// SPDX-License-Identifier: GPL-2.0-only// Copyright 2023 Google LLC// Author: Ard Biesheuvel <ardb@google.com>#include <linux/types.h>#include <linux/sizes.h>#include <asm/memory.h>#include <asm/pgalloc.h>#include <asm/pgtable.h>#include "pi.h"/** * map_range - Map a contiguous range of physical pages into virtual memory * * @pte: Address of physical pointer to array of pages to * allocate page tables from * @start: Virtual address of the start of the range * @end: Virtual address of the end of the range (exclusive) * @pa: Physical address of the start of the range * @prot: Access permissions of the range * @level: Translation level for the mapping * @tbl: The level @level page table to create the mappings in * @may_use_cont: Whether the use of the contiguous attribute is allowed * @va_offset: Offset between a physical page and its current mapping * in the VA space */void __init map_range(phys_addr_t *pte, u64 start, u64 end, phys_addr_t pa, pgprot_t prot, int level, pte_t *tbl, bool may_use_cont, u64 va_offset){ u64 cmask = (level == 3) ? CONT_PTE_SIZE - 1 : U64_MAX; ptval_t protval = pgprot_val(prot) & ~PTE_TYPE_MASK; int lshift = (3 - level) * PTDESC_TABLE_SHIFT; u64 lmask = (PAGE_SIZE << lshift) - 1; start &= PAGE_MASK; pa &= PAGE_MASK; /* Advance tbl to the entry that covers start */ tbl += (start >> (lshift + PAGE_SHIFT)) % PTRS_PER_PTE; /* * Set the right block/page bits for this level unless we are * clearing the mapping */ if (protval) protval |= (level == 2) ? PMD_TYPE_SECT : PTE_TYPE_PAGE; while (start < end) { u64 next = min((start | lmask) + 1, PAGE_ALIGN(end)); if (level < 2 || (level == 2 && (start | next | pa) & lmask)) { /* * This chunk needs a finer grained mapping. Create a * table mapping if necessary and recurse. */ if (pte_none(*tbl)) { *tbl = __pte(__phys_to_pte_val(*pte) | PMD_TYPE_TABLE | PMD_TABLE_UXN); *pte += PTRS_PER_PTE * sizeof(pte_t); } map_range(pte, start, next, pa, prot, level + 1, (pte_t *)(__pte_to_phys(*tbl) + va_offset), may_use_cont, va_offset); } else { /* * Start a contiguous range if start and pa are * suitably aligned */ if (((start | pa) & cmask) == 0 && may_use_cont) protval |= PTE_CONT; /* * Clear the contiguous attribute if the remaining * range does not cover a contiguous block */ if ((end & ~cmask) <= start) protval &= ~PTE_CONT; /* Put down a block or page mapping */ *tbl = __pte(__phys_to_pte_val(pa) | protval); } pa += next - start; start = next; tbl++; }}asmlinkage phys_addr_t __init create_init_idmap(pgd_t *pg_dir, ptval_t clrmask){ phys_addr_t ptep = (phys_addr_t)pg_dir + PAGE_SIZE; /* MMU is off */ pgprot_t text_prot = PAGE_KERNEL_ROX; pgprot_t data_prot = PAGE_KERNEL; pgprot_val(text_prot) &= ~clrmask; pgprot_val(data_prot) &= ~clrmask; /* MMU is off; pointer casts to phys_addr_t are safe */ map_range(&ptep, (u64)_stext, (u64)__initdata_begin, (phys_addr_t)_stext, text_prot, IDMAP_ROOT_LEVEL, (pte_t *)pg_dir, false, 0); map_range(&ptep, (u64)__initdata_begin, (u64)_end, (phys_addr_t)__initdata_begin, data_prot, IDMAP_ROOT_LEVEL, (pte_t *)pg_dir, false, 0); return ptep;}
// SPDX-License-Identifier: GPL-2.0-only
// Copyright 2023 Google LLC
// Author: Ard Biesheuvel <ardb@google.com>
#include <linux/types.h>
#include <linux/sizes.h>
#include <asm/memory.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include "pi.h"
/**
* map_range - Map a contiguous range of physical pages into virtual memory
*
* @pte: Address of physical pointer to array of pages to
* allocate page tables from
* @start: Virtual address of the start of the range
* @end: Virtual address of the end of the range (exclusive)
* @pa: Physical address of the start of the range
* @prot: Access permissions of the range
* @level: Translation level for the mapping
* @tbl: The level @level page table to create the mappings in
* @may_use_cont: Whether the use of the contiguous attribute is allowed
* @va_offset: Offset between a physical page and its current mapping
* in the VA space
*/
void __init map_range(phys_addr_t *pte, u64 start, u64 end, phys_addr_t pa,
pgprot_t prot, int level, pte_t *tbl, bool may_use_cont,
u64 va_offset)
{
u64 cmask = (level == 3) ? CONT_PTE_SIZE - 1 : U64_MAX;
ptval_t protval = pgprot_val(prot) & ~PTE_TYPE_MASK;
int lshift = (3 - level) * PTDESC_TABLE_SHIFT;
u64 lmask = (PAGE_SIZE << lshift) - 1;
start &= PAGE_MASK;
pa &= PAGE_MASK;
/* Advance tbl to the entry that covers start */
tbl += (start >> (lshift + PAGE_SHIFT)) % PTRS_PER_PTE;
/*
* Set the right block/page bits for this level unless we are
* clearing the mapping
*/
if (protval)
protval |= (level == 2) ? PMD_TYPE_SECT : PTE_TYPE_PAGE;
while (start < end) {
u64 next = min((start | lmask) + 1, PAGE_ALIGN(end));
if (level < 2 || (level == 2 && (start | next | pa) & lmask)) {
/*
* This chunk needs a finer grained mapping. Create a
* table mapping if necessary and recurse.
*/
if (pte_none(*tbl)) {
*tbl = __pte(__phys_to_pte_val(*pte) |
PMD_TYPE_TABLE | PMD_TABLE_UXN);
*pte += PTRS_PER_PTE * sizeof(pte_t);
}
map_range(pte, start, next, pa, prot, level + 1,
(pte_t *)(__pte_to_phys(*tbl) + va_offset),
may_use_cont, va_offset);
} else {
/*
* Start a contiguous range if start and pa are
* suitably aligned
*/
if (((start | pa) & cmask) == 0 && may_use_cont)
protval |= PTE_CONT;
/*
* Clear the contiguous attribute if the remaining
* range does not cover a contiguous block
*/
if ((end & ~cmask) <= start)
protval &= ~PTE_CONT;
/* Put down a block or page mapping */
*tbl = __pte(__phys_to_pte_val(pa) | protval);
}
pa += next - start;
start = next;
tbl++;
}
}
asmlinkage phys_addr_t __init create_init_idmap(pgd_t *pg_dir, ptval_t clrmask)
{
phys_addr_t ptep = (phys_addr_t)pg_dir + PAGE_SIZE; /* MMU is off */
pgprot_t text_prot = PAGE_KERNEL_ROX;
pgprot_t data_prot = PAGE_KERNEL;
pgprot_val(text_prot) &= ~clrmask;
pgprot_val(data_prot) &= ~clrmask;
/* MMU is off; pointer casts to phys_addr_t are safe */
map_range(&ptep, (u64)_stext, (u64)__initdata_begin,
(phys_addr_t)_stext, text_prot, IDMAP_ROOT_LEVEL,
(pte_t *)pg_dir, false, 0);
map_range(&ptep, (u64)__initdata_begin, (u64)_end,
(phys_addr_t)__initdata_begin, data_prot, IDMAP_ROOT_LEVEL,
(pte_t *)pg_dir, false, 0);
return ptep;
}