1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 */
5
6 #include <linux/kernel.h>
7 #include <linux/mm.h>
8 #include <linux/memblock.h>
9 #ifdef CONFIG_BLK_DEV_INITRD
10 #include <linux/initrd.h>
11 #endif
12 #include <linux/of_fdt.h>
13 #include <linux/swap.h>
14 #include <linux/module.h>
15 #include <linux/highmem.h>
16 #include <asm/page.h>
17 #include <asm/sections.h>
18 #include <asm/arcregs.h>
19
20 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
21 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
22 EXPORT_SYMBOL(empty_zero_page);
23
24 static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
25 static unsigned long low_mem_sz;
26
27 #ifdef CONFIG_HIGHMEM
28 static unsigned long min_high_pfn, max_high_pfn;
29 static phys_addr_t high_mem_start;
30 static phys_addr_t high_mem_sz;
31 #endif
32
33 #ifdef CONFIG_DISCONTIGMEM
34 struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
35 EXPORT_SYMBOL(node_data);
36 #endif
37
arc_get_mem_sz(void)38 long __init arc_get_mem_sz(void)
39 {
40 return low_mem_sz;
41 }
42
43 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
setup_mem_sz(char * str)44 static int __init setup_mem_sz(char *str)
45 {
46 low_mem_sz = memparse(str, NULL) & PAGE_MASK;
47
48 /* early console might not be setup yet - it will show up later */
49 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
50
51 return 0;
52 }
53 early_param("mem", setup_mem_sz);
54
early_init_dt_add_memory_arch(u64 base,u64 size)55 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
56 {
57 int in_use = 0;
58
59 if (!low_mem_sz) {
60 if (base != low_mem_start)
61 panic("CONFIG_LINUX_RAM_BASE != DT memory { }");
62
63 low_mem_sz = size;
64 in_use = 1;
65 memblock_add_node(base, size, 0);
66 } else {
67 #ifdef CONFIG_HIGHMEM
68 high_mem_start = base;
69 high_mem_sz = size;
70 in_use = 1;
71 memblock_add_node(base, size, 1);
72 memblock_reserve(base, size);
73 #endif
74 }
75
76 pr_info("Memory @ %llx [%lldM] %s\n",
77 base, TO_MB(size), !in_use ? "Not used":"");
78 }
79
arch_has_descending_max_zone_pfns(void)80 bool arch_has_descending_max_zone_pfns(void)
81 {
82 return !IS_ENABLED(CONFIG_ARC_HAS_PAE40);
83 }
84
85 /*
86 * First memory setup routine called from setup_arch()
87 * 1. setup swapper's mm @init_mm
88 * 2. Count the pages we have and setup bootmem allocator
89 * 3. zone setup
90 */
setup_arch_memory(void)91 void __init setup_arch_memory(void)
92 {
93 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
94
95 init_mm.start_code = (unsigned long)_text;
96 init_mm.end_code = (unsigned long)_etext;
97 init_mm.end_data = (unsigned long)_edata;
98 init_mm.brk = (unsigned long)_end;
99
100 /* first page of system - kernel .vector starts here */
101 min_low_pfn = ARCH_PFN_OFFSET;
102
103 /* Last usable page of low mem */
104 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
105
106 #ifdef CONFIG_FLATMEM
107 /* pfn_valid() uses this */
108 max_mapnr = max_low_pfn - min_low_pfn;
109 #endif
110
111 /*------------- bootmem allocator setup -----------------------*/
112
113 /*
114 * seed the bootmem allocator after any DT memory node parsing or
115 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
116 *
117 * Only low mem is added, otherwise we have crashes when allocating
118 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
119 * avail memory, ending in highmem with a > 32-bit address. However
120 * it then tries to memset it with a truncaed 32-bit handle, causing
121 * the crash
122 */
123
124 memblock_reserve(CONFIG_LINUX_LINK_BASE,
125 __pa(_end) - CONFIG_LINUX_LINK_BASE);
126
127 #ifdef CONFIG_BLK_DEV_INITRD
128 if (phys_initrd_size) {
129 memblock_reserve(phys_initrd_start, phys_initrd_size);
130 initrd_start = (unsigned long)__va(phys_initrd_start);
131 initrd_end = initrd_start + phys_initrd_size;
132 }
133 #endif
134
135 early_init_fdt_reserve_self();
136 early_init_fdt_scan_reserved_mem();
137
138 memblock_dump_all();
139
140 /*----------------- node/zones setup --------------------------*/
141 max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
142
143 #ifdef CONFIG_HIGHMEM
144 /*
145 * Populate a new node with highmem
146 *
147 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
148 * than addresses in normal ala low memory (0x8000_0000 based).
149 * Even with PAE, the huge peripheral space hole would waste a lot of
150 * mem with single mem_map[]. This warrants a mem_map per region design.
151 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
152 *
153 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
154 * populated with normal memory zone while node 1 only has highmem
155 */
156 node_set_online(1);
157
158 min_high_pfn = PFN_DOWN(high_mem_start);
159 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
160
161 max_zone_pfn[ZONE_HIGHMEM] = min_low_pfn;
162
163 high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
164 kmap_init();
165 #endif
166
167 free_area_init(max_zone_pfn);
168 }
169
highmem_init(void)170 static void __init highmem_init(void)
171 {
172 #ifdef CONFIG_HIGHMEM
173 unsigned long tmp;
174
175 memblock_free(high_mem_start, high_mem_sz);
176 for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
177 free_highmem_page(pfn_to_page(tmp));
178 #endif
179 }
180
181 /*
182 * mem_init - initializes memory
183 *
184 * Frees up bootmem
185 * Calculates and displays memory available/used
186 */
mem_init(void)187 void __init mem_init(void)
188 {
189 memblock_free_all();
190 highmem_init();
191 mem_init_print_info(NULL);
192 }
193
