tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9#include <linux/kernel.h>
10#include <linux/mm.h>
11#include <linux/bootmem.h>
12#include <linux/memblock.h>
13#ifdef CONFIG_BLK_DEV_INITRD
14#include <linux/initrd.h>
15#endif
16#include <linux/swap.h>
17#include <linux/module.h>
18#include <linux/highmem.h>
19#include <asm/page.h>
20#include <asm/pgalloc.h>
21#include <asm/sections.h>
22#include <asm/arcregs.h>
23
24pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
25char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
26EXPORT_SYMBOL(empty_zero_page);
27
28static const unsigned long low_mem_start = CONFIG_LINUX_LINK_BASE;
29static unsigned long low_mem_sz;
30
31#ifdef CONFIG_HIGHMEM
32static unsigned long min_high_pfn;
33static u64 high_mem_start;
34static u64 high_mem_sz;
35#endif
36
37/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
38static int __init setup_mem_sz(char *str)
39{
40 low_mem_sz = memparse(str, NULL) & PAGE_MASK;
41
42 /* early console might not be setup yet - it will show up later */
43 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
44
45 return 0;
46}
47early_param("mem", setup_mem_sz);
48
49void __init early_init_dt_add_memory_arch(u64 base, u64 size)
50{
51 int in_use = 0;
52
53 if (!low_mem_sz) {
54 BUG_ON(base != low_mem_start);
55 low_mem_sz = size;
56 in_use = 1;
57 } else {
58#ifdef CONFIG_HIGHMEM
59 high_mem_start = base;
60 high_mem_sz = size;
61 in_use = 1;
62#endif
63 }
64
65 pr_info("Memory @ %llx [%lldM] %s\n",
66 base, TO_MB(size), !in_use ? "Not used":"");
67}
68
69#ifdef CONFIG_BLK_DEV_INITRD
70static int __init early_initrd(char *p)
71{
72 unsigned long start, size;
73 char *endp;
74
75 start = memparse(p, &endp);
76 if (*endp == ',') {
77 size = memparse(endp + 1, NULL);
78
79 initrd_start = (unsigned long)__va(start);
80 initrd_end = (unsigned long)__va(start + size);
81 }
82 return 0;
83}
84early_param("initrd", early_initrd);
85#endif
86
87/*
88 * First memory setup routine called from setup_arch()
89 * 1. setup swapper's mm @init_mm
90 * 2. Count the pages we have and setup bootmem allocator
91 * 3. zone setup
92 */
93void __init setup_arch_memory(void)
94{
95 unsigned long zones_size[MAX_NR_ZONES];
96 unsigned long zones_holes[MAX_NR_ZONES];
97
98 init_mm.start_code = (unsigned long)_text;
99 init_mm.end_code = (unsigned long)_etext;
100 init_mm.end_data = (unsigned long)_edata;
101 init_mm.brk = (unsigned long)_end;
102
103 /* first page of system - kernel .vector starts here */
104 min_low_pfn = ARCH_PFN_OFFSET;
105
106 /* Last usable page of low mem */
107 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
108
109#ifdef CONFIG_HIGHMEM
110 min_high_pfn = PFN_DOWN(high_mem_start);
111 max_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
112#endif
113
114 max_mapnr = max_pfn - min_low_pfn;
115
116 /*------------- bootmem allocator setup -----------------------*/
117
118 /*
119 * seed the bootmem allocator after any DT memory node parsing or
120 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
121 *
122 * Only low mem is added, otherwise we have crashes when allocating
123 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
124 * avail memory, ending in highmem with a > 32-bit address. However
125 * it then tries to memset it with a truncaed 32-bit handle, causing
126 * the crash
127 */
128
129 memblock_add(low_mem_start, low_mem_sz);
130 memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);
131
132#ifdef CONFIG_BLK_DEV_INITRD
133 if (initrd_start)
134 memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
135#endif
136
137 memblock_dump_all();
138
139 /*----------------- node/zones setup --------------------------*/
140 memset(zones_size, 0, sizeof(zones_size));
141 memset(zones_holes, 0, sizeof(zones_holes));
142
143 zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
144 zones_holes[ZONE_NORMAL] = 0;
145
146#ifdef CONFIG_HIGHMEM
147 zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
148
149 /* This handles the peripheral address space hole */
150 zones_holes[ZONE_HIGHMEM] = min_high_pfn - max_low_pfn;
151#endif
152
153 /*
154 * We can't use the helper free_area_init(zones[]) because it uses
155 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
156 * when our kernel doesn't start at PAGE_OFFSET, i.e.
157 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
158 */
159 free_area_init_node(0, /* node-id */
160 zones_size, /* num pages per zone */
161 min_low_pfn, /* first pfn of node */
162 zones_holes); /* holes */
163
164#ifdef CONFIG_HIGHMEM
165 high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
166 kmap_init();
167#endif
168}
169
170/*
171 * mem_init - initializes memory
172 *
173 * Frees up bootmem
174 * Calculates and displays memory available/used
175 */
176void __init mem_init(void)
177{
178#ifdef CONFIG_HIGHMEM
179 unsigned long tmp;
180
181 reset_all_zones_managed_pages();
182 for (tmp = min_high_pfn; tmp < max_pfn; tmp++)
183 free_highmem_page(pfn_to_page(tmp));
184#endif
185
186 free_all_bootmem();
187 mem_init_print_info(NULL);
188}
189
190/*
191 * free_initmem: Free all the __init memory.
192 */
193void __init_refok free_initmem(void)
194{
195 free_initmem_default(-1);
196}
197
198#ifdef CONFIG_BLK_DEV_INITRD
199void __init free_initrd_mem(unsigned long start, unsigned long end)
200{
201 free_reserved_area((void *)start, (void *)end, -1, "initrd");
202}
203#endif