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/setup.h>
19 #include <asm/arcregs.h>
20
21 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
22 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
23 EXPORT_SYMBOL(empty_zero_page);
24
25 static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
26 static unsigned long low_mem_sz;
27
28 #ifdef CONFIG_HIGHMEM
29 static unsigned long min_high_pfn, max_high_pfn;
30 static phys_addr_t high_mem_start;
31 static phys_addr_t high_mem_sz;
32 unsigned long arch_pfn_offset;
33 EXPORT_SYMBOL(arch_pfn_offset);
34 #endif
35
36 long __init arc_get_mem_sz(void)
37 {
38 return low_mem_sz;
39 }
40
41 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
42 static int __init setup_mem_sz(char *str)
43 {
44 low_mem_sz = memparse(str, NULL) & PAGE_MASK;
45
46 /* early console might not be setup yet - it will show up later */
47 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
48
49 return 0;
50 }
51 early_param("mem", setup_mem_sz);
52
53 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
54 {
55 int in_use = 0;
56
57 if (!low_mem_sz) {
58 if (base != low_mem_start)
59 panic("CONFIG_LINUX_RAM_BASE != DT memory { }");
60
61 low_mem_sz = size;
62 in_use = 1;
63 memblock_add_node(base, size, 0, MEMBLOCK_NONE);
64 } else {
65 #ifdef CONFIG_HIGHMEM
66 high_mem_start = base;
67 high_mem_sz = size;
68 in_use = 1;
69 memblock_add_node(base, size, 1, MEMBLOCK_NONE);
70 memblock_reserve(base, size);
71 #endif
72 }
73
74 pr_info("Memory @ %llx [%lldM] %s\n",
75 base, TO_MB(size), !in_use ? "Not used":"");
76 }
77
78 /*
79 * First memory setup routine called from setup_arch()
80 * 1. setup swapper's mm @init_mm
81 * 2. Count the pages we have and setup bootmem allocator
82 * 3. zone setup
83 */
84 void __init setup_arch_memory(void)
85 {
86 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
87
88 setup_initial_init_mm(_text, _etext, _edata, _end);
89
90 /* first page of system - kernel .vector starts here */
91 min_low_pfn = virt_to_pfn((void *)CONFIG_LINUX_RAM_BASE);
92
93 /* Last usable page of low mem */
94 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
95
96 /*------------- bootmem allocator setup -----------------------*/
97
98 /*
99 * seed the bootmem allocator after any DT memory node parsing or
100 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
101 *
102 * Only low mem is added, otherwise we have crashes when allocating
103 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
104 * avail memory, ending in highmem with a > 32-bit address. However
105 * it then tries to memset it with a truncaed 32-bit handle, causing
106 * the crash
107 */
108
109 memblock_reserve(CONFIG_LINUX_LINK_BASE,
110 __pa(_end) - CONFIG_LINUX_LINK_BASE);
111
112 #ifdef CONFIG_BLK_DEV_INITRD
113 if (phys_initrd_size) {
114 memblock_reserve(phys_initrd_start, phys_initrd_size);
115 initrd_start = (unsigned long)__va(phys_initrd_start);
116 initrd_end = initrd_start + phys_initrd_size;
117 }
118 #endif
119
120 early_init_fdt_reserve_self();
121 early_init_fdt_scan_reserved_mem();
122
123 memblock_dump_all();
124
125 /*----------------- node/zones setup --------------------------*/
126 max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
127
128 #ifdef CONFIG_HIGHMEM
129 /*
130 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
131 * than addresses in normal aka low memory (0x8000_0000 based).
132 * Even with PAE, the huge peripheral space hole would waste a lot of
133 * mem with single contiguous mem_map[].
134 * Thus when HIGHMEM on ARC is enabled the memory map corresponding
135 * to the hole is freed and ARC specific version of pfn_valid()
136 * handles the hole in the memory map.
137 */
138
139 min_high_pfn = PFN_DOWN(high_mem_start);
140 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
141
142 /*
143 * max_high_pfn should be ok here for both HIGHMEM and HIGHMEM+PAE.
144 * For HIGHMEM without PAE max_high_pfn should be less than
145 * min_low_pfn to guarantee that these two regions don't overlap.
146 * For PAE case highmem is greater than lowmem, so it is natural
147 * to use max_high_pfn.
148 *
149 * In both cases, holes should be handled by pfn_valid().
150 */
151 max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn;
152
153 high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
154
155 arch_pfn_offset = min(min_low_pfn, min_high_pfn);
156 kmap_init();
157
158 #else /* CONFIG_HIGHMEM */
159 /* pfn_valid() uses this when FLATMEM=y and HIGHMEM=n */
160 max_mapnr = max_low_pfn - min_low_pfn;
161
162 #endif /* CONFIG_HIGHMEM */
163
164 free_area_init(max_zone_pfn);
165 }
166
167 static void __init highmem_init(void)
168 {
169 #ifdef CONFIG_HIGHMEM
170 unsigned long tmp;
171
172 memblock_phys_free(high_mem_start, high_mem_sz);
173 for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
174 free_highmem_page(pfn_to_page(tmp));
175 #endif
176 }
177
178 /*
179 * mem_init - initializes memory
180 *
181 * Frees up bootmem
182 * Calculates and displays memory available/used
183 */
184 void __init mem_init(void)
185 {
186 memblock_free_all();
187 highmem_init();
188
189 BUILD_BUG_ON((PTRS_PER_PGD * sizeof(pgd_t)) > PAGE_SIZE);
190 BUILD_BUG_ON((PTRS_PER_PUD * sizeof(pud_t)) > PAGE_SIZE);
191 BUILD_BUG_ON((PTRS_PER_PMD * sizeof(pmd_t)) > PAGE_SIZE);
192 BUILD_BUG_ON((PTRS_PER_PTE * sizeof(pte_t)) > PAGE_SIZE);
193 }
194
195 #ifdef CONFIG_HIGHMEM
196 int pfn_valid(unsigned long pfn)
197 {
198 return (pfn >= min_high_pfn && pfn <= max_high_pfn) ||
199 (pfn >= min_low_pfn && pfn <= max_low_pfn);
200 }
201 EXPORT_SYMBOL(pfn_valid);
202 #endif
203
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