197a6f43bSArd Biesheuvel // SPDX-License-Identifier: GPL-2.0-only
297a6f43bSArd Biesheuvel // Copyright 2023 Google LLC
397a6f43bSArd Biesheuvel // Author: Ard Biesheuvel <ardb@google.com>
497a6f43bSArd Biesheuvel
597a6f43bSArd Biesheuvel #include <linux/types.h>
697a6f43bSArd Biesheuvel #include <linux/sizes.h>
797a6f43bSArd Biesheuvel
897a6f43bSArd Biesheuvel #include <asm/memory.h>
997a6f43bSArd Biesheuvel #include <asm/pgalloc.h>
1097a6f43bSArd Biesheuvel #include <asm/pgtable.h>
1197a6f43bSArd Biesheuvel
1297a6f43bSArd Biesheuvel #include "pi.h"
1397a6f43bSArd Biesheuvel
1497a6f43bSArd Biesheuvel /**
1597a6f43bSArd Biesheuvel * map_range - Map a contiguous range of physical pages into virtual memory
1697a6f43bSArd Biesheuvel *
1797a6f43bSArd Biesheuvel * @pte: Address of physical pointer to array of pages to
1897a6f43bSArd Biesheuvel * allocate page tables from
1997a6f43bSArd Biesheuvel * @start: Virtual address of the start of the range
2097a6f43bSArd Biesheuvel * @end: Virtual address of the end of the range (exclusive)
2197a6f43bSArd Biesheuvel * @pa: Physical address of the start of the range
2297a6f43bSArd Biesheuvel * @prot: Access permissions of the range
2397a6f43bSArd Biesheuvel * @level: Translation level for the mapping
2497a6f43bSArd Biesheuvel * @tbl: The level @level page table to create the mappings in
2597a6f43bSArd Biesheuvel * @may_use_cont: Whether the use of the contiguous attribute is allowed
2697a6f43bSArd Biesheuvel * @va_offset: Offset between a physical page and its current mapping
2797a6f43bSArd Biesheuvel * in the VA space
2897a6f43bSArd Biesheuvel */
map_range(u64 * pte,u64 start,u64 end,u64 pa,pgprot_t prot,int level,pte_t * tbl,bool may_use_cont,u64 va_offset)2997a6f43bSArd Biesheuvel void __init map_range(u64 *pte, u64 start, u64 end, u64 pa, pgprot_t prot,
3097a6f43bSArd Biesheuvel int level, pte_t *tbl, bool may_use_cont, u64 va_offset)
3197a6f43bSArd Biesheuvel {
3297a6f43bSArd Biesheuvel u64 cmask = (level == 3) ? CONT_PTE_SIZE - 1 : U64_MAX;
3397a6f43bSArd Biesheuvel u64 protval = pgprot_val(prot) & ~PTE_TYPE_MASK;
3497a6f43bSArd Biesheuvel int lshift = (3 - level) * (PAGE_SHIFT - 3);
3597a6f43bSArd Biesheuvel u64 lmask = (PAGE_SIZE << lshift) - 1;
3697a6f43bSArd Biesheuvel
3797a6f43bSArd Biesheuvel start &= PAGE_MASK;
3897a6f43bSArd Biesheuvel pa &= PAGE_MASK;
3997a6f43bSArd Biesheuvel
4097a6f43bSArd Biesheuvel /* Advance tbl to the entry that covers start */
4197a6f43bSArd Biesheuvel tbl += (start >> (lshift + PAGE_SHIFT)) % PTRS_PER_PTE;
4297a6f43bSArd Biesheuvel
4397a6f43bSArd Biesheuvel /*
4497a6f43bSArd Biesheuvel * Set the right block/page bits for this level unless we are
4597a6f43bSArd Biesheuvel * clearing the mapping
4697a6f43bSArd Biesheuvel */
4797a6f43bSArd Biesheuvel if (protval)
4897a6f43bSArd Biesheuvel protval |= (level < 3) ? PMD_TYPE_SECT : PTE_TYPE_PAGE;
4997a6f43bSArd Biesheuvel
5097a6f43bSArd Biesheuvel while (start < end) {
5197a6f43bSArd Biesheuvel u64 next = min((start | lmask) + 1, PAGE_ALIGN(end));
5297a6f43bSArd Biesheuvel
5397a6f43bSArd Biesheuvel if (level < 3 && (start | next | pa) & lmask) {
5497a6f43bSArd Biesheuvel /*
5597a6f43bSArd Biesheuvel * This chunk needs a finer grained mapping. Create a
5697a6f43bSArd Biesheuvel * table mapping if necessary and recurse.
5797a6f43bSArd Biesheuvel */
5897a6f43bSArd Biesheuvel if (pte_none(*tbl)) {
5997a6f43bSArd Biesheuvel *tbl = __pte(__phys_to_pte_val(*pte) |
6097a6f43bSArd Biesheuvel PMD_TYPE_TABLE | PMD_TABLE_UXN);
6197a6f43bSArd Biesheuvel *pte += PTRS_PER_PTE * sizeof(pte_t);
6297a6f43bSArd Biesheuvel }
6397a6f43bSArd Biesheuvel map_range(pte, start, next, pa, prot, level + 1,
6497a6f43bSArd Biesheuvel (pte_t *)(__pte_to_phys(*tbl) + va_offset),
6597a6f43bSArd Biesheuvel may_use_cont, va_offset);
6697a6f43bSArd Biesheuvel } else {
6797a6f43bSArd Biesheuvel /*
6897a6f43bSArd Biesheuvel * Start a contiguous range if start and pa are
6997a6f43bSArd Biesheuvel * suitably aligned
7097a6f43bSArd Biesheuvel */
7197a6f43bSArd Biesheuvel if (((start | pa) & cmask) == 0 && may_use_cont)
7297a6f43bSArd Biesheuvel protval |= PTE_CONT;
7397a6f43bSArd Biesheuvel
7497a6f43bSArd Biesheuvel /*
7597a6f43bSArd Biesheuvel * Clear the contiguous attribute if the remaining
7697a6f43bSArd Biesheuvel * range does not cover a contiguous block
7797a6f43bSArd Biesheuvel */
7897a6f43bSArd Biesheuvel if ((end & ~cmask) <= start)
7997a6f43bSArd Biesheuvel protval &= ~PTE_CONT;
8097a6f43bSArd Biesheuvel
8197a6f43bSArd Biesheuvel /* Put down a block or page mapping */
8297a6f43bSArd Biesheuvel *tbl = __pte(__phys_to_pte_val(pa) | protval);
8397a6f43bSArd Biesheuvel }
8497a6f43bSArd Biesheuvel pa += next - start;
8597a6f43bSArd Biesheuvel start = next;
8697a6f43bSArd Biesheuvel tbl++;
8797a6f43bSArd Biesheuvel }
8897a6f43bSArd Biesheuvel }
8984b04d3eSArd Biesheuvel
create_init_idmap(pgd_t * pg_dir,pteval_t clrmask)90*9684ec18SArd Biesheuvel asmlinkage u64 __init create_init_idmap(pgd_t *pg_dir, pteval_t clrmask)
9184b04d3eSArd Biesheuvel {
9284b04d3eSArd Biesheuvel u64 ptep = (u64)pg_dir + PAGE_SIZE;
93*9684ec18SArd Biesheuvel pgprot_t text_prot = PAGE_KERNEL_ROX;
94*9684ec18SArd Biesheuvel pgprot_t data_prot = PAGE_KERNEL;
95*9684ec18SArd Biesheuvel
96*9684ec18SArd Biesheuvel pgprot_val(text_prot) &= ~clrmask;
97*9684ec18SArd Biesheuvel pgprot_val(data_prot) &= ~clrmask;
9884b04d3eSArd Biesheuvel
9984b04d3eSArd Biesheuvel map_range(&ptep, (u64)_stext, (u64)__initdata_begin, (u64)_stext,
100*9684ec18SArd Biesheuvel text_prot, IDMAP_ROOT_LEVEL, (pte_t *)pg_dir, false, 0);
10184b04d3eSArd Biesheuvel map_range(&ptep, (u64)__initdata_begin, (u64)_end, (u64)__initdata_begin,
102*9684ec18SArd Biesheuvel data_prot, IDMAP_ROOT_LEVEL, (pte_t *)pg_dir, false, 0);
10384b04d3eSArd Biesheuvel
10484b04d3eSArd Biesheuvel return ptep;
10584b04d3eSArd Biesheuvel }
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