10d1fb0a4SAlex Dewar // SPDX-License-Identifier: GPL-2.0
21da177e4SLinus Torvalds /*
3009ec2a9SJeff Dike * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
41da177e4SLinus Torvalds */
51da177e4SLinus Torvalds
6009ec2a9SJeff Dike #include <linux/stddef.h>
773395a00SAl Viro #include <linux/module.h>
82013288fSMike Rapoport #include <linux/memblock.h>
9009ec2a9SJeff Dike #include <linux/highmem.h>
10009ec2a9SJeff Dike #include <linux/mm.h>
11009ec2a9SJeff Dike #include <linux/swap.h>
125a0e3ad6STejun Heo #include <linux/slab.h>
13009ec2a9SJeff Dike #include <asm/fixmap.h>
14009ec2a9SJeff Dike #include <asm/page.h>
1537185b33SAl Viro #include <as-layout.h>
1637185b33SAl Viro #include <init.h>
1737185b33SAl Viro #include <kern.h>
1837185b33SAl Viro #include <kern_util.h>
1937185b33SAl Viro #include <mem_user.h>
2037185b33SAl Viro #include <os.h>
211da177e4SLinus Torvalds #include <linux/sched/task.h>
226bf79482SJeff Dike
231da177e4SLinus Torvalds #ifdef CONFIG_KASAN
2473395a00SAl Viro int kasan_um_is_ready;
kasan_init(void)2580e39311SJeff Dike void kasan_init(void)
2680e39311SJeff Dike {
2780e39311SJeff Dike /*
2880e39311SJeff Dike * kasan_map_memory will map all of the required address space and
2980e39311SJeff Dike * the host machine will allocate physical memory as necessary.
301da177e4SLinus Torvalds */
3180e39311SJeff Dike kasan_map_memory((void *)KASAN_SHADOW_START, KASAN_SHADOW_SIZE);
3280e39311SJeff Dike init_task.kasan_depth = 0;
339902abd7SJeff Dike kasan_um_is_ready = true;
345d38f324SErel Geron }
351da177e4SLinus Torvalds
361da177e4SLinus Torvalds static void (*kasan_init_ptr)(void)
3780e39311SJeff Dike __section(".kasan_init") __used
381da177e4SLinus Torvalds = kasan_init;
391da177e4SLinus Torvalds #endif
4097a1fcbbSJeff Dike
411da177e4SLinus Torvalds /* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
421da177e4SLinus Torvalds unsigned long *empty_zero_page = NULL;
43c0a9290eSWANG Cong EXPORT_SYMBOL(empty_zero_page);
441da177e4SLinus Torvalds
451da177e4SLinus Torvalds /*
461da177e4SLinus Torvalds * Initialized during boot, and readonly for initializing page tables
471da177e4SLinus Torvalds * afterwards
481da177e4SLinus Torvalds */
49ab26a527SJeff Dike pgd_t swapper_pg_dir[PTRS_PER_PGD];
504421cca0SMike Rapoport
511da177e4SLinus Torvalds /* Initialized at boot time, and readonly after that */
521da177e4SLinus Torvalds unsigned long long highmem;
531da177e4SLinus Torvalds EXPORT_SYMBOL(highmem);
54c6ffc5caSMike Rapoport int kmalloc_ok = 0;
55ca79b0c2SArun KS
563d6357deSArun KS /* Used during early boot */
571da177e4SLinus Torvalds static unsigned long brk_end;
581da177e4SLinus Torvalds
mem_init(void)591da177e4SLinus Torvalds void __init mem_init(void)
6012f49643SJeff Dike {
6112f49643SJeff Dike /* clear the zero-page */
6212f49643SJeff Dike memset(empty_zero_page, 0, PAGE_SIZE);
6312f49643SJeff Dike
6412f49643SJeff Dike /* Map in the area just after the brk now that kmalloc is about
6512f49643SJeff Dike * to be turned on.
6612f49643SJeff Dike */
67e8625dceSMike Rapoport brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
68e8625dceSMike Rapoport map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
698a7f97b9SMike Rapoport memblock_free((void *)brk_end, uml_reserved - brk_end);
708a7f97b9SMike Rapoport uml_reserved = brk_end;
718a7f97b9SMike Rapoport
728a7f97b9SMike Rapoport /* this will put all low memory onto the freelists */
7312f49643SJeff Dike memblock_free_all();
7412f49643SJeff Dike max_low_pfn = totalram_pages();
7524271ffeSYang Li max_pfn = max_low_pfn;
7612f49643SJeff Dike kmalloc_ok = 1;
7712f49643SJeff Dike }
7812f49643SJeff Dike
7912f49643SJeff Dike /*
8012f49643SJeff Dike * Create a page table and place a pointer to it in a middle page
8112f49643SJeff Dike * directory entry.
82e8625dceSMike Rapoport */
one_page_table_init(pmd_t * pmd)838a7f97b9SMike Rapoport static void __init one_page_table_init(pmd_t *pmd)
848a7f97b9SMike Rapoport {
858a7f97b9SMike Rapoport if (pmd_none(*pmd)) {
868a7f97b9SMike Rapoport pte_t *pte = (pte_t *) memblock_alloc_low(PAGE_SIZE,
8712f49643SJeff Dike PAGE_SIZE);
888bd18ef9SChangcheng Deng if (!pte)
8912f49643SJeff Dike panic("%s: Failed to allocate %lu bytes align=%lx\n",
9012f49643SJeff Dike __func__, PAGE_SIZE, PAGE_SIZE);
9112f49643SJeff Dike
921da177e4SLinus Torvalds set_pmd(pmd, __pmd(_KERNPG_TABLE +
931da177e4SLinus Torvalds (unsigned long) __pa(pte)));
941da177e4SLinus Torvalds BUG_ON(pte != pte_offset_kernel(pmd, 0));
951da177e4SLinus Torvalds }
96e19f97edSMike Rapoport }
9712f49643SJeff Dike
one_md_table_init(pud_t * pud)981da177e4SLinus Torvalds static void __init one_md_table_init(pud_t *pud)
991da177e4SLinus Torvalds {
1001da177e4SLinus Torvalds #ifdef CONFIG_3_LEVEL_PGTABLES
1011da177e4SLinus Torvalds pmd_t *pmd_table = (pmd_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
1021da177e4SLinus Torvalds if (!pmd_table)
1031da177e4SLinus Torvalds panic("%s: Failed to allocate %lu bytes align=%lx\n",
1041da177e4SLinus Torvalds __func__, PAGE_SIZE, PAGE_SIZE);
1051da177e4SLinus Torvalds
1061da177e4SLinus Torvalds set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
1071da177e4SLinus Torvalds BUG_ON(pmd_table != pmd_offset(pud, 0));
108e19f97edSMike Rapoport #endif
109e19f97edSMike Rapoport }
11012f49643SJeff Dike
fixrange_init(unsigned long start,unsigned long end,pgd_t * pgd_base)11112f49643SJeff Dike static void __init fixrange_init(unsigned long start, unsigned long end,
11212f49643SJeff Dike pgd_t *pgd_base)
113655e4ed0SJeff Dike {
11412f49643SJeff Dike pgd_t *pgd;
1151da177e4SLinus Torvalds p4d_t *p4d;
1161da177e4SLinus Torvalds pud_t *pud;
1171da177e4SLinus Torvalds pmd_t *pmd;
1181da177e4SLinus Torvalds int i, j;
1191da177e4SLinus Torvalds unsigned long vaddr;
1201da177e4SLinus Torvalds
1211da177e4SLinus Torvalds vaddr = start;
1221da177e4SLinus Torvalds i = pgd_index(vaddr);
1239a0b3869Sviro@ZenIV.linux.org.uk j = pmd_index(vaddr);
1241da177e4SLinus Torvalds pgd = pgd_base + i;
1251da177e4SLinus Torvalds
126655e4ed0SJeff Dike for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
127655e4ed0SJeff Dike p4d = p4d_offset(pgd, vaddr);
1281da177e4SLinus Torvalds pud = pud_offset(p4d, vaddr);
1291da177e4SLinus Torvalds if (pud_none(*pud))
1301da177e4SLinus Torvalds one_md_table_init(pud);
1311da177e4SLinus Torvalds pmd = pmd_offset(pud, vaddr);
1321da177e4SLinus Torvalds for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
133e8625dceSMike Rapoport one_page_table_init(pmd);
1348a7f97b9SMike Rapoport vaddr += PMD_SIZE;
1358a7f97b9SMike Rapoport }
1368a7f97b9SMike Rapoport j = 0;
1378a7f97b9SMike Rapoport }
138655e4ed0SJeff Dike }
139655e4ed0SJeff Dike
fixaddr_user_init(void)140009ec2a9SJeff Dike static void __init fixaddr_user_init( void)
141655e4ed0SJeff Dike {
142e05c7b1fSMike Rapoport #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
143655e4ed0SJeff Dike long size = FIXADDR_USER_END - FIXADDR_USER_START;
1441da177e4SLinus Torvalds pte_t *pte;
1451da177e4SLinus Torvalds phys_t p;
1461da177e4SLinus Torvalds unsigned long v, vaddr = FIXADDR_USER_START;
1471da177e4SLinus Torvalds
14836e45463SJeff Dike if (!size)
1491da177e4SLinus Torvalds return;
150fa3354e4SMike Rapoport
151fa3354e4SMike Rapoport fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
1521da177e4SLinus Torvalds v = (unsigned long) memblock_alloc_low(size, PAGE_SIZE);
153e8625dceSMike Rapoport if (!v)
154e8625dceSMike Rapoport panic("%s: Failed to allocate %lu bytes align=%lx\n",
1558a7f97b9SMike Rapoport __func__, size, PAGE_SIZE);
1568a7f97b9SMike Rapoport
1578a7f97b9SMike Rapoport memcpy((void *) v , (void *) FIXADDR_USER_START, size);
1588a7f97b9SMike Rapoport p = __pa(v);
159fa3354e4SMike Rapoport for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
160fa3354e4SMike Rapoport p += PAGE_SIZE) {
1611da177e4SLinus Torvalds pte = virt_to_kpte(vaddr);
1621da177e4SLinus Torvalds pte_set_val(*pte, p, PAGE_READONLY);
1631da177e4SLinus Torvalds }
1641da177e4SLinus Torvalds #endif
1651da177e4SLinus Torvalds }
1661da177e4SLinus Torvalds
paging_init(void)1671da177e4SLinus Torvalds void __init paging_init(void)
1681da177e4SLinus Torvalds {
1691da177e4SLinus Torvalds unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
1701da177e4SLinus Torvalds unsigned long vaddr;
1711da177e4SLinus Torvalds
1728192ab42SJeff Dike empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE,
1738192ab42SJeff Dike PAGE_SIZE);
1741da177e4SLinus Torvalds if (!empty_zero_page)
1751da177e4SLinus Torvalds panic("%s: Failed to allocate %lu bytes align=%lx\n",
1761da177e4SLinus Torvalds __func__, PAGE_SIZE, PAGE_SIZE);
1771da177e4SLinus Torvalds
1781da177e4SLinus Torvalds max_zone_pfn[ZONE_NORMAL] = end_iomem >> PAGE_SHIFT;
1791da177e4SLinus Torvalds free_area_init(max_zone_pfn);
1801da177e4SLinus Torvalds
1818192ab42SJeff Dike /*
1821da177e4SLinus Torvalds * Fixed mappings, only the page table structure has to be
1831da177e4SLinus Torvalds * created - mappings will be set by set_fixmap():
1841da177e4SLinus Torvalds */
1851da177e4SLinus Torvalds vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
1861da177e4SLinus Torvalds fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
1871da177e4SLinus Torvalds
1881da177e4SLinus Torvalds fixaddr_user_init();
1891da177e4SLinus Torvalds }
1901da177e4SLinus Torvalds
1911da177e4SLinus Torvalds /*
1921da177e4SLinus Torvalds * This can't do anything because nothing in the kernel image can be freed
1931da177e4SLinus Torvalds * since it's not in kernel physical memory.
1941da177e4SLinus Torvalds */
1951da177e4SLinus Torvalds
free_initmem(void)19643f5b308SJeff Dike void free_initmem(void)
19743f5b308SJeff Dike {
19843f5b308SJeff Dike }
19943f5b308SJeff Dike
200*91a8da02SAnshuman Khandual /* Allocate and free page tables. */
201*91a8da02SAnshuman Khandual
pgd_alloc(struct mm_struct * mm)202*91a8da02SAnshuman Khandual pgd_t *pgd_alloc(struct mm_struct *mm)
203*91a8da02SAnshuman Khandual {
204*91a8da02SAnshuman Khandual pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
205*91a8da02SAnshuman Khandual
206*91a8da02SAnshuman Khandual if (pgd) {
207*91a8da02SAnshuman Khandual memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
208*91a8da02SAnshuman Khandual memcpy(pgd + USER_PTRS_PER_PGD,
209*91a8da02SAnshuman Khandual swapper_pg_dir + USER_PTRS_PER_PGD,
210*91a8da02SAnshuman Khandual (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
211*91a8da02SAnshuman Khandual }
212*91a8da02SAnshuman Khandual return pgd;
213*91a8da02SAnshuman Khandual }
214*91a8da02SAnshuman Khandual
uml_kmalloc(int size,int flags)215*91a8da02SAnshuman Khandual void *uml_kmalloc(int size, int flags)
216*91a8da02SAnshuman Khandual {
217*91a8da02SAnshuman Khandual return kmalloc(size, flags);
218*91a8da02SAnshuman Khandual }
219*91a8da02SAnshuman Khandual
220 static const pgprot_t protection_map[16] = {
221 [VM_NONE] = PAGE_NONE,
222 [VM_READ] = PAGE_READONLY,
223 [VM_WRITE] = PAGE_COPY,
224 [VM_WRITE | VM_READ] = PAGE_COPY,
225 [VM_EXEC] = PAGE_READONLY,
226 [VM_EXEC | VM_READ] = PAGE_READONLY,
227 [VM_EXEC | VM_WRITE] = PAGE_COPY,
228 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY,
229 [VM_SHARED] = PAGE_NONE,
230 [VM_SHARED | VM_READ] = PAGE_READONLY,
231 [VM_SHARED | VM_WRITE] = PAGE_SHARED,
232 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
233 [VM_SHARED | VM_EXEC] = PAGE_READONLY,
234 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY,
235 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED,
236 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED
237 };
238 DECLARE_VM_GET_PAGE_PROT
239