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		if (base != low_mem_start)
55			panic("CONFIG_LINUX_LINK_BASE != DT memory { }");
56
57		low_mem_sz = size;
58		in_use = 1;
59	} else {
60#ifdef CONFIG_HIGHMEM
61		high_mem_start = base;
62		high_mem_sz = size;
63		in_use = 1;
64#endif
65	}
66
67	pr_info("Memory @ %llx [%lldM] %s\n",
68		base, TO_MB(size), !in_use ? "Not used":"");
69}
70
71#ifdef CONFIG_BLK_DEV_INITRD
72static int __init early_initrd(char *p)
73{
74	unsigned long start, size;
75	char *endp;
76
77	start = memparse(p, &endp);
78	if (*endp == ',') {
79		size = memparse(endp + 1, NULL);
80
81		initrd_start = (unsigned long)__va(start);
82		initrd_end = (unsigned long)__va(start + size);
83	}
84	return 0;
85}
86early_param("initrd", early_initrd);
87#endif
88
89/*
90 * First memory setup routine called from setup_arch()
91 * 1. setup swapper's mm @init_mm
92 * 2. Count the pages we have and setup bootmem allocator
93 * 3. zone setup
94 */
95void __init setup_arch_memory(void)
96{
97	unsigned long zones_size[MAX_NR_ZONES];
98	unsigned long zones_holes[MAX_NR_ZONES];
99
100	init_mm.start_code = (unsigned long)_text;
101	init_mm.end_code = (unsigned long)_etext;
102	init_mm.end_data = (unsigned long)_edata;
103	init_mm.brk = (unsigned long)_end;
104
105	/* first page of system - kernel .vector starts here */
106	min_low_pfn = ARCH_PFN_OFFSET;
107
108	/* Last usable page of low mem */
109	max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
110
111#ifdef CONFIG_HIGHMEM
112	min_high_pfn = PFN_DOWN(high_mem_start);
113	max_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
114#endif
115
116	max_mapnr = max_pfn - min_low_pfn;
117
118	/*------------- bootmem allocator setup -----------------------*/
119
120	/*
121	 * seed the bootmem allocator after any DT memory node parsing or
122	 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
123	 *
124	 * Only low mem is added, otherwise we have crashes when allocating
125	 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
126	 * avail memory, ending in highmem with a > 32-bit address. However
127	 * it then tries to memset it with a truncaed 32-bit handle, causing
128	 * the crash
129	 */
130
131	memblock_add(low_mem_start, low_mem_sz);
132	memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);
133
134#ifdef CONFIG_BLK_DEV_INITRD
135	if (initrd_start)
136		memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
137#endif
138
139	memblock_dump_all();
140
141	/*----------------- node/zones setup --------------------------*/
142	memset(zones_size, 0, sizeof(zones_size));
143	memset(zones_holes, 0, sizeof(zones_holes));
144
145	zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
146	zones_holes[ZONE_NORMAL] = 0;
147
148#ifdef CONFIG_HIGHMEM
149	zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
150
151	/* This handles the peripheral address space hole */
152	zones_holes[ZONE_HIGHMEM] = min_high_pfn - max_low_pfn;
153#endif
154
155	/*
156	 * We can't use the helper free_area_init(zones[]) because it uses
157	 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
158	 * when our kernel doesn't start at PAGE_OFFSET, i.e.
159	 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
160	 */
161	free_area_init_node(0,			/* node-id */
162			    zones_size,		/* num pages per zone */
163			    min_low_pfn,	/* first pfn of node */
164			    zones_holes);	/* holes */
165
166#ifdef CONFIG_HIGHMEM
167	high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
168	kmap_init();
169#endif
170}
171
172/*
173 * mem_init - initializes memory
174 *
175 * Frees up bootmem
176 * Calculates and displays memory available/used
177 */
178void __init mem_init(void)
179{
180#ifdef CONFIG_HIGHMEM
181	unsigned long tmp;
182
183	reset_all_zones_managed_pages();
184	for (tmp = min_high_pfn; tmp < max_pfn; tmp++)
185		free_highmem_page(pfn_to_page(tmp));
186#endif
187
188	free_all_bootmem();
189	mem_init_print_info(NULL);
190}
191
192/*
193 * free_initmem: Free all the __init memory.
194 */
195void __init_refok free_initmem(void)
196{
197	free_initmem_default(-1);
198}
199
200#ifdef CONFIG_BLK_DEV_INITRD
201void __init free_initrd_mem(unsigned long start, unsigned long end)
202{
203	free_reserved_area((void *)start, (void *)end, -1, "initrd");
204}
205#endif
206