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178 lines · 4.9 KiB

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
21pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
22
23static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
24static unsigned long low_mem_sz;
25
26#ifdef CONFIG_HIGHMEM
27static unsigned long min_high_pfn, max_high_pfn;
28static phys_addr_t high_mem_start;
29static phys_addr_t high_mem_sz;
30unsigned long arch_pfn_offset;
31EXPORT_SYMBOL(arch_pfn_offset);
32#endif
33
34long __init arc_get_mem_sz(void)
35{
36 return low_mem_sz;
37}
38
39/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
40static int __init setup_mem_sz(char *str)
41{
42 low_mem_sz = memparse(str, NULL) & PAGE_MASK;
43
44 /* early console might not be setup yet - it will show up later */
45 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
46
47 return 0;
48}
49early_param("mem", setup_mem_sz);
50
51void __init early_init_dt_add_memory_arch(u64 base, u64 size)
52{
53 int in_use = 0;
54
55 if (!low_mem_sz) {
56 if (base != low_mem_start)
57 panic("CONFIG_LINUX_RAM_BASE != DT memory { }");
58
59 low_mem_sz = size;
60 in_use = 1;
61 memblock_add_node(base, size, 0, MEMBLOCK_NONE);
62 } else {
63#ifdef CONFIG_HIGHMEM
64 high_mem_start = base;
65 high_mem_sz = size;
66 in_use = 1;
67 memblock_add_node(base, size, 1, MEMBLOCK_NONE);
68 memblock_reserve(base, size);
69#endif
70 }
71
72 pr_info("Memory @ %llx [%lldM] %s\n",
73 base, TO_MB(size), !in_use ? "Not used":"");
74}
75
76void __init arch_zone_limits_init(unsigned long *max_zone_pfn)
77{
78 /*----------------- node/zones setup --------------------------*/
79 max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
80
81#ifdef CONFIG_HIGHMEM
82 /*
83 * max_high_pfn should be ok here for both HIGHMEM and HIGHMEM+PAE.
84 * For HIGHMEM without PAE max_high_pfn should be less than
85 * min_low_pfn to guarantee that these two regions don't overlap.
86 * For PAE case highmem is greater than lowmem, so it is natural
87 * to use max_high_pfn.
88 *
89 * In both cases, holes should be handled by pfn_valid().
90 */
91 max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn;
92#endif
93}
94
95/*
96 * First memory setup routine called from setup_arch()
97 * 1. setup swapper's mm @init_mm
98 * 2. Count the pages we have and setup bootmem allocator
99 * 3. zone setup
100 */
101void __init setup_arch_memory(void)
102{
103 setup_initial_init_mm(_text, _etext, _edata, _end);
104
105 /* first page of system - kernel .vector starts here */
106 min_low_pfn = virt_to_pfn((void *)CONFIG_LINUX_RAM_BASE);
107
108 /* Last usable page of low mem */
109 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
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#ifdef CONFIG_HIGHMEM
141 /*
142 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
143 * than addresses in normal aka low memory (0x8000_0000 based).
144 * Even with PAE, the huge peripheral space hole would waste a lot of
145 * mem with single contiguous mem_map[].
146 * Thus when HIGHMEM on ARC is enabled the memory map corresponding
147 * to the hole is freed and ARC specific version of pfn_valid()
148 * handles the hole in the memory map.
149 */
150
151 min_high_pfn = PFN_DOWN(high_mem_start);
152 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
153
154 arch_pfn_offset = min(min_low_pfn, min_high_pfn);
155 kmap_init();
156#endif /* CONFIG_HIGHMEM */
157}
158
159void __init arch_mm_preinit(void)
160{
161#ifdef CONFIG_HIGHMEM
162 memblock_phys_free(high_mem_start, high_mem_sz);
163#endif
164
165 BUILD_BUG_ON((PTRS_PER_PGD * sizeof(pgd_t)) > PAGE_SIZE);
166 BUILD_BUG_ON((PTRS_PER_PUD * sizeof(pud_t)) > PAGE_SIZE);
167 BUILD_BUG_ON((PTRS_PER_PMD * sizeof(pmd_t)) > PAGE_SIZE);
168 BUILD_BUG_ON((PTRS_PER_PTE * sizeof(pte_t)) > PAGE_SIZE);
169}
170
171#ifdef CONFIG_HIGHMEM
172int pfn_valid(unsigned long pfn)
173{
174 return (pfn >= min_high_pfn && pfn <= max_high_pfn) ||
175 (pfn >= min_low_pfn && pfn <= max_low_pfn);
176}
177EXPORT_SYMBOL(pfn_valid);
178#endif