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
6 #include <linux/kernel.h>
7 #include <linux/errno.h>
8 #include <linux/swap.h>
9 #include <linux/init.h>
10 #include <linux/memblock.h>
11 #include <linux/mman.h>
12 #include <linux/nodemask.h>
13 #include <linux/initrd.h>
14 #include <linux/highmem.h>
16 #include <asm/sections.h>
17 #include <asm/setup.h>
21 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
22 DEFINE_SPINLOCK(anon_alias_lock);
23 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
26 * empty_zero_page is a special page that is used for
27 * zero-initialized data and COW.
29 struct page *empty_zero_page;
30 EXPORT_SYMBOL(empty_zero_page);
32 static void __init zone_sizes_init(void)
34 unsigned long zones_size[MAX_NR_ZONES];
36 /* Clear the zone sizes */
37 memset(zones_size, 0, sizeof(zones_size));
39 zones_size[ZONE_NORMAL] = max_low_pfn;
41 zones_size[ZONE_HIGHMEM] = max_pfn;
43 free_area_init(zones_size);
48 * Map all physical memory under high_memory into kernel's address space.
50 * This is explicitly coded for two-level page tables, so if you need
51 * something else then this needs to change.
53 static void __init map_ram(void)
55 unsigned long v, p, e;
60 /* These mark extents of read-only kernel pages...
61 * ...from vmlinux.lds.S
64 p = (u32) memblock_start_of_DRAM() & PAGE_MASK;
65 e = min((u32) memblock_end_of_DRAM(), (u32) __pa(high_memory));
68 pge = pgd_offset_k(v);
72 pue = pud_offset(pge, v);
73 pme = pmd_offset(pue, v);
75 if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) {
76 panic("%s: Kernel hardcoded for "
77 "two-level page tables", __func__);
80 /* Alloc one page for holding PTE's... */
81 pte = (pte_t *) __va(memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE));
82 memset(pte, 0, PAGE_SIZE);
83 set_pmd(pme, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
85 /* Fill the newly allocated page with PTE'S */
86 for (j = 0; p < e && j < PTRS_PER_PTE;
87 v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
88 /* Create mapping between p and v. */
89 /* TODO: more fine grant for page access permission */
90 set_pte(pte, __pte(p + pgprot_val(PAGE_KERNEL)));
96 static pmd_t *fixmap_pmd_p;
97 static void __init fixedrange_init(void)
103 #ifdef CONFIG_HIGHMEM
105 #endif /* CONFIG_HIGHMEM */
110 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1);
111 pgd = swapper_pg_dir + pgd_index(vaddr);
112 pud = pud_offset(pgd, vaddr);
113 pmd = pmd_offset(pud, vaddr);
114 fixmap_pmd_p = (pmd_t *) __va(memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE));
115 memset(fixmap_pmd_p, 0, PAGE_SIZE);
116 set_pmd(pmd, __pmd(__pa(fixmap_pmd_p) + _PAGE_KERNEL_TABLE));
118 #ifdef CONFIG_HIGHMEM
124 pgd = swapper_pg_dir + pgd_index(vaddr);
125 pud = pud_offset(pgd, vaddr);
126 pmd = pmd_offset(pud, vaddr);
127 pte = (pte_t *) __va(memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE));
128 memset(pte, 0, PAGE_SIZE);
129 set_pmd(pmd, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
130 pkmap_page_table = pte;
131 #endif /* CONFIG_HIGHMEM */
135 * paging_init() sets up the page tables, initialises the zone memory
136 * maps, and sets up the zero page, bad page and bad page tables.
138 void __init paging_init(void)
143 pr_info("Setting up paging and PTEs.\n");
144 /* clear out the init_mm.pgd that will contain the kernel's mappings */
145 for (i = 0; i < PTRS_PER_PGD; i++)
146 swapper_pg_dir[i] = __pgd(1);
152 /* allocate space for empty_zero_page */
153 zero_page = __va(memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE));
154 memset(zero_page, 0, PAGE_SIZE);
157 empty_zero_page = virt_to_page(zero_page);
158 flush_dcache_page(empty_zero_page);
161 static inline void __init free_highmem(void)
163 #ifdef CONFIG_HIGHMEM
165 for (pfn = PFN_UP(__pa(high_memory)); pfn < max_pfn; pfn++) {
166 phys_addr_t paddr = (phys_addr_t) pfn << PAGE_SHIFT;
167 if (!memblock_is_reserved(paddr))
168 free_highmem_page(pfn_to_page(pfn));
173 static void __init set_max_mapnr_init(void)
179 * mem_init() marks the free areas in the mem_map and tells us how much
180 * memory is free. This is done after various parts of the system have
181 * claimed their memory after the kernel image.
183 void __init mem_init(void)
185 phys_addr_t memory_start = memblock_start_of_DRAM();
187 set_max_mapnr_init();
191 /* this will put all low memory onto the freelists */
193 mem_init_print_info(NULL);
195 pr_info("virtual kernel memory layout:\n"
196 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
197 #ifdef CONFIG_HIGHMEM
198 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
200 " consist : 0x%08lx - 0x%08lx (%4ld MB)\n"
201 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
202 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
203 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
204 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
205 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
206 FIXADDR_START, FIXADDR_TOP, (FIXADDR_TOP - FIXADDR_START) >> 10,
207 #ifdef CONFIG_HIGHMEM
208 PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
209 (LAST_PKMAP * PAGE_SIZE) >> 10,
211 CONSISTENT_BASE, CONSISTENT_END,
212 ((CONSISTENT_END) - (CONSISTENT_BASE)) >> 20, VMALLOC_START,
213 (unsigned long)VMALLOC_END, (VMALLOC_END - VMALLOC_START) >> 20,
214 (unsigned long)__va(memory_start), (unsigned long)high_memory,
215 ((unsigned long)high_memory -
216 (unsigned long)__va(memory_start)) >> 20,
217 (unsigned long)&__init_begin, (unsigned long)&__init_end,
218 ((unsigned long)&__init_end -
219 (unsigned long)&__init_begin) >> 10, (unsigned long)&_etext,
220 (unsigned long)&_edata,
221 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
222 (unsigned long)&_text, (unsigned long)&_etext,
223 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
226 * Check boundaries twice: Some fundamental inconsistencies can
227 * be detected at build time already.
229 #ifdef CONFIG_HIGHMEM
230 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
231 BUILD_BUG_ON((CONSISTENT_END) > PKMAP_BASE);
233 BUILD_BUG_ON(VMALLOC_END > CONSISTENT_BASE);
234 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
236 #ifdef CONFIG_HIGHMEM
237 BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
238 BUG_ON(CONSISTENT_END > PKMAP_BASE);
240 BUG_ON(VMALLOC_END > CONSISTENT_BASE);
241 BUG_ON(VMALLOC_START >= VMALLOC_END);
242 BUG_ON((unsigned long)high_memory > VMALLOC_START);
247 void free_initmem(void)
249 free_initmem_default(-1);
252 #ifdef CONFIG_BLK_DEV_INITRD
253 void free_initrd_mem(unsigned long start, unsigned long end)
255 free_reserved_area((void *)start, (void *)end, -1, "initrd");
259 void __set_fixmap(enum fixed_addresses idx,
260 phys_addr_t phys, pgprot_t flags)
262 unsigned long addr = __fix_to_virt(idx);
265 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
267 pte = (pte_t *)&fixmap_pmd_p[pte_index(addr)];;
269 if (pgprot_val(flags)) {
270 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
272 pte_clear(&init_mm, addr, pte);
273 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);