Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
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_BLOCK_DEV_RAM
14#include <linux/blk.h>
15#endif
16#include <linux/swap.h>
17#include <linux/module.h>
18#include <asm/page.h>
19#include <asm/pgalloc.h>
20#include <asm/sections.h>
21#include <asm/arcregs.h>
22
23pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
24char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
25EXPORT_SYMBOL(empty_zero_page);
26
27/* Default tot mem from .config */
28static unsigned long arc_mem_sz = 0x20000000; /* some default */
29
30/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
31static int __init setup_mem_sz(char *str)
32{
33 arc_mem_sz = memparse(str, NULL) & PAGE_MASK;
34
35 /* early console might not be setup yet - it will show up later */
36 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(arc_mem_sz));
37
38 return 0;
39}
40early_param("mem", setup_mem_sz);
41
42void __init early_init_dt_add_memory_arch(u64 base, u64 size)
43{
44 arc_mem_sz = size & PAGE_MASK;
45 pr_info("Memory size set via devicetree %ldM\n", TO_MB(arc_mem_sz));
46}
47
48/*
49 * First memory setup routine called from setup_arch()
50 * 1. setup swapper's mm @init_mm
51 * 2. Count the pages we have and setup bootmem allocator
52 * 3. zone setup
53 */
54void __init setup_arch_memory(void)
55{
56 unsigned long zones_size[MAX_NR_ZONES] = { 0, 0 };
57 unsigned long end_mem = CONFIG_LINUX_LINK_BASE + arc_mem_sz;
58
59 init_mm.start_code = (unsigned long)_text;
60 init_mm.end_code = (unsigned long)_etext;
61 init_mm.end_data = (unsigned long)_edata;
62 init_mm.brk = (unsigned long)_end;
63
64 /*
65 * We do it here, so that memory is correctly instantiated
66 * even if "mem=xxx" cmline over-ride is given and/or
67 * DT has memory node. Each causes an update to @arc_mem_sz
68 * and we finally add memory one here
69 */
70 memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz);
71
72 /*------------- externs in mm need setting up ---------------*/
73
74 /* first page of system - kernel .vector starts here */
75 min_low_pfn = PFN_DOWN(CONFIG_LINUX_LINK_BASE);
76
77 /* Last usable page of low mem (no HIGHMEM yet for ARC port) */
78 max_low_pfn = max_pfn = PFN_DOWN(end_mem);
79
80 max_mapnr = num_physpages = max_low_pfn - min_low_pfn;
81
82 /*------------- reserve kernel image -----------------------*/
83 memblock_reserve(CONFIG_LINUX_LINK_BASE,
84 __pa(_end) - CONFIG_LINUX_LINK_BASE);
85
86 memblock_dump_all();
87
88 /*-------------- node setup --------------------------------*/
89 memset(zones_size, 0, sizeof(zones_size));
90 zones_size[ZONE_NORMAL] = num_physpages;
91
92 /*
93 * We can't use the helper free_area_init(zones[]) because it uses
94 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
95 * when our kernel doesn't start at PAGE_OFFSET, i.e.
96 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
97 */
98 free_area_init_node(0, /* node-id */
99 zones_size, /* num pages per zone */
100 min_low_pfn, /* first pfn of node */
101 NULL); /* NO holes */
102}
103
104/*
105 * mem_init - initializes memory
106 *
107 * Frees up bootmem
108 * Calculates and displays memory available/used
109 */
110void __init mem_init(void)
111{
112 int codesize, datasize, initsize, reserved_pages, free_pages;
113 int tmp;
114
115 high_memory = (void *)(CONFIG_LINUX_LINK_BASE + arc_mem_sz);
116
117 totalram_pages = free_all_bootmem();
118
119 /* count all reserved pages [kernel code/data/mem_map..] */
120 reserved_pages = 0;
121 for (tmp = 0; tmp < max_mapnr; tmp++)
122 if (PageReserved(mem_map + tmp))
123 reserved_pages++;
124
125 /* XXX: nr_free_pages() is equivalent */
126 free_pages = max_mapnr - reserved_pages;
127
128 /*
129 * For the purpose of display below, split the "reserve mem"
130 * kernel code/data is already shown explicitly,
131 * Show any other reservations (mem_map[ ] et al)
132 */
133 reserved_pages -= (((unsigned int)_end - CONFIG_LINUX_LINK_BASE) >>
134 PAGE_SHIFT);
135
136 codesize = _etext - _text;
137 datasize = _end - _etext;
138 initsize = __init_end - __init_begin;
139
140 pr_info("Memory Available: %dM / %ldM (%dK code, %dK data, %dK init, %dK reserv)\n",
141 PAGES_TO_MB(free_pages),
142 TO_MB(arc_mem_sz),
143 TO_KB(codesize), TO_KB(datasize), TO_KB(initsize),
144 PAGES_TO_KB(reserved_pages));
145}
146
147static void __init free_init_pages(const char *what, unsigned long begin,
148 unsigned long end)
149{
150 unsigned long addr;
151
152 pr_info("Freeing %s: %ldk [%lx] to [%lx]\n",
153 what, TO_KB(end - begin), begin, end);
154
155 /* need to check that the page we free is not a partial page */
156 for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
157 ClearPageReserved(virt_to_page(addr));
158 init_page_count(virt_to_page(addr));
159 free_page(addr);
160 totalram_pages++;
161 }
162}
163
164/*
165 * free_initmem: Free all the __init memory.
166 */
167void __init_refok free_initmem(void)
168{
169 free_init_pages("unused kernel memory",
170 (unsigned long)__init_begin,
171 (unsigned long)__init_end);
172}
173
174#ifdef CONFIG_BLK_DEV_INITRD
175void __init free_initrd_mem(unsigned long start, unsigned long end)
176{
177 free_init_pages("initrd memory", start, end);
178}
179#endif
180
181#ifdef CONFIG_OF_FLATTREE
182void __init early_init_dt_setup_initrd_arch(unsigned long start,
183 unsigned long end)
184{
185 pr_err("%s(%lx, %lx)\n", __func__, start, end);
186}
187#endif /* CONFIG_OF_FLATTREE */