1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 1995-2005 Russell King
3 // Copyright (C) 2012 ARM Ltd.
4 // Copyright (C) 2013-2017 Andes Technology Corporation
5
6 #include <linux/kernel.h>
7 #include <linux/errno.h>
8 #include <linux/swap.h>
9 #include <linux/init.h>
10 #include <linux/bootmem.h>
11 #include <linux/mman.h>
12 #include <linux/nodemask.h>
13 #include <linux/initrd.h>
14 #include <linux/highmem.h>
15 #include <linux/memblock.h>
16
17 #include <asm/sections.h>
18 #include <asm/setup.h>
19 #include <asm/tlb.h>
20 #include <asm/page.h>
21
22 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
23 DEFINE_SPINLOCK(anon_alias_lock);
24 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
25 extern unsigned long phys_initrd_start;
26 extern unsigned long phys_initrd_size;
27
28 /*
29 * empty_zero_page is a special page that is used for
30 * zero-initialized data and COW.
31 */
32 struct page *empty_zero_page;
33 EXPORT_SYMBOL(empty_zero_page);
34
zone_sizes_init(void)35 static void __init zone_sizes_init(void)
36 {
37 unsigned long zones_size[MAX_NR_ZONES];
38
39 /* Clear the zone sizes */
40 memset(zones_size, 0, sizeof(zones_size));
41
42 zones_size[ZONE_NORMAL] = max_low_pfn;
43 #ifdef CONFIG_HIGHMEM
44 zones_size[ZONE_HIGHMEM] = max_pfn;
45 #endif
46 free_area_init(zones_size);
47
48 }
49
50 /*
51 * Map all physical memory under high_memory into kernel's address space.
52 *
53 * This is explicitly coded for two-level page tables, so if you need
54 * something else then this needs to change.
55 */
map_ram(void)56 static void __init map_ram(void)
57 {
58 unsigned long v, p, e;
59 pgd_t *pge;
60 pud_t *pue;
61 pmd_t *pme;
62 pte_t *pte;
63 /* These mark extents of read-only kernel pages...
64 * ...from vmlinux.lds.S
65 */
66
67 p = (u32) memblock_start_of_DRAM() & PAGE_MASK;
68 e = min((u32) memblock_end_of_DRAM(), (u32) __pa(high_memory));
69
70 v = (u32) __va(p);
71 pge = pgd_offset_k(v);
72
73 while (p < e) {
74 int j;
75 pue = pud_offset(pge, v);
76 pme = pmd_offset(pue, v);
77
78 if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) {
79 panic("%s: Kernel hardcoded for "
80 "two-level page tables", __func__);
81 }
82
83 /* Alloc one page for holding PTE's... */
84 pte = (pte_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
85 memset(pte, 0, PAGE_SIZE);
86 set_pmd(pme, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
87
88 /* Fill the newly allocated page with PTE'S */
89 for (j = 0; p < e && j < PTRS_PER_PTE;
90 v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
91 /* Create mapping between p and v. */
92 /* TODO: more fine grant for page access permission */
93 set_pte(pte, __pte(p + pgprot_val(PAGE_KERNEL)));
94 }
95
96 pge++;
97 }
98 }
99 static pmd_t *fixmap_pmd_p;
fixedrange_init(void)100 static void __init fixedrange_init(void)
101 {
102 unsigned long vaddr;
103 pgd_t *pgd;
104 pud_t *pud;
105 pmd_t *pmd;
106 #ifdef CONFIG_HIGHMEM
107 pte_t *pte;
108 #endif /* CONFIG_HIGHMEM */
109
110 /*
111 * Fixed mappings:
112 */
113 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1);
114 pgd = swapper_pg_dir + pgd_index(vaddr);
115 pud = pud_offset(pgd, vaddr);
116 pmd = pmd_offset(pud, vaddr);
117 fixmap_pmd_p = (pmd_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
118 memset(fixmap_pmd_p, 0, PAGE_SIZE);
119 set_pmd(pmd, __pmd(__pa(fixmap_pmd_p) + _PAGE_KERNEL_TABLE));
120
121 #ifdef CONFIG_HIGHMEM
122 /*
123 * Permanent kmaps:
124 */
125 vaddr = PKMAP_BASE;
126
127 pgd = swapper_pg_dir + pgd_index(vaddr);
128 pud = pud_offset(pgd, vaddr);
129 pmd = pmd_offset(pud, vaddr);
130 pte = (pte_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
131 memset(pte, 0, PAGE_SIZE);
132 set_pmd(pmd, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
133 pkmap_page_table = pte;
134 #endif /* CONFIG_HIGHMEM */
135 }
136
137 /*
138 * paging_init() sets up the page tables, initialises the zone memory
139 * maps, and sets up the zero page, bad page and bad page tables.
140 */
paging_init(void)141 void __init paging_init(void)
142 {
143 int i;
144 void *zero_page;
145
146 pr_info("Setting up paging and PTEs.\n");
147 /* clear out the init_mm.pgd that will contain the kernel's mappings */
148 for (i = 0; i < PTRS_PER_PGD; i++)
149 swapper_pg_dir[i] = __pgd(1);
150
151 map_ram();
152
153 fixedrange_init();
154
155 /* allocate space for empty_zero_page */
156 zero_page = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
157 memset(zero_page, 0, PAGE_SIZE);
158 zone_sizes_init();
159
160 empty_zero_page = virt_to_page(zero_page);
161 flush_dcache_page(empty_zero_page);
162 }
163
free_highmem(void)164 static inline void __init free_highmem(void)
165 {
166 #ifdef CONFIG_HIGHMEM
167 unsigned long pfn;
168 for (pfn = PFN_UP(__pa(high_memory)); pfn < max_pfn; pfn++) {
169 phys_addr_t paddr = (phys_addr_t) pfn << PAGE_SHIFT;
170 if (!memblock_is_reserved(paddr))
171 free_highmem_page(pfn_to_page(pfn));
172 }
173 #endif
174 }
175
set_max_mapnr_init(void)176 static void __init set_max_mapnr_init(void)
177 {
178 max_mapnr = max_pfn;
179 }
180
181 /*
182 * mem_init() marks the free areas in the mem_map and tells us how much
183 * memory is free. This is done after various parts of the system have
184 * claimed their memory after the kernel image.
185 */
mem_init(void)186 void __init mem_init(void)
187 {
188 phys_addr_t memory_start = memblock_start_of_DRAM();
189 BUG_ON(!mem_map);
190 set_max_mapnr_init();
191
192 free_highmem();
193
194 /* this will put all low memory onto the freelists */
195 free_all_bootmem();
196 mem_init_print_info(NULL);
197
198 pr_info("virtual kernel memory layout:\n"
199 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
200 #ifdef CONFIG_HIGHMEM
201 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
202 #endif
203 " consist : 0x%08lx - 0x%08lx (%4ld MB)\n"
204 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
205 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
206 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
207 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
208 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
209 FIXADDR_START, FIXADDR_TOP, (FIXADDR_TOP - FIXADDR_START) >> 10,
210 #ifdef CONFIG_HIGHMEM
211 PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
212 (LAST_PKMAP * PAGE_SIZE) >> 10,
213 #endif
214 CONSISTENT_BASE, CONSISTENT_END,
215 ((CONSISTENT_END) - (CONSISTENT_BASE)) >> 20, VMALLOC_START,
216 (unsigned long)VMALLOC_END, (VMALLOC_END - VMALLOC_START) >> 20,
217 (unsigned long)__va(memory_start), (unsigned long)high_memory,
218 ((unsigned long)high_memory -
219 (unsigned long)__va(memory_start)) >> 20,
220 (unsigned long)&__init_begin, (unsigned long)&__init_end,
221 ((unsigned long)&__init_end -
222 (unsigned long)&__init_begin) >> 10, (unsigned long)&_etext,
223 (unsigned long)&_edata,
224 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
225 (unsigned long)&_text, (unsigned long)&_etext,
226 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
227
228 /*
229 * Check boundaries twice: Some fundamental inconsistencies can
230 * be detected at build time already.
231 */
232 #ifdef CONFIG_HIGHMEM
233 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
234 BUILD_BUG_ON((CONSISTENT_END) > PKMAP_BASE);
235 #endif
236 BUILD_BUG_ON(VMALLOC_END > CONSISTENT_BASE);
237 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
238
239 #ifdef CONFIG_HIGHMEM
240 BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
241 BUG_ON(CONSISTENT_END > PKMAP_BASE);
242 #endif
243 BUG_ON(VMALLOC_END > CONSISTENT_BASE);
244 BUG_ON(VMALLOC_START >= VMALLOC_END);
245 BUG_ON((unsigned long)high_memory > VMALLOC_START);
246
247 return;
248 }
249
free_initmem(void)250 void free_initmem(void)
251 {
252 free_initmem_default(-1);
253 }
254
255 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)256 void free_initrd_mem(unsigned long start, unsigned long end)
257 {
258 free_reserved_area((void *)start, (void *)end, -1, "initrd");
259 }
260 #endif
261
__set_fixmap(enum fixed_addresses idx,phys_addr_t phys,pgprot_t flags)262 void __set_fixmap(enum fixed_addresses idx,
263 phys_addr_t phys, pgprot_t flags)
264 {
265 unsigned long addr = __fix_to_virt(idx);
266 pte_t *pte;
267
268 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
269
270 pte = (pte_t *)&fixmap_pmd_p[pte_index(addr)];;
271
272 if (pgprot_val(flags)) {
273 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
274 } else {
275 pte_clear(&init_mm, addr, pte);
276 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
277 }
278 }
279