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/of_fdt.h>
17 #include <linux/swap.h>
18 #include <linux/module.h>
19 #include <linux/highmem.h>
20 #include <asm/page.h>
21 #include <asm/pgalloc.h>
22 #include <asm/sections.h>
23 #include <asm/arcregs.h>
24
25 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
26 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
27 EXPORT_SYMBOL(empty_zero_page);
28
29 static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
30 static unsigned long low_mem_sz;
31
32 #ifdef CONFIG_HIGHMEM
33 static unsigned long min_high_pfn, max_high_pfn;
34 static u64 high_mem_start;
35 static u64 high_mem_sz;
36 #endif
37
38 #ifdef CONFIG_DISCONTIGMEM
39 struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
40 EXPORT_SYMBOL(node_data);
41 #endif
42
arc_get_mem_sz(void)43 long __init arc_get_mem_sz(void)
44 {
45 return low_mem_sz;
46 }
47
48 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
setup_mem_sz(char * str)49 static int __init setup_mem_sz(char *str)
50 {
51 low_mem_sz = memparse(str, NULL) & PAGE_MASK;
52
53 /* early console might not be setup yet - it will show up later */
54 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
55
56 return 0;
57 }
58 early_param("mem", setup_mem_sz);
59
early_init_dt_add_memory_arch(u64 base,u64 size)60 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
61 {
62 int in_use = 0;
63
64 if (!low_mem_sz) {
65 if (base != low_mem_start)
66 panic("CONFIG_LINUX_RAM_BASE != DT memory { }");
67
68 low_mem_sz = size;
69 in_use = 1;
70 } else {
71 #ifdef CONFIG_HIGHMEM
72 high_mem_start = base;
73 high_mem_sz = size;
74 in_use = 1;
75 #endif
76 }
77
78 pr_info("Memory @ %llx [%lldM] %s\n",
79 base, TO_MB(size), !in_use ? "Not used":"");
80 }
81
82 #ifdef CONFIG_BLK_DEV_INITRD
early_initrd(char * p)83 static int __init early_initrd(char *p)
84 {
85 unsigned long start, size;
86 char *endp;
87
88 start = memparse(p, &endp);
89 if (*endp == ',') {
90 size = memparse(endp + 1, NULL);
91
92 initrd_start = (unsigned long)__va(start);
93 initrd_end = (unsigned long)__va(start + size);
94 }
95 return 0;
96 }
97 early_param("initrd", early_initrd);
98 #endif
99
100 /*
101 * First memory setup routine called from setup_arch()
102 * 1. setup swapper's mm @init_mm
103 * 2. Count the pages we have and setup bootmem allocator
104 * 3. zone setup
105 */
setup_arch_memory(void)106 void __init setup_arch_memory(void)
107 {
108 unsigned long zones_size[MAX_NR_ZONES];
109 unsigned long zones_holes[MAX_NR_ZONES];
110
111 init_mm.start_code = (unsigned long)_text;
112 init_mm.end_code = (unsigned long)_etext;
113 init_mm.end_data = (unsigned long)_edata;
114 init_mm.brk = (unsigned long)_end;
115
116 /* first page of system - kernel .vector starts here */
117 min_low_pfn = ARCH_PFN_OFFSET;
118
119 /* Last usable page of low mem */
120 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
121
122 #ifdef CONFIG_FLATMEM
123 /* pfn_valid() uses this */
124 max_mapnr = max_low_pfn - min_low_pfn;
125 #endif
126
127 /*------------- bootmem allocator setup -----------------------*/
128
129 /*
130 * seed the bootmem allocator after any DT memory node parsing or
131 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
132 *
133 * Only low mem is added, otherwise we have crashes when allocating
134 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
135 * avail memory, ending in highmem with a > 32-bit address. However
136 * it then tries to memset it with a truncaed 32-bit handle, causing
137 * the crash
138 */
139
140 memblock_add_node(low_mem_start, low_mem_sz, 0);
141 memblock_reserve(CONFIG_LINUX_LINK_BASE,
142 __pa(_end) - CONFIG_LINUX_LINK_BASE);
143
144 #ifdef CONFIG_BLK_DEV_INITRD
145 if (initrd_start)
146 memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
147 #endif
148
149 early_init_fdt_reserve_self();
150 early_init_fdt_scan_reserved_mem();
151
152 memblock_dump_all();
153
154 /*----------------- node/zones setup --------------------------*/
155 memset(zones_size, 0, sizeof(zones_size));
156 memset(zones_holes, 0, sizeof(zones_holes));
157
158 zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
159 zones_holes[ZONE_NORMAL] = 0;
160
161 /*
162 * We can't use the helper free_area_init(zones[]) because it uses
163 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
164 * when our kernel doesn't start at PAGE_OFFSET, i.e.
165 * PAGE_OFFSET != CONFIG_LINUX_RAM_BASE
166 */
167 free_area_init_node(0, /* node-id */
168 zones_size, /* num pages per zone */
169 min_low_pfn, /* first pfn of node */
170 zones_holes); /* holes */
171
172 #ifdef CONFIG_HIGHMEM
173 /*
174 * Populate a new node with highmem
175 *
176 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
177 * than addresses in normal ala low memory (0x8000_0000 based).
178 * Even with PAE, the huge peripheral space hole would waste a lot of
179 * mem with single mem_map[]. This warrants a mem_map per region design.
180 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
181 *
182 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
183 * populated with normal memory zone while node 1 only has highmem
184 */
185 node_set_online(1);
186
187 min_high_pfn = PFN_DOWN(high_mem_start);
188 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
189
190 zones_size[ZONE_NORMAL] = 0;
191 zones_holes[ZONE_NORMAL] = 0;
192
193 zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn;
194 zones_holes[ZONE_HIGHMEM] = 0;
195
196 free_area_init_node(1, /* node-id */
197 zones_size, /* num pages per zone */
198 min_high_pfn, /* first pfn of node */
199 zones_holes); /* holes */
200
201 high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
202 kmap_init();
203 #endif
204 }
205
206 /*
207 * mem_init - initializes memory
208 *
209 * Frees up bootmem
210 * Calculates and displays memory available/used
211 */
mem_init(void)212 void __init mem_init(void)
213 {
214 #ifdef CONFIG_HIGHMEM
215 unsigned long tmp;
216
217 reset_all_zones_managed_pages();
218 for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
219 free_highmem_page(pfn_to_page(tmp));
220 #endif
221
222 free_all_bootmem();
223 mem_init_print_info(NULL);
224 }
225
226 /*
227 * free_initmem: Free all the __init memory.
228 */
free_initmem(void)229 void __ref free_initmem(void)
230 {
231 free_initmem_default(-1);
232 }
233
234 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)235 void __init free_initrd_mem(unsigned long start, unsigned long end)
236 {
237 free_reserved_area((void *)start, (void *)end, -1, "initrd");
238 }
239 #endif
240