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 <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#ifdef CONFIG_BLK_DEV_INITRD
49static int __init early_initrd(char *p)
50{
51	unsigned long start, size;
52	char *endp;
53
54	start = memparse(p, &endp);
55	if (*endp == ',') {
56		size = memparse(endp + 1, NULL);
57
58		initrd_start = (unsigned long)__va(start);
59		initrd_end = (unsigned long)__va(start + size);
60	}
61	return 0;
62}
63early_param("initrd", early_initrd);
64#endif
65
66/*
67 * First memory setup routine called from setup_arch()
68 * 1. setup swapper's mm @init_mm
69 * 2. Count the pages we have and setup bootmem allocator
70 * 3. zone setup
71 */
72void __init setup_arch_memory(void)
73{
74	unsigned long zones_size[MAX_NR_ZONES];
75	unsigned long end_mem = CONFIG_LINUX_LINK_BASE + arc_mem_sz;
76
77	init_mm.start_code = (unsigned long)_text;
78	init_mm.end_code = (unsigned long)_etext;
79	init_mm.end_data = (unsigned long)_edata;
80	init_mm.brk = (unsigned long)_end;
81
82	/*
83	 * We do it here, so that memory is correctly instantiated
84	 * even if "mem=xxx" cmline over-ride is given and/or
85	 * DT has memory node. Each causes an update to @arc_mem_sz
86	 * and we finally add memory one here
87	 */
88	memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz);
89
90	/*------------- externs in mm need setting up ---------------*/
91
92	/* first page of system - kernel .vector starts here */
93	min_low_pfn = ARCH_PFN_OFFSET;
94
95	/* Last usable page of low mem (no HIGHMEM yet for ARC port) */
96	max_low_pfn = max_pfn = PFN_DOWN(end_mem);
97
98	max_mapnr = max_low_pfn - min_low_pfn;
99
100	/*------------- reserve kernel image -----------------------*/
101	memblock_reserve(CONFIG_LINUX_LINK_BASE,
102			 __pa(_end) - CONFIG_LINUX_LINK_BASE);
103
104#ifdef CONFIG_BLK_DEV_INITRD
105	/*------------- reserve initrd image -----------------------*/
106	if (initrd_start)
107		memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
108#endif
109
110	memblock_dump_all();
111
112	/*-------------- node setup --------------------------------*/
113	memset(zones_size, 0, sizeof(zones_size));
114	zones_size[ZONE_NORMAL] = max_mapnr;
115
116	/*
117	 * We can't use the helper free_area_init(zones[]) because it uses
118	 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
119	 * when our kernel doesn't start at PAGE_OFFSET, i.e.
120	 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
121	 */
122	free_area_init_node(0,			/* node-id */
123			    zones_size,		/* num pages per zone */
124			    min_low_pfn,	/* first pfn of node */
125			    NULL);		/* NO holes */
126
127	high_memory = (void *)end_mem;
128}
129
130/*
131 * mem_init - initializes memory
132 *
133 * Frees up bootmem
134 * Calculates and displays memory available/used
135 */
136void __init mem_init(void)
137{
138	free_all_bootmem();
139	mem_init_print_info(NULL);
140}
141
142/*
143 * free_initmem: Free all the __init memory.
144 */
145void __init_refok free_initmem(void)
146{
147	free_initmem_default(-1);
148}
149
150#ifdef CONFIG_BLK_DEV_INITRD
151void __init free_initrd_mem(unsigned long start, unsigned long end)
152{
153	free_reserved_area((void *)start, (void *)end, -1, "initrd");
154}
155#endif
156