSET;

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

#ifdef CONFIG_HIGHMEM
	min_high_pfn = PFN_DOWN(high_mem_start);
	max_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
#endif

	max_mapnr = max_pfn - min_low_pfn;

	/*------------- 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_add(low_mem_start, low_mem_sz);
	memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);

#ifdef CONFIG_BLK_DEV_INITRD
	if (initrd_start)
		memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
#endif

	memblock_dump_all();

	/*----------------- node/zones setup --------------------------*/
	memset(zones_size, 0, sizeof(zones_size));
	memset(zones_holes, 0, sizeof(zones_holes));

	zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
	zones_holes[ZONE_NORMAL] = 0;

#ifdef CONFIG_HIGHMEM
	zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;

	/* This handles the peripheral address space hole */
	zones_holes[ZONE_HIGHMEM] = min_high_pfn - max_low_pfn;
#endif

	/*
	 * We can't use the helper free_area_init(zones[]) because it uses
	 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
	 * when our kernel doesn't start at PAGE_OFFSET, i.e.
	 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
	 */
	free_area_init_node(0,			/* node-id */
			    zones_size,		/* num pages per zone */
			    min_low_pfn,	/* first pfn of node */
			    zones_holes);	/* holes */

#ifdef CONFIG_HIGHMEM
	high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
	kmap_init();
#endif
}

/*
 * mem_init - initializes memory
 *
 * Frees up bootmem
 * Calculates and displays memory available/used
 */
void __init mem_init(void)
{
#ifdef CONFIG_HIGHMEM
	unsigned long tmp;

	reset_all_zones_managed_pages();
	for (tmp = min_high_pfn; tmp < max_pfn; tmp++)
		free_highmem_page(pfn_to_page(tmp));
#endif

	free_all_bootmem();
	mem_init_print_info(NULL);
}

/*
 * free_initmem: Free all the __init memory.
 */
void __init_refok free_initmem(void)
{
	free_initmem_default(-1);
}

#ifdef CONFIG_BLK_DEV_INITRD
void __init free_initrd_mem(unsigned long start, unsigned long end)
{
	free_reserved_area((void *)start, (void *)end, -1, "initrd");
}
#endif